Placing of a hydroxyl group on a compound in a position where one did not exist before. (Stedman, 26th ed)
Widely distributed enzymes that carry out oxidation-reduction reactions in which one atom of the oxygen molecule is incorporated into the organic substrate; the other oxygen atom is reduced and combined with hydrogen ions to form water. They are also known as monooxygenases or hydroxylases. These reactions require two substrates as reductants for each of the two oxygen atoms. There are different classes of monooxygenases depending on the type of hydrogen-providing cosubstrate (COENZYMES) required in the mixed-function oxidation.
A superfamily of hundreds of closely related HEMEPROTEINS found throughout the phylogenetic spectrum, from animals, plants, fungi, to bacteria. They include numerous complex monooxygenases (MIXED FUNCTION OXYGENASES). In animals, these P-450 enzymes serve two major functions: (1) biosynthesis of steroids, fatty acids, and bile acids; (2) metabolism of endogenous and a wide variety of exogenous substrates, such as toxins and drugs (BIOTRANSFORMATION). They are classified, according to their sequence similarities rather than functions, into CYP gene families (>40% homology) and subfamilies (>59% homology). For example, enzymes from the CYP1, CYP2, and CYP3 gene families are responsible for most drug metabolism.
Closed vesicles of fragmented endoplasmic reticulum created when liver cells or tissue are disrupted by homogenization. They may be smooth or rough.
A mixed-function oxygenase that catalyzes the hydroxylation of a prolyl-glycyl containing peptide, usually in PROTOCOLLAGEN, to a hydroxyprolylglycyl-containing-peptide. The enzyme utilizes molecular OXYGEN with a concomitant oxidative decarboxylation of 2-oxoglutarate to SUCCINATE. The enzyme occurs as a tetramer of two alpha and two beta subunits. The beta subunit of procollagen-proline dioxygenase is identical to the enzyme PROTEIN DISULFIDE-ISOMERASES.
Cytochrome P-450 monooxygenases (MIXED FUNCTION OXYGENASES) that are important in steroid biosynthesis and metabolism.
A large group of cytochrome P-450 (heme-thiolate) monooxygenases that complex with NAD(P)H-FLAVIN OXIDOREDUCTASE in numerous mixed-function oxidations of aromatic compounds. They catalyze hydroxylation of a broad spectrum of substrates and are important in the metabolism of steroids, drugs, and toxins such as PHENOBARBITAL, carcinogens, and insecticides.
A liver microsomal cytochrome P450 enzyme that catalyzes the 16-alpha-hydroxylation of a broad spectrum of steroids, fatty acids, and xenobiotics in the presence of molecular oxygen and NADPH-FERRIHEMOPROTEIN REDUCTASE. This enzyme is encoded by a number of genes from several CYP2 subfamilies.
The chemical alteration of an exogenous substance by or in a biological system. The alteration may inactivate the compound or it may result in the production of an active metabolite of an inactive parent compound. The alterations may be divided into METABOLIC DETOXICATION, PHASE I and METABOLIC DETOXICATION, PHASE II.
An adrenergic neuron-blocking drug similar in effects to GUANETHIDINE. It is also noteworthy in being a substrate for a polymorphic cytochrome P-450 enzyme. Persons with certain isoforms of this enzyme are unable to properly metabolize this and many other clinically important drugs. They are commonly referred to as having a debrisoquin 4-hydroxylase polymorphism.
An NAPH-dependent cytochrome P450 enzyme that catalyzes the oxidation of the side chain of sterol intermediates such as the 27-hydroxylation of 5-beta-cholestane-3-alpha,7-alpha,12-alpha-triol.
An anticonvulsant effective in tonic-clonic epilepsy (EPILEPSY, TONIC-CLONIC). It may cause blood dyscrasias.
A cytochrome P-450 suptype that has specificity for a broad variety of lipophilic compounds, including STEROIDS; FATTY ACIDS; and XENOBIOTICS. This enzyme has clinical significance due to its ability to metabolize a diverse array of clinically important drugs such as CYCLOSPORINE; VERAPAMIL; and MIDAZOLAM. This enzyme also catalyzes the N-demethylation of ERYTHROMYCIN.
The removing of alkyl groups from a compound. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed)
Oxidoreductases, N-Demethylating are enzymes that catalyze the oxidation of N-methyl groups to carbonyl groups, typically found in xenobiotic metabolism, involving the removal of methyl groups from various substrates using molecular oxygen.
A hydroxylated derivative of the amino acid LYSINE that is present in certain collagens.
A flavoprotein that catalyzes the reduction of heme-thiolate-dependent monooxygenases and is part of the microsomal hydroxylating system. EC 1.6.2.4.
The rate dynamics in chemical or physical systems.
Liquid chromatographic techniques which feature high inlet pressures, high sensitivity, and high speed.
Oxidases that specifically introduce DIOXYGEN-derived oxygen atoms into a variety of organic molecules.
A characteristic feature of enzyme activity in relation to the kind of substrate on which the enzyme or catalytic molecule reacts.
A drug-metabolizing, cytochrome P-448 (P-450) enzyme which catalyzes the hydroxylation of benzopyrene to 3-hydroxybenzopyrene in the presence of reduced flavoprotein and molecular oxygen. Also acts on certain anthracene derivatives. An aspect of EC 1.14.14.1.
Artifactual vesicles formed from the endoplasmic reticulum when cells are disrupted. They are isolated by differential centrifugation and are composed of three structural features: rough vesicles, smooth vesicles, and ribosomes. Numerous enzyme activities are associated with the microsomal fraction. (Glick, Glossary of Biochemistry and Molecular Biology, 1990; from Rieger et al., Glossary of Genetics: Classical and Molecular, 5th ed)
A cytochrome P450 enzyme subtype that has specificity for relatively planar heteroaromatic small molecules, such as CAFFEINE and ACETAMINOPHEN.
A cytochrome P450 enzyme that catalyzes the hydroxylation of many drugs and environmental chemicals, such as DEBRISOQUINE; ADRENERGIC RECEPTOR ANTAGONISTS; and TRICYCLIC ANTIDEPRESSANTS. This enzyme is deficient in up to 10 percent of the Caucasian population.
A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471).
Dioxygenase enzymes that specifically hydroxylate a PROLINE residue on the HYPOXIA-INDUCIBLE FACTOR 1, ALPHA SUBUNIT. They are OXYGEN-dependent enzymes that play an important role in mediating cellular adaptive responses to HYPOXIA.
The facilitation of a chemical reaction by material (catalyst) that is not consumed by the reaction.
Derivatives of the saturated steroid cholestane with methyl groups at C-18 and C-19 and an iso-octyl side chain at C-17.
A non-essential amino acid that is synthesized from GLUTAMIC ACID. It is an essential component of COLLAGEN and is important for proper functioning of joints and tendons.
An enzyme of the oxidoreductase class that catalyzes the formation of L-TYROSINE, dihydrobiopterin, and water from L-PHENYLALANINE, tetrahydrobiopterin, and oxygen. Deficiency of this enzyme may cause PHENYLKETONURIAS and PHENYLKETONURIA, MATERNAL. EC 1.14.16.1.
2- or 4-Hydroxyestrogens. Substances that are physiologically active in mammals, especially in the control of gonadotropin secretion. Physiological activity can be ascribed to either an estrogenic action or interaction with the catecholaminergic system.
Organic compounds containing a BENZENE ring attached to a flavone group. Some of these are potent arylhydrocarbon hydroxylase inhibitors. They may also inhibit the binding of NUCLEIC ACIDS to BENZOPYRENES and related compounds. The designation includes all isomers; the 7,8-isomer is most frequently encountered.
A centrally acting central muscle relaxant with sedative properties. It is claimed to inhibit muscle spasm by exerting an effect primarily at the level of the spinal cord and subcortical areas of the brain. (From Martindale, The Extra Pharmacopoea, 30th ed, p1202)
12-Carbon saturated monocarboxylic acids.
A macrolide antibiotic that is similar to ERYTHROMYCIN.
The phenomenon whereby compounds whose molecules have the same number and kind of atoms and the same atomic arrangement, but differ in their spatial relationships. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed)
A mixed-function oxygenase that catalyzes the hydroxylation of peptidyllysine, usually in protocollagen, to peptidylhydroxylysine. The enzyme utilizes molecular oxygen with concomitant oxidative decarboxylation of the cosubstrate 2-oxoglutarate to succinate. EC 1.14.11.4.
Derivative of 7-dehydroxycholesterol formed by ULTRAVIOLET RAYS breaking of the C9-C10 bond. It differs from ERGOCALCIFEROL in having a single bond between C22 and C23 and lacking a methyl group at C24.
A microanalytical technique combining mass spectrometry and gas chromatography for the qualitative as well as quantitative determinations of compounds.
A family of compounds containing an oxo group with the general structure of 1,5-pentanedioic acid. (From Lehninger, Principles of Biochemistry, 1982, p442)
Benzoate derivatives substituted by one or more hydroxy groups in any position on the benzene ring.
A sulfonilamide anti-infective agent.
Nicotinamide adenine dinucleotide phosphate. A coenzyme composed of ribosylnicotinamide 5'-phosphate (NMN) coupled by pyrophosphate linkage to the 5'-phosphate adenosine 2',5'-bisphosphate. It serves as an electron carrier in a number of reactions, being alternately oxidized (NADP+) and reduced (NADPH). (Dorland, 27th ed)
A barbituric acid derivative that acts as a nonselective central nervous system depressant. It potentiates GAMMA-AMINOBUTYRIC ACID action on GABA-A RECEPTORS, and modulates chloride currents through receptor channels. It also inhibits glutamate induced depolarizations.
An analytical method used in determining the identity of a chemical based on its mass using mass analyzers/mass spectrometers.
Cholestanes substituted in any position with one or more hydroxy groups. They are found in feces and bile. In contrast to bile acids and salts, they are not reabsorbed.
A hydroxylated form of the imino acid proline. A deficiency in ASCORBIC ACID can result in impaired hydroxyproline formation.
A soluble cytochrome P-450 enzyme that catalyzes camphor monooxygenation in the presence of putidaredoxin, putidaredoxin reductase, and molecular oxygen. This enzyme, encoded by the CAMC gene also known as CYP101, has been crystallized from bacteria and the structure is well defined. Under anaerobic conditions, this enzyme reduces the polyhalogenated compounds bound at the camphor-binding site.
Hypoxia-inducible factor 1, alpha subunit is a basic helix-loop-helix transcription factor that is regulated by OXYGEN availability and is targeted for degradation by VHL TUMOR SUPPRESSOR PROTEIN.
An element with atomic symbol O, atomic number 8, and atomic weight [15.99903; 15.99977]. It is the most abundant element on earth and essential for respiration.
Protein motif that contains a 33-amino acid long sequence that often occurs in tandem arrays. This repeating sequence of 33-amino acids was discovered in ANKYRIN where it is involved in interaction with the anion exchanger (ANION EXCHANGE PROTEIN 1, ERYTHROCYTE). Ankyrin repeats cooperatively fold into domains that mediate molecular recognition via protein-protein interactions.
Synthetic or naturally occurring substances related to coumarin, the delta-lactone of coumarinic acid.
A bicyclic monoterpene ketone found widely in plants, especially CINNAMOMUM CAMPHORA. It is used topically as a skin antipruritic and as an anti-infective agent.
An ethanol-inducible cytochrome P450 enzyme that metabolizes several precarcinogens, drugs, and solvents to reactive metabolites. Substrates include ETHANOL; INHALATION ANESTHETICS; BENZENE; ACETAMINOPHEN and other low molecular weight compounds. CYP2E1 has been used as an enzyme marker in the study of alcohol abuse.
The location of the atoms, groups or ions relative to one another in a molecule, as well as the number, type and location of covalent bonds.
An enzyme of the oxidoreductase class that catalyzes the reaction between catechol and oxygen to yield benzoquinone and water. It is a complex of copper-containing proteins that acts also on a variety of substituted catechols. EC 1.10.3.1.
Cytochromes of the b group that are found bound to cytoplasmic side of ENDOPLASMIC RETICULUM. They serve as electron carrier proteins for a variety of membrane-bound OXYGENASES. They are reduced by the enzyme CYTOCHROME-B(5) REDUCTASE.
Structurally related forms of an enzyme. Each isoenzyme has the same mechanism and classification, but differs in its chemical, physical, or immunological characteristics.
A unicyclic, aminoketone antidepressant. The mechanism of its therapeutic actions is not well understood, but it does appear to block dopamine uptake. The hydrochloride is available as an aid to smoking cessation treatment.
A P450 oxidoreductase that catalyzes the hydroxylation of the terminal carbon of linear hydrocarbons such as octane and FATTY ACIDS in the omega position. The enzyme may also play a role in the oxidation of a variety of structurally unrelated compounds such as XENOBIOTICS, and STEROIDS.
Proteins prepared by recombinant DNA technology.
Industrial chemicals which have become widespread environmental pollutants. Each aroclor is a mixture of chlorinated biphenyls (1200 series) or chlorinated terphenyls (5400 series) or a combination of both (4400 series).
Norbornanes are a class of bicyclic organic compounds consisting of a hydrocarbon skeleton made up of two fused 5-membered rings, where five of the six ring carbons are bonded to hydrogens and one is bonded to two additional carbon atoms, forming a bridge between the rings.
Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.
An essential aromatic amino acid that is a precursor of MELANIN; DOPAMINE; noradrenalin (NOREPINEPHRINE), and THYROXINE.
A large lobed glandular organ in the abdomen of vertebrates that is responsible for detoxification, metabolism, synthesis and storage of various substances.
A flavoprotein that catalyzes the synthesis of protocatechuic acid from 4-hydroxybenzoate in the presence of molecular oxygen. EC 1.14.13.2.
An inhibitor of drug metabolism and CYTOCHROME P-450 ENZYME SYSTEM activity.
The generic name for the group of aliphatic hydrocarbons Cn-H2n+2. They are denoted by the suffix -ane. (Grant & Hackh's Chemical Dictionary, 5th ed)
Compounds containing phenyl-1-butanone.
An optical isomer of quinine, extracted from the bark of the CHINCHONA tree and similar plant species. This alkaloid dampens the excitability of cardiac and skeletal muscles by blocking sodium and potassium currents across cellular membranes. It prolongs cellular ACTION POTENTIALS, and decreases automaticity. Quinidine also blocks muscarinic and alpha-adrenergic neurotransmission.
Steroids in which one or more hydroxy groups have been substituted for hydrogen atoms either within the ring skeleton or on any of the side chains.
The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.
Non-heme iron-containing enzymes that incorporate two atoms of OXYGEN into the substrate. They are important in biosynthesis of FLAVONOIDS; GIBBERELLINS; and HYOSCYAMINE; and for degradation of AROMATIC HYDROCARBONS.
A mitochondrial cytochrome P450 enzyme that catalyzes the 11-beta-hydroxylation of steroids in the presence of molecular oxygen and NADPH-FERRIHEMOPROTEIN REDUCTASE. This enzyme, encoded by CYP11B1 gene, is important in the synthesis of CORTICOSTERONE and HYDROCORTISONE. Defects in CYP11B1 cause congenital adrenal hyperplasia (ADRENAL HYPERPLASIA, CONGENITAL).
A polypeptide substance comprising about one third of the total protein in mammalian organisms. It is the main constituent of SKIN; CONNECTIVE TISSUE; and the organic substance of bones (BONE AND BONES) and teeth (TOOTH).
The art or process of comparing photometrically the relative intensities of the light in different parts of the spectrum.
A sympathomimetic agent with properties similar to DEXTROAMPHETAMINE. It is used in the treatment of obesity. (From Martindale, The Extra Pharmacopoeia, 30th ed, p1222)
A phenylacetamide that was formerly used in ANALGESICS but nephropathy and METHEMOGLOBINEMIA led to its withdrawal from the market. (From Smith and Reynard, Textbook of Pharmacology,1991, p431)
A beta-hydroxylated derivative of phenylalanine. The D-form of dihydroxyphenylalanine has less physiologic activity than the L-form and is commonly used experimentally to determine whether the pharmacological effects of LEVODOPA are stereospecific.
Broad spectrum antifungal agent used for long periods at high doses, especially in immunosuppressed patients.
Steroid derivatives formed by oxidation of a methyl group on the side chain or a methylene group in the ring skeleton to form a ketone.
An adrenal microsomal cytochrome P450 enzyme that catalyzes the 21-hydroxylation of steroids in the presence of molecular oxygen and NADPH-FERRIHEMOPROTEIN REDUCTASE. This enzyme, encoded by CYP21 gene, converts progesterones to precursors of adrenal steroid hormones (CORTICOSTERONE; HYDROCORTISONE). Defects in CYP21 cause congenital adrenal hyperplasia (ADRENAL HYPERPLASIA, CONGENITAL).
A quinolizidine alkaloid isolated from several FABACEAE including LUPINUS; SPARTIUM; and CYTISUS. It has been used as an oxytocic and an anti-arrhythmia agent. It has also been of interest as an indicator of CYP2D6 genotype.
A six carbon compound related to glucose. It is found naturally in citrus fruits and many vegetables. Ascorbic acid is an essential nutrient in human diets, and necessary to maintain connective tissue and bone. Its biologically active form, vitamin C, functions as a reducing agent and coenzyme in several metabolic pathways. Vitamin C is considered an antioxidant.
(13E,15S)-15-Hydroxy-9-oxoprosta-10,13-dien-1-oic acid (PGA(1)); (5Z,13E,15S)-15-hydroxy-9-oxoprosta-5,10,13-trien-1-oic acid (PGA(2)); (5Z,13E,15S,17Z)-15-hydroxy-9-oxoprosta-5,10,13,17-tetraen-1-oic acid (PGA(3)). A group of naturally occurring secondary prostaglandins derived from PGE; PGA(1) and PGA(2) as well as their 19-hydroxy derivatives are found in many organs and tissues.
Salts and esters of gentisic acid.
A fungistatic compound that is widely used as a food preservative. It is conjugated to GLYCINE in the liver and excreted as hippuric acid.
An iron-sulfur protein which serves as an electron carrier in enzymatic steroid hydroxylation reactions in adrenal cortex mitochondria. The electron transport system which catalyzes this reaction consists of adrenodoxin reductase, NADP, adrenodoxin, and cytochrome P-450.
A group of 1,2-benzenediols that contain the general formula R-C6H5O2.
A basic helix-loop-helix transcription factor that plays a role in APOPTOSIS. It is composed of two subunits: ARYL HYDROCARBON RECEPTOR NUCLEAR TRANSLOCATOR and HYPOXIA-INDUCIBLE FACTOR 1, ALPHA SUBUNIT.
An enzyme that catalyzes the oxidation and reduction of FERREDOXIN or ADRENODOXIN in the presence of NADP. EC 1.18.1.2 was formerly listed as EC 1.6.7.1 and EC 1.6.99.4.
A drug-metabolizing, cytochrome P-450 enzyme which catalyzes the hydroxylation of aniline to hydroxyaniline in the presence of reduced flavoprotein and molecular oxygen. EC 1.14.14.-.
A colorless liquid used as a solvent and an antiseptic. It is one of the ketone bodies produced during ketoacidosis.
A major cytochrome P-450 enzyme which is inducible by PHENOBARBITAL in both the LIVER and SMALL INTESTINE. It is active in the metabolism of compounds like pentoxyresorufin, TESTOSTERONE, and ANDROSTENEDIONE. This enzyme, encoded by CYP2B1 gene, also mediates the activation of CYCLOPHOSPHAMIDE and IFOSFAMIDE to MUTAGENS.
Aniline compounds, also known as aromatic amines, are organic chemicals derived from aniline (aminobenzene), characterized by the substitution of hydrogen atoms in the benzene ring with amino groups (-NH2).
A ubiquitin-protein ligase that mediates OXYGEN-dependent polyubiquitination of HYPOXIA-INDUCIBLE FACTOR 1, ALPHA SUBUNIT. It is inactivated in VON HIPPEL-LINDAU SYNDROME.
Chromatographic techniques in which the mobile phase is a liquid.
An increase in the rate of synthesis of an enzyme due to the presence of an inducer which acts to derepress the gene responsible for enzyme synthesis.
Compounds based on imidazolidine dione. Some derivatives are ANTICONVULSANTS.
A nucleoside monophosphate sugar which donates N-acetylneuraminic acid to the terminal sugar of a ganglioside or glycoprotein.
A genus of saprobic mushrooms in the family Bolbitiaceae that grow in grass, dung, garden mulch, or in woods.
CHOLESTENES with one or more double bonds and substituted by any number of keto groups.
An acquired blood vessel disorder caused by severe deficiency of vitamin C (ASCORBIC ACID) in the diet leading to defective collagen formation in small blood vessels. Scurvy is characterized by bleeding in any tissue, weakness, ANEMIA, spongy gums, and a brawny induration of the muscles of the calves and legs.
A member of the P450 superfamily, this enzyme catalyzes the first oxidative step of the phenylpropanoid pathway in higher PLANTS by transforming trans-cinnamate into p-coumarate.
A coenzyme composed of ribosylnicotinamide 5'-diphosphate coupled to adenosine 5'-phosphate by pyrophosphate linkage. It is found widely in nature and is involved in numerous enzymatic reactions in which it serves as an electron carrier by being alternately oxidized (NAD+) and reduced (NADH). (Dorland, 27th ed)
Compounds or agents that combine with an enzyme in such a manner as to prevent the normal substrate-enzyme combination and the catalytic reaction.
Determination of the spectra of ultraviolet absorption by specific molecules in gases or liquids, for example Cl2, SO2, NO2, CS2, ozone, mercury vapor, and various unsaturated compounds. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
A reagent used for the determination of iron.
A genus of bacteria that form a nonfragmented aerial mycelium. Many species have been identified with some being pathogenic. This genus is responsible for producing a majority of the ANTI-BACTERIAL AGENTS of practical value.
The univalent radical OH. Hydroxyl radical is a potent oxidizing agent.
Hydroxycinnamic acid and its derivatives. Act as activators of the indoleacetic acid oxidizing system, thereby producing a decrease in the endogenous level of bound indoleacetic acid in plants.
An antiseptic and disinfectant aromatic alcohol.
Cresols, also known as hydroxytoluene, are a group of phenolic compounds including ortho-cresol, meta-cresol, and para-cresol, which differ in the position of the hydroxyl group on the benzene ring.
Spectroscopic method of measuring the magnetic moment of elementary particles such as atomic nuclei, protons or electrons. It is employed in clinical applications such as NMR Tomography (MAGNETIC RESONANCE IMAGING).
Compounds based on 2-amino-4-hydroxypteridine.
A short-acting hypnotic-sedative drug with anxiolytic and amnestic properties. It is used in dentistry, cardiac surgery, endoscopic procedures, as preanesthetic medication, and as an adjunct to local anesthesia. The short duration and cardiorespiratory stability makes it useful in poor-risk, elderly, and cardiac patients. It is water-soluble at pH less than 4 and lipid-soluble at physiological pH.
COLLAGEN DISEASES characterized by brittle, osteoporotic, and easily fractured bones. It may also present with blue sclerae, loose joints, and imperfect dentin formation. Most types are autosomal dominant and are associated with mutations in COLLAGEN TYPE I.
A non-essential amino acid that is involved in the metabolic control of cell functions in nerve and brain tissue. It is biosynthesized from ASPARTIC ACID and AMMONIA by asparagine synthetase. (From Concise Encyclopedia Biochemistry and Molecular Biology, 3rd ed)
Cinnamates are organic compounds that contain a cinnamic acid moiety, widely used in pharmaceutical and cosmetic industries as esters, with various applications ranging from UV absorbers to local anesthetics and antimicrobial agents.
Compounds with a core of 10 carbons generally formed via the mevalonate pathway from the combination of 3,3-dimethylallyl pyrophosphate and isopentenyl pyrophosphate. They are cyclized and oxidized in a variety of ways. Due to the low molecular weight many of them exist in the form of essential oils (OILS, VOLATILE).
A class of compounds that contain a -NH2 and a -NO radical. Many members of this group have carcinogenic and mutagenic properties.
The major circulating metabolite of VITAMIN D3. It is produced in the LIVER and is the best indicator of the body's vitamin D stores. It is effective in the treatment of RICKETS and OSTEOMALACIA, both in azotemic and non-azotemic patients. Calcifediol also has mineralizing properties.
Deuterium. The stable isotope of hydrogen. It has one neutron and one proton in the nucleus.
A basic science concerned with the composition, structure, and properties of matter; and the reactions that occur between substances and the associated energy exchange.
Any of various enzymatically catalyzed post-translational modifications of PEPTIDES or PROTEINS in the cell of origin. These modifications include carboxylation; HYDROXYLATION; ACETYLATION; PHOSPHORYLATION; METHYLATION; GLYCOSYLATION; ubiquitination; oxidation; proteolysis; and crosslinking and result in changes in molecular weight and electrophoretic motility.
The composition, conformation, and properties of atoms and molecules, and their reaction and interaction processes.
The salts or esters of salicylic acids, or salicylate esters of an organic acid. Some of these have analgesic, antipyretic, and anti-inflammatory activities by inhibiting prostaglandin synthesis.

