Organic compounds containing the carboxy group (-COOH). This group of compounds includes amino acids and fatty acids. Carboxylic acids can be saturated, unsaturated, or aromatic.

A class of amino acids characterized by a closed ring structure.

Derivatives of ethylene, a simple organic gas of biological origin with many industrial and biological use.

A proline analog that acts as a stoichiometric replacement of proline. It causes the production of abnormal proteins with impaired biological activity.

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.

A cyclized derivative of L-GLUTAMIC ACID. Elevated blood levels may be associated with problems of GLUTAMINE or GLUTATHIONE metabolism.

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 class of enzymes that catalyze the cleavage of C-C, C-O, and C-N, and other bonds by other means than by hydrolysis or oxidation. (Enzyme Nomenclature, 1992) EC 4.

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).

Reduced (protonated) form of THIAZOLES. They can be oxidized to THIAZOLIDINEDIONES.

A psychoactive compound extracted from the resin of Cannabis sativa (marihuana, hashish). The isomer delta-9-tetrahydrocannabinol (THC) is considered the most active form, producing characteristic mood and perceptual changes associated with this compound.

The relationship between the chemical structure of a compound and its biological or pharmacological activity. Compounds are often classed together because they have structural characteristics in common including shape, size, stereochemical arrangement, and distribution of functional groups.

Spectrophotometry in the infrared region, usually for the purpose of chemical analysis through measurement of absorption spectra associated with rotational and vibrational energy levels of molecules. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)

A microanalytical technique combining mass spectrometry and gas chromatography for the qualitative as well as quantitative determinations of compounds.

Inhibits the activity of prostaglandins.

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.

A group of compounds with three aromatic rings joined in linear arrangement.

A fungistatic compound that is widely used as a food preservative. It is conjugated to GLYCINE in the liver and excreted as hippuric acid.

Liquid chromatographic techniques which feature high inlet pressures, high sensitivity, and high speed.

Organic compounds that generally contain an amino (-NH2) and a carboxyl (-COOH) group. Twenty alpha-amino acids are the subunits which are polymerized to form proteins.

Compounds with a 5-membered ring of four carbons and an oxygen. They are aromatic heterocycles. The reduced form is tetrahydrofuran.

Enzymes that catalyze the cleavage of a carbon-carbon bond by means other than hydrolysis or oxidation. This subclass contains the DECARBOXYLASES, the ALDEHYDE-LYASES, and the OXO-ACID-LYASES. EC 4.1.

The rate dynamics in chemical or physical systems.

The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH = log 1/2[1/(H+)], where (H+) is the hydrogen ion concentration in gram equivalents per liter of solution. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)

Changing an open-chain hydrocarbon to a closed ring. (McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed)

Organic compounds containing a carbonyl group in the form -CHO.

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.

Alkyl compounds containing a hydroxyl group. They are classified according to relation of the carbon atom: primary alcohols, R-CH2OH; secondary alcohols, R2-CHOH; tertiary alcohols, R3-COH. (From Grant & Hackh's Chemical Dictionary, 5th ed)

Any of the hormones produced naturally in plants and active in controlling growth and other functions. There are three primary classes: auxins, cytokinins, and gibberellins.

2-, 3-, or 4-Pyridinecarboxylic acids. Pyridine derivatives substituted with a carboxy group at the 2-, 3-, or 4-position. The 3-carboxy derivative (NIACIN) is active as a vitamin.

Substances used for the detection, identification, analysis, etc. of chemical, biological, or pathologic processes or conditions. Indicators are substances that change in physical appearance, e.g., color, at or approaching the endpoint of a chemical titration, e.g., on the passage between acidity and alkalinity. Reagents are substances used for the detection or determination of another substance by chemical or microscopical means, especially analysis. Types of reagents are precipitants, solvents, oxidizers, reducers, fluxes, and colorimetric reagents. (From Grant & Hackh's Chemical Dictionary, 5th ed, p301, p499)

An analytical method used in determining the identity of a chemical based on its mass using mass analyzers/mass spectrometers.

Organic compounds containing the -CO-NH2 radical. Amides are derived from acids by replacement of -OH by -NH2 or from ammonia by the replacement of H by an acyl group. (From Grant & Hackh's Chemical Dictionary, 5th ed)

Derivatives of propionic acid. Included under this heading are a broad variety of acid forms, salts, esters, and amides that contain the carboxyethane structure.

