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Oxepine
Oxepin is an oxygen-containing heterocycle consisting of a seven-membered ring with three double bonds. The parent C6H6O exists as an equilibrium mixture with benzene oxide. The oxepin–benzene oxide equilibrium is affected by the ring substituents. A related dimethyl derivative exists mainly as the oxepin isomer, an orange liquid. Oxepin is an intermediate in the oxidation of benzene by the cytochrome P450 (CYP). Other arene oxide In chemistry, an arene oxide is an epoxide of an arene. Two important families of arene oxides are benzene oxides and naphthalene oxides as these are intermediates in the oxidative degradation of benzene and naphthalene, two common pollutants. B ...s are metabolites of the parent arene. References {{Reflist ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyclohexene Oxide
Cyclohexene oxide is a cycloaliphatic epoxide. It can react in cationic polymerization to poly(cyclohexene oxide). As cyclohexene is monovalent, poly(cyclohexene oxide) is a thermoplastic. Production Cyclohexene oxide is produced in epoxidation reaction from cyclohexene. The epoxidation can take place either in a homogeneous reaction by peracids or heterogeneous catalysis (e.g. silver and molecular oxygen). :250px In industrial production the heterogeneously catalyzed synthesis is preferred because of better atom economy, a simpler separation of the product and easier recycling of catalyst. A short overview and an investigation of the oxidation of cyclohexene by hydrogen peroxide is given in the literature. In recent times the catalytic oxidation of cyclohexene by (immobilized) metalloporphyrin complexes has been found to be an efficient way. In laboratory, cyclohexene oxide can also be prepared by reacting cyclohexene with magnesium monoperoxyphthalate (MMPP) in a mixture o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxygen
Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as well as with other compounds. Oxygen is Earth's most abundant element, and after hydrogen and helium, it is the third-most abundant element in the universe. At standard temperature and pressure, two atoms of the element bind to form dioxygen, a colorless and odorless diatomic gas with the formula . Diatomic oxygen gas currently constitutes 20.95% of the Earth's atmosphere, though this has changed considerably over long periods of time. Oxygen makes up almost half of the Earth's crust in the form of oxides.Atkins, P.; Jones, L.; Laverman, L. (2016).''Chemical Principles'', 7th edition. Freeman. Many major classes of organic molecules in living organisms contain oxygen atoms, such as proteins, nucleic acids, carbohydrates, and fats, as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heterocycle
A heterocyclic compound or ring structure is a cyclic compound that has atoms of at least two different chemical element, elements as members of its ring(s). Heterocyclic chemistry is the branch of organic chemistry dealing with the synthesis, properties, and applications of these heterocycles. Examples of heterocyclic compounds include all of the nucleic acids, the majority of drugs, most biomass (cellulose and related materials), and many natural and synthetic dyes. More than half of known compounds are heterocycles. 59% of US FDA-approved drugs contain nitrogen heterocycles. Classification The study of heterocyclic chemistry focuses especially on unsaturated derivatives, and the preponderance of work and applications involves unstrained 5- and 6-membered rings. Included are pyridine, thiophene, pyrrole, and furan. Another large class of heterocycles refers to those fused to benzene rings. For example, the fused benzene derivatives of pyridine, thiophene, pyrrole, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ring (chemistry)
In chemistry, a ring is an ambiguous term referring either to a simple cycle of atoms and bonds in a molecule or to a connected set of atoms and bonds in which every atom and bond is a member of a cycle (also called a ring system). A ring system that is a simple cycle is called a monocycle or simple ring, and one that is not a simple cycle is called a polycycle or polycyclic ring system. A simple ring contains the same number of sigma bonds as atoms, and a polycyclic ring system contains more sigma bonds than atoms. A molecule containing one or more rings is called a cyclic compound, and a molecule containing two or more rings (either in the same or different ring systems) is termed a polycyclic compound. A molecule containing no rings is called an acyclic or open-chain compound. Homocyclic and heterocyclic rings A homocycle or homocyclic ring is a ring in which all atoms are of the same chemical element. A heterocycle or heterocyclic ring is a ring containing atoms of at least ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Double Bond
In chemistry, a double bond is a covalent bond between two atoms involving four bonding electrons as opposed to two in a single bond. Double bonds occur most commonly between two carbon atoms, for example in alkenes. Many double bonds exist between two different elements: for example, in a carbonyl group between a carbon atom and an oxygen atom. Other common double bonds are found in azo compounds (N=N), imines (C=N), and sulfoxides (S=O). In a skeletal formula, a double bond is drawn as two parallel lines (=) between the two connected atoms; typographically, the equals sign is used for this. Double bonds were first introduced in chemical notation by Russian chemist Alexander Butlerov. Double bonds involving carbon are stronger and shorter than single bonds. The bond order is two. Double bonds are also electron-rich, which makes them potentially more reactive in the presence of a strong electron acceptor (as in addition reactions of the halogens). File:Ethene structural.svg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemical Equilibrium