In vivo modulation of alternative pathways of P-450-catalyzed cyclophosphamide metabolism: impact on pharmacokinetics and antitumor activity. (1/2276)

The widely used anticancer prodrug cyclophosphamide (CPA) is activated in liver by a 4-hydroxylation reaction primarily catalyzed by cytochrome P-4502B and P-4502C enzymes. An alternative metabolic pathway involves CPA N-dechloroethylation to yield chloroacetaldehyde (CA), a P-4503A-catalyzed deactivation/neurotoxication reaction. The in vivo modulation of these alternative, competing pathways of P-450 metabolism was investigated in pharmacokinetic studies carried out in the rat model. Peak plasma concentrations (Cmax) for 4-OH-CPA and CA were increased by 3- to 4-fold, and apparent plasma half-lives of both metabolites were correspondingly shortened in rats pretreated with phenobarbital (PB), an inducer of P-4502B and P-4503A enzymes. However, PB had no net impact on the extent of drug activation or its partitioning between these alternative metabolic pathways, as judged from AUC values (area-under-the-plasma concentration x time curve) for 4-OH-CPA and CA. The P-4503A inhibitor troleandomycin (TAO) decreased plasma Cmax and AUC of CA (80-85% decrease) without changing the Cmax or AUC of 4-OH-CPA in uninduced rats. In PB-induced rats, TAO decreased AUCCA by 73%, whereas it increased AUC4-OH-CPA by 93%. TAO thus selectively suppresses CPA N-dechloroethylation, thereby increasing the availability of drug for P-450 activation via 4-hydroxylation. By contrast, dexamethasone, a P-4503A inducer and antiemetic widely used in patients with cancer, stimulated large, undesirable increases in the Cmax and AUC of CA (8- and 4-fold, respectively) while reducing the AUC of the 4-hydroxylation pathway by approximately 60%. Tumor excision/in vitro colony formation and tumor growth delay assays using an in vivo 9L gliosarcoma solid tumor model revealed that TAO suppression of CPA N-dechloroethylation could be achieved without compromising the antitumor effect of CPA. The combination of PB with TAO did not, however, enhance the antitumor activity of CPA, despite the approximately 2-fold increase in AUC4-OH-CPA, suggesting that other PB-inducible activities, such as aldehyde dehydrogenase, may counter this increase through enhanced deactivation of the 4-hydroxy metabolite. Together, these studies demonstrate that the P-4503A inhibitor TAO can be used to effectively modulate CPA metabolism and pharmacokinetics in vivo in a manner that decreases the formation of toxic metabolites that do not contribute to antitumor activity.  (+info)

Involvement of cytochromes P-450 2E1 and 3A4 in the 5-hydroxylation of salicylate in humans. (2/2276)

Hydroxylation of salicylate into 2,3 and 2,5-dihydroxybenzoic acids (2,3-DHBA and 2,5-DHBA) by human liver microsomal preparations was investigated. Kinetic studies demonstrated that salicylate was 5-hydroxylated with two apparent Km: one high-affinity Km of 606 microM and one low-affinity Km greater than 2 mM. Liver microsomes prepared from 15 human samples catalyzed the formation of 2,5-DHBA at metabolic rate of 21.7 +/- 8.5 pmol/mg/min. The formation of 2, 3-DHBA was not P-450 dependent. Formation of 2,5-DHBA was inhibited by 36 +/- 14% following preincubation of microsomes with diethyldithiocarbamate, a mechanism-based selective inhibitor of P-450 2E1. Furthermore, the efficiency of inhibition was significantly correlated with four catalytic activities specific to P-450 2E1, whereas the residual activity was correlated with three P-450 3A4 catalytic activities. Troleandomycin, a mechanism-based inhibitor selective to P-450 3A4, inhibited by 30 +/- 12% the 5-hydroxylation of salicylate, and this inhibition was significantly correlated with nifedipine oxidation, specific to P-450 3A4. The capability of seven recombinant human P-450s to hydroxylate salicylate demonstrated that P-450 2E1 and 3A4 contributed to 2, 5-DHBA formation in approximately equal proportions. The Km values of recombinant P-450 2E1 and 3A4, 280 and 513 microM, respectively, are in the same range as the high-affinity Km measured with human liver microsomes. The plasmatic metabolic ratio 2,5-DHBA/salicylate, measured 2 h after ingestion of 1 g acetylsalicylate, was increased 3-fold in 12 alcoholic patients at the beginning of their withdrawal period versus 15 control subjects. These results confirm that P-450 2E1, inducible by ethanol, is involved in the 5-hydroxylation of salicylate in humans. Furthermore, this ratio was still increased by 2-fold 1 week after ethanol withdrawal. This finding suggests that P-450 3A4, known to be also inducible by alcoholic beverages, plays an important role in this increase, because P-450 2E1 returned to normal levels in less than 3 days after ethanol withdrawal. Finally, in vivo and in vitro data demonstrated that P-450 2E1 and P-450 3A4, both inducible by alcohols, catalyzed the 5-hydroxylation of salicylate.  (+info)

Reliability of the omeprazole hydroxylation index for CYP2C19 phenotyping: possible effect of age, liver disease and length of therapy. (3/2276)

AIMS: To evaluate the reliability of the omeprazole hydroxylation index as a marker for polymorphic CYP2C19 activity in a Japanese population of healthy young subjects (n = 78) and patients with peptic ulcer (n = 72). METHODS: Healthy subjects were administered a single dose of omeprazole (20 mg), whereas patients received 20 mg daily for at least 1 week. The ratio of the serum concentration of omeprazole to hydroxyomeprazole at 3 h postdose was determined and used as a measure of CYP2C19 activity. The CYP2C19 wild type (wt) gene and four mutant alleles associated with the poor metaboliser phenotype of (S)-mephenytoin, CYP2C19*2 in exon 5, CYP2C19*3 in exon 4, CYP2C19m4 in exon 9, and CYP2C19m3 in the initial codon were analysed. RESULTS: In the healthy volunteer study there was complete concordance between genotype and phenotype. However, eight of the patients who had the EM genotype had a high value for their hydroxylation index, and were classified as phenotypic PMs. No CYP2C19m4 and CYP2C19m3 mutations were detected in the eight mismatched patients. They were all genotypic heterozygous EMs, elderly (> or = 65 years) and/or had hepatic disease. Therefore, impaired CYP2C19 activity combined with partial saturation of omeprazole metabolism during multiple dosing may have contributed to the discrepancy between CYP2C19 genotyping and phenotyping. CONCLUSION: Although omeprazole has been used instead of mephenytoin as a probe for polymorphic CYP2C19, it does not appear to be reliable enough for clinical application in Japanese patients.  (+info)

In vitro metabolism of quinidine: the (3S)-3-hydroxylation of quinidine is a specific marker reaction for cytochrome P-4503A4 activity in human liver microsomes. (4/2276)

The aim of this study was to evaluate the (3S)-3-hydroxylation and the N-oxidation of quinidine as biomarkers for cytochrome P-450 (CYP)3A4 activity in human liver microsome preparations. An HPLC method was developed to assay the metabolites (3S)-3-hydroxyquinidine (3-OH-Q) and quinidine N-oxide (Q-N-OX) formed during incubation with microsomes from human liver and from Saccharomyces cerevisiae strains expressing 10 human CYPs. 3-OH-Q formation complied with Michaelis-Menten kinetics (mean values of Vmax and Km: 74.4 nmol/mg/h and 74.2 microM, respectively). Q-N-OX formation followed two-site kinetics with mean values of Vmax, Km and Vmax/Km for the low affinity isozyme of 15.9 nmol/mg/h, 76.1 microM and 0.03 ml/mg/h, respectively. 3-OH-Q and Q-N-OX formations were potently inhibited by ketoconazole, itraconazole, and triacetyloleandomycin. Isozyme specific inhibitors of CYP1A2, -2C9, -2C19, -2D6, and -2E1 did not inhibit 3-OH-Q or Q-N-OX formation, with Ki values comparable with previously reported values. Statistically significant correlations were observed between CYP3A4 content and formations of 3-OH-Q and Q-N-OX in 12 human liver microsome preparations. Studies with yeast-expressed isozymes revealed that only CYP3A4 actively catalyzed the (3S)-3-hydroxylation. CYP3A4 was the most active enzyme in Q-N-OX formation, but CYP2C9 and 2E1 also catalyzed minor proportions of the N-oxidation. In conclusion, our studies demonstrate that only CYP3A4 is actively involved in the formation of 3-OH-Q. Hence, the (3S)-3-hydroxylation of quinidine is a specific probe for CYP3A4 activity in human liver microsome preparations, whereas the N-oxidation of quinidine is a somewhat less specific marker reaction for CYP3A4 activity, because the presence of a low affinity enzyme is demonstrated by different approaches.  (+info)

Potential mechanisms of thyroid disruption in humans: interaction of organochlorine compounds with thyroid receptor, transthyretin, and thyroid-binding globulin. (5/2276)

Organochlorine compounds, particularly polychlorinated biphenyls (PCBs), alter serum thyroid hormone levels in humans. Hydroxylated organochlorines have relatively high affinities for the serum transport protein transthyretin, but the ability of these compounds to interact with the human thyroid receptor is unknown. Using a baculovirus expression system in insect cells (Sf9 cells), we produced recombinant human thyroid receptor ss (hTRss). In competitive binding experiments, the recombinant receptor had the expected relative affinity for thyroid hormones and their analogs. In competitive inhibition experiments with PCBs, hydroxylated PCBs (OH-PCBs), DDT and its metabolites, and several organochlorine herbicides, only the OH-PCBs competed for binding. The affinity of hTRss for OH-PCBs was 10,000-fold lower (Ki = 20-50 microM) than its affinity for thyroid hormone (3,3',5-triiodothyronine, T3; Ki = 10 nM). Because their relative affinity for the receptor was low, we tested the ability of OH-PCBs to interact with the serum transport proteins--transthyretin and thyroid-binding globulin (TBG). With the exception of one compound, the OH-PCBs had the same affinity (Ki = 10-80 nM) for transthyretin as thyroid hormone (thyroxine; T4). Only two of the OH-PCBs bound TBG (Ki = 3-7 microM), but with a 100-fold lower affinity than T4. Hydroxylated PCBs have relatively low affinities for the human thyroid receptor in vitro, but they have a thyroid hormonelike affinity for the serum transport protein transthyretin. Based on these results, OH-PCBs in vivo are more likely to compete for binding to serum transport proteins than for binding to the thyroid receptor.  (+info)

The epidermal growth factor precursor. A calcium-binding, beta-hydroxyasparagine containing modular protein present on the surface of platelets. (6/2276)

Various human body fluids and secretions contain a soluble form of the epidermal growth factor (EGF) precursor. The EGF precursor molecule contains eight EGF modules in addition to EGF itself. Using monoclonal antibodies specific for the EGF modules 7 and 8, we have purified the soluble form of the EGF precursor from human urine to homogeneity. The protein was shown to have a molecular mass of about 160 kDa and the N-terminal sequence SAPNHWSXPE. EGF modules 2, 7 and 8 of the precursor have the consensus sequence for post-translational beta-hydroxylation of Asp/Asn residues. We identified the presence of erythro-beta-hydroxy-aspartic acid (Hya) in acid hydrolysates of the EGF precursor (2.4 M.M protein-1). As the DNA sequence encodes Asn in the corresponding position, the Hya represents erythro-beta-hydroxyasparagine (Hyn). The Hyn-containing modules have a consensus calcium-binding motif immediately N-terminal of the first Cys residue. The synthetic EGF module 2 (residues 356-395) of the EGF precursor was found to bind calcium with low affinity, Kd approximately 3.5 mM, i.e. similar to the affinity of other isolated calcium-binding EGF modules. EGF module 7, when part of the intact protein, was found to bind Ca2+ with a Kd approximately 0.2 microM, i.e. approximately 10(4)-fold higher than that of isolated EGF modules presumably due to the influence of neighboring modules. We have detected EGF precursor in platelet-rich plasma and demonstrated it to be associated to platelets. The platelets were found to have 30-160 EGF molecules each.  (+info)

Enzymatic properties of mouse 25-hydroxyvitamin D3 1 alpha-hydroxylase expressed in Escherichia coli. (7/2276)

Renal 25-hydroxyvitamin D3 1 alpha-hydroxylase cDNA cloned from the kidneys of mice lacking the vitamin D receptor was expressed in Escherichia coli JM109. As expected, the bacterially-expressed enzyme catalyzes the 1 alpha-hydroxylation of 25-hydroxyvitamin D3 with a Michaelis constant, K(m), value of 2.7 microM. Unexpectedly, the enzyme also hydroxylates the 1 alpha-position of 24,25-dihydroxyvitamin D3 with a K(m) of 1.3 microM, and a fourfold higher Vmax/K(m) compared with the 25-hydroxyvitamin D3 hydroxylase activity, suggesting that 24,25-dihydroxyvitamin D3 is a better substrate than 25-hydroxyvitamin D3 for 1 alpha-hydroxylase. In addition, the enzyme showed 1 alpha-hydroxylase activity toward 24-oxo-25-hydroxyvitamin D3. However, it showed only slight activity towards 23,25-dihydroxyvitamin D3 and 24-oxo-23,25-dihydroxyvitamin D3, and no detectable activity towards vitamin D3 and 24,25,26,27-tetranor-23-hydroxyvitamin D3. These results suggest that the 25-hydroxyl group of vitamin D3 is essential for the 1 alpha-hydroxylase activity and the 24-hydroxyl group enhances the activity, but the 23-hydroxyl group greatly reduced the activity. Another remarkable finding is that living recombinant E. coli cells can convert the substrates into the 1 alpha-hydroxylated products, suggesting the presence of a redox partner of 1 alpha-hydroxylase in E. coli cells.  (+info)

Effect of L-azetidine-2-carboxylic acid on glycosylations of collagen in chick-embryo tendon cells. (8/2276)

The glycosylations of hydroxylysine during collagen biosynthesis in isolated chick-embryo tendon cells were studied by using pulse-chase labelling experiments with [14C]-lysine. The hydroxylation of lysine and the glycosylations of hydroxylysine continued after a 5 min pulse label for up to about 10 min during the chase period. These data differ from those obtained previously in isolated chick-embryo cartilage cells, in which, after a similar 5 min pulse label, these reactions continued during the chase period for up to about 20 min. The collagen synthesized by the isolated chick-embryo tendon cells differed markedly from the type I collagen of adult tissues in its degree of hydroxylation of lysine residues and glycosylations of hydroxylysine residues. When the isolated tendon cells were incubated in the presence of L-azetidine-2-carboxylic acid, the degree of glycosylations of hydroxylysine during the first 10 min of the chase period was identical with that in cells incubated without thcarboxylic acid for at least 60 min, whereas no additional glycosylations took place in the control cells after the 10 min time-point. As a consequence, the collagen synthesized in the presence of this compound contained more carbohydrate than did the collagen synthesized by the control cells. Additional experiments indicated that azetidine-2-carboxylic acid did not increase the collagen glycosyltransferase activities in the tendon cells or the rate of glycosylation reactions when added directly to the enzyme incubation mixture. Control experiments with colchicine indicated that the delay in the rate of collagen secretion, which was observed in the presence of azetidine-2-carboxylic acid, did not in itself affect the degree of glycosylations of collagen. The results thus suggest that the increased glycosylations were due to inhibition of the collagen triple-helix formation, which is known to occur in the presence of azetidine-2-carboxylic acid.  (+info)

Hydroxylation is a biochemical process that involves the addition of a hydroxyl group (-OH) to a molecule, typically a steroid or xenobiotic compound. This process is primarily catalyzed by enzymes called hydroxylases, which are found in various tissues throughout the body.

In the context of medicine and biochemistry, hydroxylation can have several important functions:

1. Drug metabolism: Hydroxylation is a common way that the liver metabolizes drugs and other xenobiotic compounds. By adding a hydroxyl group to a drug molecule, it becomes more polar and water-soluble, which facilitates its excretion from the body.
2. Steroid hormone biosynthesis: Hydroxylation is an essential step in the biosynthesis of many steroid hormones, including cortisol, aldosterone, and the sex hormones estrogen and testosterone. These hormones are synthesized from cholesterol through a series of enzymatic reactions that involve hydroxylation at various steps.
3. Vitamin D activation: Hydroxylation is also necessary for the activation of vitamin D in the body. In order to become biologically active, vitamin D must undergo two successive hydroxylations, first in the liver and then in the kidneys.
4. Toxin degradation: Some toxic compounds can be rendered less harmful through hydroxylation. For example, phenol, a toxic compound found in cigarette smoke and some industrial chemicals, can be converted to a less toxic form through hydroxylation by enzymes in the liver.

Overall, hydroxylation is an important biochemical process that plays a critical role in various physiological functions, including drug metabolism, hormone biosynthesis, and toxin degradation.

Mixed Function Oxygenases (MFOs) are a type of enzyme that catalyze the addition of one atom each from molecular oxygen (O2) to a substrate, while reducing the other oxygen atom to water. These enzymes play a crucial role in the metabolism of various endogenous and exogenous compounds, including drugs, carcinogens, and environmental pollutants.

MFOs are primarily located in the endoplasmic reticulum of cells and consist of two subunits: a flavoprotein component that contains FAD or FMN as a cofactor, and an iron-containing heme protein. The most well-known example of MFO is cytochrome P450, which is involved in the oxidation of xenobiotics and endogenous compounds such as steroids, fatty acids, and vitamins.

MFOs can catalyze a variety of reactions, including hydroxylation, epoxidation, dealkylation, and deamination, among others. These reactions often lead to the activation or detoxification of xenobiotics, making MFOs an important component of the body's defense system against foreign substances. However, in some cases, these reactions can also produce reactive intermediates that may cause toxicity or contribute to the development of diseases such as cancer.

The Cytochrome P-450 (CYP450) enzyme system is a group of enzymes found primarily in the liver, but also in other organs such as the intestines, lungs, and skin. These enzymes play a crucial role in the metabolism and biotransformation of various substances, including drugs, environmental toxins, and endogenous compounds like hormones and fatty acids.

The name "Cytochrome P-450" refers to the unique property of these enzymes to bind to carbon monoxide (CO) and form a complex that absorbs light at a wavelength of 450 nm, which can be detected spectrophotometrically.

The CYP450 enzyme system is involved in Phase I metabolism of xenobiotics, where it catalyzes oxidation reactions such as hydroxylation, dealkylation, and epoxidation. These reactions introduce functional groups into the substrate molecule, which can then undergo further modifications by other enzymes during Phase II metabolism.

There are several families and subfamilies of CYP450 enzymes, each with distinct substrate specificities and functions. Some of the most important CYP450 enzymes include:

1. CYP3A4: This is the most abundant CYP450 enzyme in the human liver and is involved in the metabolism of approximately 50% of all drugs. It also metabolizes various endogenous compounds like steroids, bile acids, and vitamin D.
2. CYP2D6: This enzyme is responsible for the metabolism of many psychotropic drugs, including antidepressants, antipsychotics, and beta-blockers. It also metabolizes some endogenous compounds like dopamine and serotonin.
3. CYP2C9: This enzyme plays a significant role in the metabolism of warfarin, phenytoin, and nonsteroidal anti-inflammatory drugs (NSAIDs).
4. CYP2C19: This enzyme is involved in the metabolism of proton pump inhibitors, antidepressants, and clopidogrel.
5. CYP2E1: This enzyme metabolizes various xenobiotics like alcohol, acetaminophen, and carbon tetrachloride, as well as some endogenous compounds like fatty acids and prostaglandins.

Genetic polymorphisms in CYP450 enzymes can significantly affect drug metabolism and response, leading to interindividual variability in drug efficacy and toxicity. Understanding the role of CYP450 enzymes in drug metabolism is crucial for optimizing pharmacotherapy and minimizing adverse effects.