A basic science concerned with the composition, structure, and properties of matter; and the reactions that occur between substances and the associated energy exchange.

Inorganic derivatives of phosphorus trihydroxide (P(OH)3) and its tautomeric form dihydroxyphosphine oxide (HP=O(OH)2). Note that organic derivatives of phosphonic acids are listed under are ORGANOPHOSPHONATES.

The facilitation of a chemical reaction by material (catalyst) that is not consumed by the reaction.

A mass spectrometry technique used for analysis of nonvolatile compounds such as proteins and macromolecules. The technique involves preparing electrically charged droplets from analyte molecules dissolved in solvent. The electrically charged droplets enter a vacuum chamber where the solvent is evaporated. Evaporation of solvent reduces the droplet size, thereby increasing the coulombic repulsion within the droplet. As the charged droplets get smaller, the excess charge within them causes them to disintegrate and release analyte molecules. The volatilized analyte molecules are then analyzed by mass spectrometry.

The composition, conformation, and properties of atoms and molecules, and their reaction and interaction processes.

A genus of gram-negative, aerobic, rod-shaped bacteria widely distributed in nature. Some species are pathogenic for humans, animals, and plants.

A class of enzymes that catalyze oxidation-reduction reactions of amino acids.

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).

Benzopyrroles with the nitrogen at the number one carbon adjacent to the benzyl portion, in contrast to ISOINDOLES which have the nitrogen away from the six-membered ring.

Detection of drugs that have been abused, overused, or misused, including legal and illegal drugs. Urine screening is the usual method of detection.

The characteristic three-dimensional shape of a molecule.

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.

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 group of ISOQUINOLINES in which the nitrogen containing ring is protonated. They derive from the non-enzymatic Pictet-Spengler condensation of CATECHOLAMINES with ALDEHYDES.

Chemical compounds which yield hydrogen ions or protons when dissolved in water, whose hydrogen can be replaced by metals or basic radicals, or which react with bases to form salts and water (neutralization). An extension of the term includes substances dissolved in media other than water. (Grant & Hackh's Chemical Dictionary, 5th ed)

A group of pyrido-indole compounds. Included are any points of fusion of pyridine with the five-membered ring of indole and any derivatives of these compounds. These are similar to CARBAZOLES which are benzo-indoles.

Aliphatic acids that contain four carbons in a branched-chain configuration. Included under this heading are a broad variety of acid forms, salts, esters, and amides that contain the 2-carboxypropane structure.

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.

Benzoic acids, salts, or esters that contain an amino group attached to carbon number 2 or 6 of the benzene ring structure.

A mass spectrometric technique that is used for the analysis of a wide range of biomolecules, such as glycoalkaloids, glycoproteins, polysaccharides, and peptides. Positive and negative fast atom bombardment spectra are recorded on a mass spectrometer fitted with an atom gun with xenon as the customary beam. The mass spectra obtained contain molecular weight recognition as well as sequence information.

A characteristic feature of enzyme activity in relation to the kind of substrate on which the enzyme or catalytic molecule reacts.

Theoretical representations that simulate the behavior or activity of chemical processes or phenomena; includes the use of mathematical equations, computers, and other electronic equipment.

A group of broad-spectrum antibiotics first isolated from the Mediterranean fungus ACREMONIUM. They contain the beta-lactam moiety thia-azabicyclo-octenecarboxylic acid also called 7-aminocephalosporanic acid.

A colorless, flammable, poisonous liquid, CS2. It is used as a solvent, and is a counterirritant and has local anesthetic properties but is not used as such. It is highly toxic with pronounced CNS, hematologic, and dermatologic effects.

The removal of a carboxyl group, usually in the form of carbon dioxide, from a chemical compound.

Derivatives of ACETIC ACID. Included under this heading are a broad variety of acid forms, salts, esters, and amides that contain the carboxymethane structure.

Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.

One of the three domains of life (the others being Eukarya and ARCHAEA), also called Eubacteria. They are unicellular prokaryotic microorganisms which generally possess rigid cell walls, multiply by cell division, and exhibit three principal forms: round or coccal, rodlike or bacillary, and spiral or spirochetal. Bacteria can be classified by their response to OXYGEN: aerobic, anaerobic, or facultatively anaerobic; by the mode by which they obtain their energy: chemotrophy (via chemical reaction) or PHOTOTROPHY (via light reaction); for chemotrophs by their source of chemical energy: CHEMOLITHOTROPHY (from inorganic compounds) or chemoorganotrophy (from organic compounds); and by their source for CARBON; NITROGEN; etc.; HETEROTROPHY (from organic sources) or AUTOTROPHY (from CARBON DIOXIDE). They can also be classified by whether or not they stain (based on the structure of their CELL WALLS) with CRYSTAL VIOLET dye: gram-negative or gram-positive.

