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Coronaric Acid
Coronaric acid (leukotoxin or leukotoxin A) is a mono-unsaturated, epoxide derivative of the di-unsaturated fatty acid, linoleic acid (i.e. 9(''Z''),12(''Z'') octadecadienoic acid). It is a mixture of the two optically active isomers of 12(''Z'') 9,10-epoxy-octadecenoic acid. This mixture is also termed 9,10-epoxy-12Z-octadecenoic acid or 9(10)-EpOME (for Epoxy-Octadeca-MonoEnoic acid) and when formed by or studied in mammalians, leukotoxin. Occurrence Coronaric acid is found in the seed oils derived from plants in the sunflower family, such as ''Helianthus annuus'' and ''Xeranthemum annuum''. Coronaric acid is also formed by the cells and tissues of various mammalian (including human) species through the metabolism of linoleic acid by cytochrome P450 (CYP) epoxygenase enzymes. These CYPs (CYP2C9 and probably other CYPs that metabolize polyunsaturated fatty acids to epoxides) metabolize linoleic acid to 9''S'',10''R''-epoxy-12(''Z'')-octadecenoic acid and 9''R'',10''S''-epoxy-12 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epoxide
In organic chemistry, an epoxide is a cyclic ether, where the ether forms a three-atom ring: two atoms of carbon and one atom of oxygen. This triangular structure has substantial ring strain, making epoxides highly reactive, more so than other ethers. They are produced on a large scale for many applications. In general, low molecular weight epoxides are colourless and nonpolar, and often volatile. Nomenclature A compound containing the epoxide functional group can be called an epoxy, epoxide, oxirane, and ethoxyline. Simple epoxides are often referred to as oxides. Thus, the epoxide of ethylene (C2H4) is ethylene oxide (C2H4O). Many compounds have trivial names; for instance, ethylene oxide is called "oxirane". Some names emphasize the presence of the epoxide functional group, as in the compound ''1,2-epoxyheptane'', which can also be called ''1,2-heptene oxide''. A polymer formed from epoxide precursors is called an ''epoxy''. However, few if any of the epoxy groups i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Linoleic Acid
Linoleic acid (LA) is an organic compound with the formula . Both alkene groups () are ''cis''. It is a fatty acid sometimes denoted 18:2 (n−6) or 18:2 ''cis''-9,12. A linoleate is a salt or ester of this acid. Linoleic acid is a polyunsaturated, omega−6 fatty acid. It is a colorless liquid that is virtually insoluble in water but soluble in many organic solvents. It typically occurs in nature as a triglyceride (ester of glycerin) rather than as a free fatty acid. It is one of two essential fatty acids for humans, who must obtain it through their diet, and the most essential, because the body uses it as a base to make the others. The word "linoleic" derives , reflecting the fact that it was first isolated from linseed oil. History In 1844, F. Sacc, working at the laboratory of Justus von Liebig Justus ''Freiherr'' von Liebig (12 May 1803 – 18 April 1873) was a Germans, German scientist who made major contributions to the theory, practice, and pedagogy of che ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isomers
In chemistry, isomers are molecules or polyatomic ions with identical molecular formula – that is, the same number of atoms of each element – but distinct arrangements of atoms in space. ''Isomerism'' refers to the existence or possibility of isomers. Isomers do not necessarily share similar chemical or physical properties. Two main forms of isomerism are structural (or constitutional) isomerism, in which '' bonds'' between the atoms differ; and stereoisomerism (or spatial isomerism), in which the bonds are the same but the ''relative positions'' of the atoms differ. Isomeric relationships form a hierarchy. Two chemicals might be the same constitutional isomer, but upon deeper analysis be stereoisomers of each other. Two molecules that are the same stereoisomer as each other might be in different conformational forms or be different isotopologues. The depth of analysis depends on the field of study or the chemical and physical properties of interest. The English word ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sunflower
The common sunflower (''Helianthus annuus'') is a species of large annual forb of the daisy family Asteraceae. The common sunflower is harvested for its edible oily seeds, which are often eaten as a snack food. They are also used in the production of cooking oil, as food for livestock, as bird food, and as plantings in domestic gardens for aesthetics. Wild plants are known for their multiple flower heads, whereas the domestic sunflower often possesses a single large flower head atop an unbranched stem. Description The plant has an erect rough-hairy stem, reaching typical heights of . The tallest sunflower on record achieved . Sunflower leaves are broad, coarsely toothed, rough and mostly alternate; those near the bottom are largest and commonly heart-shaped. Flower The plant flowers in summer. What is often called the " flower" of the sunflower is actually a "flower head" ( pseudanthium), wide, of numerous small individual five-petaled flowers (" florets"). The out ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cytochrome P450
Cytochromes P450 (P450s or CYPs) are a Protein superfamily, superfamily of enzymes containing heme as a cofactor (biochemistry), cofactor that mostly, but not exclusively, function as monooxygenases. However, they are not omnipresent; for example, they have not been found in ''Escherichia coli''. In mammals, these enzymes oxidize steroids, fatty acids, xenobiotics, and participate in many biosyntheses. By hydroxylation, CYP450 enzymes convert xenobiotics into hydrophilic derivatives, which are more readily excreted. P450s are, in general, the terminal oxidase enzymes in electron transfer chains, broadly categorized as P450-containing systems. The term "P450" is derived from the spectrophotometry, spectrophotometric peak at the wavelength of the absorption spectroscopy, absorption maximum of the enzyme (450 nanometre, nm) when it is in the redox, reduced state and complexed with carbon monoxide. Most P450s require a protein partner to deliver one or more electrons to reduc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epoxygenase