Microsomes, liver refers to a subcellular fraction of liver cells (hepatocytes) that are obtained during tissue homogenization and subsequent centrifugation. These microsomal fractions are rich in membranous structures known as the endoplasmic reticulum (ER), particularly the rough ER. They are involved in various important cellular processes, most notably the metabolism of xenobiotics (foreign substances) including drugs, toxins, and carcinogens.

The liver microsomes contain a variety of enzymes, such as cytochrome P450 monooxygenases, that are crucial for phase I drug metabolism. These enzymes help in the oxidation, reduction, or hydrolysis of xenobiotics, making them more water-soluble and facilitating their excretion from the body. Additionally, liver microsomes also host other enzymes involved in phase II conjugation reactions, where the metabolites from phase I are further modified by adding polar molecules like glucuronic acid, sulfate, or acetyl groups.

In summary, liver microsomes are a subcellular fraction of liver cells that play a significant role in the metabolism and detoxification of xenobiotics, contributing to the overall protection and maintenance of cellular homeostasis within the body.

Procollagen-proline dioxygenase is an enzyme that belongs to the family of oxidoreductases, specifically those acting on the CH-NH group of donors with oxygen as an acceptor. This enzyme is involved in the post-translational modification of procollagens, which are the precursors of collagen, a crucial protein found in connective tissues such as tendons, ligaments, and skin.

Procollagen-proline dioxygenase catalyzes the reaction that adds two hydroxyl groups to specific proline residues in the procollagen molecule, converting them into hydroxyprolines. This modification is essential for the proper folding and stabilization of the collagen triple helix structure, which provides strength and resilience to connective tissues.

The enzyme requires iron as a cofactor and molecular oxygen as a substrate, with vitamin C (ascorbic acid) acting as an essential cofactor in the reaction cycle. The proper functioning of procollagen-proline dioxygenase is critical for maintaining the integrity and health of connective tissues, and deficiencies or mutations in this enzyme can lead to various connective tissue disorders, such as scurvy (caused by vitamin C deficiency) or certain forms of osteogenesis imperfecta (a genetic disorder characterized by fragile bones).

Steroid hydroxylases are enzymes that catalyze the addition of a hydroxyl group (-OH) to a steroid molecule. These enzymes are located in the endoplasmic reticulum and play a crucial role in the biosynthesis of various steroid hormones, such as cortisol, aldosterone, and sex hormones. The hydroxylation reaction catalyzed by these enzymes increases the polarity and solubility of steroids, allowing them to be further metabolized and excreted from the body.

The most well-known steroid hydroxylases are part of the cytochrome P450 family, specifically CYP11A1, CYP11B1, CYP11B2, CYP17A1, CYP19A1, and CYP21A2. Each enzyme has a specific function in steroid biosynthesis, such as converting cholesterol to pregnenolone (CYP11A1), hydroxylating the 11-beta position of steroids (CYP11B1 and CYP11B2), or performing multiple hydroxylation reactions in the synthesis of sex hormones (CYP17A1, CYP19A1, and CYP21A2).

Defects in these enzymes can lead to various genetic disorders, such as congenital adrenal hyperplasia, which is characterized by impaired steroid hormone biosynthesis.

Aryl hydrocarbon hydroxylases (AHH) are a group of enzymes that play a crucial role in the metabolism of various aromatic and heterocyclic compounds, including potentially harmful substances such as polycyclic aromatic hydrocarbons (PAHs) and dioxins. These enzymes are primarily located in the endoplasmic reticulum of cells, particularly in the liver, but can also be found in other tissues.

The AHH enzymes catalyze the addition of a hydroxyl group (-OH) to the aromatic ring structure of these compounds, which is the first step in their biotransformation and eventual elimination from the body. This process can sometimes lead to the formation of metabolites that are more reactive and potentially toxic than the original compound. Therefore, the overall impact of AHH enzymes on human health is complex and depends on various factors, including the specific compounds being metabolized and individual genetic differences in enzyme activity.

Steroid 16-alpha-Hydroxylase is an enzyme that catalyzes the reaction adding a hydroxyl group to the sixteen (16) alpha position of steroid molecules. This enzyme is involved in the metabolic pathways of various steroids, including cortisol, aldosterone, and some sex hormones.

The gene that encodes this enzyme is CYP3A4, which is part of the cytochrome P450 family. The 16-alpha-hydroxylase activity of this enzyme has been implicated in several physiological and pathophysiological processes, such as steroid hormone biosynthesis, drug metabolism, and cancer progression.

It's worth noting that the activity of this enzyme can vary among individuals, which may contribute to differences in steroid hormone levels and susceptibility to certain diseases.

Biotransformation is the metabolic modification of a chemical compound, typically a xenobiotic (a foreign chemical substance found within an living organism), by a biological system. This process often involves enzymatic conversion of the parent compound to one or more metabolites, which may be more or less active, toxic, or mutagenic than the original substance.

In the context of pharmacology and toxicology, biotransformation is an important aspect of drug metabolism and elimination from the body. The liver is the primary site of biotransformation, but other organs such as the kidneys, lungs, and gastrointestinal tract can also play a role.

Biotransformation can occur in two phases: phase I reactions involve functionalization of the parent compound through oxidation, reduction, or hydrolysis, while phase II reactions involve conjugation of the metabolite with endogenous molecules such as glucuronic acid, sulfate, or acetate to increase its water solubility and facilitate excretion.

Debrisoquine is a drug that belongs to a class of medications called non-selective beta blockers. It works by blocking the action of certain natural substances in your body, such as adrenaline, on the heart and blood vessels. This results in a decrease in heart rate and blood pressure, which makes debrisoquine useful in treating certain conditions like hypertension (high blood pressure) and angina (chest pain).

Debrisoquine is no longer commonly used due to its short duration of action and the availability of more effective and safer beta blockers. It was also found that some people have a genetic variation that affects how their body metabolizes debrisoquine, which can lead to unpredictable drug levels and side effects. This discovery led to the development of the concept of "pharmacogenetics," or how genetic factors influence drug response.

It's important to note that debrisoquine should only be taken under the supervision of a healthcare professional, as it can have serious side effects, especially if not used correctly.

Cholestanetriol 26-monooxygenase is an enzyme that is involved in the metabolism of bile acids and steroids in the body. This enzyme is responsible for adding a hydroxyl group (-OH) to the cholestanetriol molecule at position 26, which is a critical step in the conversion of cholestanetriol to bile acids.

The gene that encodes this enzyme is called CYP3A4, which is located on chromosome 7 in humans. Mutations in this gene can lead to various metabolic disorders, including impaired bile acid synthesis and altered steroid hormone metabolism.

Deficiency or dysfunction of cholestanetriol 26-monooxygenase has been associated with several diseases, such as liver disease, cerebrotendinous xanthomatosis, and some forms of cancer. Therefore, understanding the function and regulation of this enzyme is essential for developing new therapies and treatments for these conditions.

Mephenytoin is defined as an anticonvulsant drug, specifically a hydantoin derivative, that is used in the treatment of complex partial seizures and generalized tonic-clonic seizures. It works by decreasing abnormal electrical activity in the brain. Mephenytoin has been largely replaced by other anticonvulsants due to its adverse effects such as rash, agranulocytosis, and liver toxicity. It is also known as Mesantoin or Mefenitoin.

Please note that this definition is for informational purposes only and should not be used as a medical advice. Always consult with a healthcare professional for accurate information regarding medications and their effects.

Cytochrome P-450 CYP3A is a subfamily of the cytochrome P-450 enzyme superfamily, which are primarily involved in drug metabolism in the human body. These enzymes are found predominantly in the liver, but also in other tissues such as the small intestine, kidneys, and brain.

CYP3A enzymes are responsible for metabolizing a wide variety of drugs, including many statins, benzodiazepines, antidepressants, and opioids. They can also metabolize endogenous compounds such as steroids and bile acids. The activity of CYP3A enzymes can be influenced by various factors, including genetic polymorphisms, age, sex, pregnancy, and the presence of other drugs or diseases.

The name "cytochrome P-450" refers to the fact that these enzymes contain a heme group that absorbs light at a wavelength of 450 nanometers when it is complexed with carbon monoxide. The term "CYP3A" denotes the specific subfamily of cytochrome P-450 enzymes that share a high degree of sequence similarity and function.

Dealkylation is a chemical process that involves the removal of an alkyl group from a molecule. In the context of medical and biological sciences, dealkylation often refers to the breakdown of drugs or other xenobiotics (foreign substances) in the body by enzymes.

Dealkylation is one of the major metabolic pathways for the biotransformation of many drugs, including chemotherapeutic agents, opioids, and benzodiazepines. This process can result in the formation of more polar and water-soluble metabolites, which can then be excreted from the body through the urine or bile.

Dealkylation can occur via several mechanisms, including oxidative dealkylation catalyzed by cytochrome P450 enzymes, as well as non-oxidative dealkylation mediated by other enzymes. The specific dealkylation pathway depends on the structure of the substrate and the type of enzyme involved.

Oxidoreductases are a class of enzymes that catalyze oxidation-reduction reactions, where a electron is transferred from one molecule to another. N-Demethylating oxidoreductases are a specific subclass of these enzymes that catalyze the removal of a methyl group (-CH3) from a nitrogen atom (-N) in a molecule, which is typically a xenobiotic compound (a foreign chemical substance found within an living organism). This process often involves the transfer of electrons and the formation of water as a byproduct.

The reaction catalyzed by N-demethylating oxidoreductases can be represented as follows:
R-N-CH3 + O2 + H2O → R-N-H + CH3OH + H2O2

where R represents the rest of the molecule. The removal of the methyl group is often an important step in the metabolism and detoxification of xenobiotic compounds, as it can make them more water soluble and facilitate their excretion from the body.

Hydroxylysine is a modified form of the amino acid lysine, which is formed by the addition of a hydroxyl group (-OH) to the lysine molecule. This process is known as hydroxylation and is catalyzed by the enzyme lysyl hydroxylase.

In the human body, hydroxylysine is an important component of collagen, which is a protein that provides structure and strength to tissues such as skin, tendons, ligaments, and bones. Hydroxylysine helps to stabilize the triple-helix structure of collagen by forming cross-links between individual collagen molecules.

Abnormalities in hydroxylysine metabolism can lead to various connective tissue disorders, such as Ehlers-Danlos syndrome and osteogenesis imperfecta, which are characterized by joint hypermobility, skin fragility, and bone fractures.

NADPH-ferrihemoprotein reductase, also known as diaphorase or NO synthase reductase, is an enzyme that catalyzes the reduction of ferrihemoproteins using NADPH as a reducing cofactor. This reaction plays a crucial role in various biological processes such as the detoxification of certain compounds and the regulation of cellular signaling pathways.

The systematic name for this enzyme is NADPH:ferrihemoprotein oxidoreductase, and it belongs to the family of oxidoreductases that use NADH or NADPH as electron donors. The reaction catalyzed by this enzyme can be represented as follows:

NADPH + H+ + ferrihemoprotein ↔ NADP+ + ferrohemoprotein

In this reaction, the ferric (FeIII) form of hemoproteins is reduced to its ferrous (FeII) form by accepting electrons from NADPH. This enzyme is widely distributed in various tissues and organisms, including bacteria, fungi, plants, and animals. It has been identified as a component of several multi-enzyme complexes involved in different metabolic pathways, such as nitric oxide synthase (NOS) and cytochrome P450 reductase.

In summary, NADPH-ferrihemoprotein reductase is an essential enzyme that catalyzes the reduction of ferrihemoproteins using NADPH as a reducing agent, playing a critical role in various biological processes and metabolic pathways.

In the context of medicine and pharmacology, "kinetics" refers to the study of how a drug moves throughout the body, including its absorption, distribution, metabolism, and excretion (often abbreviated as ADME). This field is called "pharmacokinetics."

1. Absorption: This is the process of a drug moving from its site of administration into the bloodstream. Factors such as the route of administration (e.g., oral, intravenous, etc.), formulation, and individual physiological differences can affect absorption.

2. Distribution: Once a drug is in the bloodstream, it gets distributed throughout the body to various tissues and organs. This process is influenced by factors like blood flow, protein binding, and lipid solubility of the drug.

3. Metabolism: Drugs are often chemically modified in the body, typically in the liver, through processes known as metabolism. These changes can lead to the formation of active or inactive metabolites, which may then be further distributed, excreted, or undergo additional metabolic transformations.

4. Excretion: This is the process by which drugs and their metabolites are eliminated from the body, primarily through the kidneys (urine) and the liver (bile).

Understanding the kinetics of a drug is crucial for determining its optimal dosing regimen, potential interactions with other medications or foods, and any necessary adjustments for special populations like pediatric or geriatric patients, or those with impaired renal or hepatic function.

High-performance liquid chromatography (HPLC) is a type of chromatography that separates and analyzes compounds based on their interactions with a stationary phase and a mobile phase under high pressure. The mobile phase, which can be a gas or liquid, carries the sample mixture through a column containing the stationary phase.

In HPLC, the mobile phase is a liquid, and it is pumped through the column at high pressures (up to several hundred atmospheres) to achieve faster separation times and better resolution than other types of liquid chromatography. The stationary phase can be a solid or a liquid supported on a solid, and it interacts differently with each component in the sample mixture, causing them to separate as they travel through the column.

HPLC is widely used in analytical chemistry, pharmaceuticals, biotechnology, and other fields to separate, identify, and quantify compounds present in complex mixtures. It can be used to analyze a wide range of substances, including drugs, hormones, vitamins, pigments, flavors, and pollutants. HPLC is also used in the preparation of pure samples for further study or use.

Oxygenases are a class of enzymes that catalyze the incorporation of molecular oxygen (O2) into their substrates. They play crucial roles in various biological processes, including the biosynthesis of many natural products, as well as the detoxification and degradation of xenobiotics (foreign substances).

There are two main types of oxygenases: monooxygenases and dioxygenases. Monooxygenases introduce one atom of molecular oxygen into a substrate while reducing the other to water. An example of this type of enzyme is cytochrome P450, which is involved in drug metabolism and steroid hormone synthesis. Dioxygenases, on the other hand, incorporate both atoms of molecular oxygen into their substrates, often leading to the formation of new carbon-carbon bonds or the cleavage of existing ones.

It's important to note that while oxygenases are essential for many life-sustaining processes, they can also contribute to the production of harmful reactive oxygen species (ROS) during normal cellular metabolism. An imbalance in ROS levels can lead to oxidative stress and damage to cells and tissues, which has been linked to various diseases such as cancer, neurodegeneration, and cardiovascular disease.

Substrate specificity in the context of medical biochemistry and enzymology refers to the ability of an enzyme to selectively bind and catalyze a chemical reaction with a particular substrate (or a group of similar substrates) while discriminating against other molecules that are not substrates. This specificity arises from the three-dimensional structure of the enzyme, which has evolved to match the shape, charge distribution, and functional groups of its physiological substrate(s).

Substrate specificity is a fundamental property of enzymes that enables them to carry out highly selective chemical transformations in the complex cellular environment. The active site of an enzyme, where the catalysis takes place, has a unique conformation that complements the shape and charge distribution of its substrate(s). This ensures efficient recognition, binding, and conversion of the substrate into the desired product while minimizing unwanted side reactions with other molecules.

Substrate specificity can be categorized as:

1. Absolute specificity: An enzyme that can only act on a single substrate or a very narrow group of structurally related substrates, showing no activity towards any other molecule.
2. Group specificity: An enzyme that prefers to act on a particular functional group or class of compounds but can still accommodate minor structural variations within the substrate.
3. Broad or promiscuous specificity: An enzyme that can act on a wide range of structurally diverse substrates, albeit with varying catalytic efficiencies.

Understanding substrate specificity is crucial for elucidating enzymatic mechanisms, designing drugs that target specific enzymes or pathways, and developing biotechnological applications that rely on the controlled manipulation of enzyme activities.

Benzopyrene hydroxylase is an enzyme that is involved in the metabolism and detoxification of polycyclic aromatic hydrocarbons (PAHs), which are a group of environmental pollutants found in cigarette smoke, air pollution, and charred or overcooked foods. Benzopyrene hydroxylase is primarily found in the liver and is responsible for adding a hydroxyl group to benzopyrene, a type of PAH, making it more water-soluble and easier to excrete from the body. This enzyme plays an important role in the body's defense against the harmful effects of PAHs.

Microsomes are subcellular membranous vesicles that are obtained as a byproduct during the preparation of cellular homogenates. They are not naturally occurring structures within the cell, but rather formed due to fragmentation of the endoplasmic reticulum (ER) during laboratory procedures. Microsomes are widely used in various research and scientific studies, particularly in the fields of biochemistry and pharmacology.

Microsomes are rich in enzymes, including the cytochrome P450 system, which is involved in the metabolism of drugs, toxins, and other xenobiotics. These enzymes play a crucial role in detoxifying foreign substances and eliminating them from the body. As such, microsomes serve as an essential tool for studying drug metabolism, toxicity, and interactions, allowing researchers to better understand and predict the effects of various compounds on living organisms.

Cytochrome P-450 CYP1A2 is a specific isoform of the cytochrome P-450 enzyme system, which is involved in the metabolism of various xenobiotics, including drugs and toxins, in the body. This enzyme is primarily located in the endoplasmic reticulum of hepatocytes, or liver cells, and plays a significant role in the oxidative metabolism of certain medications, such as caffeine, theophylline, and some antidepressants.

CYP1A2 is induced by various factors, including smoking, charcoal-grilled foods, and certain medications, which can increase its enzymatic activity and potentially affect the metabolism and clearance of drugs that are substrates for this enzyme. Genetic polymorphisms in the CYP1A2 gene can also lead to differences in enzyme activity among individuals, resulting in variable drug responses and potential adverse effects.

In summary, Cytochrome P-450 CYP1A2 is a liver enzyme involved in the metabolism of various drugs and toxins, with genetic and environmental factors influencing its activity and impacting individual responses to medications.

Cytochrome P-450 CYP2D6 is a specific isoenzyme belonging to the Cytochrome P-450 (CYP) family of enzymes, which are primarily located in the liver and play a crucial role in the metabolism of various drugs and xenobiotics. The term "P-450" refers to the absorption spectrum of these enzymes when they are combined with carbon monoxide, exhibiting a peak absorbance at 450 nanometers.

CYP2D6 is involved in the metabolism of approximately 20-25% of clinically prescribed drugs, including many antidepressants, neuroleptics, beta-blockers, opioids, and antiarrhythmics. This enzyme can demonstrate genetic polymorphisms, leading to variations in drug metabolism rates among individuals. These genetic differences can result in four distinct phenotypes: poor metabolizers (PM), intermediate metabolizers (IM), extensive metabolizers (EM), and ultra-rapid metabolizers (UM).

Poor metabolizers have decreased or absent CYP2D6 enzyme activity due to genetic mutations, leading to an accumulation of drugs in the body and increased susceptibility to adverse drug reactions. In contrast, ultra-rapid metabolizers possess multiple copies of the functional CYP2D6 gene, resulting in enhanced enzymatic activity and rapid drug clearance. This can lead to therapeutic failure due to insufficient drug exposure at the target site.

Understanding the genetic variations in CYP2D6 is essential for personalized medicine, as it allows healthcare providers to tailor drug therapy based on an individual's metabolic capacity and minimize the risk of adverse reactions or treatment failures.

Oxidation-Reduction (redox) reactions are a type of chemical reaction involving a transfer of electrons between two species. The substance that loses electrons in the reaction is oxidized, and the substance that gains electrons is reduced. Oxidation and reduction always occur together in a redox reaction, hence the term "oxidation-reduction."

In biological systems, redox reactions play a crucial role in many cellular processes, including energy production, metabolism, and signaling. The transfer of electrons in these reactions is often facilitated by specialized molecules called electron carriers, such as nicotinamide adenine dinucleotide (NAD+/NADH) and flavin adenine dinucleotide (FAD/FADH2).

The oxidation state of an element in a compound is a measure of the number of electrons that have been gained or lost relative to its neutral state. In redox reactions, the oxidation state of one or more elements changes as they gain or lose electrons. The substance that is oxidized has a higher oxidation state, while the substance that is reduced has a lower oxidation state.

Overall, oxidation-reduction reactions are fundamental to the functioning of living organisms and are involved in many important biological processes.

Hypoxia-Inducible Factor (HIF) is a transcription factor that plays a crucial role in the body's response to low oxygen levels (hypoxia). HIF is composed of two subunits: an alpha subunit and a beta subunit. Under normal oxygen conditions, the alpha subunit is constantly being broken down by prolyl hydroxylase domain-containing proteins, which are a type of enzyme known as HIF-Proline Dioxygenases (HIF-PDOs).

HIF-PDOs post-translationally modify the HIF alpha subunit by adding a hydroxyl group to specific proline residues. This modification marks the HIF alpha subunit for degradation by the proteasome, a complex that breaks down unneeded or damaged proteins in the cell. However, under hypoxic conditions, the activity of HIF-PDOs is inhibited, leading to the stabilization and accumulation of HIF alpha subunits.

Once stabilized, HIF alpha subunits dimerize with HIF beta subunits and translocate to the nucleus where they bind to hypoxia response elements (HREs) in the DNA. This binding induces the expression of genes involved in various cellular responses to hypoxia, such as angiogenesis, metabolic reprogramming, and erythropoiesis. Therefore, HIF-PDOs play a critical role in regulating the body's response to low oxygen levels by controlling the stability and activity of HIF.

Catalysis is the process of increasing the rate of a chemical reaction by adding a substance known as a catalyst, which remains unchanged at the end of the reaction. A catalyst lowers the activation energy required for the reaction to occur, thereby allowing the reaction to proceed more quickly and efficiently. This can be particularly important in biological systems, where enzymes act as catalysts to speed up metabolic reactions that are essential for life.

Cholestanes are a type of steroid compound that are derived from cholesterol. They are characterized by a fully saturated steroid nucleus, which means that all of the double bonds in the cholesterol molecule have been reduced to single bonds through a process called hydrogenation.

Cholestanes are important intermediates in the biosynthesis of other steroids, such as bile acids and steroid hormones. They can also be found in some natural sources, including certain plants and fungi.

It's worth noting that cholestanes themselves do not have any specific medical significance, but they are important for understanding the biochemistry of steroids and their role in human health and disease.

Proline is an organic compound that is classified as a non-essential amino acid, meaning it can be produced by the human body and does not need to be obtained through the diet. It is encoded in the genetic code as the codon CCU, CCC, CCA, or CCG. Proline is a cyclic amino acid, containing an unusual secondary amine group, which forms a ring structure with its carboxyl group.