Derivatives of BENZOIC ACID. Included under this heading are a broad variety of acid forms, salts, esters, and amides that contain the carboxybenzene structure.

Chemical compounds derived from acids by the elimination of a molecule of water.

Cell membrane glycoproteins that form channels to selectively pass chloride ions. Nonselective blockers include FENAMATES; ETHACRYNIC ACID; and TAMOXIFEN.

An amino acid formed by cyclization of leucine. It has cytostatic, immunosuppressive and antineoplastic activities.

Chemical substances which inhibit the process of spermatozoa formation at either the first stage, in which spermatogonia develop into spermatocytes and then into spermatids, or the second stage, in which spermatids transform into spermatozoa.

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.

Insoluble polymers of TYROSINE derivatives found in and causing darkness in skin (SKIN PIGMENTATION), hair, and feathers providing protection against SUNBURN induced by SUNLIGHT. CAROTENES contribute yellow and red coloration.

The relationship between the dose of an administered drug and the response of the organism to the drug.

Unstable isotopes of carbon that decay or disintegrate emitting radiation. C atoms with atomic weights 10, 11, and 14-16 are radioactive carbon isotopes.

The process of cleaving a chemical compound by the addition of a molecule of water.

Unsaturated hydrocarbons of the type Cn-H2n, indicated by the suffix -ene. (Grant & Hackh's Chemical Dictionary, 5th ed, p408)

One of the SCHISTOSOMICIDES, it has been replaced largely by HYCANTHONE and more recently PRAZIQUANTEL. (From Martindale The Extrapharmacopoeia, 30th ed., p46)

Enzymes which catalyze the hydrolysis of carboxylic acid esters with the formation of an alcohol and a carboxylic acid anion.

Chromatography on thin layers of adsorbents rather than in columns. The adsorbent can be alumina, silica gel, silicates, charcoals, or cellulose. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)

A group of enzymes that catalyze the reduction of 1-pyrroline carboxylate to proline in the presence of NAD(P)H. Includes both the 2-oxidoreductase (EC 1.5.1.1) and the 5-oxidoreductase (EC 1.5.1.2). The former also reduces 1-piperidine-2-carboxylate to pipecolate and the latter also reduces 1-pyrroline-3-hydroxy-5-carboxylate to hydroxyproline.

A plant species of the family SOLANACEAE, native of South America, widely cultivated for their edible, fleshy, usually red fruit.

The usually underground portions of a plant that serve as support, store food, and through which water and mineral nutrients enter the plant. (From American Heritage Dictionary, 1982; Concise Dictionary of Biology, 1990)

A broad-spectrum 6-fluoronaphthyridinone antibacterial agent that is structurally related to NALIDIXIC ACID.

Azoles of one NITROGEN and two double bonds that have aromatic chemical properties.

Derivatives of caproic acid. Included under this heading are a broad variety of acid forms, salts, esters, and amides that contain a carboxy terminated six carbon aliphatic structure.

A group of alicyclic hydrocarbons with the general formula R-C5H9.

A group of tetraterpenes, with four terpene units joined head-to-tail. Biologically active members of this class are used clinically in the treatment of severe cystic ACNE; PSORIASIS; and other disorders of keratinization.

A spectroscopic technique in which a range of wavelengths is presented simultaneously with an interferometer and the spectrum is mathematically derived from the pattern thus obtained.

A CD98 antigen light chain that when heterodimerized with CD98 antigen heavy chain (ANTIGENS, CD98 HEAVY CHAIN) forms a protein that mediates sodium-independent L-type amino acid transport.

A reagent used for the determination of iron.

A tricyclo bridged hydrocarbon.

An analgesic and anti-inflammatory agent used in the treatment of rheumatoid arthritis.

Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control of gene action in plants.

Substances that reduce the growth or reproduction of BACTERIA.

Inorganic compounds derived from hydrochloric acid that contain the Cl- ion.

An essential branched-chain amino acid important for hemoglobin formation.

