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.Sulfur Compounds: Inorganic or organic compounds that contain sulfur as an integral part of the molecule.Volatile Organic Compounds: Organic compounds that have a relatively high VAPOR PRESSURE at room temperature.Structure-Activity Relationship: 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.Plant Extracts: Concentrated pharmaceutical preparations of plants obtained by removing active constituents with a suitable solvent, which is evaporated away, and adjusting the residue to a prescribed standard.Drug Evaluation, Preclinical: Preclinical testing of drugs in experimental animals or in vitro for their biological and toxic effects and potential clinical applications.Magnetic 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).Phenols: Benzene derivatives that include one or more hydroxyl groups attached to the ring structure.Heterocyclic Compounds: Ring compounds having atoms other than carbon in their nuclei. (Grant & Hackh's Chemical Dictionary, 5th ed)Inhibitory Concentration 50: The concentration of a compound needed to reduce population growth of organisms, including eukaryotic cells, by 50% in vitro. Though often expressed to denote in vitro antibacterial activity, it is also used as a benchmark for cytotoxicity to eukaryotic cells in culture.Biphenyl CompoundsSulfhydryl Compounds: Compounds containing the -SH radical.Small Molecule Libraries: Large collections of small molecules (molecular weight about 600 or less), of similar or diverse nature which are used for high-throughput screening analysis of the gene function, protein interaction, cellular processing, biochemical pathways, or other chemical interactions.Organotin Compounds: Organic compounds which contain tin in the molecule. Used widely in industry and agriculture.Aniline CompoundsSpiro Compounds: A group of compounds consisting in part of two rings sharing one atom (usually a carbon) in common.Nitrogen Compounds: Inorganic compounds that contain nitrogen as an integral part of the molecule.Chromatography, High Pressure Liquid: Liquid chromatographic techniques which feature high inlet pressures, high sensitivity, and high speed.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)Drug Design: 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.Dose-Response Relationship, Drug: The relationship between the dose of an administered drug and the response of the organism to the drug.Nitroso CompoundsOrganometallic Compounds: A class of compounds of the type R-M, where a C atom is joined directly to any other element except H, C, N, O, F, Cl, Br, I, or At. (Grant & Hackh's Chemical Dictionary, 5th ed)Organoselenium Compounds: Organic compounds which contain selenium as an integral part of the molecule.Drug Screening Assays, Antitumor: Methods of investigating the effectiveness of anticancer cytotoxic drugs and biologic inhibitors. These include in vitro cell-kill models and cytostatic dye exclusion tests as well as in vivo measurement of tumor growth parameters in laboratory animals.Organophosphorus Compounds: Organic compounds that contain phosphorus as an integral part of the molecule. Included under this heading is broad array of synthetic compounds that are used as PESTICIDES and DRUGS.Azo CompoundsGas Chromatography-Mass Spectrometry: A microanalytical technique combining mass spectrometry and gas chromatography for the qualitative as well as quantitative determinations of compounds.Kinetics: The rate dynamics in chemical or physical systems.Epoxy Compounds: Organic compounds that include a cyclic ether with three ring atoms in their structure. They are commonly used as precursors for POLYMERS such as EPOXY RESINS.Volatilization: A phase transition from liquid state to gas state, which is affected by Raoult's law. It can be accomplished by fractional distillation.High-Throughput Screening Assays: Rapid methods of measuring the effects of an agent in a biological or chemical assay. The assay usually involves some form of automation or a way to conduct multiple assays at the same time using sample arrays.Quaternary Ammonium Compounds: Derivatives of ammonium compounds, NH4+ Y-, in which all four of the hydrogens bonded to nitrogen have been replaced with hydrocarbyl groups. These are distinguished from IMINES which are RN=CR2.Drug Discovery: The process of finding chemicals for potential therapeutic use.Polycyclic Compounds: Compounds consisting of two or more fused ring structures.p-Methoxy-N-methylphenethylamine: A potent mast cell degranulator. It is involved in histamine release.Hydrocarbons, Aromatic: Organic compounds containing carbon and hydrogen in the form of an unsaturated, usually hexagonal ring structure. The compounds can be single ring, or double, triple, or multiple fused rings.Antineoplastic Agents: Substances that inhibit or prevent the proliferation of NEOPLASMS.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.Mass Spectrometry: An analytical method used in determining the identity of a chemical based on its mass using mass analyzers/mass spectrometers.Benzyl CompoundsOrganic Chemicals: A broad class of substances containing carbon and its derivatives. Many of these chemicals will frequently contain hydrogen with or without oxygen, nitrogen, sulfur, phosphorus, and other elements. They exist in either carbon chain or carbon ring form.Terphenyl Compounds: Compounds consisting of benzene rings linked to each other in either ortho, meta or para positions. Permitted are any substitutions, but ring fusion to any of the benzene rings is not allowed.Cell Line, Tumor: A cell line derived from cultured tumor cells.TriterpenesFurans: Compounds with a 5-membered ring of four carbons and an oxygen. They are aromatic heterocycles. The reduced form is tetrahydrofuran.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).Molecular Conformation: The characteristic three-dimensional shape of a molecule.Allyl CompoundsModels, Molecular: Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.