In proteins, proline acts as a structural helix breaker, disrupting the alpha-helix structure and leading to the formation of turns and bends in the protein chain. This property is important for the proper folding and function of many proteins. Proline also plays a role in the stability of collagen, a major structural protein found in connective tissues such as tendons, ligaments, and skin.

In addition to its role in protein structure, proline has been implicated in various cellular processes, including signal transduction, apoptosis, and oxidative stress response. It is also a precursor for the synthesis of other biologically important compounds such as hydroxyproline, which is found in collagen and elastin, and glutamate, an excitatory neurotransmitter in the brain.

Phenylalanine Hydroxylase (PAH) is an enzyme that plays a crucial role in the metabolism of the essential amino acid phenylalanine. This enzyme is primarily found in the liver and is responsible for converting phenylalanine into tyrosine, another amino acid. PAH requires a cofactor called tetrahydrobiopterin (BH4) to function properly.

Defects or mutations in the gene that encodes PAH can lead to a genetic disorder known as Phenylketonuria (PKU). In PKU, the activity of PAH is significantly reduced or absent, causing an accumulation of phenylalanine in the body. If left untreated, this condition can result in severe neurological damage and intellectual disability due to the toxic effects of high phenylalanine levels on the developing brain. A strict low-phenylalanine diet and regular monitoring of blood phenylalanine levels are essential for managing PKU and preventing associated complications.

I'm sorry for any confusion, but "Estrogens, Catechol" is not a recognized medical term or classification. Estrogens are a group of steroid hormones that are primarily responsible for the development and maintenance of female sexual characteristics. They are produced mainly in the ovaries, but also in other tissues such as fat, liver, and breast tissue.

Catechols, on the other hand, are a type of chemical compound that contain a benzene ring with two hydroxyl groups attached to it in a particular arrangement. Some estrogens can be metabolized into catechol estrogen metabolites, which have been studied for their potential role in cancer development and progression.

If you have any specific questions about estrogens or catechols, I'd be happy to try to help answer them!

Benzoflavones are a type of chemical compound that consist of a benzene ring (a basic unit of organic chemistry made up of six carbon atoms arranged in a flat, hexagonal shape) fused to a flavone structure. Flavones are a type of flavonoid, which is a class of plant pigments widely present in fruits and vegetables. Benzoflavones have been studied for their potential medicinal properties, including anti-inflammatory, antioxidant, and anticancer activities. However, more research is needed to fully understand their effects and safety profile in humans.

Chlorzoxazone is a muscle relaxant medication that works by helping to reduce muscle spasms. It does not directly affect the muscles themselves, but rather works on the central nervous system to help decrease the sensation of pain and allow the muscles to relax. Chlorzoxazone is often used in combination with physical therapy, rest, and other treatments for muscle injuries or disorders.

Like all medications, chlorzoxazone can have side effects, including dizziness, drowsiness, and upset stomach. It is important to follow your healthcare provider's instructions carefully when taking this medication, and to avoid activities that require alertness, such as driving or operating heavy machinery, until you know how the drug affects you.

It is worth noting that chlorzoxazone is a prescription medication, and should only be used under the guidance of a licensed healthcare provider. If you have any questions about this medication or its use, it is important to speak with your doctor or pharmacist for more information.

Lauric acid is a type of saturated fatty acid, meaning it contains only single bonds between its carbon atoms. It is named after the laurel tree, from which it was originally isolated, and has the chemical formula CH3(CH2)10COOH.

In a medical context, lauric acid is often discussed in relation to its presence in certain foods and its potential effects on health. For example, lauric acid is the primary fatty acid found in coconut oil, making up about 50% of its total fat content. It is also found in smaller amounts in other foods such as palm kernel oil, dairy products, and human breast milk.

Some studies have suggested that lauric acid may have beneficial effects on health, such as raising levels of "good" HDL cholesterol and having antimicrobial properties. However, it is also high in calories and can contribute to weight gain if consumed in excess. Additionally, like other saturated fats, it can raise levels of "bad" LDL cholesterol when consumed in large amounts, which may increase the risk of heart disease over time.

Overall, while lauric acid may have some potential health benefits, it is important to consume it in moderation as part of a balanced diet.

Troleandomycin is an antibiotic drug that belongs to the family of macrolides. It is primarily used to treat infections caused by bacteria, particularly those that are resistant to penicillin or other antibiotics. Troleandomycin works by inhibiting bacterial protein synthesis, thereby preventing the growth and multiplication of the bacteria.

The medical definition of Troleandomycin is as follows:

Troleandomycin (INN, USAN, BAN), also known as Troidemycin, is a macrolide antibiotic with a chemical formula of (3R,5S,8R,9S,11R,12S,13S,15R,16R,17R,19E,21E,23E)-3-[(2R,4R,5S,6S)-4-dimethylamino-5-hydroxy-6-methyloxan-2-yl]oxy-15-{[2-(2-methoxyethoxy)ethoxy]methyl}-8-{(1E,3S)-3-[2-(2-methoxyethoxy)ethoxy]prop-1-enyl}-9,11,13-trihydroxy-17-(2-hydroxyethyl)-19,21,23-nonatriene-2,4,6,10,14,16,18-heptaone.

Troleandomycin is used to treat a variety of bacterial infections, including respiratory tract infections, skin and soft tissue infections, and sexually transmitted diseases. It is also used to prevent endocarditis (inflammation of the lining of the heart) in patients with certain heart conditions who are undergoing dental or surgical procedures.

Like other macrolide antibiotics, Troleandomycin may cause gastrointestinal side effects such as nausea, vomiting, and diarrhea. It may also interact with other medications, including warfarin, oral contraceptives, and digoxin, leading to potentially serious adverse effects. Therefore, it is important to inform healthcare providers of all medications being taken before starting Troleandomycin therapy.

Stereoisomerism is a type of isomerism (structural arrangement of atoms) in which molecules have the same molecular formula and sequence of bonded atoms, but differ in the three-dimensional orientation of their atoms in space. This occurs when the molecule contains asymmetric carbon atoms or other rigid structures that prevent free rotation, leading to distinct spatial arrangements of groups of atoms around a central point. Stereoisomers can have different chemical and physical properties, such as optical activity, boiling points, and reactivities, due to differences in their shape and the way they interact with other molecules.

There are two main types of stereoisomerism: enantiomers (mirror-image isomers) and diastereomers (non-mirror-image isomers). Enantiomers are pairs of stereoisomers that are mirror images of each other, but cannot be superimposed on one another. Diastereomers, on the other hand, are non-mirror-image stereoisomers that have different physical and chemical properties.

Stereoisomerism is an important concept in chemistry and biology, as it can affect the biological activity of molecules, such as drugs and natural products. For example, some enantiomers of a drug may be active, while others are inactive or even toxic. Therefore, understanding stereoisomerism is crucial for designing and synthesizing effective and safe drugs.

Procollagen-Lysine, 2-Oxoglutarate 5-Dioxygenase is an enzyme that plays a crucial role in the biosynthesis of collagen. The medical definition of this enzyme is:

"An enzyme that catalyzes the post-translational modification of specific lysine residues in procollagens and related proteins. This enzyme requires Fe2+, 2-oxoglutarate, molecular oxygen, and ascorbic acid as cofactors. It hydroxylates certain lysine residues to form hydroxylysine, which is essential for the stabilization of collagen triple helices and for the formation of covalent cross-links between individual collagen molecules. Mutations in this gene have been associated with several types of Ehlers-Danlos syndrome."

The systematic name for this enzyme is "procollagen-lysine, 2-oxoglutarate 5-dioxygenase (hydroxylating)." It is also known as "procollagen-lysine, lysine hydroxylase," or simply "LH." This enzyme is responsible for the hydroxylation of specific lysine residues in procollagens and related proteins during their biosynthesis. The hydroxylation reaction catalyzed by this enzyme involves the incorporation of a hydroxyl group (-OH) into the lysine side chain, resulting in the formation of hydroxylysine. This modification is essential for the proper folding and stabilization of collagen molecules, as well as for their subsequent cross-linking and assembly into extracellular matrix structures.

Defects or mutations in the gene encoding this enzyme can lead to various types of Ehlers-Danlos syndrome (EDS), a group of heritable connective tissue disorders characterized by joint hypermobility, skin hyperextensibility, and tissue fragility.

Cholecalciferol is the chemical name for Vitamin D3. It is a fat-soluble vitamin that is essential for the regulation of calcium and phosphate levels in the body, which helps to maintain healthy bones and teeth. Cholecalciferol can be synthesized by the skin upon exposure to sunlight or obtained through dietary sources such as fatty fish, liver, and fortified foods. It is also available as a dietary supplement.

Gas Chromatography-Mass Spectrometry (GC-MS) is a powerful analytical technique that combines the separating power of gas chromatography with the identification capabilities of mass spectrometry. This method is used to separate, identify, and quantify different components in complex mixtures.

In GC-MS, the mixture is first vaporized and carried through a long, narrow column by an inert gas (carrier gas). The various components in the mixture interact differently with the stationary phase inside the column, leading to their separation based on their partition coefficients between the mobile and stationary phases. As each component elutes from the column, it is then introduced into the mass spectrometer for analysis.

The mass spectrometer ionizes the sample, breaks it down into smaller fragments, and measures the mass-to-charge ratio of these fragments. This information is used to generate a mass spectrum, which serves as a unique "fingerprint" for each compound. By comparing the generated mass spectra with reference libraries or known standards, analysts can identify and quantify the components present in the original mixture.

GC-MS has wide applications in various fields such as forensics, environmental analysis, drug testing, and research laboratories due to its high sensitivity, specificity, and ability to analyze volatile and semi-volatile compounds.

Alpha-ketoglutaric acid, also known as 2-oxoglutarate, is not an acid in the traditional sense but is instead a key molecule in the Krebs cycle (citric acid cycle), which is a central metabolic pathway involved in cellular respiration. Alpha-ketoglutaric acid is a crucial intermediate in the process of converting carbohydrates, fats, and proteins into energy through oxidation. It plays a vital role in amino acid synthesis and the breakdown of certain amino acids. Additionally, it serves as an essential cofactor for various enzymes involved in numerous biochemical reactions within the body. Any medical conditions or disorders related to alpha-ketoglutaric acid would typically be linked to metabolic dysfunctions or genetic defects affecting the Krebs cycle.

Hydroxybenzoates are the salts or esters of hydroxybenzoic acids. They are commonly used as preservatives in food, cosmetics, and pharmaceutical products due to their antimicrobial and antifungal properties. The most common examples include methylparaben, ethylparaben, propylparaben, and butylparaben. These compounds work by inhibiting the growth of bacteria and fungi, thereby increasing the shelf life and safety of various products. However, there has been some concern about their potential health effects, including possible hormonal disruption, and their use in certain applications is being re-evaluated.

Sulfaphenazole is a type of medication known as a sulfonamide antibiotic. It is used to treat bacterial infections by preventing the growth of bacteria. Sulfaphenazole works by interfering with the bacteria's ability to synthesize folic acid, which is necessary for the bacteria to survive and multiply.

Here is a medical definition of Sulfaphenazole:

"Sulfaphenazole is a sulfonamide antibiotic with bacteriostatic activity against a wide range of gram-positive and gram-negative bacteria. It is used in the treatment of various infections, including urinary tract infections, respiratory tract infections, and skin and soft tissue infections. Sulfaphenazole is administered orally and is available as a prescription medication."

It's important to note that overuse or misuse of antibiotics like sulfaphenazole can lead to antibiotic resistance, which makes it difficult to treat infections with these medications in the future. Therefore, sulfaphenazole should only be used under the direction and supervision of a healthcare provider.

NADP (Nicotinamide Adenine Dinucleotide Phosphate) is a coenzyme that plays a crucial role as an electron carrier in various redox reactions in the human body. It exists in two forms: NADP+, which functions as an oxidizing agent and accepts electrons, and NADPH, which serves as a reducing agent and donates electrons.

NADPH is particularly important in anabolic processes, such as lipid and nucleotide synthesis, where it provides the necessary reducing equivalents to drive these reactions forward. It also plays a critical role in maintaining the cellular redox balance by participating in antioxidant defense mechanisms that neutralize harmful reactive oxygen species (ROS).

In addition, NADP is involved in various metabolic pathways, including the pentose phosphate pathway and the Calvin cycle in photosynthesis. Overall, NADP and its reduced form, NADPH, are essential molecules for maintaining proper cellular function and energy homeostasis.

Phenobarbital is a barbiturate medication that is primarily used for the treatment of seizures and convulsions. It works by suppressing the abnormal electrical activity in the brain that leads to seizures. In addition to its anticonvulsant properties, phenobarbital also has sedative and hypnotic effects, which can be useful for treating anxiety, insomnia, and agitation.

Phenobarbital is available in various forms, including tablets, capsules, and elixirs, and it is typically taken orally. The medication works by binding to specific receptors in the brain called gamma-aminobutyric acid (GABA) receptors, which help to regulate nerve impulses in the brain. By increasing the activity of GABA, phenobarbital can help to reduce excessive neural activity and prevent seizures.

While phenobarbital is an effective medication for treating seizures and other conditions, it can also be habit-forming and carries a risk of dependence and addiction. Long-term use of the medication can lead to tolerance, meaning that higher doses may be needed to achieve the same effects. Abruptly stopping the medication can also lead to withdrawal symptoms, such as anxiety, restlessness, and seizures.

Like all medications, phenobarbital can have side effects, including dizziness, drowsiness, and impaired coordination. It can also interact with other medications, such as certain antidepressants and sedatives, so it is important to inform your healthcare provider of all medications you are taking before starting phenobarbital.

In summary, phenobarbital is a barbiturate medication used primarily for the treatment of seizures and convulsions. It works by binding to GABA receptors in the brain and increasing their activity, which helps to reduce excessive neural activity and prevent seizures. While phenobarbital can be effective, it carries a risk of dependence and addiction and can have side effects and drug interactions.

Mass spectrometry (MS) is an analytical technique used to identify and quantify the chemical components of a mixture or compound. It works by ionizing the sample, generating charged molecules or fragments, and then measuring their mass-to-charge ratio in a vacuum. The resulting mass spectrum provides information about the molecular weight and structure of the analytes, allowing for identification and characterization.

In simpler terms, mass spectrometry is a method used to determine what chemicals are present in a sample and in what quantities, by converting the chemicals into ions, measuring their masses, and generating a spectrum that shows the relative abundances of each ion type.

Cholestanols are a type of sterol that is similar in structure to cholesterol. They are found in small amounts in the body and can also be found in some foods. Cholestanols are formed when cholesterol undergoes a chemical reaction called isomerization, which changes its structure.

Cholestanols are important because they can accumulate in the body and contribute to the development of certain medical conditions. For example, elevated levels of cholestanols in the blood have been associated with an increased risk of cardiovascular disease. Additionally, some genetic disorders can cause an accumulation of cholestanols in various tissues, leading to a range of symptoms such as liver damage, neurological problems, and cataracts.

Medically, cholestanols are often used as markers for the diagnosis and monitoring of certain conditions related to cholesterol metabolism.

Hydroxyproline is not a medical term per se, but it is a significant component in the medical field, particularly in the study of connective tissues and collagen. Here's a scientific definition:

Hydroxyproline is a modified amino acid that is formed by the post-translational modification of the amino acid proline in collagen and some other proteins. This process involves the addition of a hydroxyl group (-OH) to the proline residue, which alters its chemical properties and contributes to the stability and structure of collagen fibers. Collagen is the most abundant protein in the human body and is a crucial component of connective tissues such as tendons, ligaments, skin, and bones. The presence and quantity of hydroxyproline can serve as a marker for collagen turnover and degradation, making it relevant to various medical and research contexts, including the study of diseases affecting connective tissues like osteoarthritis, rheumatoid arthritis, and Ehlers-Danlos syndrome.

Camphor 5-monooxygenase is an enzyme that catalyzes the conversion of camphor to 5-exo-hydroxycamphor, which is the first step in the degradation of camphor by certain bacteria. This enzyme is a member of the cytochrome P450 family and requires NADPH and molecular oxygen for its activity. The gene that encodes this enzyme is often used as a marker for the presence of camphor-degrading bacteria in environmental samples.

Hypoxia-Inducible Factor 1 (HIF-1) is a transcription factor that plays a crucial role in the body's response to low oxygen levels, also known as hypoxia. HIF-1 is a heterodimeric protein composed of two subunits: an alpha subunit (HIF-1α) and a beta subunit (HIF-1β).

The alpha subunit, HIF-1α, is the regulatory subunit that is subject to oxygen-dependent degradation. Under normal oxygen conditions (normoxia), HIF-1α is constantly produced in the cell but is rapidly degraded by proteasomes due to hydroxylation of specific proline residues by prolyl hydroxylase domain-containing proteins (PHDs). This hydroxylation reaction requires oxygen as a substrate, and under hypoxic conditions, the activity of PHDs is inhibited, leading to the stabilization and accumulation of HIF-1α.

Once stabilized, HIF-1α translocates to the nucleus, where it heterodimerizes with HIF-1β and binds to hypoxia-responsive elements (HREs) in the promoter regions of target genes. This binding results in the activation of gene transcription programs that promote cellular adaptation to low oxygen levels. These adaptive responses include increased erythropoiesis, angiogenesis, glucose metabolism, and pH regulation, among others.

Therefore, HIF-1α is a critical regulator of the body's response to hypoxia, and its dysregulation has been implicated in various pathological conditions, including cancer, cardiovascular disease, and neurodegenerative disorders.

Oxygen is a colorless, odorless, tasteless gas that constitutes about 21% of the earth's atmosphere. It is a crucial element for human and most living organisms as it is vital for respiration. Inhaled oxygen enters the lungs and binds to hemoglobin in red blood cells, which carries it to tissues throughout the body where it is used to convert nutrients into energy and carbon dioxide, a waste product that is exhaled.

Medically, supplemental oxygen therapy may be provided to patients with conditions such as chronic obstructive pulmonary disease (COPD), pneumonia, heart failure, or other medical conditions that impair the body's ability to extract sufficient oxygen from the air. Oxygen can be administered through various devices, including nasal cannulas, face masks, and ventilators.

An ankyrin repeat is a protein structural motif, which is characterized by the repetition of a 33-amino acid long sequence. This motif is responsible for mediating protein-protein interactions and is found in a wide variety of proteins with diverse functions. Ankyrin repeats are known to play a role in various cellular processes such as signal transduction, cell cycle regulation, and ion transport. In particular, ankyrin repeat-containing proteins have been implicated in various human diseases, including cardiovascular disease, neurological disorders, and cancer.

Coumarins are a class of organic compounds that occur naturally in certain plants, such as sweet clover and tonka beans. They have a characteristic aroma and are often used as fragrances in perfumes and flavorings in food products. In addition to their use in consumer goods, coumarins also have important medical applications.

One of the most well-known coumarins is warfarin, which is a commonly prescribed anticoagulant medication used to prevent blood clots from forming or growing larger. Warfarin works by inhibiting the activity of vitamin K-dependent clotting factors in the liver, which helps to prolong the time it takes for blood to clot.

Other medical uses of coumarins include their use as anti-inflammatory agents and antimicrobial agents. Some coumarins have also been shown to have potential cancer-fighting properties, although more research is needed in this area.

It's important to note that while coumarins have many medical uses, they can also be toxic in high doses. Therefore, it's essential to use them only under the guidance of a healthcare professional.

Camphor is a waxy, flammable solid with a strong aroma, derived from the wood of the camphor laurel (Cinnamomum camphora). In a medical context, camphor is used topically as a skin protectant and a counterirritant, and in some over-the-counter products such as nasal decongestants and muscle rubs. It can also be found in some insect repellents and embalming fluids.

Camphor works by stimulating nerve endings and increasing blood flow to the area where it is applied. This can help to relieve pain, reduce inflammation, and alleviate congestion. However, camphor should be used with caution, as it can be toxic if ingested or absorbed in large amounts through the skin. It is important to follow the instructions on product labels carefully and avoid using camphor on broken or irritated skin.

Cytochrome P-450 CYP2E1 is a specific isoform of the cytochrome P-450 enzyme system, which is involved in the metabolism of various xenobiotics and endogenous compounds. This enzyme is primarily located in the liver and to some extent in other organs such as the lungs, brain, and kidneys.

CYP2E1 plays a significant role in the metabolic activation of several procarcinogens, including nitrosamines, polycyclic aromatic hydrocarbons, and certain solvents. It also contributes to the oxidation of various therapeutic drugs, such as acetaminophen, anesthetics, and anticonvulsants. Overexpression or induction of CYP2E1 has been linked to increased susceptibility to chemical-induced toxicity, carcinogenesis, and alcohol-related liver damage.

The activity of CYP2E1 can be influenced by various factors, including genetic polymorphisms, age, sex, smoking status, and exposure to certain chemicals or drugs. Understanding the regulation and function of this enzyme is crucial for predicting individual susceptibility to chemical-induced toxicities and diseases, as well as for optimizing drug therapy and minimizing adverse effects.

Molecular structure, in the context of biochemistry and molecular biology, refers to the arrangement and organization of atoms and chemical bonds within a molecule. It describes the three-dimensional layout of the constituent elements, including their spatial relationships, bond lengths, and angles. Understanding molecular structure is crucial for elucidating the functions and reactivities of biological macromolecules such as proteins, nucleic acids, lipids, and carbohydrates. Various experimental techniques, like X-ray crystallography, nuclear magnetic resonance (NMR) spectroscopy, and cryo-electron microscopy (cryo-EM), are employed to determine molecular structures at atomic resolution, providing valuable insights into their biological roles and potential therapeutic targets.

Catechol oxidase, also known as polyphenol oxidase, is an enzyme that catalyzes the oxidation of catechols and other phenolic compounds to quinones. These quinones can then undergo further reactions to form various pigmented compounds, such as melanins. Catechol oxidase is widely distributed in nature and is found in plants, fungi, and some bacteria. In humans, catechol oxidase is involved in the metabolism of neurotransmitters such as dopamine and epinephrine.

Cytochrome b5 is a type of hemoprotein, which is a protein that contains a heme group. The heme group is a cofactor that contains an iron atom and is responsible for the red color of cytochromes. Cytochrome b5 is found in the endoplasmic reticulum and mitochondria of cells and plays a role in various cellular processes, including electron transport and fatty acid desaturation. It can exist in two forms: a soluble form located in the cytosol, and a membrane-bound form associated with the endoplasmic reticulum or mitochondrial inner membrane. The reduced form of cytochrome b5 donates an electron to various enzymes involved in oxidation-reduction reactions.

