Hydroxylation: Placing of a hydroxyl group on a compound in a position where one did not exist before. (Stedman, 26th ed)Mixed Function Oxygenases: 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.Cytochrome P-450 Enzyme System: 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.Microsomes, Liver: Closed vesicles of fragmented endoplasmic reticulum created when liver cells or tissue are disrupted by homogenization. They may be smooth or rough.Procollagen-Proline Dioxygenase: 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.Steroid Hydroxylases: Cytochrome P-450 monooxygenases (MIXED FUNCTION OXYGENASES) that are important in steroid biosynthesis and metabolism.Aryl Hydrocarbon Hydroxylases: 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.Steroid 16-alpha-Hydroxylase: 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.Biotransformation: 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.Debrisoquin: 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.Cholestanetriol 26-Monooxygenase: 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.Mephenytoin: An anticonvulsant effective in tonic-clonic epilepsy (EPILEPSY, TONIC-CLONIC). It may cause blood dyscrasias.Cytochrome P-450 CYP3A: 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.Dealkylation: The removing of alkyl groups from a compound. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed)Oxidoreductases, N-DemethylatingHydroxylysine: A hydroxylated derivative of the amino acid LYSINE that is present in certain collagens.NADPH-Ferrihemoprotein Reductase: A flavoprotein that catalyzes the reduction of heme-thiolate-dependent monooxygenases and is part of the microsomal hydroxylating system. EC The rate dynamics in chemical or physical systems.Chromatography, High Pressure Liquid: Liquid chromatographic techniques which feature high inlet pressures, high sensitivity, and high speed.Oxygenases: Oxidases that specifically introduce DIOXYGEN-derived oxygen atoms into a variety of organic molecules.Substrate Specificity: A characteristic feature of enzyme activity in relation to the kind of substrate on which the enzyme or catalytic molecule reacts.Benzopyrene Hydroxylase: 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 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)Cytochrome P-450 CYP1A2: A cytochrome P450 enzyme subtype that has specificity for relatively planar heteroaromatic small molecules, such as CAFFEINE and ACETAMINOPHEN.Cytochrome P-450 CYP2D6: 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.Oxidation-Reduction: 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).Hypoxia-Inducible Factor-Proline Dioxygenases: 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.Catalysis: The facilitation of a chemical reaction by material (catalyst) that is not consumed by the reaction.Cholestanes: Derivatives of the saturated steroid cholestane with methyl groups at C-18 and C-19 and an iso-octyl side chain at C-17.Proline: 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.Phenylalanine Hydroxylase: 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, Catechol: 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.Benzoflavones: 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.Chlorzoxazone: 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)Lauric Acids: 12-Carbon saturated monocarboxylic acids.Troleandomycin: A macrolide antibiotic that is similar to ERYTHROMYCIN.Stereoisomerism: 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)Procollagen-Lysine, 2-Oxoglutarate 5-Dioxygenase: 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 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.Gas Chromatography-Mass Spectrometry: A microanalytical technique combining mass spectrometry and gas chromatography for the qualitative as well as quantitative determinations of compounds.Ketoglutaric Acids: A family of compounds containing an oxo group with the general structure of 1,5-pentanedioic acid. (From Lehninger, Principles of Biochemistry, 1982, p442)Hydroxybenzoates: Benzoate derivatives substituted by one or more hydroxy groups in any position on the benzene ring.Sulfaphenazole: A sulfonilamide anti-infective agent.NADP: 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)Phenobarbital: 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.Mass Spectrometry: An analytical method used in determining the identity of a chemical based on its mass using mass analyzers/mass spectrometers.Cholestanols: 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.Hydroxyproline: A hydroxylated form of the imino acid proline. A deficiency in ASCORBIC ACID can result in impaired hydroxyproline formation.Camphor 5-Monooxygenase: 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: 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.Oxygen: 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.Ankyrin Repeat: 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.Coumarins: Synthetic or naturally occurring substances related to coumarin, the delta-lactone of coumarinic acid.Camphor: 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.Cytochrome P-450 CYP2E1: 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.Molecular Structure: 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.Catechol Oxidase: 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 b5: 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.Isoenzymes: Structurally related forms of an enzyme. Each isoenzyme has the same mechanism and classification, but differs in its chemical, physical, or immunological characteristics.Bupropion: 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.Alkane 1-Monooxygenase: 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.Recombinant Proteins: Proteins prepared by recombinant DNA technology.Aroclors: 