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)Glycosides: Any compound that contains a constituent sugar, in which the hydroxyl group attached to the first carbon is substituted by an alcoholic, phenolic, or other group. They are named specifically for the sugar contained, such as glucoside (glucose), pentoside (pentose), fructoside (fructose), etc. Upon hydrolysis, a sugar and nonsugar component (aglycone) are formed. (From Dorland, 28th ed; From Miall's Dictionary of Chemistry, 5th ed)Heterocyclic Compounds, 2-Ring: A class of organic compounds containing two ring structures, one of which is made up of more than one kind of atom, usually carbon plus another atom. The heterocycle may be either aromatic or nonaromatic.PicratesSpectrophotometry, Infrared: 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)Selenium Compounds: Inorganic compounds that contain selenium as an integral part of the molecule.Plant Bark: The outer layer of the woody parts of plants.Plants, Medicinal: Plants whose roots, leaves, seeds, bark, or other constituent parts possess therapeutic, tonic, purgative, curative or other pharmacologic attributes, when administered to man or animals.Anti-Bacterial Agents: Substances that reduce the growth or reproduction of BACTERIA.Quantitative Structure-Activity Relationship: A quantitative prediction of the biological, ecotoxicological or pharmaceutical activity of a molecule. It is based upon structure and activity information gathered from a series of similar compounds.Indicators and Reagents: 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)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.Trialkyltin Compounds: Organometallic compounds which contain tin and three alkyl groups.Molecular 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.Cell Line: Established cell cultures that have the potential to propagate indefinitely.Plant Components, Aerial: The above-ground plant without the roots.Flavonoids: A group of phenyl benzopyrans named for having structures like FLAVONES.Bicyclo CompoundsBiodegradation, Environmental: Elimination of ENVIRONMENTAL POLLUTANTS; PESTICIDES and other waste using living organisms, usually involving intervention of environmental or sanitation engineers.Chromatography, Thin Layer: 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)Microbial Sensitivity Tests: Any tests that demonstrate the relative efficacy of different chemotherapeutic agents against specific microorganisms (i.e., bacteria, fungi, viruses).SesquiterpenesDiterpenes: Twenty-carbon compounds derived from MEVALONIC ACID or deoxyxylulose phosphate.Biological Products: Complex pharmaceutical substances, preparations, or matter derived from organisms usually obtained by biological methods or assay.Terpenes: A class of compounds composed of repeating 5-carbon units of HEMITERPENES.Bridged Compounds: Cyclic hydrocarbons that contain multiple rings and share one or more atoms.Heterocyclic Compounds with 4 or More Rings: A class of organic compounds containing four or more ring structures, one of which is made up of more than one kind of atom, usually carbon plus another atom. The heterocycle may be either aromatic or nonaromatic.KetonesCell Survival: The span of viability of a cell characterized by the capacity to perform certain functions such as metabolism, growth, reproduction, some form of responsiveness, and adaptability.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.Pharmaceutical Preparations: Drugs intended for human or veterinary use, presented in their finished dosage form. Included here are materials used in the preparation and/or formulation of the finished dosage form.Combinatorial Chemistry Techniques: 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.ThiazolesHydrogen-Ion Concentration: 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)Bacteria: 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.Antioxidants: Naturally occurring or synthetic substances that inhibit or retard the oxidation of a substance to which it is added. They counteract the harmful and damaging effects of oxidation in animal tissues.Chemical Phenomena: The composition, conformation, and properties of atoms and molecules, and their reaction and interaction processes.Indoles: 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.GlucosidesBenzofurans: Compounds that contain a BENZENE ring fused to a furan ring.Benzene DerivativesSpectrometry, Mass, Electrospray Ionization: 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.Binding Sites: The parts of a macromolecule that directly participate in its specific combination with another molecule.Monoterpenes: 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).Gold Compounds: Inorganic compounds that contain gold as an integral part of the molecule.Ligands: A molecule that binds to another molecule, used especially to refer to a small molecule that binds specifically to a larger molecule, e.g., an antigen binding to an antibody, a hormone or neurotransmitter binding to a receptor, or a substrate or allosteric effector binding to an enzyme. Ligands are also molecules that donate or accept a pair of electrons to form a coordinate covalent bond with the central metal atom of a coordination complex. (From Dorland, 27th ed)Mutation: Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.Ferrous Compounds: Inorganic or organic compounds that contain divalent iron.Plant Leaves: Expanded structures, usually green, of vascular plants, characteristically consisting of a bladelike expansion attached to a stem, and functioning as the principal organ of photosynthesis and transpiration. (American Heritage Dictionary, 2d ed)Models, Chemical: Theoretical representations that simulate the behavior or activity of chemical processes or phenomena; includes the use of mathematical equations, computers, and other electronic equipment.Benzhydryl Compounds: Compounds which contain the methyl radical substituted with two benzene rings. Permitted are any substituents, but ring fusion to any of the benzene rings is not allowed.Chromatography, Gas: 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.Cells, Cultured: Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.Coumarins: Synthetic or naturally occurring substances related to coumarin, the delta-lactone of coumarinic acid.Amines: A group of compounds derived from ammonia by substituting organic radicals for the hydrogens. (From Grant & Hackh's Chemical Dictionary, 5th ed)Time Factors: Elements of limited time intervals, contributing to particular results or situations.Protein Binding: The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.Ruthenium Compounds: Inorganic compounds that contain ruthenium as an integral part of the molecule.Substrate Specificity: A characteristic feature of enzyme activity in relation to the kind of substrate on which the enzyme or catalytic molecule