Isoenzymes, also known as isoforms, are multiple forms of an enzyme that catalyze the same chemical reaction but differ in their amino acid sequence, structure, and/or kinetic properties. They are encoded by different genes or alternative splicing of the same gene. Isoenzymes can be found in various tissues and organs, and they play a crucial role in biological processes such as metabolism, detoxification, and cell signaling. Measurement of isoenzyme levels in body fluids (such as blood) can provide valuable diagnostic information for certain medical conditions, including tissue damage, inflammation, and various diseases.

Bupropion is an antidepressant medication used primarily to treat depression, but it also has uses in helping people quit smoking and treating attention deficit hyperactivity disorder (ADHD). It works by affecting the chemicals in the brain called dopamine and norepinephrine, which regulate mood and behavior.

Bupropion is available under various brand names, including Wellbutrin, Aplenzin, and Forfivo. It comes in several forms, such as immediate-release tablets, sustained-release tablets, and extended-release tablets, which are taken orally. The dosage and form of bupropion prescribed will depend on the individual's medical condition and response to treatment.

As with any medication, bupropion can have side effects, including dry mouth, headache, insomnia, nausea, and dizziness. In some cases, it may cause more severe side effects, such as seizures, high blood pressure, or allergic reactions. It is essential to follow the prescribing physician's instructions carefully when taking bupropion and report any bothersome or concerning symptoms promptly.

It is important to note that bupropion can interact with other medications, including certain antidepressants, antipsychotics, and anti-seizure drugs. Therefore, it is crucial to inform the prescribing physician of all current medications before starting bupropion therapy.

Alkane 1-monooxygenase is an enzyme that catalyzes the addition of one oxygen atom from molecular oxygen to a alkane, resulting in the formation of an alcohol. This reaction also requires the cofactor NADH or NADPH and generates water as a byproduct.

The general reaction catalyzed by alkane 1-monooxygenase can be represented as follows:

R-CH3 + O2 + NAD(P)H + H+ -> R-CH2OH + H2O + NAD(P)+

where R represents an alkyl group.

This enzyme is found in various microorganisms, such as bacteria and fungi, and plays a crucial role in their ability to degrade hydrocarbons, including alkanes, which are major components of fossil fuels. Alkane 1-monooxygenase has potential applications in bioremediation and the production of biofuels from renewable resources.

Recombinant proteins are artificially created proteins produced through the use of recombinant DNA technology. This process involves combining DNA molecules from different sources to create a new set of genes that encode for a specific protein. The resulting recombinant protein can then be expressed, purified, and used for various applications in research, medicine, and industry.

Recombinant proteins are widely used in biomedical research to study protein function, structure, and interactions. They are also used in the development of diagnostic tests, vaccines, and therapeutic drugs. For example, recombinant insulin is a common treatment for diabetes, while recombinant human growth hormone is used to treat growth disorders.

The production of recombinant proteins typically involves the use of host cells, such as bacteria, yeast, or mammalian cells, which are engineered to express the desired protein. The host cells are transformed with a plasmid vector containing the gene of interest, along with regulatory elements that control its expression. Once the host cells are cultured and the protein is expressed, it can be purified using various chromatography techniques.

Overall, recombinant proteins have revolutionized many areas of biology and medicine, enabling researchers to study and manipulate proteins in ways that were previously impossible.

Aroclors are a series of polychlorinated biphenyl (PCB) mixtures that were manufactured by the Monsanto Company. They were widely used as cooling and insulating fluids in electrical equipment, such as transformers and capacitors, due to their non-flammability, chemical stability, and electrical insulating properties.

The term "Aroclor" is followed by a four-digit number that indicates the specific mixture and its average degree of chlorination. For example, Aroclor 1242 contains approximately 42% chlorine by weight, while Aroclor 1260 contains approximately 60% chlorine by weight.

Because of their persistence in the environment and potential toxicity to humans and wildlife, the production and use of PCBs, including Aroclors, were banned in the United States in 1979 under the Toxic Substances Control Act. However, due to their widespread historical use, PCBs continue to be a significant environmental pollutant and can still be found in many older electrical equipment, building materials, and soil and water samples.

Norbornanes are a class of compounds in organic chemistry that contain a norbornane skeleton, which is a bicyclic structure consisting of two fused cyclohexane rings. One of the rings is saturated, while the other contains a double bond. The name "norbornane" comes from the fact that it is a "nor" (short for "norcarene") derivative of bornane, which has a similar structure but with a methyl group attached to one of the carbon atoms in the saturated ring.

Norbornanes have a variety of applications in organic synthesis and medicinal chemistry. Some derivatives of norbornane have been explored for their potential as drugs, particularly in the areas of central nervous system agents and anti-inflammatory agents. However, there is no specific medical definition associated with "norbornanes" as they are a class of chemical compounds rather than a medical term or condition.

Molecular sequence data refers to the specific arrangement of molecules, most commonly nucleotides in DNA or RNA, or amino acids in proteins, that make up a biological macromolecule. This data is generated through laboratory techniques such as sequencing, and provides information about the exact order of the constituent molecules. This data is crucial in various fields of biology, including genetics, evolution, and molecular biology, allowing for comparisons between different organisms, identification of genetic variations, and studies of gene function and regulation.

Phenylalanine is an essential amino acid, meaning it cannot be produced by the human body and must be obtained through diet or supplementation. It's one of the building blocks of proteins and is necessary for the production of various molecules in the body, such as neurotransmitters (chemical messengers in the brain).

Phenylalanine has two forms: L-phenylalanine and D-phenylalanine. L-phenylalanine is the form found in proteins and is used by the body for protein synthesis, while D-phenylalanine has limited use in humans and is not involved in protein synthesis.

Individuals with a rare genetic disorder called phenylketonuria (PKU) must follow a low-phenylalanine diet or take special medical foods because they are unable to metabolize phenylalanine properly, leading to its buildup in the body and potential neurological damage.

The liver is a large, solid organ located in the upper right portion of the abdomen, beneath the diaphragm and above the stomach. It plays a vital role in several bodily functions, including:

1. Metabolism: The liver helps to metabolize carbohydrates, fats, and proteins from the food we eat into energy and nutrients that our bodies can use.
2. Detoxification: The liver detoxifies harmful substances in the body by breaking them down into less toxic forms or excreting them through bile.
3. Synthesis: The liver synthesizes important proteins, such as albumin and clotting factors, that are necessary for proper bodily function.
4. Storage: The liver stores glucose, vitamins, and minerals that can be released when the body needs them.
5. Bile production: The liver produces bile, a digestive juice that helps to break down fats in the small intestine.
6. Immune function: The liver plays a role in the immune system by filtering out bacteria and other harmful substances from the blood.

Overall, the liver is an essential organ that plays a critical role in maintaining overall health and well-being.

4-Hydroxybenzoate-3-Monooxygenase is a type of enzyme that catalyzes the conversion of 4-hydroxybenzoate to 3,4-dihydroxybenzoate using NADPH and oxygen as cofactors. This enzyme plays a role in the degradation of aromatic compounds in some bacteria. The systematic name for this enzyme is 4-hydroxybenzoate,NAD(P)H:oxygen oxidoreductase (3-hydroxylating).

Proadifen is not typically referred to as a medical term or definition in modern medicine. However, it is an old antihistamine drug that was used in the past for its properties as a monoamine oxidase inhibitor (MAOI). MAOIs were used primarily in the treatment of depression but have largely been replaced by newer classes of drugs due to their potential for serious side effects.

Here is a brief medical definition of Proadifen as an MAOI:

Proadifen (SKF-525A): An older, nonselective and irreversible monoamine oxidase inhibitor (MAOI) that was used in the past for its antidepressant effects. Its use has been largely discontinued due to the risk of serious adverse reactions, such as hypertensive crises, when combined with certain foods or medications containing tyramine.

Alkanes are a group of saturated hydrocarbons, which are characterized by the presence of single bonds between carbon atoms in their molecular structure. The general formula for alkanes is CnH2n+2, where n represents the number of carbon atoms in the molecule.

The simplest and shortest alkane is methane (CH4), which contains one carbon atom and four hydrogen atoms. As the number of carbon atoms increases, the length and complexity of the alkane chain also increase. For example, ethane (C2H6) contains two carbon atoms and six hydrogen atoms, while propane (C3H8) contains three carbon atoms and eight hydrogen atoms.

Alkanes are important components of fossil fuels such as natural gas, crude oil, and coal. They are also used as starting materials in the production of various chemicals and materials, including plastics, fertilizers, and pharmaceuticals. In the medical field, alkanes may be used as anesthetics or as solvents for various medical applications.

Butyrophenones are a group of synthetic antipsychotic drugs that are primarily used to treat symptoms of schizophrenia and other psychotic disorders. They act as dopamine receptor antagonists, which means they block the action of dopamine, a neurotransmitter in the brain associated with mood, motivation, and pleasure.

Some examples of butyrophenones include haloperidol, droperidol, and benperidol. These drugs are known for their potent antipsychotic effects and can also be used to manage agitation, aggression, and other behavioral disturbances in patients with various psychiatric and neurological disorders.

In addition to their antipsychotic properties, butyrophenones have been used off-label for their sedative and analgesic effects. However, they are associated with a range of side effects, including extrapyramidal symptoms (EPS), such as involuntary muscle spasms and tremors, as well as other neurological and cardiovascular adverse reactions. Therefore, their use is typically reserved for cases where other treatments have been ineffective or contraindicated.

Quinidine is a Class IA antiarrhythmic medication that is primarily used to treat and prevent various types of cardiac arrhythmias (abnormal heart rhythms). It works by blocking the rapid sodium channels in the heart, which helps to slow down the conduction of electrical signals within the heart and stabilize its rhythm.

Quinidine is derived from the bark of the Cinchona tree and has been used for centuries as a treatment for malaria. However, its antiarrhythmic properties were discovered later, and it became an important medication in cardiology.

In addition to its use in treating arrhythmias, quinidine may also be used off-label for other indications such as the treatment of nocturnal leg cramps or myasthenia gravis. It is available in various forms, including tablets and injectable solutions.

It's important to note that quinidine has a narrow therapeutic index, meaning that there is only a small difference between an effective dose and a toxic one. Therefore, it must be carefully monitored to ensure that the patient is receiving a safe and effective dose. Common side effects of quinidine include gastrointestinal symptoms such as nausea, vomiting, and diarrhea, as well as visual disturbances, headache, and dizziness. More serious side effects can include QT prolongation, which can lead to dangerous arrhythmias, and hypersensitivity reactions.

Hydroxysteroids are steroid hormones or steroid compounds that contain one or more hydroxyl groups (-OH) as a functional group. These molecules have a steroid nucleus, which is a core structure composed of four fused carbon rings, and one or more hydroxyl groups attached to the rings.

The presence of hydroxyl groups makes hydroxysteroids polar and more soluble in water compared to other steroids. They are involved in various physiological processes, such as metabolism, bile acid synthesis, and steroid hormone regulation. Some examples of hydroxysteroids include certain forms of estrogens, androgens, corticosteroids, and bile acids.

It is important to note that the specific medical definition may vary depending on the context or source.

An amino acid sequence is the specific order of amino acids in a protein or peptide molecule, formed by the linking of the amino group (-NH2) of one amino acid to the carboxyl group (-COOH) of another amino acid through a peptide bond. The sequence is determined by the genetic code and is unique to each type of protein or peptide. It plays a crucial role in determining the three-dimensional structure and function of proteins.

Dioxygenases are a class of enzymes that catalyze the incorporation of both atoms of molecular oxygen (O2) into their substrates. They are classified based on the type of reaction they catalyze and the number of iron atoms in their active site. The two main types of dioxygenases are:

1. Intradiol dioxygenases: These enzymes cleave an aromatic ring by inserting both atoms of O2 into a single bond between two carbon atoms, leading to the formation of an unsaturated diol (catechol) intermediate and the release of CO2. They contain a non-heme iron(III) center in their active site.

An example of intradiol dioxygenase is catechol 1,2-dioxygenase, which catalyzes the conversion of catechol to muconic acid.

2. Extradiol dioxygenases: These enzymes cleave an aromatic ring by inserting one atom of O2 at a position adjacent to the hydroxyl group and the other atom at a more distant position, leading to the formation of an unsaturated lactone or cyclic ether intermediate. They contain a non-heme iron(II) center in their active site.

An example of extradiol dioxygenase is homogentisate 1,2-dioxygenase, which catalyzes the conversion of homogentisate to maleylacetoacetate in the tyrosine degradation pathway.

Dioxygenases play important roles in various biological processes, including the metabolism of aromatic compounds, the biosynthesis of hormones and signaling molecules, and the detoxification of xenobiotics.

Steroid 11-beta-hydroxylase is a crucial enzyme involved in the steroidogenesis pathway, specifically in the synthesis of cortisol and aldosterone, which are vital hormones produced by the adrenal glands. This enzyme is encoded by the CYP11B1 gene in humans.

The enzyme's primary function is to catalyze the conversion of 11-deoxycortisol to cortisol and 11-deoxycorticosterone to aldosterone through the process of hydroxylation at the 11-beta position of the steroid molecule. Cortisol is a critical glucocorticoid hormone that helps regulate metabolism, immune response, and stress response, while aldosterone is a mineralocorticoid hormone responsible for maintaining electrolyte and fluid balance in the body.

Deficiencies or mutations in the CYP11B1 gene can lead to various disorders, such as congenital adrenal hyperplasia (CAH), which may result in impaired cortisol and aldosterone production, causing hormonal imbalances and associated symptoms.

Collagen is the most abundant protein in the human body, and it is a major component of connective tissues such as tendons, ligaments, skin, and bones. Collagen provides structure and strength to these tissues and helps them to withstand stretching and tension. It is made up of long chains of amino acids, primarily glycine, proline, and hydroxyproline, which are arranged in a triple helix structure. There are at least 16 different types of collagen found in the body, each with slightly different structures and functions. Collagen is important for maintaining the integrity and health of tissues throughout the body, and it has been studied for its potential therapeutic uses in various medical conditions.

Spectrophotometry is a technical analytical method used in the field of medicine and science to measure the amount of light absorbed or transmitted by a substance at specific wavelengths. This technique involves the use of a spectrophotometer, an instrument that measures the intensity of light as it passes through a sample.

In medical applications, spectrophotometry is often used in laboratory settings to analyze various biological samples such as blood, urine, and tissues. For example, it can be used to measure the concentration of specific chemicals or compounds in a sample by measuring the amount of light that is absorbed or transmitted at specific wavelengths.

In addition, spectrophotometry can also be used to assess the properties of biological tissues, such as their optical density and thickness. This information can be useful in the diagnosis and treatment of various medical conditions, including skin disorders, eye diseases, and cancer.

Overall, spectrophotometry is a valuable tool for medical professionals and researchers seeking to understand the composition and properties of various biological samples and tissues.

Benzphetamine is a sympathomimetic amine, which is a type of drug that stimulates the sympathetic nervous system. It is a central nervous system stimulant and an appetite suppressant. Benzphetamine is used as a short-term supplement to diet and exercise in the treatment of obesity.

The medical definition of benzphetamine is:

A CNS stimulant and anorectic, structurally related to amphetamines, but pharmacologically related to the phenylethylamines. It has a longer duration of action than other amphetamines because it is absorbed more slowly and is excreted more slowly. Benzphetamine is used as an appetite suppressant in the treatment of obesity.

It's important to note that benzphetamine, like other weight-loss medications, should be used in conjunction with a reduced-calorie diet and exercise. It also has a risk for abuse and dependence, so it is usually prescribed for short-term use only.

Phenacetin is not typically defined in a medical dictionary as it is an obsolete drug. However, it was previously used as a painkiller and fever reducer. It is a compound that has been used in various forms of medication, such as headache powders and cough medicines. Phenacetin is no longer widely available or recommended for use due to its association with kidney damage and increased risk of cancer when taken in high doses or over long periods of time.

In modern medical contexts, phenacetin may be mentioned as a component of some older medications or as a historical example in discussions of the evolution of pharmaceuticals and their regulation.

Dihydroxyphenylalanine is not a medical term per se, but it is a chemical compound that is often referred to in the context of biochemistry and neuroscience. It is also known as levodopa or L-DOPA for short.

L-DOPA is a precursor to dopamine, a neurotransmitter that plays a critical role in regulating movement, emotion, and cognition. In the brain, L-DOPA is converted into dopamine through the action of an enzyme called tyrosine hydroxylase.

L-DOPA is used medically to treat Parkinson's disease, a neurological disorder characterized by motor symptoms such as tremors, rigidity, and bradykinesia (slowness of movement). In Parkinson's disease, the dopamine-producing neurons in the brain gradually degenerate, leading to a deficiency of dopamine. By providing L-DOPA as a replacement therapy, doctors can help alleviate some of the symptoms of the disease.

It is important to note that L-DOPA has potential side effects and risks, including nausea, dizziness, and behavioral changes. Long-term use of L-DOPA can also lead to motor complications such as dyskinesias (involuntary movements) and fluctuations in response to the medication. Therefore, it is typically used in combination with other medications and under the close supervision of a healthcare provider.

Ketoconazole is an antifungal medication that is primarily used to treat various fungal infections, including those caused by dermatophytes, Candida, and pityrosporum. It works by inhibiting the synthesis of ergosterol, a crucial component of fungal cell membranes, which leads to increased permeability and ultimately results in fungal cell death.

Ketoconazole is available as an oral tablet for systemic use and as a topical cream or shampoo for localized applications. The oral formulation is used to treat severe or invasive fungal infections, while the topical preparations are primarily indicated for skin and scalp infections, such as athlete's foot, ringworm, jock itch, candidiasis, and seborrheic dermatitis.

Common side effects of oral ketoconazole include nausea, vomiting, headache, and altered liver function tests. Rare but serious adverse reactions may include hepatotoxicity, adrenal insufficiency, and interactions with other medications that can affect the metabolism and elimination of drugs. Topical ketoconazole is generally well-tolerated, with local irritation being the most common side effect.

It's important to note that due to its potential for serious liver toxicity and drug-drug interactions, oral ketoconazole has been largely replaced by other antifungal agents, such as fluconazole and itraconazole, which have more favorable safety profiles. Topical ketoconazole remains a valuable option for treating localized fungal infections due to its effectiveness and lower risk of systemic side effects.

Ketosteroids are a type of steroid compound that contain a ketone functional group in their chemical structure. They are derived from cholesterol and are present in both animal and plant tissues. Some ketosteroids are produced endogenously, while others can be introduced exogenously through the diet or medication.

Endogenous ketosteroids include steroid hormones such as testosterone, estradiol, and cortisol, which contain a ketone group in their structure. Exogenous ketosteroids can be found in certain medications, such as those used to treat hormonal imbalances or inflammation.

Ketosteroids have been studied for their potential therapeutic uses, including as anti-inflammatory agents and for the treatment of hormone-related disorders. However, more research is needed to fully understand their mechanisms of action and potential benefits.

Steroid 21-hydroxylase, also known as CYP21A2, is a crucial enzyme involved in the synthesis of steroid hormones in the adrenal gland. Specifically, it catalyzes the conversion of 17-hydroxyprogesterone to 11-deoxycortisol and progesterone to deoxycorticosterone in the glucocorticoid and mineralocorticoid pathways, respectively.

Deficiency or mutations in this enzyme can lead to a group of genetic disorders called congenital adrenal hyperplasia (CAH), which is characterized by impaired cortisol production and disrupted hormonal balance. Depending on the severity of the deficiency, CAH can result in various symptoms such as ambiguous genitalia, precocious puberty, sexual infantilism, infertility, and increased risk of adrenal crisis.

Sparteine is not typically referred to as a "medical definition" in the context of modern medicine. However, it is a chemical compound with some historical use in medicine and a well-defined chemical structure.

Here's a chemical definition of sparteine:

Sparteine is an alkaloid derived from plants of the genus *Colutea* and *Genista*, but most notably from *Crotalaria sagittalis* (rattlebox) and *Echium plantagineum* (viper's bugloss). Its chemical formula is C15H24N2, and it has a molecular weight of 228.36 g/mol.

Sparteine is a stereoisomer of lupanine and is structurally related to other natural alkaloids such as nicotine and coniine. It is a chiral compound with two stereocenters, existing as four different stereoisomers: (−)-sparteine, (+)-sparteine, (−)-pseudosparteine, and (+)-pseudosparteine.

Historically, sparteine has been used in medicine as a cardiotonic, uterine stimulant, and antispasmodic. However, due to its narrow therapeutic index and the availability of safer alternatives, it is no longer in common clinical use today.

Ascorbic acid is the chemical name for Vitamin C. It is a water-soluble vitamin that is essential for human health. Ascorbic acid is required for the synthesis of collagen, a protein that plays a role in the structure of bones, tendons, ligaments, and blood vessels. It also functions as an antioxidant, helping to protect cells from damage caused by free radicals.

Ascorbic acid cannot be produced by the human body and must be obtained through diet or supplementation. Good food sources of vitamin C include citrus fruits, strawberries, bell peppers, broccoli, and spinach.

In the medical field, ascorbic acid is used to treat or prevent vitamin C deficiency and related conditions, such as scurvy. It may also be used in the treatment of various other health conditions, including common cold, cancer, and cardiovascular disease, although its effectiveness for these uses is still a matter of scientific debate.

I'm sorry for any confusion, but there is no such thing as "Prostaglandins A." Prostaglandins are a group of lipid compounds that are derived enzymatically from fatty acids in the body, and they have diverse hormone-like effects in various tissues. They are typically classified into several groups based on their chemical structure, including prostaglandin D, E, F, I, and THC (tetrahydrocannabinol). Prostaglandin A is not a recognized subtype of prostaglandins.

If you have any questions about a specific type of prostaglandin or another medical topic, please don't hesitate to ask!

I'm sorry for any confusion, but "Gentisates" does not appear to be a recognized term in medical or physiological sciences. It is possible that you may have misspelled or misremembered the term. If you meant "Gentiates," then it refers to a class of enzymes (also known as beta-galactosidases) that can break down certain complex carbohydrates, such as the disaccharide melibiose into galactose and glucose. However, I would recommend double-checking the spelling or context to ensure you have the correct term, as my response is based on the assumption that "Gentiates" was the intended word.