A plant genus in the family PINACEAE, order Pinales, class Pinopsida, division Coniferophyta. They are coniferous evergreen trees with long, flat, spirally arranged needles that grow directly from the branch.

A sodium-independent neutral amino acid transporter system with specificity for large amino acids. One of the functions of the transporter system is to supply large neutral amino acids to the brain.

The application of medical knowledge to questions of law.

Organic compounds composed exclusively of carbon and hydrogen forming a closed ring that may be either alicyclic or aromatic.

Ring compounds having atoms other than carbon in their nuclei. (Grant & Hackh's Chemical Dictionary, 5th ed)

A technology, in which sets of reactions for solution or solid-phase synthesis, is used to create molecular libraries for analysis of compounds on a large scale.

A group of compounds derived from ammonia by substituting organic radicals for the hydrogens. (From Grant & Hackh's Chemical Dictionary, 5th ed)

Liquids that dissolve other substances (solutes), generally solids, without any change in chemical composition, as, water containing sugar. (Grant & Hackh's Chemical Dictionary, 5th ed)

Azoles of two nitrogens at the 1,2 positions, next to each other, in contrast with IMIDAZOLES in which they are at the 1,3 positions.

A strain of albino rat used widely for experimental purposes because of its calmness and ease of handling. It was developed by the Sprague-Dawley Animal Company.

Organic compounds that contain silicon as an integral part of the molecule.

Acetic acid derivatives of the heterocyclic compound indole. (Merck Index, 11th 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.

Antibiotic pigment produced by Pseudomonas aeruginosa.

A clear, odorless, tasteless liquid that is essential for most animal and plant life and is an excellent solvent for many substances. The chemical formula is hydrogen oxide (H2O). (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)

Derivatives of acetic acid with one or more fluorines attached. They are almost odorless, difficult to detect chemically, and very stable. The acid itself, as well as the derivatives that are broken down in the body to the acid, are highly toxic substances, behaving as convulsant poisons with a delayed action. (From Miall's Dictionary of Chemistry, 5th ed)

A plant family of the order Santalales, subclass Rosidae, class Magnoliopsida. They are parasites that form connections (haustoria) to their hosts to obtain water and nutrients. The one-seeded fruit may be surrounded by a brightly colored nut-like structure.

A class of acids containing a ring structure in which at least one atom other than CARBON is incorporated.

A non-essential amino acid. It is found primarily in gelatin and silk fibroin and used therapeutically as a nutrient. It is also a fast inhibitory neurotransmitter.

The parts of a macromolecule that directly participate in its specific combination with another molecule.

A generic grouping for dihydric alcohols with the hydroxy groups (-OH) located on different carbon atoms. They are viscous liquids with high boiling points for their molecular weights.

A group of derivatives of naphthyridine carboxylic acid, quinoline carboxylic acid, or NALIDIXIC ACID.

Negatively charged atoms, radicals or groups of atoms which travel to the anode or positive pole during electrolysis.

A species of nonpathogenic fluorescent bacteria found in feces, sewage, soil, and water, and which liquefy gelatin.

The volatile portions of substances perceptible by the sense of smell. (Grant & Hackh's Chemical Dictionary, 5th ed)

The molecular designing of drugs for specific purposes (such as DNA-binding, enzyme inhibition, anti-cancer efficacy, etc.) based on knowledge of molecular properties such as activity of functional groups, molecular geometry, and electronic structure, and also on information cataloged on analogous molecules. Drug design is generally computer-assisted molecular modeling and does not include pharmacokinetics, dosage analysis, or drug administration analysis.

Fractionation of a vaporized sample as a consequence of partition between a mobile gaseous phase and a stationary phase held in a column. Two types are gas-solid chromatography, where the fixed phase is a solid, and gas-liquid, in which the stationary phase is a nonvolatile liquid supported on an inert solid matrix.

The class of all enzymes catalyzing oxidoreduction reactions. The substrate that is oxidized is regarded as a hydrogen donor. The systematic name is based on donor:acceptor oxidoreductase. The recommended name will be dehydrogenase, wherever this is possible; as an alternative, reductase can be used. Oxidase is only used in cases where O2 is the acceptor. (Enzyme Nomenclature, 1992, p9)

A genus of gram-positive, aerobic bacteria whose species are widely distributed and are abundant in soil. Some strains are pathogenic opportunists for humans and animals.