reacts.Carboxylic Acids: 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.Drugs, Chinese Herbal: Chinese herbal or plant extracts which are used as drugs to treat diseases or promote general well-being. The concept does not include synthesized compounds manufactured in China.Hydrocarbons, HalogenatedFungi: A kingdom of eukaryotic, heterotrophic organisms that live parasitically as saprobes, including MUSHROOMS; YEASTS; smuts, molds, etc. They reproduce either sexually or asexually, and have life cycles that range from simple to complex. Filamentous fungi, commonly known as molds, refer to those that grow as multicellular colonies.EthersBiological Assay: A method of measuring the effects of a biologically active substance using an intermediate in vivo or in vitro tissue or cell model under controlled conditions. It includes virulence studies in animal fetuses in utero, mouse convulsion bioassay of insulin, quantitation of tumor-initiator systems in mouse skin, calculation of potentiating effects of a hormonal factor in an isolated strip of contracting stomach muscle, etc.Antiviral Agents: Agents used in the prophylaxis or therapy of VIRUS DISEASES. Some of the ways they may act include preventing viral replication by inhibiting viral DNA polymerase; binding to specific cell-surface receptors and inhibiting viral penetration or uncoating; inhibiting viral protein synthesis; or blocking late stages of virus assembly.Boron Compounds: Inorganic or organic compounds that contain boron as an integral part of the molecule.Spectrometry, Mass, Fast Atom Bombardment: 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.Benzylidene Compounds: Compounds containing the PhCH= radical.Vanadium Compounds: Inorganic compounds that contain vanadium as an integral part of the molecule.Hydroxybenzoates: Benzoate derivatives substituted by one or more hydroxy groups in any position on the benzene ring.Oils, Volatile: Oils which evaporate readily. The volatile oils occur in aromatic plants, to which they give odor and other characteristics. Most volatile oils consist of a mixture of two or more TERPENES or of a mixture of an eleoptene (the more volatile constituent of a volatile oil) with a stearopten (the more solid constituent). The synonym essential oils refers to the essence of a plant, as its perfume or scent, and not to its indispensability.Rats, Sprague-Dawley: 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.EstersSulfonium Compounds: Sulfur compounds in which the sulfur atom is attached to three organic radicals and an electronegative element or radical.Ferric Compounds: Inorganic or organic compounds containing trivalent iron.Benzoates: Derivatives of BENZOIC ACID. Included under this heading are a broad variety of acid forms, salts, esters, and amides that contain the carboxybenzene structure.Heterocyclic Compounds, 3-Ring: A class of organic compounds containing three ring structures, one of which is made up of more than one kind of atom, usually carbon plus another atom. The heterocycle may be either aromatic or nonaromaticCatechols: A group of 1,2-benzenediols that contain the general formula R-C6H5O2.Organothiophosphorus Compounds: Compounds containing carbon-phosphorus bonds in which the phosphorus component is also bonded to one or more sulfur atoms. Many of these compounds function as CHOLINERGIC AGENTS and as INSECTICIDES.Antifungal Agents: Substances that destroy fungi by suppressing their ability to grow or reproduce. They differ from FUNGICIDES, INDUSTRIAL because they defend against fungi present in human or animal tissues.Hydrocarbons, Chlorinated: Hydrocarbon compounds with one or more of the hydrogens replaced by CHLORINE.Liver: A large lobed glandular organ in the abdomen of vertebrates that is responsible for detoxification, metabolism, synthesis and storage of various substances.Hydrocarbons, FluorinatedPyridinium CompoundsMethanol: A colorless, flammable liquid used in the manufacture of FORMALDEHYDE and ACETIC ACID, in chemical synthesis, antifreeze, and as a solvent. Ingestion of methanol is toxic and may cause blindness.HydrocarbonsPolyphenols: A large class of organic compounds having more than one PHENOL group.Lactones: Cyclic esters of hydroxy carboxylic acids, containing a 1-oxacycloalkan-2-one structure. Large cyclic lactones of over a dozen atoms are MACROLIDES.Sulfides: Chemical groups containing the covalent sulfur bonds -S-. The sulfur atom can be bound to inorganic or organic moieties.Compound Eye, Arthropod: Light sensory organ in ARTHROPODS consisting of a large number of ommatidia, each functioning as an independent photoreceptor unit.Molecular Docking Simulation: A computer simulation technique that is used to model the interaction between two molecules. Typically the docking simulation measures the interactions of a small molecule or ligand with a part of a larger molecule such as a protein.Free Radical Scavengers: Substances that influence the course of a chemical reaction by ready combination with free radicals. Among other effects, this combining activity protects pancreatic islets against damage by cytokines and prevents myocardial and pulmonary perfusion injuries.CinnamatesPyransPyridines: Compounds with a six membered aromatic ring containing NITROGEN. The saturated version is PIPERIDINES.Rats, Wistar: A strain of albino rat developed at the Wistar Institute that has spread widely at other institutions. This has markedly diluted the original strain.Vinyl CompoundsSulfonic Acids: Inorganic or organic oxy acids of sulfur which contain the RSO2(OH) radical.Crystallography, X-Ray: The study of crystal structure using X-RAY DIFFRACTION techniques. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Escherichia coli: 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.