Benzoic acid is an organic compound with the formula C6H5COOH. It is a colorless crystalline solid that is slightly soluble in water and more soluble in organic solvents. Benzoic acid occurs naturally in various plants and serves as an intermediate in the synthesis of other chemical compounds.

In medical terms, benzoic acid and its salts (sodium benzoate, potassium benzoate) are used as preservatives in food, beverages, and cosmetics to prevent bacterial growth. They work by inhibiting the growth of bacteria, particularly gram-positive bacteria, through the disruption of their energy production processes.

Additionally, sodium benzoate is sometimes used as a treatment for hyperammonemia, a condition characterized by high levels of ammonia in the blood. In this case, sodium benzoate acts as a detoxifying agent by binding to excess ammonia and converting it into a more easily excreted compound called hippuric acid.

It is important to note that benzoic acid and its salts can cause allergic reactions or skin irritation in some individuals, particularly those with pre-existing sensitivities or conditions. As with any medication or chemical substance, it should be used under the guidance of a healthcare professional.

Adrenodoxin is a small iron-sulfur protein that plays a crucial role in the steroidogenesis process within the mitochondria of cells. It functions as an electron carrier in the final steps of steroid hormone biosynthesis, specifically during the conversion of cholesterol to pregnenolone. This conversion is catalyzed by the cytochrome P450 side-chain cleavage enzyme (P450scc), which requires adrenodoxin to donate electrons for its activity. Adrenodoxin itself receives electrons from another protein, adrenodoxin reductase, in a series of redox reactions. Proper adrenodoxin function is essential for the production of various steroid hormones, including cortisol, aldosterone, and sex hormones.

Catechols are a type of chemical compound that contain a benzene ring with two hydroxyl groups (-OH) attached to it in the ortho position. The term "catechol" is often used interchangeably with "ortho-dihydroxybenzene." Catechols are important in biology because they are produced through the metabolism of certain amino acids, such as phenylalanine and tyrosine, and are involved in the synthesis of various neurotransmitters and hormones. They also have antioxidant properties and can act as reducing agents. In chemistry, catechols can undergo various reactions, such as oxidation and polymerization, to form other classes of compounds.

Hypoxia-Inducible Factor 1 (HIF-1) is a transcription factor that plays a crucial role in the cellular response to low oxygen levels, also known as hypoxia. It is a heterodimeric protein composed of two subunits: HIF-1α and HIF-1β.

Under normoxic conditions (adequate oxygen supply), HIF-1α is constantly produced but rapidly degraded by proteasomes due to the action of prolyl hydroxylases, which mark it for destruction in the presence of oxygen. However, under hypoxic conditions, the activity of prolyl hydroxylases is inhibited, leading to the stabilization and accumulation of HIF-1α.

Once stabilized, HIF-1α translocates to the nucleus and forms a complex with HIF-1β. This complex then binds to hypoxia-responsive elements (HREs) in the promoter regions of various genes involved in angiogenesis, glucose metabolism, erythropoiesis, cell survival, and other processes that help cells adapt to low oxygen levels.

By activating these target genes, HIF-1 plays a critical role in regulating the body's response to hypoxia, including promoting the formation of new blood vessels (angiogenesis), enhancing anaerobic metabolism, and inhibiting cell proliferation and apoptosis under low oxygen conditions. Dysregulation of HIF-1 has been implicated in several diseases, such as cancer, cardiovascular disease, and ischemic disorders.

Ferredoxin-NADP Reductase (FDNR) is an enzyme that catalyzes the electron transfer from ferredoxin to NADP+, reducing it to NADPH. This reaction plays a crucial role in several metabolic pathways, including photosynthesis and nitrogen fixation.

In photosynthesis, FDNR is located in the stroma of chloroplasts and receives electrons from ferredoxin, which is reduced by photosystem I. The enzyme then transfers these electrons to NADP+, generating NADPH, which is used in the Calvin cycle for carbon fixation.

In nitrogen fixation, FDNR is found in the nitrogen-fixing bacteria and receives electrons from ferredoxin, which is reduced by nitrogenase. The enzyme then transfers these electrons to NADP+, generating NADPH, which is used in the reduction of nitrogen gas (N2) to ammonia (NH3).

FDNR is a flavoprotein that contains a FAD cofactor and an iron-sulfur cluster. The enzyme catalyzes the electron transfer through a series of conformational changes that bring ferredoxin and NADP+ in close proximity, allowing for efficient electron transfer.

Aniline hydroxylase is an enzyme that is involved in the metabolism of aromatic compounds, including aniline and other related substances. The enzyme catalyzes the addition of a hydroxyl group (-OH) to the aromatic ring of these compounds, which helps to make them more water-soluble and facilitates their excretion from the body.

Aniline hydroxylase is found in various tissues throughout the body, including the liver, lung, and kidney. It is a member of the cytochrome P450 family of enzymes, which are known for their role in drug metabolism and other xenobiotic-metabolizing reactions.

It's important to note that exposure to aniline and its derivatives can be harmful and may cause various health effects, including damage to the liver and other organs. Therefore, it is essential to handle these substances with care and follow appropriate safety precautions.

Acetone is a colorless, volatile, and flammable liquid organic compound with the chemical formula (CH3)2CO. It is the simplest and smallest ketone, and its molecules consist of a carbonyl group linked to two methyl groups. Acetone occurs naturally in the human body and is produced as a byproduct of normal metabolic processes, particularly during fat burning.

In clinical settings, acetone can be measured in breath or blood to assess metabolic status, such as in cases of diabetic ketoacidosis, where an excess production of acetone and other ketones occurs due to insulin deficiency and high levels of fatty acid breakdown. High concentrations of acetone can lead to a sweet, fruity odor on the breath, often described as "fruity acetone" or "acetone breath."

Cytochrome P-450 CYP2B1 is a specific isoform of the cytochrome P-450 enzyme system, which is involved in the metabolism of drugs and other xenobiotics in the liver. This particular isoenzyme is primarily found in rats and is responsible for the metabolism of a variety of substrates, including certain drugs, steroids, and environmental toxins.

The cytochrome P-450 system is a group of enzymes located in the endoplasmic reticulum of cells, particularly in the liver. These enzymes play a crucial role in the metabolism of various substances, including drugs, hormones, and toxins. They work by catalyzing oxidation-reduction reactions that convert lipophilic compounds into more hydrophilic ones, which can then be excreted from the body.

CYP2B1 is one of many isoforms of cytochrome P-450, and it has a preference for certain types of substrates. It is involved in the metabolism of drugs such as cyclophosphamide, ifosfamide, and methadone, as well as steroids like progesterone and environmental toxins like pentachlorophenol.

It's important to note that while CYP2B1 is an essential enzyme in rats, its human counterpart, CYP2B6, plays a similar role in drug metabolism in humans. Understanding the function and regulation of these enzymes can help in predicting drug interactions, designing new drugs, and tailoring therapies to individual patients based on their genetic makeup.

Aniline compounds, also known as aromatic amines, are organic compounds that contain a benzene ring substituted with an amino group (-NH2). Aniline itself is the simplest and most common aniline compound, with the formula C6H5NH2.

Aniline compounds are important in the chemical industry and are used in the synthesis of a wide range of products, including dyes, pharmaceuticals, and rubber chemicals. They can be produced by reducing nitrobenzene or by directly substituting ammonia onto benzene in a process called amination.

It is important to note that aniline compounds are toxic and can cause serious health effects, including damage to the liver, kidneys, and central nervous system. They can also be absorbed through the skin and are known to have carcinogenic properties. Therefore, appropriate safety measures must be taken when handling aniline compounds.

The Von Hippel-Lindau (VHL) tumor suppressor protein is a crucial component in the regulation of cellular growth and division, specifically through its role in oxygen sensing and the ubiquitination of hypoxia-inducible factors (HIFs). The VHL protein forms part of an E3 ubiquitin ligase complex that targets HIFs for degradation under normoxic conditions. In the absence of functional VHL protein or in hypoxic environments, HIFs accumulate and induce the transcription of genes involved in angiogenesis, cell proliferation, and metabolism.

Mutations in the VHL gene can lead to the development of Von Hippel-Lindau syndrome, a rare inherited disorder characterized by the growth of tumors and cysts in various organs, including the central nervous system, retina, kidneys, adrenal glands, and pancreas. These tumors often arise from the overactivation of HIF-mediated signaling pathways due to the absence or dysfunction of VHL protein.

Liquid chromatography (LC) is a type of chromatography technique used to separate, identify, and quantify the components in a mixture. In this method, the sample mixture is dissolved in a liquid solvent (the mobile phase) and then passed through a stationary phase, which can be a solid or a liquid that is held in place by a solid support.

The components of the mixture interact differently with the stationary phase and the mobile phase, causing them to separate as they move through the system. The separated components are then detected and measured using various detection techniques, such as ultraviolet (UV) absorbance or mass spectrometry.

Liquid chromatography is widely used in many areas of science and medicine, including drug development, environmental analysis, food safety testing, and clinical diagnostics. It can be used to separate and analyze a wide range of compounds, from small molecules like drugs and metabolites to large biomolecules like proteins and nucleic acids.

Enzyme induction is a process by which the activity or expression of an enzyme is increased in response to some stimulus, such as a drug, hormone, or other environmental factor. This can occur through several mechanisms, including increasing the transcription of the enzyme's gene, stabilizing the mRNA that encodes the enzyme, or increasing the translation of the mRNA into protein.

In some cases, enzyme induction can be a beneficial process, such as when it helps the body to metabolize and clear drugs more quickly. However, in other cases, enzyme induction can have negative consequences, such as when it leads to the increased metabolism of important endogenous compounds or the activation of harmful procarcinogens.

Enzyme induction is an important concept in pharmacology and toxicology, as it can affect the efficacy and safety of drugs and other xenobiotics. It is also relevant to the study of drug interactions, as the induction of one enzyme by a drug can lead to altered metabolism and effects of another drug that is metabolized by the same enzyme.

Hydantoins are a class of chemical compounds that contain a five-membered ring containing two nitrogen atoms, with one of the nitrogens being part of a urea group. They are important in medicine as a specific group of anticonvulsant drugs used to treat seizures, known as hydantoin derivatives or hydantoins proper. The most well-known example is phenytoin (diphenylhydantoin), which has been widely used for this purpose since the 1930s.

The structure of hydantoins allows them to interact with and stabilize voltage-gated sodium channels in the brain, reducing their excitability and thus the likelihood of seizures. However, long-term use of hydantoin derivatives can lead to several side effects, including dizziness, unsteady gait, tremors, and behavioral changes. Regular monitoring of blood levels is necessary to ensure safe and effective treatment with these medications.

Cytidine monophosphate N-acetylneuraminic acid, often abbreviated as CMP-Neu5Ac or CMP-NANA, is a nucleotide sugar that plays a crucial role in the biosynthesis of complex carbohydrates known as glycoconjugates. These molecules are important components of cell membranes and have various functions, including cell recognition and communication.

CMP-Neu5Ac is formed from N-acetylneuraminic acid (Neu5Ac) and cytidine triphosphate (CTP) in a reaction catalyzed by the enzyme CMP-sialic acid synthetase. Once synthesized, CMP-Neu5Ac serves as the activated donor of Neu5Ac residues in the process of glycosylation, where Neu5Ac is added to the non-reducing end of oligosaccharide chains on glycoproteins and gangliosides. This reaction is catalyzed by sialyltransferases, a family of enzymes that use CMP-Neu5Ac as their substrate.

Abnormal levels or functions of CMP-Neu5Ac and its associated enzymes have been implicated in various diseases, including cancer, neurodevelopmental disorders, and microbial infections. Therefore, understanding the biology of CMP-Neu5Ac and its role in glycosylation is essential for developing new therapeutic strategies to target these conditions.

Agrocybe is a genus of fungi in the family Strophariaceae. These mushrooms are commonly known as "meadow mushrooms" or " lawn mushrooms." They are saprobic, meaning they obtain their nutrients by decomposing organic matter. Some species of Agrocybe are considered edible and are found in many parts of the world. However, it is important to note that some species can be toxic and should not be consumed without proper identification by a trained mycologist.

Here is a medical definition of Agrocybe:

A genus (Agrocybe) of fungi in the family Strophariaceae, characterized by brown to yellow-brown pileus (cap), adnexed to adnate gills, and a stipe (stem) that is often bulbous at the base. Some species are considered edible, while others can be toxic. Proper identification of Agrocybe species is important before consumption.

Cholestenones are a group of steroid compounds that are derived from cholesterol. They include several biologically important compounds, such as bile acids and their intermediates, which play crucial roles in the digestion and absorption of fats and fat-soluble vitamins. Cholestenones are also used as intermediates in the synthesis of various steroid hormones, including cortisol, aldosterone, and sex hormones.

Cholestenones are characterized by a carbon skeleton consisting of four fused rings, with a double bond between the second and third carbons and a ketone group at the third carbon atom. Some examples of cholestenones include 7-dehydrocholesterol, which is a precursor to vitamin D, and desmosterol, which is an intermediate in the biosynthesis of cholesterol.

It's worth noting that while cholestenones are important biomolecules, they can also accumulate in various tissues and fluids under certain pathological conditions, such as in some inherited metabolic disorders. For example, elevated levels of certain cholestenones in the blood or urine may indicate the presence of Smith-Lemli-Opitz syndrome, a genetic disorder that affects cholesterol biosynthesis.

Scurvy is a medical condition caused by a deficiency of vitamin C (ascorbic acid) in the diet, which leads to the breakdown of collagen. This results in various symptoms such as anemia, gum disease, and skin hemorrhages. In severe cases, it can lead to death. It was prevalent among sailors during long voyages before the 18th century when fresh fruits and vegetables were not available, and the condition was eventually linked to the lack of vitamin C in their diet. Nowadays, scurvy is rare in developed countries but can still occur in individuals with extreme diets deficient in vitamin C.

Trans-cinnamate 4-monooxygenase is an enzyme that belongs to the class of oxidoreductases. It is specifically categorized as a member of the family of single-donor oxidoreductases, which use NAD or NADP as electron acceptors. This enzyme participates in the phenylpropanoid metabolic pathway and catalyzes the conversion of trans-cinnamic acid to p-coumaric acid using NADPH and oxygen as cofactors. The reaction can be represented as follows:

trans-cinnamic acid + NADPH + H+ + O2 -> p-coumaric acid + NADP+ + H2O

The gene encoding this enzyme is often used as a marker for plant defense responses and stress tolerance.

NAD (Nicotinamide Adenine Dinucleotide) is a coenzyme found in all living cells. It plays an essential role in cellular metabolism, particularly in redox reactions, where it acts as an electron carrier. NAD exists in two forms: NAD+, which accepts electrons and becomes reduced to NADH. This pairing of NAD+/NADH is involved in many fundamental biological processes such as generating energy in the form of ATP during cellular respiration, and serving as a critical cofactor for various enzymes that regulate cellular functions like DNA repair, gene expression, and cell death.

Maintaining optimal levels of NAD+/NADH is crucial for overall health and longevity, as it declines with age and in certain disease states. Therefore, strategies to boost NAD+ levels are being actively researched for their potential therapeutic benefits in various conditions such as aging, neurodegenerative disorders, and metabolic diseases.

Enzyme inhibitors are substances that bind to an enzyme and decrease its activity, preventing it from catalyzing a chemical reaction in the body. They can work by several mechanisms, including blocking the active site where the substrate binds, or binding to another site on the enzyme to change its shape and prevent substrate binding. Enzyme inhibitors are often used as drugs to treat various medical conditions, such as high blood pressure, abnormal heart rhythms, and bacterial infections. They can also be found naturally in some foods and plants, and can be used in research to understand enzyme function and regulation.

Spectrophotometry, Ultraviolet (UV-Vis) is a type of spectrophotometry that measures how much ultraviolet (UV) and visible light is absorbed or transmitted by a sample. It uses a device called a spectrophotometer to measure the intensity of light at different wavelengths as it passes through a sample. The resulting data can be used to determine the concentration of specific components within the sample, identify unknown substances, or evaluate the physical and chemical properties of materials.

UV-Vis spectroscopy is widely used in various fields such as chemistry, biology, pharmaceuticals, and environmental science. It can detect a wide range of substances including organic compounds, metal ions, proteins, nucleic acids, and dyes. The technique is non-destructive, meaning that the sample remains unchanged after the measurement.

In UV-Vis spectroscopy, the sample is placed in a cuvette or other container, and light from a source is directed through it. The light then passes through a monochromator, which separates it into its component wavelengths. The monochromatic light is then directed through the sample, and the intensity of the transmitted or absorbed light is measured by a detector.

The resulting absorption spectrum can provide information about the concentration and identity of the components in the sample. For example, if a compound has a known absorption maximum at a specific wavelength, its concentration can be determined by measuring the absorbance at that wavelength and comparing it to a standard curve.

Overall, UV-Vis spectrophotometry is a versatile and powerful analytical technique for quantitative and qualitative analysis of various samples in different fields.

'2,2'-Dipyridyl is an organic compound with the formula (C5H4N)2. It is a bidentate chelating ligand, which means that it can form stable coordination complexes with many metal ions by donating both of its nitrogen atoms to the metal. This ability to form complexes makes '2,2'-Dipyridyl useful in various applications, including as a catalyst in chemical reactions and as a reagent in the analysis of metal ions.

The compound is a solid at room temperature and has a molecular weight of 108.13 g/mol. It is soluble in organic solvents such as ethanol, acetone, and dichloromethane, but is insoluble in water. '2,2'-Dipyridyl is synthesized by the reaction of pyridine with formaldehyde and hydrochloric acid.

In medical contexts, '2,2'-Dipyridyl may be used as a reagent in diagnostic tests to detect the presence of certain metal ions in biological samples. However, it is not itself a drug or therapeutic agent.

Streptomyces is a genus of Gram-positive, aerobic, saprophytic bacteria that are widely distributed in soil, water, and decaying organic matter. They are known for their complex morphology, forming branching filaments called hyphae that can differentiate into long chains of spores.

Streptomyces species are particularly notable for their ability to produce a wide variety of bioactive secondary metabolites, including antibiotics, antifungals, and other therapeutic compounds. In fact, many important antibiotics such as streptomycin, neomycin, tetracycline, and erythromycin are derived from Streptomyces species.

Because of their industrial importance in the production of antibiotics and other bioactive compounds, Streptomyces have been extensively studied and are considered model organisms for the study of bacterial genetics, biochemistry, and ecology.

A hydroxyl radical is defined in biochemistry and medicine as an extremely reactive species, characterized by the presence of an oxygen atom bonded to a hydrogen atom (OH-). It is formed when a water molecule (H2O) is split into a hydroxide ion (OH-) and a hydrogen ion (H+) in the process of oxidation.

In medical terms, hydroxyl radicals are important in understanding free radical damage and oxidative stress, which can contribute to the development of various diseases, including cancer, cardiovascular disease, and neurodegenerative disorders. They are also involved in the body's natural defense mechanisms against pathogens. However, an overproduction of hydroxyl radicals can cause damage to cellular components such as DNA, proteins, and lipids, leading to cell dysfunction and death.

Coumaric acids are a type of phenolic acid that are widely distributed in plants. They are found in various foods such as fruits, vegetables, and grains. The most common forms of coumaric acids are p-coumaric acid, o-coumaric acid, and m-coumaric acid.

Coumaric acids have been studied for their potential health benefits, including their antioxidant, anti-inflammatory, and antimicrobial properties. They may also play a role in preventing chronic diseases such as cancer and cardiovascular disease. However, more research is needed to fully understand the potential health benefits of coumaric acids.

It's worth noting that coumaric acids are not to be confused with warfarin (also known as Coumadin), a medication used as an anticoagulant. While both coumaric acids and warfarin contain a similar chemical structure, they have different effects on the body.

Phenol, also known as carbolic acid, is an organic compound with the molecular formula C6H5OH. It is a white crystalline solid that is slightly soluble in water and has a melting point of 40-42°C. Phenol is a weak acid, but it is quite reactive and can be converted into a variety of other chemicals.

In a medical context, phenol is most commonly used as a disinfectant and antiseptic. It has a characteristic odor that is often described as "tarry" or " medicinal." Phenol is also used in some over-the-counter products, such as mouthwashes and throat lozenges, to help kill bacteria and freshen breath.

However, phenol is also a toxic substance that can cause serious harm if it is swallowed, inhaled, or absorbed through the skin. It can cause irritation and burns to the eyes, skin, and mucous membranes, and it can damage the liver and kidneys if ingested. Long-term exposure to phenol has been linked to an increased risk of cancer.

Because of its potential for harm, phenol is regulated as a hazardous substance in many countries, and it must be handled with care when used in medical or industrial settings.

Cresols are a group of chemical compounds that are phenolic derivatives of benzene, consisting of methyl substituted cresidines. They have the formula C6H4(OH)(\_3CH3). There are three isomers of cresol, depending on the position of the methyl group: ortho-cresol (m-cresol), meta-cresol (p-cresol), and para-cresol (o-cresol). Cresols are used as disinfectants, antiseptics, and preservatives in various industrial and commercial applications. They have a characteristic odor and are soluble in alcohol and ether. In medical terms, cresols may be used as topical antiseptic agents, but they can also cause skin irritation and sensitization.

Magnetic Resonance Spectroscopy (MRS) is a non-invasive diagnostic technique that provides information about the biochemical composition of tissues, including their metabolic state. It is often used in conjunction with Magnetic Resonance Imaging (MRI) to analyze various metabolites within body tissues, such as the brain, heart, liver, and muscles.

During MRS, a strong magnetic field, radio waves, and a computer are used to produce detailed images and data about the concentration of specific metabolites in the targeted tissue or organ. This technique can help detect abnormalities related to energy metabolism, neurotransmitter levels, pH balance, and other biochemical processes, which can be useful for diagnosing and monitoring various medical conditions, including cancer, neurological disorders, and metabolic diseases.

There are different types of MRS, such as Proton (^1^H) MRS, Phosphorus-31 (^31^P) MRS, and Carbon-13 (^13^C) MRS, each focusing on specific elements or metabolites within the body. The choice of MRS technique depends on the clinical question being addressed and the type of information needed for diagnosis or monitoring purposes.

Pterins are a group of naturally occurring pigments that are derived from purines. They are widely distributed in various organisms, including bacteria, fungi, and animals. In humans, pterins are primarily found in the eye, skin, and hair. Some pterins have been found to play important roles as cofactors in enzymatic reactions and as electron carriers in metabolic pathways.