Placing of a hydroxyl group on a compound in a position where one did not exist before. (Stedman, 26th ed)

Six-membered heterocycles containing an oxygen and a nitrogen.

Chromatographic techniques in which the mobile phase is a liquid.

Elimination of ENVIRONMENTAL POLLUTANTS; PESTICIDES and other waste using living organisms, usually involving intervention of environmental or sanitation engineers.

A group of compounds with the heterocyclic ring structure of benzo(c)pyridine. The ring structure is characteristic of the group of opium alkaloids such as papaverine. (From Stedman, 25th ed)

A powerful herbicide used as a selective weed killer.

Stable carbon atoms that have the same atomic number as the element carbon, but differ in atomic weight. C-13 is a stable carbon isotope.

A family of fused-ring hydrocarbons isolated from coal tar that act as intermediates in various chemical reactions and are used in the production of coumarone-indene resins.

Eighteen-carbon cyclopentyl polyunsaturated fatty acids derived from ALPHA-LINOLENIC ACID via an oxidative pathway analogous to the EICOSANOIDS in animals. Biosynthesis is inhibited by SALICYLATES. A key member, jasmonic acid of PLANTS, plays a similar role to ARACHIDONIC ACID in animals.

Derivatives of BUTYRIC ACID that include a double bond between carbon 2 and 3 of the aliphatic structure. Included under this heading are a broad variety of acid forms, salts, esters, and amides that include the aminobutryrate structure.

The process of converting an acid into an alkyl or aryl derivative. Most frequently the process consists of the reaction of an acid with an alcohol in the presence of a trace of mineral acid as catalyst or the reaction of an acyl chloride with an alcohol. Esterification can also be accomplished by enzymatic processes.

A plant species of the family CARYOPHYLLACEAE. It is a source of SAPONINS. The common name "Soapwort" is also used with VACCARIA. The common name of "Bouncing Bet" is occasionally used with VIOLA.

An inhibitor of anion conductance including band 3-mediated anion transport.

A plant genus of the family BRASSICACEAE known for the root used in hot SPICES. It is also the source of HORSERADISH PEROXIDASE which is widely used in laboratories.

Derivatives of ACETIC ACID which contain an hydroxy group attached to the methyl carbon.

Elements of limited time intervals, contributing to particular results or situations.

A cephalosporin antibiotic that is administered intravenously or intramuscularly. It is active against most common gram-positive and gram-negative microorganisms, is a potent inhibitor of Enterobacteriaceae, and is highly resistant to hydrolysis by beta-lactamases. The drug has a high rate of efficacy in many types of infection and to date no severe side effects have been noted.

A very strong halogenated derivative of acetic acid. It is used in acid catalyzed reactions, especially those where an ester is cleaved in peptide synthesis.

The phenomenon whereby certain chemical compounds have structures that are different although the compounds possess the same elemental composition. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed)

A non-essential amino acid present abundantly throughout the body and is involved in many metabolic processes. It is synthesized from GLUTAMIC ACID and AMMONIA. It is the principal carrier of NITROGEN in the body and is an important energy source for many cells.

A group of compounds that are derivatives of the amino acid 2-amino-2-methylpropanoic acid.

Organic compounds that are acyclic and contain three acid groups. A member of this class is citric acid which is the first product formed by reaction of pyruvate and oxaloacetate. (From Lehninger, Principles of Biochemistry, 1982, p443)

Alicyclic hydrocarbons in which three or more of the carbon atoms in each molecule are united in a ring structure and each of the ring carbon atoms is joined to two hydrogen atoms or alkyl groups. The simplest members are cyclopropane (C3H6), cyclobutane (C4H8), cyclohexane (C6H12), and derivatives of these such as methylcyclohexane (C6H11CH3). (From Sax, et al., Hawley's Condensed Chemical Dictionary, 11th ed)

Any tests that demonstrate the relative efficacy of different chemotherapeutic agents against specific microorganisms (i.e., bacteria, fungi, viruses).

The property of objects that determines the direction of heat flow when they are placed in direct thermal contact. The temperature is the energy of microscopic motions (vibrational and translational) of the particles of atoms.

A colorless, slightly viscous liquid used as a defoaming or wetting agent. It is also used as a solvent for protective coatings, waxes, and oils, and as a raw material for plasticizers. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed)

The study of crystal structure using X-RAY DIFFRACTION techniques. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)

A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.

Inhaling and exhaling the smoke from CANNABIS.