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.Alcohols: 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)Parasitic Sensitivity Tests: Tests that demonstrate the relative effectiveness of chemotherapeutic agents against specific parasites.Antiprotozoal Agents: Substances that are destructive to protozoans.Aldehydes: Organic compounds containing a carbonyl group in the form -CHO.Fermentation: 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.Acetates: Derivatives of ACETIC ACID. Included under this heading are a broad variety of acid forms, salts, esters, and amides that contain the carboxymethane structure.Apoptosis: One of the mechanisms by which CELL DEATH occurs (compare with NECROSIS and AUTOPHAGOCYTOSIS). Apoptosis is the mechanism responsible for the physiological deletion of cells and appears to be intrinsically programmed. It is characterized by distinctive morphologic changes in the nucleus and cytoplasm, chromatin cleavage at regularly spaced sites, and the endonucleolytic cleavage of genomic DNA; (DNA FRAGMENTATION); at internucleosomal sites. This mode of cell death serves as a balance to mitosis in regulating the size of animal tissues and in mediating pathologic processes associated with tumor growth.Alkaloids: Organic nitrogenous bases. Many alkaloids of medical importance occur in the animal and vegetable kingdoms, and some have been synthesized. (Grant & Hackh's Chemical Dictionary, 5th ed)Solvents: 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)Mutagens: Chemical agents that increase the rate of genetic mutation by interfering with the function of nucleic acids. A clastogen is a specific mutagen that causes breaks in chromosomes.Stilbenes: Organic compounds that contain 1,2-diphenylethylene as a functional group.Porifera: The phylum of sponges which are sessile, suspension-feeding, multicellular animals that utilize flagellated cells called choanocytes to circulate water. Most are hermaphroditic. They are probably an early evolutionary side branch that gave rise to no other group of animals. Except for about 150 freshwater species, sponges are marine animals. They are a source of ALKALOIDS; STEROLS; and other complex molecules useful in medicine and biological research.Trypanocidal Agents: Agents destructive to the protozoal organisms belonging to the suborder TRYPANOSOMATINA.Imidazoles: Compounds containing 1,3-diazole, a five membered aromatic ring containing two nitrogen atoms separated by one of the carbons. Chemically reduced ones include IMIDAZOLINES and IMIDAZOLIDINES. Distinguish from 1,2-diazole (PYRAZOLES).Chalcones: Compounds based on CHALCONE. They are important intermediates in the formation of FLAVONOIDS.QuinolinesSpectrophotometry: The art or process of comparing photometrically the relative intensities of the light in different parts of the spectrum.Naphthoquinones: Naphthalene rings which contain two ketone moieties in any position. They can be substituted in any position except at the ketone groups.Mutagenicity Tests: Tests of chemical substances and physical agents for mutagenic potential. They include microbial, insect, mammalian cell, and whole animal tests.Plant Roots: 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)Chlorogenic Acid: A naturally occurring phenolic acid which is a carcinogenic inhibitor. It has also been shown to prevent paraquat-induced oxidative stress in rats. (From J Chromatogr A 1996;741(2):223-31; Biosci Biotechnol Biochem 1996;60(5):765-68).Xenobiotics: Chemical substances that are foreign to the biological system. They include naturally occurring compounds, drugs, environmental agents, carcinogens, insecticides, etc.Platinum Compounds: Inorganic compounds which contain platinum as the central atom.Binding, Competitive: The interaction of two or more substrates or ligands with the same binding site. The displacement of one by the other is used in quantitative and selective affinity measurements.Organosilicon Compounds: Organic compounds that contain silicon as an integral part of the molecule.Mercury Compounds: Inorganic compounds that contain mercury as an integral part of the molecule.Spectrum Analysis: The measurement of the amplitude of the components of a complex waveform throughout the frequency range of the waveform. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Flavones: A group of 4-keto-FLAVONOIDS.Cell Proliferation: All of the processes involved in increasing CELL NUMBER including CELL DIVISION.Organogold Compounds: Organic compounds that contain GOLD as an integral part of the molecule. Some are used as ANTIRHEUMATIC AGENTS. The term chrysotherapy derives from an ancient Greek term for gold.BenzaldehydesStreptomyces: 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.Bicyclo Compounds, Heterocyclic: A class of saturated compounds consisting of two rings only, having two or more atoms in common, containing at least one hetero atom, and that take the name of an open chain hydrocarbon containing the same total number of atoms. (From Riguady et al., Nomenclature of Organic Chemistry, 1979, p31)Anthraquinones: Compounds based on ANTHRACENES which contain two KETONES in any position. Substitutions can be in any position except on the ketone groups.Environmental Pollutants: Substances or energies, for example heat or light, which when introduced into the air, water, or land threaten life or health of individuals or ECOSYSTEMS.Lethal Dose 50: The dose amount of poisonous or toxic substance or dose of ionizing radiation required to kill 50% of the tested population.PeroxidasesPhenol: An antiseptic and disinfectant aromatic alcohol.Rhizome: Root-like underground horizontal stem of plants that produces shoots above and roots below. Distinguished from true roots which don't have buds and nodes. Similar to true roots in being underground and thickened by storage deposits.Phytotherapy: Use of plants or herbs to treat diseases or to alleviate pain.Toxicity Tests: An array of tests used to determine the toxicity of a substance to living systems. These include tests on clinical drugs, foods, and environmental pollutants.Water Pollutants, Chemical: Chemical compounds which pollute the water of rivers, streams, lakes, the sea, reservoirs, or other bodies of water.Anti-Infective Agents: Substances that prevent infectious agents or organisms from spreading or kill infectious agents in order to prevent the spread of infection.Pyrazoles: 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.Antineoplastic Agents, Phytogenic: Agents obtained from higher plants that have demonstrable cytostatic or antineoplastic activity.Carcinogens: Substances that increase the risk of NEOPLASMS in humans or animals. Both genotoxic chemicals, which affect DNA directly, and nongenotoxic chemicals, which induce neoplasms by other mechanism, are included.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)Cricetinae: A subfamily in the family MURIDAE, comprising the hamsters. Four of the more common genera are Cricetus, CRICETULUS; MESOCRICETUS; and PHODOPUS.Calcium Compounds: Inorganic compounds that contain calcium as an integral part of the molecule.