Abnormal levels of certain pterins can be indicative of genetic disorders or other medical conditions. For example, an excess of biopterin, a type of pterin, is associated with phenylketonuria (PKU), a genetic disorder that affects the body's ability to metabolize the amino acid phenylalanine. Similarly, low levels of neopterin, another type of pterin, can be indicative of immune system dysfunction or certain types of cancer.

Medical professionals may measure pterin levels in blood, urine, or other bodily fluids to help diagnose and monitor these conditions.

Midazolam is a medication from the class of drugs known as benzodiazepines. It works by enhancing the effect of a neurotransmitter called gamma-aminobutyric acid (GABA), which has a calming effect on the brain and nervous system. Midazolam is often used for its sedative, hypnotic, anxiolytic, anticonvulsant, and muscle relaxant properties.

Medically, midazolam is used for various purposes, including:

1. Preoperative medication (sedation before surgery)
2. Procedural sedation (for minor surgical or diagnostic procedures)
3. Treatment of seizures (status epilepticus)
4. Sedation in critically ill patients
5. As an adjunct to anesthesia during surgeries
6. Treatment of alcohol withdrawal symptoms
7. To induce amnesia for certain medical or dental procedures

Midazolam is available in various forms, such as tablets, intravenous (IV) solutions, and intranasal sprays. It has a rapid onset of action and a short duration, making it suitable for brief, intermittent procedures. However, midazolam can cause side effects like drowsiness, confusion, respiratory depression, and memory impairment. Therefore, its use should be carefully monitored by healthcare professionals.

Osteogenesis Imperfecta (OI), also known as brittle bone disease, is a group of genetic disorders that mainly affect the bones. It is characterized by bones that break easily, often from little or no apparent cause. This happens because the body produces an insufficient amount of collagen or poor quality collagen, which are crucial for the formation of healthy bones.

The severity of OI can vary greatly, even within the same family. Some people with OI have only a few fractures in their lifetime while others may have hundreds. Other symptoms can include blue or gray sclera (the white part of the eye), hearing loss, short stature, curved or bowed bones, loose joints, and a triangular face shape.

There are several types of OI, each caused by different genetic mutations. Most types of OI are inherited in an autosomal dominant pattern, meaning only one copy of the altered gene is needed to cause the condition. However, some types are inherited in an autosomal recessive pattern, which means that two copies of the altered gene must be present for the condition to occur.

There is no cure for OI, but treatment can help manage symptoms and prevent complications. Treatment may include medication to strengthen bones, physical therapy, bracing, and surgery.

Asparagine is an organic compound that is classified as a naturally occurring amino acid. It contains an amino group, a carboxylic acid group, and a side chain consisting of a single carbon atom bonded to a nitrogen atom, making it a neutral amino acid. Asparagine is encoded by the genetic codon AAU or AAC in the DNA sequence.

In the human body, asparagine plays important roles in various biological processes, including serving as a building block for proteins and participating in the synthesis of other amino acids. It can also act as a neurotransmitter and is involved in the regulation of cellular metabolism. Asparagine can be found in many foods, particularly in high-protein sources such as meat, fish, eggs, and dairy products.

Cinnamates are organic compounds that are derived from cinnamic acid. They contain a carbon ring with a double bond and a carboxylic acid group, making them aromatic acids. Cinnamates are widely used in the perfume industry due to their pleasant odor, and they also have various applications in the pharmaceutical and chemical industries.

In a medical context, cinnamates may be used as topical medications for the treatment of skin conditions such as fungal infections or inflammation. For example, cinnamate esters such as cinoxacin and ciclopirox are commonly used as antifungal agents in creams, lotions, and shampoos. These compounds work by disrupting the cell membranes of fungi, leading to their death.

Cinnamates may also have potential therapeutic benefits for other medical conditions. For instance, some studies suggest that cinnamate derivatives may have anti-inflammatory, antioxidant, and neuroprotective properties, making them promising candidates for the development of new drugs to treat diseases such as Alzheimer's and Parkinson's. However, more research is needed to confirm these effects and determine their safety and efficacy in humans.

Monoterpenes are a class of terpenes that consist of two isoprene units and have the molecular formula C10H16. They are major components of many essential oils found in plants, giving them their characteristic fragrances and flavors. Monoterpenes can be further classified into various subgroups based on their structural features, such as acyclic (e.g., myrcene), monocyclic (e.g., limonene), and bicyclic (e.g., pinene) compounds. In the medical field, monoterpenes have been studied for their potential therapeutic properties, including anti-inflammatory, antimicrobial, and anticancer activities. However, more research is needed to fully understand their mechanisms of action and clinical applications.

Nitrosamines are a type of chemical compound that are formed by the reaction between nitrous acid (or any nitrogen oxide) and secondary amines. They are often found in certain types of food, such as cured meats and cheeses, as well as in tobacco products and cosmetics.

Nitrosamines have been classified as probable human carcinogens by the International Agency for Research on Cancer (IARC). Exposure to high levels of nitrosamines has been linked to an increased risk of cancer, particularly in the digestive tract. They can also cause DNA damage and interfere with the normal functioning of cells.

In the medical field, nitrosamines have been a topic of concern due to their potential presence as contaminants in certain medications. For example, some drugs that contain nitrofurantoin, a medication used to treat urinary tract infections, have been found to contain low levels of nitrosamines. While the risk associated with these low levels is not well understood, efforts are underway to minimize the presence of nitrosamines in medications and other products.

Calcifediol is the medical term for 25-hydroxyvitamin D, which is a form of vitamin D that is produced in the liver when it processes vitamin D from sunlight or from dietary sources. It is an important precursor to the active form of vitamin D, calcitriol, and is often used as a supplement for people who have low levels of vitamin D. Calcifediol is converted to calcitriol in the kidneys, where it plays a role in regulating calcium and phosphate levels in the body, which are important for maintaining healthy bones and teeth.

Deuterium is a stable and non-radioactive isotope of hydrogen. The atomic nucleus of deuterium, called a deuteron, contains one proton and one neutron, giving it an atomic weight of approximately 2.014 atomic mass units (amu). It is also known as heavy hydrogen or heavy water because its hydrogen atoms contain one neutron in addition to the usual one proton found in common hydrogen atoms.

Deuterium occurs naturally in trace amounts in water and other organic compounds, typically making up about 0.015% to 0.018% of all hydrogen atoms. It can be separated from regular hydrogen through various methods such as electrolysis or distillation, and it has many applications in scientific research, particularly in the fields of chemistry and physics.

In medical contexts, deuterium is sometimes used as a tracer to study metabolic processes in the body. By replacing hydrogen atoms in specific molecules with deuterium atoms, researchers can track the movement and transformation of those molecules within living organisms. This technique has been used to investigate various physiological processes, including drug metabolism, energy production, and lipid synthesis.

In the context of medicine, "chemistry" often refers to the field of study concerned with the properties, composition, and structure of elements and compounds, as well as their reactions with one another. It is a fundamental science that underlies much of modern medicine, including pharmacology (the study of drugs), toxicology (the study of poisons), and biochemistry (the study of the chemical processes that occur within living organisms).

In addition to its role as a basic science, chemistry is also used in medical testing and diagnosis. For example, clinical chemistry involves the analysis of bodily fluids such as blood and urine to detect and measure various substances, such as glucose, cholesterol, and electrolytes, that can provide important information about a person's health status.

Overall, chemistry plays a critical role in understanding the mechanisms of diseases, developing new treatments, and improving diagnostic tests and techniques.

Post-translational protein processing refers to the modifications and changes that proteins undergo after their synthesis on ribosomes, which are complex molecular machines responsible for protein synthesis. These modifications occur through various biochemical processes and play a crucial role in determining the final structure, function, and stability of the protein.

The process begins with the translation of messenger RNA (mRNA) into a linear polypeptide chain, which is then subjected to several post-translational modifications. These modifications can include:

1. Proteolytic cleavage: The removal of specific segments or domains from the polypeptide chain by proteases, resulting in the formation of mature, functional protein subunits.
2. Chemical modifications: Addition or modification of chemical groups to the side chains of amino acids, such as phosphorylation (addition of a phosphate group), glycosylation (addition of sugar moieties), methylation (addition of a methyl group), acetylation (addition of an acetyl group), and ubiquitination (addition of a ubiquitin protein).
3. Disulfide bond formation: The oxidation of specific cysteine residues within the polypeptide chain, leading to the formation of disulfide bonds between them. This process helps stabilize the three-dimensional structure of proteins, particularly in extracellular environments.
4. Folding and assembly: The acquisition of a specific three-dimensional conformation by the polypeptide chain, which is essential for its function. Chaperone proteins assist in this process to ensure proper folding and prevent aggregation.
5. Protein targeting: The directed transport of proteins to their appropriate cellular locations, such as the nucleus, mitochondria, endoplasmic reticulum, or plasma membrane. This is often facilitated by specific signal sequences within the protein that are recognized and bound by transport machinery.

Collectively, these post-translational modifications contribute to the functional diversity of proteins in living organisms, allowing them to perform a wide range of cellular processes, including signaling, catalysis, regulation, and structural support.

Chemical phenomena refer to the changes and interactions that occur at the molecular or atomic level when chemicals are involved. These phenomena can include chemical reactions, in which one or more substances (reactants) are converted into different substances (products), as well as physical properties that change as a result of chemical interactions, such as color, state of matter, and solubility. Chemical phenomena can be studied through various scientific disciplines, including chemistry, biochemistry, and physics.

Salicylates are a group of chemicals found naturally in certain fruits, vegetables, and herbs, as well as in some medications like aspirin. They are named after willow bark's active ingredient, salicin, from which they were derived. Salicylates have anti-inflammatory, analgesic (pain-relieving), and antipyretic (fever-reducing) properties.

In a medical context, salicylates are often used to relieve pain, reduce inflammation, and lower fever. High doses of salicylates can have blood thinning effects and may be used in the prevention of strokes or heart attacks. Commonly prescribed salicylate medications include aspirin, methylsalicylate, and sodium salicylate.

It is important to note that some people may have allergic reactions to salicylates, and overuse can lead to side effects such as stomach ulcers, ringing in the ears, and even kidney or liver damage.