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).NorbornanesMolecular Sequence Data: 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.Phenylalanine: An essential aromatic amino acid that is a precursor of MELANIN; DOPAMINE; noradrenalin (NOREPINEPHRINE), and THYROXINE.Liver: A large lobed glandular organ in the abdomen of vertebrates that is responsible for detoxification, metabolism, synthesis and storage of various substances.4-Hydroxybenzoate-3-Monooxygenase: A flavoprotein that catalyzes the synthesis of protocatechuic acid from 4-hydroxybenzoate in the presence of molecular oxygen. EC An inhibitor of drug metabolism and CYTOCHROME P-450 ENZYME SYSTEM activity.Alkanes: 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)Butyrophenones: Compounds containing phenyl-1-butanone.Quinidine: 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.Hydroxysteroids: 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.Amino Acid Sequence: 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.Dioxygenases: 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.Steroid 11-beta-Hydroxylase: 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).Collagen: 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).Spectrophotometry: The art or process of comparing photometrically the relative intensities of the light in different parts of the spectrum.Benzphetamine: A sympathomimetic agent with properties similar to DEXTROAMPHETAMINE. It is used in the treatment of obesity. (From Martindale, The Extra Pharmacopoeia, 30th ed, p1222)Phenacetin: 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)Dihydroxyphenylalanine: 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.Ketoconazole: Broad spectrum antifungal agent used for long periods at high doses, especially in immunosuppressed patients.Ketosteroids: 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.Steroid 21-Hydroxylase: 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).Sparteine: 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.Ascorbic Acid: 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.Prostaglandins A: (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.Gentisates: Salts and esters of gentisic acid.Benzoic 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.Adrenodoxin: 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.Catechols: A group of 1,2-benzenediols that contain the general formula R-C6H5O2.Hypoxia-Inducible Factor 1: 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.Ferredoxin-NADP Reductase: An enzyme that catalyzes the oxidation and reduction of FERREDOXIN or ADRENODOXIN in the presence of NADP. EC was formerly listed as EC and EC Hydroxylase: 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.-.Acetone: A colorless liquid used as a solvent and an antiseptic. It is one of the ketone bodies produced during ketoacidosis.Cytochrome P-450 CYP2B1: 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 CompoundsVon Hippel-Lindau Tumor Suppressor Protein: A ubiquitin-protein ligase that mediates OXYGEN-dependent polyubiquitination of HYPOXIA-INDUCIBLE FACTOR 1, ALPHA SUBUNIT. It is inactivated in VON HIPPEL-LINDAU SYNDROME.Chromatography, Liquid: Chromatographic techniques in which the mobile phase is a liquid.Enzyme Induction: 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.Hydantoins: Compounds based on imidazolidine dione. Some derivatives are ANTICONVULSANTS.Cytidine Monophosphate N-Acetylneuraminic Acid: A nucleoside monophosphate sugar which donates N-acetylneuraminic acid to the terminal sugar of a ganglioside or glycoprotein.Agrocybe: A genus of saprobic mushrooms in the family Bolbitiaceae that grow in grass, dung, garden mulch, or in woods.Cholestenones: CHOLESTENES with one or more double bonds and substituted by any number of keto groups.Scurvy: 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.Trans-Cinnamate 4-Monooxygenase: 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.NAD: 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)Enzyme Inhibitors: Compounds or agents that combine with an enzyme in such a manner as to prevent the normal substrate-enzyme combination and the catalytic reaction.Spectrophotometry, Ultraviolet: 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)2,2'-Dipyridyl: A reagent used for the determination of iron.Streptomyces: 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.Hydroxyl Radical: The univalent radical OH. Hydroxyl radical is a potent oxidizing agent.Coumaric Acids: 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.Phenol: An antiseptic and disinfectant aromatic alcohol.CresolsMagnetic Resonance Spectroscopy: 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).Pterins: Compounds based on 2-amino-4-hydroxypteridine.Midazolam: 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.Osteogenesis Imperfecta: 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.Asparagine: 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)CinnamatesMonoterpenes: 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).Nitrosamines: A class of compounds that contain a -NH2 and a -NO radical. Many members of this group have carcinogenic and mutagenic properties.Calcifediol: 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: Deuterium. The stable isotope of hydrogen. It has one neutron and one proton in the nucleus.Chemistry: A basic science concerned with the composition, structure, and properties of matter; and the reactions that occur between substances and the associated energy exchange.Protein Processing, Post-Translational: 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.Chemical Phenomena: The composition, conformation, and properties of atoms and molecules, and their reaction and interaction processes.Salicylates: 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.