Influence of a new antiulcer agent, ammonium 7-oxobicyclo (2, 2, 1) hept-5-ene-3-carbamoyl-2-carboxylate (KF-392) on gastric lesions and gastric mucosal barrier in rats. (1/528)

Antiulcer effects of KF-392 were studied in several experimental gastric ulcer models in rats. It was found that KF-392 given orally at 1.0 to 5.0 mg/kg had a marked suppression on the developments of Shay ulcer as well as the aspirin-, stress-, and reserpine-induced gastric lesions. The influence of KF-392 on gastric mucosal barrier was also studied. A back diffusion of H+ into the gastric mucosa and a fall of transmucosal potential difference were induced with KF-392 given orally at the above mentioned doses. KF-392 given s.c. at 5.0 mg/kg showed no inhibition of Shay ulcer and no induction of back diffusion of H+ into the gastric mucosa.  (+info)

BE-31405, a new antifungal antibiotic produced by Penicillium minioluteum. I. Description of producing organism, fermentation, isolation, physico-chemical and biological properties. (2/528)

A new antifungal antibiotic, BE-31405, was isolated from the culture broth of a fungal strain, Penicillium minioluteum F31405. BE-31405 was isolated by adsorption on high porous polymer resin (Diaion HP-20), followed by solvent extraction, precipitation and crystallization. BE-31405 showed potent growth inhibitory activity against pathogenic fungal strains such as Candida albicans, Candida glabrata and Cryptococcus neoformans, but did not show cytotoxic activity against mammalian cells such as P388 mouse leukemia. The mechanism studies indicated that BE-31405 inhibited the protein synthesis of C. albicans but not of mammalian cells.  (+info)

A phosphatidylcholine-specific phospholipase C regulates activation of p42/44 mitogen-activated protein kinases in lipopolysaccharide-stimulated human alveolar macrophages. (3/528)

This study uses human alveolar macrophages to determine whether activation of a phosphatidylcholine (PC)-specific phospholipase C (PC-PLC) is linked to activation of the p42/44 (ERK) kinases by LPS. LPS-induced ERK kinase activation was inhibited by tricyclodecan-9-yl xanthogenate (D609), a relatively specific inhibitor of PC-PLC. LPS also increased amounts of diacylglycerol (DAG), and this increase in DAG was inhibited by D609. LPS induction of DAG was, at least in part, derived from PC hydrolysis. Ceramide was also increased in LPS-treated alveolar macrophages, and this increase in ceramide was inhibited by D609. Addition of exogenous C2 ceramide or bacterial-derived sphingomyelinase to alveolar macrophages increased ERK kinase activity. LPS also activated PKC zeta, and this activation was inhibited by D609. LPS-activated PKC zeta phosphorylated MAP kinase kinase, the kinase directly upstream of the ERK kinases. LPS-induced cytokine production (RNA and protein) was also inhibited by D609. As an aggregate, these studies support the hypothesis that one way by which LPS activates the ERK kinases is via activation of PC-PLC and that activation of a PC-PLC is an important component of macrophage activation by LPS.  (+info)