In a chemical reaction, chemical equilibrium is the state in which both the reactants and products are present in concentrations which have no further tendency to change with time, so that there is no observable change in the properties of the system. This state results when the forward reaction proceeds at the same rate as the reverse reaction. The reaction rates of the forward and backward reactions are generally not zero, but they are equal. Thus, there are no net changes in the concentrations of the reactants and products. Such a state is known as dynamic equilibrium. Historical introduction The concept of chemical equilibrium was developed in 1803, after Berthollet found that some chemical reactions are reversible. For any reaction mixture to exist at equilibrium, the rates of the forward and backward (reverse) reactions must be equal. In the following chemical equation, arrows point both ways to indicate equilibrium. A and B are reactant chemical species, S and T are p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Substituent
A substituent is one or a group of atoms that replaces (one or more) atoms, thereby becoming a moiety in the resultant (new) molecule. (In organic chemistry and biochemistry, the terms ''substituent'' and ''functional group'', as well as ''side chain'' and '' pendant group'', are used almost interchangeably to describe those branches from the parent structure, though certain distinctions are made in polymer chemistry. In polymers, side chains extend from the backbone structure. In proteins, side chains are attached to the alpha carbon atoms of the amino acid backbone.) The suffix ''-yl'' is used when naming organic compounds that contain a single bond replacing one hydrogen; ''-ylidene'' and ''-ylidyne'' are used with double bonds and triple bonds, respectively. In addition, when naming hydrocarbons that contain a substituent, positional numbers are used to indicate which carbon atom the substituent attaches to when such information is needed to distinguish between isomers. Su ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Benzene
Benzene is an organic chemical compound with the molecular formula C6H6. The benzene molecule is composed of six carbon atoms joined in a planar ring with one hydrogen atom attached to each. Because it contains only carbon and hydrogen atoms, benzene is classed as a hydrocarbon. Benzene is a natural constituent of petroleum and is one of the elementary petrochemicals. Due to the cyclic continuous pi bonds between the carbon atoms, benzene is classed as an aromatic hydrocarbon. Benzene is a colorless and highly flammable liquid with a sweet smell, and is partially responsible for the aroma of gasoline. It is used primarily as a precursor to the manufacture of chemicals with more complex structure, such as ethylbenzene and cumene, of which billions of kilograms are produced annually. Although benzene is a major industrial chemical, it finds limited use in consumer items because of its toxicity. History Discovery The word "''benzene''" derives from "''gum benzoin''" (benzoin res ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cytochrome P450
Cytochromes P450 (CYPs) are a Protein superfamily, superfamily of enzymes containing heme as a cofactor (biochemistry), cofactor that functions as monooxygenases. In mammals, these proteins oxidize steroids, fatty acids, and xenobiotics, and are important for the clearance (pharmacology), clearance of various compounds, as well as for hormone synthesis and breakdown. In 1963, Ronald W. Estabrook, Estabrook, David Y. Cooper, Cooper, and Otto Rosenthal, Rosenthal described the role of CYP as a catalyst in steroid hormone synthesis and drug metabolism. In plants, these proteins are important for the biosynthesis of secondary metabolite, defensive compounds, fatty acids, and hormones. CYP enzymes have been identified in all kingdom (biology), kingdoms of life: animals, plants, fungus, fungi, protists, bacteria, and archaea, as well as in viruses. However, they are not omnipresent; for example, they have not been found in ''Escherichia coli''. , more than 300,000 distinct CYP proteins ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arene Oxide
In chemistry, an arene oxide is an epoxide of an arene. Two important families of arene oxides are benzene oxides and naphthalene oxides as these are intermediates in the oxidative degradation of benzene and naphthalene, two common pollutants. Benzopyrene is also converted to an epoxide, (+)-benzo yrene-7,8-epoxide. Selected reactions Benzene oxide (C6H6O) exists as an equilibrium mixture with the seven-membered ring oxepin, which has three double bonds. They are valence isomers and in equilibrium via disrotatory 6π ring closing and opening. Arene oxides are highly reactive. Benzene oxide and naphthalene-1,2-oxide hydrate to give dihydroxydihydrobenzene and 1,2-dihydroxydihydronaphthalene, respectively. The hydration is catalyzed by epoxide hydrolase Epoxide hydrolases (EH's), also known as epoxide hydratases, are enzymes that metabolize compounds that contain an epoxide residue; they convert this residue to two hydroxyl residues through an epoxide hydrolysis reaction ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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