A nonmetallic element with atomic symbol C, atomic number 6, and atomic weight [12.0096; 12.0116]. It may occur as several different allotropes including DIAMOND; CHARCOAL; and GRAPHITE; and as SOOT from incompletely burned fuel.

Attachment of isoprenoids (TERPENES) to other compounds, especially PROTEINS and FLAVONOIDS.

An enzyme that catalyzes the release of a N-terminal pyroglutamyl group from a polypeptide provided the next residue is not proline. It is inhibited by thiol-blocking reagents and occurs in mammalian tissues, microorganisms, and plants. (From Enzyme Nomenclature, 1992) EC 3.4.19.3.

A family of nonmetallic, generally electronegative, elements that form group 17 (formerly group VIIa) of the periodic table.

The 8-hydroxy derivatives inhibit various enzymes and their halogenated derivatives, though neurotoxic, are used as topical anti-infective agents, among other uses.

The movement of materials (including biochemical substances and drugs) through a biological system at the cellular level. The transport can be across cell membranes and epithelial layers. It also can occur within intracellular compartments and extracellular compartments.

Agents, either mechanical or chemical, which destroy spermatozoa in the male genitalia and block spermatogenesis.

SESQUITERPENES cyclized to one 10-carbon ring.

A compound that, on administration, must undergo chemical conversion by metabolic processes before becoming the pharmacologically active drug for which it is a prodrug.

Chemical substances that are foreign to the biological system. They include naturally occurring compounds, drugs, environmental agents, carcinogens, insecticides, etc.

QUINOLONES containing a 4-oxo (a carbonyl in the para position to the nitrogen). They inhibit the A subunit of DNA GYRASE and are used as antimicrobials. Second generation 4-quinolones are also substituted with a 1-piperazinyl group at the 7-position and a fluorine at the 6-position.

A low-energy attractive force between hydrogen and another element. It plays a major role in determining the properties of water, proteins, and other compounds.

Techniques used to separate mixtures of substances based on differences in the relative affinities of the substances for mobile and stationary phases. A mobile phase (fluid or gas) passes through a column containing a stationary phase of porous solid or liquid coated on a solid support. Usage is both analytical for small amounts and preparative for bulk amounts.

A family of hexahydropyridines.

Glycosides of GLUCURONIC ACID formed by the reaction of URIDINE DIPHOSPHATE GLUCURONIC ACID with certain endogenous and exogenous substances. Their formation is important for the detoxification of drugs, steroid excretion and BILIRUBIN metabolism to a more water-soluble compound that can be eliminated in the URINE and BILE.

A plant genus of the family ARALIACEAE. Ciwujia extract, which is prepared from plants of this genus, contains ciwujianosides and is used to enhance PHYSICAL ENDURANCE.

Derivatives of BUTYRIC ACID. Included under this heading are a broad variety of acid forms, salts, esters, and amides that contain the carboxypropane structure.

Enzymes that catalyze the formation of acyl-CoA derivatives. EC 6.2.1.

Tree-like, highly branched, polymeric compounds. They grow three-dimensionally by the addition of shells of branched molecules to a central core. The overall globular shape and presence of cavities gives potential as drug carriers and CONTRAST AGENTS.

A plant genus of the family BRASSICACEAE that contains ARABIDOPSIS PROTEINS and MADS DOMAIN PROTEINS. The species A. thaliana is used for experiments in classical plant genetics as well as molecular genetic studies in plant physiology, biochemistry, and development.

Anaerobic degradation of GLUCOSE or other organic nutrients to gain energy in the form of ATP. End products vary depending on organisms, substrates, and enzymatic pathways. Common fermentation products include ETHANOL and LACTIC ACID.

The directional growth of organisms in response to gravity. In plants, the main root is positively gravitropic (growing downwards) and a main stem is negatively gravitropic (growing upwards), irrespective of the positions in which they are placed. Plant gravitropism is thought to be controlled by auxin (AUXINS), a plant growth substance. (From Concise Dictionary of Biology, 1990)

Closed vesicles of fragmented endoplasmic reticulum created when liver cells or tissue are disrupted by homogenization. They may be smooth or rough.

A chemical element having an atomic weight of 106.4, atomic number of 46, and the symbol Pd. It is a white, ductile metal resembling platinum, and following it in abundance and importance of applications. It is used in dentistry in the form of gold, silver, and copper alloys.