... of tyrosine residues is also very vital in living organisms because hydroxylation at C-3 of tyrosine creates 3,4 ... Hydroxylation is often the first step in the degradation of organic compounds in air. Hydroxylation is important in ... In chemistry, hydroxylation can refer to: (i) most commonly, hydroxylation describes a chemical process that introduces a ... ii) the degree of hydroxylation refers to the number of OH groups in a molecule. The pattern of hydroxylation refers to the ...
The Milas hydroxylation is an organic reaction converting an alkene to a vicinal diol, and was developed by Nicholas A. Milas ... In 1949, the Milas hydroxylation was applied to a study of the demethylation of N-Dimethyl-p-Amino-azobenzene, otherwise known ... Previously it was discovered that the hydroxylation of butter yellow or its demethylated derivatives exist within rats, and ... The Use of Vanadium Pentoxide and Chromium Trioxide as Catalysts of Hydroxylation". Journal of the American Chemical Society. ...
The hydroxylation of estradiol is one of the major routes of metabolism of the estrogen steroid hormone estradiol. It is ... Whereas 4-hydroxylation constitutes the minor pathway in the liver, the greater proportion of CYP1B1 expression in extrahepatic ... Extrahepatic 2-hydroxylation is chiefly mediated by CYP1A1 and CYP3A4. 2-Hydroxyestradiol (2-OHE2) can experience three ... The enzyme most responsible for estradiol 4-hydroxylation is CYP1B1. In humans, CYP1B1 mRNA and protein exhibit constitutive ...
The Woodward cis-hydroxylation (also known as the Woodward reaction) is the chemical reaction of alkenes with iodine and silver ... Mangoni, L.; Dovinola, V. (1969). "The stereochemistry of woodward cis-hydroxylation in some steroidal olefins". Tetrahedron ... "cis-Hydroxylation of a Synthetic Steroid Intermediate with Iodine, Silver Acetate and Wet Acetic Acid". J. Am. Chem. Soc. 80 (1 ...
... is an enzyme-catalyzed, bacterial chemical reaction. Benzoate is degraded aerobically ...
... hydroxylation); vanadium and manganese (enzyme regulation or functioning); chromium (glucose utilisation); nickel (cell growth ...
I 18-hydroxylation and 18hydroxy dehydrogenation. II beta-hydroxylation". Acta Endocrinol. 69 (4): I 701-717, II 718-730. doi: ...
The Hydroxylation of Olefins". J. Am. Chem. Soc. 76 (13): 3472-3474. doi:10.1021/ja01642a031. Freeman, Jeremiah P. (November 14 ...
The Hydroxylation of Olefins". J. Am. Chem. Soc. 76 (13): 3472-3474. doi:10.1021/ja01642a031. Emmons, William D.; Pagano, ... Treiber, Alexander (2002). "Mechanism of the Aromatic Hydroxylation of Thiophene by Acid-Catalyzed Peracid Oxidation". J. Org. ...
Minato, M.; Yamamoto, K.; Tsuji, J. (1990). "Osmium tetraoxide catalyzed vicinal hydroxylation of higher olefins by using ... Asymmetric catalytic oxidation Milas hydroxylation Upjohn dihydroxylation Sharpless aminohydroxylation Noe, Mark C.; Letavic, ... "Enantioselective vicinal hydroxylation of terminal and E-1,2-disubstituted olefins by a chiral complex of osmium tetroxide. An ... see the Milas hydroxylation. Drawbacks of peroxides include chemoselectivity issues. Trialkylammonium N-oxides, such as NMO-as ...
First, hydroxylation at C-8. Second, O-methylation at OHC-8. Third, dehydration at C-17 OH. Last, C-16 and C-17 olefin is ...
Hydronium Ion Oxide Hydroxylation "Alcohols". IUPAC. Retrieved 23 March 2015. "Hydrolysis - an overview , ScienceDirect Topics ...
... is an effective reagent for the hydroxylation of aromatic rings. The conversion of mesitylene to ... Ogata, Yoshiro; Sawaki, Yasuhiko; Tomizawa, Kohtaro; Ohno, Takashi (1981). "Aromatic Hydroxylation with Peroxymonophosphoric ...
These enzymes catalyze hydroxylation reactions. Beside the CYP family NNK can also be activated by metabolic genes, like ... In the oxidative metabolism NNK undergoes an α-hydroxylation catalyzed by cytochrome P450. This reaction can be done by two ...
3. Enzymic hydroxylation by rat-liver microsomes". Biochem. J. 66 (1): 73-8. doi:10.1042/bj0660073. PMC 1199967. PMID 13426111 ... Role of the cytochrome P-450 and P-448 fractions in drug and steroid hydroxylations". J. Biol. Chem. 247 (6): 1727-34. PMID ... MITOMA C, POSNER HS, REITZ HC, UDENFRIEND S (1956). "Enzymatic hydroxylation of aromatic compounds". Arch. Biochem. Biophys. 61 ... Evidence for several monooxygenases catalyzing omega- and omega-1-hydroxylation". J. Biol. Chem. 254 (20): 10405-14. PMID ...
Ogata, Yoshiro; Sawaki, Yasuhiko; Tomizawa, Kohtaro; Ohno, Takashi (1981). "Aromatic hydroxylation with peroxymonophosphoric ...
9, p. 383 Atta-ur-Rahman; Shah, Zahir (1993). "Asymmetric Hydroxylations". Stereoselectove Synthesis in Organic Chemistry. ...
Shibahara M, Moody JA, Smith LL (1970). "Microbial hydroxylations. V. 11-alpha-hydroxylation of progesterone by cell-free ...
Hydroxylation of biphenyl oxide has been studied in C. echinulata. Webster, John (1980). Introduction to Fungi. Cambridge: ... "Biphenyl oxide hydroxylation by Cunninghamella echinulata". Journal of Agricultural and Food Chemistry. 39 (2): 428. doi: ... The presence of an active monooxygenase system allows this species to perform oxidative demethylation and hydroxylation. The ...
Ortiz de Montellano PR (February 2010). "Hydrocarbon hydroxylation by cytochrome P450 enzymes". Chemical Reviews. 110 (2): 932- ... anchoring the hydroxylation site (C-24, C-25) near the catalytic center of the enzyme (5.7Å from the iron core of the heme ... molecule to allow oxyferryl intermediates to perform the cholesterol hydroxylation). A loop region, known as the B'-C loop, has ... hydroxylase HMDB Database entry RCSB Protein Data Bank Entry Review on Cholesterol-24 Hydroxylase Heme hydroxylation mechanism ...
1 July 1976). "Hydroxylation with ozone on silica gel. The synthesis of 1.alpha.,25-dihydroxyvitamin D3". The Journal of ... During his PhD studies he developed a method for dry ozonation, which enabled regioselective hydroxylation of tertiary carbon ... Cohen, Z; Keinan, E; Mazur, Y; Varkony, T.H. (1975). "Method for stereoselective hydroxylation of saturated compounds on silica ...
Sørensen, L. B., Sørensen, R. N., Miners, J. O., et al., Polymorphic hydroxylation of perhexiline in vitro. British Journal of ... The major route of perhexiline metabolism in humans is hydroxylation by microsomal CYP2D6. The two main metabolites of ...
Then steviol is produced by hydroxylation. The steviol is subsequently glycosylated in the cytoplasm. Bridel, M.; Lavieille, R ...
Guroff, G.; Daly, J.W.; Jerina, D.M.; Renson, J.; Witkop, B.; Udenfriend, S. (1967). "Hydroxylation-induced migration: the NIH ... PMID 6038165.. Bassan, A.; Blomberg, M.R.A.; Siegbahn, P.E.M. (2003). "Mechanism of Aromatic Hydroxylation by an Activated FeIV ... Recent experiments reveal an unexpected and general result of enzymatic hydroxylation of aromatic compounds". Science. 157 ( ... rearrangement where a hydrogen atom on an aromatic ring undergoes an intramolecular migration primarily during a hydroxylation ...
Hydroxylation of phenylalanine by ferryl oxo intermediate. Because the mechanism involves a Fe(IV)=O (as opposed to a ... PAH) (EC 1.14.16.1) is an enzyme that catalyzes the hydroxylation of the aromatic side-chain of phenylalanine to generate ... Bassan A, Blomberg MR, Siegbahn PE (September 2003). "Mechanism of aromatic hydroxylation by an activated FeIV=O core in ... Fitzpatrick PF (December 2003). "Mechanism of aromatic amino acid hydroxylation". Biochemistry. 42 (48): 14083-91. doi:10.1021/ ...
Bankel L, Lindstedt G, Lindstedt S (1972). "Thymidine 2'-hydroxylation in Neurospora crassa". J. Biol. Chem. 247 (19): 6128-34 ... of two alpha-ketoglutarate-dependent dioxygenases in extracts of Rhodotorula glutinis catalyzing deoxyuridine hydroxylation". J ...
doi:10.1016/S0277-5387(00)81474-6. Huang, Xiongyi; Groves, John T. (2017). "Beyond Ferryl‑Mediated Hydroxylation: 40 Years of ... Ortiz de Montellano, Paul R. (2010). "Hydrocarbon Hydroxylation by Cytochrome P450 Enzymes". Chemical Reviews. 110 (2): 932-948 ...
Rieutord A, Stupans I, Shenfield GM, Gross AS (December 1995). "Gliclazide hydroxylation by rat liver microsomes". Xenobiotica ...
... is metabolized mainly via hydroxylation. The 1β- and 6β-hydroxy metabolites of trimegestone are progestogens with ...
Hydroxylation of Carbonyl Compounds via Silyl Enol Ethers". J. Org. Chem. 40 (23): 3427-3429. doi:10.1021/jo00911a027. Rubottom ... Chen, B. C.; Zhou, P.; Davis, F. A.; Ciganek, E. (2003) "α-Hydroxylation of Enolates and Silyl Enol Ethers." in Organic ... chem.harvard.edu Christoffers, J.; Baro, A.; Werner, T. (2004). "α-Hydroxylation Of β-Dicarbonyl Compounds". Adv. Synth. Catal ... these α-hydroxylations do not proceed via silyl enol ether intermediates and are therefore not technically Rubottom oxidations ...
Hydroxylation of tyrosine residues is also very vital in living organisms because hydroxylation at C-3 of tyrosine creates 3,4 ... Hydroxylation is often the first step in the degradation of organic compounds in air. Hydroxylation is important in ... In chemistry, hydroxylation can refer to: (i) most commonly, hydroxylation describes a chemical process that introduces a ... ii) the degree of hydroxylation refers to the number of OH groups in a molecule. The pattern of hydroxylation refers to the ...
1997) Relationship between CYP2C9 and 2C19 genotypes and tolbutamide methyl hydroxylation and S-mephenytoin 4′-hydroxylation ... CYP2C Enzymes Catalyzing Tolbutamide Hydroxylation.. We recently reported that tolbutamide hydroxylation in human liver ... CYP2C19 Participates in Tolbutamide Hydroxylation by Human Liver Microsomes. Michael R. Wester, Jerome M. Lasker, Eric F. ... CYP2C19 Participates in Tolbutamide Hydroxylation by Human Liver Microsomes. Michael R. Wester, Jerome M. Lasker, Eric F. ...
... hydroxylation, was investigated in human liver microsomes. Inhibition studies were performed with tolbutamide and ... Diclofenac 4-hydroxylation displayed single enzyme Michaelis-Menten kinetics and was similar in microsomes from one poor and ... Cytochrome P450TB (CYP2C): a major monooxygenase catalyzing diclofenac 4-hydroxylation in human liver Life Sci. 1993;52(1):29- ... The nature of the enzyme(s) catalyzing the major metabolic pathway of diclofenac, 4-hydroxylation, was investigated in human ...
Inhibition experiments were performed using (S)-[2H4]propafenone as an inhibitor of the 5-hydroxylation of (R)-propafenone, and ... We used the cytochrome P450IID6-mediated 5-hydroxylation of propafenone as a model pathway, because this metabolic step ... The Michaelis-Menten kinetics for 5-hydroxylation were determined after incubation of (R)- and (S)-propafenone and a ... In conclusion, the enantiomers of propafenone interact with respect to 5-hydroxylation, with (R)-propafenone being a more ...
Hydroxylation mediates chromatin demethylation」の研究トピックを掘り下げます。これらがまとまってユニークなフィンガープリントを構成します。 ... Hydroxylation mediates chromatin demethylation. / Tsukada, Yu Ichi. In: Journal of biochemistry, Vol. 151, No. 3, 03.2012, p. ... Hydroxylation mediates chromatin demethylation. Journal of biochemistry. 2012 3月;151(3):229-246. doi: 10.1093/jb/mvs003 ... Hydroxylation mediates chromatin demethylation. In: Journal of biochemistry. 2012 ;
As a consequence of reduced prolyl hydroxylation, the stability of newly synthesized procollagen triple helix was shown to be ... Doxorubicin-induced inhibition of prolyl hydroxylation during collagen biosynthesis in human skin fibroblast cultures. ... there was a significant inhibition of prolyl hydroxylation during collagen biosynthesis, as indicated by a reduction in the ...
Optimal Translational Termination Requires C4 Lysyl Hydroxylation of eRF1 Feng T., Yamamoto A., Wilkins SE., Sokolova E., Yates ...
Studies of Enzymatic and Biomimetic Halogenation and Hydroxylation in Nonheme Iron Systems. File: application/pdf, -1 bytes ... Of current debate are the factors separating halogenation and hydroxylation and in this thesis we have investigated the ... Studies of Enzymatic and Biomimetic Halogenation and Hydroxylation in Nonheme Iron Systems. Timmins, A. (Author). 31 Dec 2018 ... Studies of Enzymatic and Biomimetic Halogenation and Hydroxylation in Nonheme Iron Systems ...
keywords = "Collagen, prolyl hydroxylation, lysyl hydroxylation, connective tissue disorders, fibrosis, Bruck syndrome, ... Gjaltema, R. A. F., & Bank, R. A. (2017). Molecular insights into prolyl and lysyl hydroxylation of fibrillar collagens in ... Gjaltema, Rutger A. F. ; Bank, Ruud A. / Molecular insights into prolyl and lysyl hydroxylation of fibrillar collagens in ... Molecular insights into prolyl and lysyl hydroxylation of fibrillar collagens in health and disease. / Gjaltema, Rutger A. F.; ...
Prolyl hydroxylation of collagen type I is required for efficient binding to integrin alpha 1 beta 1 and platelet glycoprotein ... Prolyl hydroxylation of collagen type I is required for efficient binding to integrin alpha 1 beta 1 and platelet glycoprotein ...
Overall the work has defined 13 new FIH-dependent hydroxylation sites with a degenerate consensus corresponding to that of the ... However, following the recognition that oxygen-sensitive prolyl and asparaginyl hydroxylation are central to the regulation of ... These findings indicate that asparaginyl hydroxylation is likely to be widespread among the approximately 300 ARD-containing ... revealed eight sites that were differentially sensitive to FIH-catalyzed hydroxylation. ...
Abutilon theophrastis Root Associated Microorganisms Support Hydroxylation-dependent Benzoxazolinone Detoxification and ... Abutilon theophrastis Root Associated Microorganisms Support Hydroxylation-dependent Benzoxazolinone Detoxification and ... Abutilon theophrastis Root Associated Microorganisms Support Hydroxylation-dependent Benzoxazolinone Detoxification and ...
Optimal Translational Termination Requires C4 Lysyl Hydroxylation of eRF1 Share Share Share ...
We identify conditions where Rps23p hydroxylation status determines viability as a consequence of nonsense codon suppression. ... undergoes posttranslational hydroxylation. We identify RPS23 hydroxylases as a highly conserved eukaryotic subfamily of Fe(II) ... we reveal Rps23p hydroxylation as its molecular basis. In contrast to most previously characterized accuracy modulators, ... including antibiotics and the prion state of the S. cerevisiae translation termination factor eRF3, Rps23p hydroxylation can ...
Double hydroxylation reactions of benzoic acid,ioluic acid, cumic acid and phthalic acid as well as the metabolic fate of ... The enzymes involved in the double hydroxylation of the compounds in bacteria have teen compared with those of the fungal ...
PHD3-mediated prolyl hydroxylation of nonmuscle actin impairs polymerization and cell motility. Molecular biology of the cell. ... PHD3-mediated prolyl hydroxylation of nonmuscle actin impairs polymerization and cell motility. In: Molecular biology of the ... PHD3-mediated prolyl hydroxylation of nonmuscle actin impairs polymerization and cell motility. / Luo, Weibo; Lin, Benjamin; ... Here we report that prolyl hydroxylase 3 (PHD3) interacts with nonmuscle actin in human cells and catalyzes hydroxylation of ...
These data show acquisition of the host FIH by a pathogen-containing vacuole and that asparaginyl-hydroxylation of translocated ... These data show acquisition of the host FIH by a pathogen-containing vacuole and that asparaginyl-hydroxylation of translocated ... These data show acquisition of the host FIH by a pathogen-containing vacuole and that asparaginyl-hydroxylation of translocated ... These data show acquisition of the host FIH by a pathogen-containing vacuole and that asparaginyl-hydroxylation of translocated ...
Hydrophobic Outer Membrane Pores Boost Testosterone Hydroxylation by Cytochrome P450 BM3 Containing Cells.docx ... whole-cell biocatalysissteroid hydroxylationsubstrate uptakecytochrome P450 monooxygenasehydrophobic membrane poresAlkL ... DataSheet1_Hydrophobic Outer Membrane Pores Boost Testosterone Hydroxylation by Cytochrome P450 BM3 Containing Cells. .docx (. ... The implementation of biocatalytic steroid hydroxylation processes at an industrial scale still suffers from low conversion ...
Hydroxylation * Metabolic Detoxication, Phase I / physiology* * Middle Aged * Mixed Function Oxygenases / metabolism ...
involved_in lipid hydroxylation IDA Inferred from Direct Assay. more info. PubMed ...
Mammalian P450s are unusual enzymes capable of binding and modifying many different drugs mainly through hydroxylation. The ...
Dataset to "An Enzymatic Route to α‐Tocopherol Synthons: Aromatic Hydroxylation of Pseudocumene and Mesitylene with P450 BM3" ... Dataset to "An Enzymatic Route to α‐Tocopherol Synthons: Aromatic Hydroxylation of Pseudocumene and Mesitylene with P450 BM3". ... You Are Here: Dataset to "An Enzymatic Route to α‐Tocopherol Synthons: Aromatic Hydroxylation of Pseudocumene and Mesitylene ... You Are Here:Dataset to "An Enzymatic Route to α‐Tocopherol Synthons: Aromatic Hydroxylation of Pseudocumene and Mesitylene ...
Participation of two distinct hydroxylating intermediates in iron(III) porphyrin complex-catalyzed hydroxylation of Alkanes. ... porphyrin complex-catalyzed hydroxylation of Alkanes. Together they form a unique fingerprint. ...
Hayaishi O. Enzymatic hydroxylation. Am Rev Biochem. 1969. 38:21-44. *. Barrow CS, Alarie Y, Warrick JC, Stock MF. Comparison ...
Herein, we report a Ni-catalyzed C(sp2)-H hydroxylation of aryl bromides with N2O as an oxygen-atom donor. The reaction is ... C(sp,sup,2,/sup,)-H Hydroxylation via Catalytic 1,4-Ni Migration with N,sub,2,/sub,O. ... C(sp2)-H Hydroxylation via Catalytic 1,4-Ni Migration with N2O. ...
Hydroxylation has been shown to stabilize localized regions of the ARD fold in the case of a three-repeat consensus ankyrin ... Hydroxylation has been shown to stabilize localized regions of the ARD fold in the case of a three-repeat consensus ankyrin ... Hydroxylation has been shown to stabilize localized regions of the ARD fold in the case of a three-repeat consensus ankyrin ... Hydroxylation has been shown to stabilize localized regions of the ARD fold in the case of a three-repeat consensus ankyrin ...
... that could be easily substituted by hydrogen peroxide and yielded the active peroxo intermediate for further hydroxylation of ... that could be easily substituted by hydrogen peroxide and yielded the active peroxo intermediate for further hydroxylation of ... that could be easily substituted by hydrogen peroxide and yielded the active peroxo intermediate for further hydroxylation of ... that could be easily substituted by hydrogen peroxide and yielded the active peroxo intermediate for further hydroxylation of ...
  • Proteomics-based identification of novel factor inhibiting hypoxia-inducible factor (FIH) substrates indicates widespread asparaginyl hydroxylation of ankyrin repeat domain-containing proteins. (ox.ac.uk)
  • However, following the recognition that oxygen-sensitive prolyl and asparaginyl hydroxylation are central to the regulation of the transcription factor hypoxia-inducible factor (HIF), interest has centered on the possibility that these enzymes may have other substrates in the proteome. (ox.ac.uk)
  • These findings indicate that asparaginyl hydroxylation is likely to be widespread among the approximately 300 ARD-containing species in the human proteome. (ox.ac.uk)
  • FIH-mediated post-translational modification through asparaginyl hydroxylation of eukaryotic proteins impacts regulation of protein-protein interaction. (huji.ac.il)
  • Mass spectrometry analyses of the AnkB and AnkH effectors of L. pneumophila confirm their asparaginyl hydroxylation. (huji.ac.il)
  • These data show acquisition of the host FIH by a pathogen-containing vacuole and that asparaginyl-hydroxylation of translocated effectors is indispensable for their function. (huji.ac.il)
  • Studies on hypoxia-sensitive pathways have revealed a series of Fe(II)-dependent dioxygenases that regulate hypoxia-inducible factor (HIF) by prolyl and asparaginyl hydroxylation. (ox.ac.uk)
  • Although most studies have implicated CYP2C9 as the exclusive catalyst of hepatic tolbutamide hydroxylation in humans, there is evidence that other CYP2C enzymes (e.g. (aspetjournals.org)
  • Using mass spectrometric analyses of Saccharomyces cerevisiae ribosomes, we found that the amino acid residue in closest proximity to the decoding center, Pro-64 of the 40S subunit ribosomal protein Rps23p (RPS23 Pro-62 in humans) undergoes posttranslational hydroxylation. (ox.ac.uk)
  • The use of smokeless tobacco by in the mouth, against the cheek or humans is a voluntary practice en behind the lip and sucked (dipped) Evaluations of smokeless tobac gaged in by hundreds of mil ions of or chewed. (who.int)
  • Inhibition experiments were performed using (S)-[2H4]propafenone as an inhibitor of the 5-hydroxylation of (R)-propafenone, and vice versa. (aspetjournals.org)
  • Application of the model revealed Ki values of 2.9 and 5.2 microM for the inhibition of 5-hydroxylation of (S)-[2H4]-propafenone by (R)-propafenone and for inhibition of 5-hydroxylation of (R)-propafenone by (S)-[2H4]-propafenone, respectively. (aspetjournals.org)
  • Doxorubicin-induced inhibition of prolyl hydroxylation during collagen biosynthesis in human skin fibroblast cultures. (qxmd.com)
  • Blocking PHD3 expression or catalytic activity by short hairpin RNA knockdown or pharmacological inhibition, respectively, decreased actin prolyl hydroxylation. (johnshopkins.edu)
  • These residues are formed due to the hydroxylation of phenylalanine and tyrosine, a process in which the hydroxylation converts phenylalanine residues into tyrosine residues. (wikipedia.org)
  • Hydroxylation of tyrosine residues is also very vital in living organisms because hydroxylation at C-3 of tyrosine creates 3,4- dihydroxy phenylalanine (DOPA), which is a precursor to hormones and can be converted into dopamine. (wikipedia.org)
  • To pursue these potential FIH substrates we used conventional data-directed tandem MS together with alternating low/high collision energy tandem MS to assign and quantitate hydroxylation at target asparaginyl residues. (ox.ac.uk)
  • Here we report that prolyl hydroxylase 3 (PHD3) interacts with nonmuscle actin in human cells and catalyzes hydroxylation of actin at proline residues 307 and 322. (johnshopkins.edu)
  • FIH also catalyzes the hydroxylation of highly conserved Asn residues within the ubiquitous ankyrin repeat domain (ARD)-containing proteins. (birmingham.ac.uk)
  • Unexpectedly we found that aspartate residues in ankyrinR and ankyrinB are hydroxylated and that FIH-catalyzed aspartate hydroxylation also occurs in other naturally occurring AR sequences. (birmingham.ac.uk)
  • Gjaltema, RAF & Bank, RA 2017, ' Molecular insights into prolyl and lysyl hydroxylation of fibrillar collagens in health and disease ', Critical reviews in biochemistry and molecular biology , vol. 52, nr. 1, blz. (rug.nl)
  • Hydroxylation occurs at the γ-C atom, forming hydroxyproline (Hyp), which stabilizes the secondary structure of collagen due to the strong electronegative effects of oxygen. (wikipedia.org)
  • Deprivation of ascorbate leads to deficiencies in proline hydroxylation, which leads to less stable collagen, which can manifest itself as the disease scurvy. (wikipedia.org)
  • Monospecific anti-CYP2C9 was also found to inhibit rates of tolbutamide hydroxylation by 93 ± 4 and 78 ± 6% in CYP2C19-deficient and CYP2C19-containing human liver microsomes, respectively. (aspetjournals.org)
  • Taken together, our results indicate that both CYP2C9 and CYP2C19 are involved in tolbutamide hydroxylation by human liver microsomes, and that CYP2C19 underlies at least 14 to 22% of tolbutamide metabolism. (aspetjournals.org)
  • The nature of the enzyme(s) catalyzing the major metabolic pathway of diclofenac, 4'-hydroxylation, was investigated in human liver microsomes. (nih.gov)
  • The crystal structure of an FIH variant in complex with an Asp-substrate peptide together with NMR analyses of the hydroxylation product identifies the 3S regio- and stereoselectivity of the FIH-catalyzed Asp hydroxylation, revealing a previously unprecedented posttranslational modification. (birmingham.ac.uk)
  • Age influenced CYP2D6 metabolism and dapsone hydroxylation. (nih.gov)
  • Enantiomeric separation and quantification of warfarin enantiomers and clinically important major hydroxylation metabolites are essential for drug interaction studies and phenotypic characterization of CYP2C9 and CYP3A4, the major Cytochrome P450 (CYP) enzymes involved in warfarin metabolism. (austinpublishinggroup.com)
  • Dataset to "An Enzymatic Route to α‐Tocopherol Synthons: Aromatic Hydroxylation. (rwth-aachen.de)
  • Factor-inhibiting hypoxia-inducible factor (FIH) catalyzes the β-hydroxylation of an asparagine residue in the C-terminal transcriptional activation domain of the hypoxia inducible factor (HIF), a modification that negatively regulates HIF transcriptional activity. (birmingham.ac.uk)
  • The hydroxylation of proteins occurs as a post-translational modification, and is catalyzed by 2-oxoglutarate-dependent dioxygenases. (wikipedia.org)
  • Post-translational hydroxylation has been considered an unusual modification on intracellular proteins. (ox.ac.uk)
  • Overall the work has defined 13 new FIH-dependent hydroxylation sites with a degenerate consensus corresponding to that of the ankyrin repeat and a range of ARD-containing proteins as actual and potential substrates for FIH. (ox.ac.uk)
  • Several ARD-containing proteins were multiply hydroxylated, and detailed studies of one, Tankyrase-2, revealed eight sites that were differentially sensitive to FIH-catalyzed hydroxylation. (ox.ac.uk)
  • Whereas many hydroxylations insert O atoms into C−H bonds, some reactions add OH groups to unsaturated substrates. (wikipedia.org)
  • Here we report that the cytoskeletal ankyrin family are substrates for FIH-catalyzed hydroxylations. (birmingham.ac.uk)
  • The principal hydroxylation agent in nature is cytochrome P-450, hundreds of variations of which are known. (wikipedia.org)
  • Tolbutamide is a sulfonylurea-type oral hypoglycemic agent whose action is terminated by hydroxylation of the tolylsulfonyl methyl moiety catalyzed by cytochrome P-450 (CYP) enzymes of the human CYP2C subfamily. (aspetjournals.org)
  • Hydroxylation of the D34 region of ankyrinR ARD (ankyrin repeats 13-24) increases its conformational stability and leads to a reduction in its interaction with the cytoplasmic domain of band 3 (CDB3), demonstrating the potential for FIH-catalyzed hydroxylation to modulate protein-protein interactions. (birmingham.ac.uk)
  • the human Tpa1p homolog OGFOD1 catalyzes prolyl trans-3-hydroxylation. (ox.ac.uk)
  • CYP2C9 catalyzes the 6- and 7-hydroxylation of S -warfarin: with S-7-hydroxywarfarin (S-7-OH-warfarin) being the predominant metabolite: and the 4'-hydroxylation of R -warfarin [6]. (austinpublishinggroup.com)
  • 15%) inhibitory effect on S -mephenytoin 4′-hydroxylation by purified CYP2C19 or hepatic microsomes containing CYP2C19. (aspetjournals.org)
  • Diclofenac 4'-hydroxylation displayed single enzyme Michaelis-Menten kinetics and was similar in microsomes from one poor and five extensive metabolizers of debrisoquin (CYP2D6), with a Km of 5.6 +/- 1.5 microM (mean +/- sd) and a Vmax of 60.6 +/- 23.5 nmol/mgP/h. (nih.gov)
  • In biochemistry, hydroxylation reactions are often facilitated by enzymes called hydroxylases. (wikipedia.org)
  • Hydroxylation is important in detoxification since it converts lipophilic compounds into water-soluble (hydrophilic) products that are more readily removed by the kidneys or liver and excreted. (wikipedia.org)
  • Double hydroxylation reactions of benzoic acid,ioluic acid, cumic acid and phthalic acid as well as the metabolic fate of aniline and anthranilic acid are illustrated. (iisc.ernet.in)
  • None of these methoxyflavones inhibited 6β-hydroxylation of testosterone catalyzed by CYP3A4. (aspetjournals.org)
  • Hydroxylation of the eukaryotic ribosomal decoding center affects translational accuracy. (ox.ac.uk)
  • Sulfaphenazole competitively inhibited diclofenac 4'-hydroxylation (Ki = 0.11 +/- 0.08 microM, n = 3). (nih.gov)
  • Diclofenac 4'-hydroxylation is predominantly catalyzed by a cytochrome P450 isozyme of the CYP2C subfamily, most likely CYP2C9. (nih.gov)
  • The formation of octahedral vanadium oxide samples possess much removable mobile ligands in the catalytic center that could be easily substituted by hydrogen peroxide and yielded the active peroxo intermediate for further hydroxylation of benzene. (tmu.edu.tw)
  • The tetrahedral coordination of vanadium oxide catalysts showed less mobile ligands in the catalytic medium and yielded lower activity toward the hydroxylation of benzene. (tmu.edu.tw)
  • In this study, we selected variants of the self-sufficient cytochrome P450 monooxygenase BM3 from Bacillus megaterium (BM3) for the hydroxylation of testosterone either at the 2β- or 15β-position. (figshare.com)
  • Indeed, the application of four candidates led to increased initial testosterone hydroxylation rates. (figshare.com)
  • Proline hydroxylation is also a vital component of hypoxia response via hypoxia inducible factors. (wikipedia.org)
  • In conclusion, the enantiomers of propafenone interact with respect to 5-hydroxylation, with (R)-propafenone being a more potent inhibitor than the S-enantiomer with respect to cytochrome P450IID6-mediated 5-hydroxylation. (aspetjournals.org)
  • The implementation of biocatalytic steroid hydroxylation processes at an industrial scale still suffers from low conversion rates. (figshare.com)
  • These findings demonstrate that this type of protein hydroxylation is not restricted to HIF and strongly suggest that FIH-dependent ARD hydroxylation is a common occurrence, potentially providing an oxygen-sensitive signal to a diverse range of processes. (ox.ac.uk)
  • Hydroxylation is often the first step in the degradation of organic compounds in air. (wikipedia.org)
  • The enzymes involved in the double hydroxylation of the compounds in bacteria have teen compared with those of the fungal system. (iisc.ernet.in)
  • C. elegans EGL-9 and mammalian homologs define a family of dioxygenases that regulate HIF by prolyl hydroxylation. (ox.ac.uk)
  • Moreover, the use of such correlation analyses for determining the metabolic specificity of CYP2C19 and/or CYP2C9 toward tolbutamide suffers from inherent limitations, including the inability to reveal strong relationships when allelic variants exist at a relatively high frequency, but contribute only slightly to tolbutamide hydroxylation. (aspetjournals.org)
  • We used the cytochrome P450IID6-mediated 5-hydroxylation of propafenone as a model pathway, because this metabolic step constitutes the major route of biotransformation of propafenone. (aspetjournals.org)
  • As a consequence of reduced prolyl hydroxylation, the stability of newly synthesized procollagen triple helix was shown to be compromised. (qxmd.com)
  • We identify conditions where Rps23p hydroxylation status determines viability as a consequence of nonsense codon suppression. (ox.ac.uk)
  • Hydroxylation has been shown to stabilize localized regions of the ARD fold in the case of a three-repeat consensus ankyrin protein, but this phenomenon has not been demonstrated for the extensive naturally occurring ARDs. (birmingham.ac.uk)
  • In chemistry, hydroxylation can refer to: (i) most commonly, hydroxylation describes a chemical process that introduces a hydroxyl group (−OH) into an organic compound. (wikipedia.org)
  • In spite of nearly identical digoxin content of the plant, the hydroxylating capacity of the corresponding cell strains varied from high 12 b -hydroxylation to total lack of any activity. (nzdl.org)
  • In order to find the cell strains with high and selective 12 b -hydroxylation capacity, the relationship between the hydroxylation capacity of D. lanata plants and cell cultures was studied. (nzdl.org)
  • 17α-Hydroxylase Cholesterol 7 alpha-hydroxylase Dopamine β-hydroxylase Phenylalanine hydroxylase Tyrosine hydroxylase One example of non-biological hydroxylation is the hydrogen peroxide hydroxylation of phenol to form hydroquinone. (wikipedia.org)
  • In the studies conducted to determine the influence of macroelements, carbon sources, and light on hydroxylation capacity of the cell cultures, it was found that there was no absolute correlation between the hydroxylation capacity of the plants and that of the cell cultures. (nzdl.org)
  • Environmental controls - influence of different culture conditions on the hydroxylation capacity of cell cultures. (nzdl.org)
  • The results showed that there was some relationship between the hydroxylation rates of leaves and cell strains. (nzdl.org)
  • However, no direct correlation was observed between digoxin content of the leaves and the hydroxylation rates of the corresponding cell cultures. (nzdl.org)
  • To achieve its biological function, 1,25-dihydroxyvitamin D3 requires two sequential hydroxylation steps from vitamin D3 catalyzed by 25-hydroxylase and 1 α -hydroxylase. (medscape.com)