In vitro endothelial differentiation of long-term cultured murine embryonic yolk sac cells induced by matrigel. (4/528)

The yolk sac of an early mammalian embryo contains progenitors of hematopoietic cells and vascular endothelial cells. We established a cell line, YS4, from murine embryonic yolk sac 10 years ago. The line has been successfully cultured since then. To determine whether these long-term cultured yolk sac cells still have the potential to differentiate into endothelial cells, an in vitro model of yolk sac cell differentiation into tubeforming endothelial cells was established in the present study by culturing the yolk sac cells on basement membrane proteins (Matrigel). The results indicate that upon plating onto Matrigel, YS4 cells attach quickly, align in tandem, and form a complete network of capillary structures within 12 h. By using antibodies against the known components of Matrigel in a tube formation inhibition assay, we found that extracellular matrix proteins such as laminin, collagen IV, vitronectin, and fibronectin are the most important components in the Matrigel which induce the yolk sac cells to undergo endothelial differentiation. New basement membrane proteins are also required for the endothelial differentiation process, as indicated by the fact that base membrane protein synthesis inhibitor, D609, can block the differentiation process. Furthermore, our experiments revealed the involvement of several signal transduction pathways, such as protein kinase A, C and protein tyrosine kinase in this differentiation process.  (+info)

Analysis of the behaviour of selected CCKB/gastrin receptor antagonists in radioligand binding assays performed in mouse and rat cerebral cortex. (5/528)

1. The previously described complex behaviour of the CCKB/gastrin receptor antagonist, L-365,260, in radioligand binding assays could be explained by a variable population of two binding sites. We have investigated whether other CCKB/gastrin receptor ligands (PD134,308, PD140,376, YM022 and JB93182) can distinguish between these sites. 2. In the mouse cortex assay, Hill slopes were not different from unity and the ligand pKI values did not differ when either [125I]-BH-CCK-8S or [3H]-PD140,376 was used as label as expected for a single site (G2). 3. In the rat cortex, where previous analysis of replicate (n=48) L-365,260 data indicated the presence of two CCKB/gastrin sites (G1 and G2), the competition data for PD134,308, PD140,376, YM022 and JB93182 could be explained by a homogeneous population of CCKB/gastrin sites because the Hill slope estimates were not significantly different from unity. However, the estimated affinity values for JB93182 and YM022 were significantly higher and that for PD134,308 was significantly lower than those obtained in the mouse cortex when the same radioligand was used. In view of our previous data obtained with L-365,260, the rat cortex data were also interpreted using a two-site model. In this analysis, SR27897 expressed approximately 9 fold, PD134,308 approximately 13 fold and PD140,376 approximately 11 fold selectivity for the G2 site. In contrast, JB93182 expressed approximately 23 fold and YM022 approximately 4 fold selectivity for the G1 site. If the two-site interpretation of the data is valid then, because of its reverse selectivity to L-365,260, JB93182 has been identified as a compound which if radiolabelled could provide a test of this receptor subdivision.  (+info)

Characterization of the binding of a novel radioligand to CCKB/gastrin receptors in membranes from rat cerebral cortex. (6/528)

1. We have investigated the binding of a novel radiolabelled CCKB/gastrin receptor ligand, [3H]-JB93182 (5[[[(1S)-[[(3,5-dicarboxyphenyl)amino]carbonyl]-2-phenylethyla mino]-carbonyl]-6-[[(1-adamantylmethyl) amino]carbonyl]-indole), to sites in rat cortex membranes. 2. The [3H]-JB93182 was 97% radiochemically pure as assessed by reverse-phase HPLC (RP-HPLC) and was not degraded by incubation (150 min) with rat cortex membranes. 3. Saturation analysis indicated that [3H]-JB93182 labelled a homogeneous population of receptors in rat cortex membranes (pKD=9.48+/-0.08, Bmax=3.61+/-0.65 pmol g(-1) tissue, nH=0.97+/-0.02, n=5). The pKD was not significantly different when estimated by association-dissociation analysis (pKD=9.73+/-0.11; n=10). 4. In competition studies, the low affinity of the CCKA receptor antagonists, L-364,718; SR27897 and 2-NAP, suggest that, under the assay conditions employed, [3H]-JB93182 (0.3 nM) does not label CCKA receptors in the rat cortex. 5. The affinity estimates obtained for reference CCKB/gastrin receptor antagonists were indistinguishable from one of the affinity values obtained when a two site model was used to interpret [125I]-BH-CCK8S competition curves obtained in the same tissue (Harper et al., 1999). 6. This study provides further evidence for the existence of two CCKB/gastrin sites in rat cortex. [3H]-JB93182 appears to label selectively sites previously designated as gastrin-G1 and therefore it may be a useful compound for the further discrimination and characterization of these putative receptor subtypes.  (+info)