Epoxygenases are a set of membrane-bound, heme-containing cytochrome P450 (CYP450 or just CYP) enzymes that metabolize polyunsaturated fatty acids (PUFAs) to epoxide products that have a range of biological activities. The most thoroughly-studied substrate of the CYP epoxygenases is the PUFA arachidonic acid (AA). Eicosanoids are created from AA in three pathways: # Cyclooxygenases metabolize AA to various prostaglandin, thromboxane, and prostacyclin metabolites. # Lipoxygenases metabolize AA to hydroxyeicosatetraenoic acids (e.g. 5-HETE or 12-HETE) and leukotrienes (e.g. leukotriene B4 or leukotriene C4). # CYP epoxygenases metabolize AA to epoxyeicosatrienoic acids (EETs). Like the first two pathways, the third acts as a signaling pathway wherein the eicosatrienoic acid epoxide products work as secondary signals to activate their parent or nearby cells and thereby orchestrate functional responses. However, these enzymes are not limited to metabolizing AA to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polyunsaturated Fatty Acids
In biochemistry and nutrition, a polyunsaturated fat is a fat that contains a polyunsaturated fatty acid (abbreviated PUFA), which is a subclass of fatty acid characterized by a backbone with two or more carbon–carbon double bonds. Some polyunsaturated fatty acids are essentials. Polyunsaturated fatty acids are precursors to and are derived from polyunsaturated fats, which include drying oils. Nomenclature The position of the carbon-carbon double bonds in carboxylic acid chains in fats is designated by Greek letters. The carbon atom closest to the carboxyl group is the ''alpha'' carbon, the next carbon is the ''beta'' carbon and so on. In fatty acids the carbon atom of the methyl group at the end of the hydrocarbon chain is called the ''omega'' carbon because ''omega'' is the last letter of the Greek alphabet. Omega-3 fatty acids have a double bond three carbons away from the methyl carbon, whereas omega-6 fatty acids have a double bond six carbons away from the methyl ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Optical Isomers
In chemistry, a molecule or ion is called chiral () if it cannot be superposed on its mirror image by any combination of rotations, translations, and some conformational changes. This geometric property is called chirality (). The terms are derived from Ancient Greek (''cheir'') 'hand'; which is the canonical example of an object with this property. A chiral molecule or ion exists in two stereoisomers that are mirror images of each other, called enantiomers; they are often distinguished as either "right-handed" or "left-handed" by their absolute configuration or some other criterion. The two enantiomers have the same chemical properties, except when reacting with other chiral compounds. They also have the same physical properties, except that they often have opposite optical activities. A homogeneous mixture of the two enantiomers in equal parts is said to be racemic, and it usually differs chemically and physically from the pure enantiomers. Chiral molecules will usua ... [...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 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] |
Vernolic Acid
Vernolic acid (leukotoxin B or isoleukotoxin) is a long chain fatty acid that is monounsaturated and contains an epoxide. It is a ''cis'' epoxide derived from the C12–C13 alkene of linoleic acid. Vernolic acid was first definitively characterized in 1954 and its absolute configuration determined in 1966. It is a major component in vernonia oil, which is produced in abundance by the genera '' Vernonia'' and ''Euphorbia'' and is a potentially useful biofeedstock. Occurrence Vernonia oil is extracted from the seeds of the '' Vernonia galamensis'' (ironweed), a plant native to eastern Africa. The seeds contain about 40 to 42% oil of which 73 to 80% is vernolic acid. The best varieties of ''V. anthelmintica'' contain about 30% less vernolic acid. Vernolic acid is not commonly found in plants in significant quantities, but some plants which do contain it are '' Vernonia'', '' Stokesia'', '' Crepis'' (from the daisy family), and '' Euphorbia lagascae'' and '' Bernardia pulchella ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Autoxidation
Autoxidation (sometimes auto-oxidation) refers to oxidations brought about by reactions with oxygen at normal temperatures, without the intervention of flame or electric spark. The term is usually used to describe the gradual degradation of organic compounds in air at ambient temperatures. Many common phenomena can be attributed to autoxidation, such as food going rancid, the ' drying' of varnishes and paints, and the perishing of rubber. It is also an important concept in both industrial chemistry and biology. Autoxidation is therefore a fairly broad term and can encompass examples of photooxygenation and catalytic oxidation. The common mechanism is a free radical chain reaction, where the addition of oxygen gives rise to hydroperoxides and their associated peroxy radicals (ROO•). Typically, an induction period is seen at the start where there is little activity; this is followed by a gradually accelerating take-up of oxygen, giving an autocatalytic reaction which can on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stereoisomer
In stereochemistry, stereoisomerism, or spatial isomerism, is a form of isomerism in which molecules have the same molecular formula and sequence of bonded atoms (constitution), but differ in the three-dimensional orientations of their atoms in space. This contrasts with structural isomers, which share the same molecular formula, but the bond connections or their order differs. By definition, molecules that are stereoisomers of each other represent the same structural isomer. Enantiomers Enantiomers, also known as optical isomers, are two stereoisomers that are related to each other by a reflection: they are mirror images of each other that are non-superposable. Human hands are a macroscopic analog of this. Every stereogenic center in one has the opposite configuration in the other. Two compounds that are enantiomers of each other have the same physical properties, except for the direction in which they rotate polarized light and how they interact with different enantiomers of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