Nuclei contain two differentially regulated pools of diacylglycerol. (7/528)

A number of recent studies have highlighted the presence of a nuclear pool of inositol lipids [1] [2] that is regulated during progression through the cell cycle [1] [3], differentiation [1] [2] and after DNA damage [2], suggesting that a number of different regulatory pathways impinge upon this pool of lipids. It has been suggested that the downstream consequence of the activation of one of these nuclear phosphoinositide (PI) regulatory pathways is the generation of nuclear diacylglycerol (DAG) [1] [3] [4], which is important in the activation of nuclear protein kinase C (PKC) [5] [6] [7]. Activation of PKC in turn appears to regulate the progression of cells through G1 and into S phase [4] and through G2 to mitosis [3] [8] [9] [10] [11]. Although the evidence is enticing, there is as yet no direct demonstration that nuclear PIs can be hydrolysed to generate nuclear DAG. Previous data in murine erythroleukemia (MEL) cells have suggested that nuclear phosphoinositidase Cbeta1 (PIC-beta1) activity is important in the generation of nuclear DAG. Here, we demonstrate that the molecular species of nuclear DAG bears little resemblance to the PI pool and is unlikely to be generated directly by hydrolysis of these inositol lipids. Further, we show that there are in fact two distinct subnuclear pools of DAG; one that is highly disaturated and mono-unsaturated (representing more than 90% of the total nuclear DAG) and one that is highly polyunsaturated and is likely to be derived from the hydrolysis of PI. Analysis of these pools, either after differentiation or during cell-cycle progression, suggests that the pools are independently regulated, possibly by the regulation of two different nuclear phospholipase Cs (PLCs).  (+info)

DNA damage increases sensitivity to vinca alkaloids and decreases sensitivity to taxanes through p53-dependent repression of microtubule-associated protein 4. (8/528)

Taxanes and Vinca alkaloids are among the most active classes of drugs in the treatment of cancer. Yet, fewer than 50% of previously untreated patients respond, and clinicians have few ways of predicting who will benefit from treatment and who will not. Mutations in p53 occur in more than half of human malignancies and may alter the sensitivity to a variety of anticancer therapies. We have shown that the transcriptional status of p53 determines the sensitivity to antimicrotubule drugs and that this is mediated through the regulation of microtubule-associated protein 4 (MAP4). Expression of MAP4 is transcriptionally repressed by wild-type p53. Increased expression of MAP4, which occurs when p53 is transcriptionally inactive, increases microtubule polymerization, paclitaxel binding, and sensitivity to paclitaxel, a drug that stabilizes polymerized microtubules. In contrast, overexpression of MAP4 decreases microtubule binding and sensitivity to Vinca alkaloids, which promotes microtubule depolymerization. To determine whether induction of endogenous wild-type p53 by DNA-damaging agents alters the expression of MAP4 and changes the sensitivity to antimicrotubule drugs, we assayed cell lines with wild-type or mutant p53 for the expression of MAP4 and drug sensitivity before and after DNA damage. UV irradiation, bleomycin, and doxorubicin increased wild-type p53 expression and decreased MAP4 expression. These changes were associated with decreased sensitivity to paclitaxel and increased sensitivity to vinblastine. These changes in drug sensitivity were no longer observed when p53 and MAP4 returned to baseline levels. Changes in drug sensitivity following DNA-damaging agents were associated with decreased binding of paclitaxel and increased binding of Vinca alkaloids. In contrast, DNA damage did not alter the sensitivity to non-microtubule-active drugs, such as 1-beta-D-arabinofuranosylcytosine and doxorubicin. Changes in drug sensitivity following DNA-damaging drugs were not observed in cells with mutant p53. These studies demonstrate that induction of wild-type p53 by DNA-damaging agents can affect the sensitivity to antimicrotubule drugs through the regulation of MAP4 expression and may have implications for the design of clinical anticancer therapies.  (+info)

  • The aminolysis of a number of acyclic and cyclic compounds containing P-NR-P or P-CH2-P skeletons have been studied. (
  • In 2017, the lab of Marinella Mazzanti at EPFL was able to convert molecular nitrogen into ammonia in ambient conditions by synthesizing a compound containing two uranium(III) ions and three potassium centers held together by a nitride group. (
  • In particular, the collagen cross-linking is achieved by a Laccase-induced peptide cross-linking and suitable bridge molecules. (
  • Essentially substituted dihydroxyarmotes and/or substrates of the lignolytic polyphenoloxidases, such as Laccases, are suitable as bridge molecules. (
  • The acid catalysed dehydration either turns the bridge into a double bond (ozonolysis of this product yields 2 molecules of cyclopentanone) or else turns a neighbouring bond into a double bond (ozonolysis of this one yields a molecule with an aldehyde at one end of the chain, a ketone in the middle and a cyclopentane ring at the other end of the chain). (
  • Wastes from fruits and vegetable processing are shown to contained valuable molecules (antioxidants, dietary fibers, proteins, natural colorants, aroma compounds, etc.) which can be extracted, purified and valorized in value-added products. (
  • 1996 , 118(24) , 5826-5827 (Dimolybdenum Compounds with Crosswise-Bridging Acetonitrile Molecules). (
  • 5. The intermetallic compounds of claim 1, further reacted with a halide activator selected from the group consisting of alkyl aluminum halides, silicon halides, alkyl silicon halides, titanium halides, boron halides and alkyl boron halides. (
  • 9. A catalyst component for the polymerization of alpha olefins, comprising the intermetallic compound of any one of claims 1-3 and 6-8, further reacted with a halide activator selected from the group consisting of an alkyl aluminum halide, asilicon halide, an alkyl silicon halide, a titanium halide, a boron halide, and an alkyl boron halide. (
  • Salts, chelates, alcoholates (except Ti/Zr), phenates involving a single ligand are classified as the parent compound (metal containing porphyrin C07D 487/22 ). (
  • Provided is a production method for a catalyst, by which a catalyst that is a metallocene compound can be produced with high purity and high yield by using a ligand of a specific structure containing a fluorene skeleton. (
  • abstract = "The heteronuclear MM quadruply bonded oxalate bridged compound [(t-BuCO2)3MoW]2(μ-C2O 4) (I) has been prepared from the reaction between MoW(O 2Ct-Bu)4 and oxalic acid and characterized by elemental analysis, 1H NMR and UV-vis spectroscopy, and electrochemical studies. (
  • Disclosed is a method for separating aromatic compounds using a simulated moving bed (SMB) operation, characterized by injecting each raw material having a. (
  • The presence of a phenyl bridge between donor and acceptor cores leads to a considerable decrease of the triplet energy due to extension of the overlap electron and hole orbitals over the triazine-phenyl core of the molecule. (
  • The invention relates to a method for producing cationic silicon (II) compounds of general formula (RaSi) +HA- (I) by reacting the silicon (II) compounds of general formula II (Rb-H) (RaSi)+ (II) with a hydride acceptor compound A, where. (
  • In the theranostic pair of technetium and radium, a compound comprising radioactive technetium is used to image a disease-affected region such as a tumour, and the same compound comprising radioactive rhenium is then used to treat the region. (
  • The data are analyzed by representing the intramolecular energy flux as a diffusion process and using hot absorption spectra of the two chromophores of the compounds for measuring their energy contents. (
  • Secondary, a non ionic salt bridge is used so again, the ions movement from salt bridge as explanation for charge equilibration does not need any comment. (
  • To examine the structural basis of this phenomenon, we have solved four crystal structures of single-stranded DNA's containing either oxygen or sulfur at a 3'-bridging position bound in conjunction with various metal ions at the 3'-5' exonucleolytic active site of the Klenow fragment (KF) of DNA polymerase I from Escherichia coli. (
  • It therefore appears that the ability of the bridging sulfur compounds to exclude nonthiophilic metal ions from metal ion site B explains the low activity of KF exonuclease on these substrates in the presence of Mg2+ (Curley et al. (
  • A salt bridge is a conductor with ions as charge carriers. (
  • The latter results are compared with the properties of their related homonuclear Mo 4 - and W 4 -oxalate bridged compounds and their respective radical cations. (
  • Mn2+) stimulate the hydrolysis of compounds in which sulfur takes the place of the leaving oxygen. (
  • Two structures of KF bound to a deoxyoligonucleotide that contained a 3'-bridging sulfur at the scissile phosphate were refined at 2.03-A resolution. (
  • Although the bridging sulfur compounds bind in a manner very similar to that of the normal oligonucleotides, the presence of the sulfur changes the metal ion binding properties of the active site such that Mn2+ and Zn2+ are observed at metal ion site B, but Mg2+ is not. (
  • As with the other elements in group 3 - e.g. yttrium , forming organoyttrium compounds - and the lanthanides , the dominant oxidation state for scandium in organometallic compounds is +3 ( electron configuration [Ar] 3d 1 4s 2 ). (
  • Note that scandium has many unique boron compounds, as shown in figure 2, because of the much smaller ionic radius compared with other rare-earth elements. (
  • A self-repairing polyurethane resin material is produced by reaction of a polyisocyanate compound consisting of aliphatic polyisocyanate and/or araliphatic. (
  • aryl = benzene or anthracene) compounds is observed using time-resolved pump-probe laser spectroscopy. (
  • The title compound, C 28 H 52 Si 8 , was synthesized by condensation of two mol-ecules of 1,2,3,4-tetra-kis-(chloro-dimethyl-sil-yl)benzene with lithium. (
  • N.B.: when the compound per se is novel, the medicinal preparation and/or methods of use are not classified in A61K 31/00 in CPC). (
  • Methods: A series of 1-(1H-benzimidazol-2-yl)-3-aryl-2-propen-1-one compounds (6a-z) was. (
  • N-N = pyrazine, 4,4′-bipyridine or Phenazine and X = Cl or Br) with bridging heterocycles have been isolated and their reactions with carbon monoxide, 2,2′-bipyridine and 1,10-phenanthroline investigated. (