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Pinosylvin
Pinosylvin is an organic compound with the formula C6H5CH=CHC6H3(OH)2. A white solid, it is related to trans-stilbene, but with two hydroxy groups on one of the phenyl substituents. It is very soluble in many organic solvents, such as acetone. Occurrence Pinosylvin is produced in plants in response to fungal infections, ozone-induced stress, and physical damage for example. It is a fungitoxin protecting the wood from fungal infection. It is present in the heartwood of ''Pinaceae'' and also found in '' Gnetum cleistostachyum''. Injected in rats, pinosylvin undergoes rapid glucuronidation and a poor bioavailability. Biosynthesis Pinosylvin synthase, an enzyme, catalyzes the biosynthesis of pinosylvin from malonyl-CoA and cinnamoyl-CoA: :3 malonyl-S-CoA + cinnamoyl-S-CoA → 4 CoA-SH + pinosylvin + 4 CO2 This biosynthesis is noteworthy because plant biosyntheses employing cinnamic acid as a starting point are rare compared to the more common use of ''p''-coumaric acid. Tw ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cinnamoyl-CoA
Cinnamoyl-Coenzyme A is an intermediate in the phenylpropanoids metabolic pathway. Enzymes using Cinnamoyl-Coenzyme A * Cinnamoyl-CoA reductase, an enzyme that catalyzes the chemical reaction cinnamaldehyde + CoA + NADP+ → cinnamoyl-CoA + NADPH + H+ * Pinosylvin synthase, an enzyme that catalyzes the chemical reaction 3 malonyl-CoA + cinnamoyl-CoA → 4 CoA + pinosylvin Pinosylvin is an organic compound with the formula C6H5CH=CHC6H3(OH)2. A white solid, it is related to trans-stilbene, but with two hydroxy groups on one of the phenyl substituents. It is very soluble in many organic solvents, such as acetone. O ... + 4 CO2 * Cinnamoyl-CoA:phenyllactate CoA-transferase, an enzyme that catalyzes the chemical reaction (E)-cinnamoyl-CoA + (R)-phenyllactate → (E)-cinnamate + (R)-phenyllactyl-CoA References Thioesters of coenzyme A Cinnamate esters {{aromatic-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organic Compound
In chemistry, organic compounds are generally any chemical compounds that contain carbon-hydrogen or carbon-carbon bonds. Due to carbon's ability to catenate (form chains with other carbon atoms), millions of organic compounds are known. The study of the properties, reactions, and syntheses of organic compounds comprise the discipline known as organic chemistry. For historical reasons, a few classes of carbon-containing compounds (e.g., carbonate salts and cyanide salts), along with a few other exceptions (e.g., carbon dioxide, hydrogen cyanide), are not classified as organic compounds and are considered inorganic. Other than those just named, little consensus exists among chemists on precisely which carbon-containing compounds are excluded, making any rigorous definition of an organic compound elusive. Although organic compounds make up only a small percentage of Earth's crust, they are of central importance because all known life is based on organic compounds. Liv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bioavailability
In pharmacology, bioavailability is a subcategory of absorption and is the fraction (%) of an administered drug that reaches the systemic circulation. By definition, when a medication is administered intravenously, its bioavailability is 100%. However, when a medication is administered via routes other than intravenous, its bioavailability is generally lower than that of intravenous due to intestinal endothelium absorption and first-pass metabolism. Thereby, mathematically, bioavailability equals the ratio of comparing the area under the plasma drug concentration curve versus time (AUC) for the extravascular formulation to the AUC for the intravascular formulation. AUC is used because AUC is proportional to the dose that has entered the systemic circulation. Bioavailability of a drug is an average value; to take population variability into account, deviation range is shown as ±. To ensure that the drug taker who has poor absorption is dosed appropriately, the bottom value ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cinnamic Acid
Cinnamic acid is an organic compound with the formula C6H5-CH=CH- COOH. It is a white crystalline compound that is slightly soluble in water, and freely soluble in many organic solvents. Classified as an unsaturated carboxylic acid, it occurs naturally in a number of plants. It exists as both a ''cis'' and a ''trans'' isomer, although the latter is more common. Occurrence and production Biosynthesis Cinnamic acid is a central intermediate in the biosynthesis of a myriad of natural products including lignols (precursors to lignin and lignocellulose), flavonoids, isoflavonoids, coumarins, aurones, stilbenes, catechin, and phenylpropanoids. Its biosynthesis involves the action of the enzyme phenylalanine ammonia-lyase (PAL) on phenylalanine. Natural occurrence It is obtained from oil of cinnamon, or from balsams such as storax. It is also found in shea butter. Cinnamic acid has a honey-like odor; it and its more volatile ethyl ester ( ethyl cinnamate) are flavor components in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Malonyl-CoA
Malonyl-CoA is a coenzyme A derivative of malonic acid. Functions It plays a key role in chain elongation in fatty acid biosynthesis and polyketide biosynthesis. Fatty acid biosynthesis Malonyl-CoA provides 2-carbon units to fatty acids and commits them to fatty acid chain synthesis. Malonyl-CoA is formed by carboxylating acetyl-CoA using the enzyme acetyl-CoA carboxylase. One molecule of acetyl-CoA joins with a molecule of bicarbonate,Nelson D, Cox M (2008) ''Lehninger principles of biochemistry''. 5th Ed: p. 806 requiring energy rendered from ATP. Malonyl-CoA is utilised in fatty acid biosynthesis by the enzyme malonyl coenzyme A:acyl carrier protein transacylase (MCAT). MCAT serves to transfer malonate from malonyl-CoA to the terminal thiol of ''holo''- acyl carrier protein (ACP). Polyketide biosynthesis MCAT is also involved in bacterial polyketide biosynthesis. The enzyme MCAT together with an acyl carrier protein (ACP), and a polyketide synthase (PKS) and chain-len ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enzyme
Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products. Almost all metabolic processes in the cell need enzyme catalysis in order to occur at rates fast enough to sustain life. Metabolic pathways depend upon enzymes to catalyze individual steps. The study of enzymes is called ''enzymology'' and the field of pseudoenzyme analysis recognizes that during evolution, some enzymes have lost the ability to carry out biological catalysis, which is often reflected in their amino acid sequences and unusual 'pseudocatalytic' properties. Enzymes are known to catalyze more than 5,000 biochemical reaction types. Other biocatalysts are catalytic RNA molecules, called ribozymes. Enzymes' specificity comes from their unique three-dimensional structures. Like all catalysts, enzymes increase the react ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pinosylvin Synthase
In enzymology, a pinosylvin synthase () is an enzyme that catalyzes the chemical reaction :3 malonyl-CoA + cinnamoyl-CoA \rightleftharpoons 4 CoA + pinosylvin + 4 CO2 Thus, the two substrates of this enzyme are malonyl-CoA and cinnamoyl-CoA, whereas its 3 products are CoA, pinosylvin, and CO2. This enzyme belongs to the family of transferases, specifically those acyltransferases transferring groups other than aminoacyl groups. The systematic name of this enzyme class is malonyl-CoA:cinnamoyl-CoA malonyltransferase (cyclizing). Other names in common use include stilbene synthase, and pine stilbene synthase. This enzyme participates in phenylpropanoid biosynthesis The biosynthesis of phenylpropanoids involves a number of enzymes. From amino acids to cinnamates In plants, all phenylpropanoids are derived from the amino acids phenylalanine and tyrosine. Phenylalanine ammonia-lyase (PAL, a.k.a. phenylalanine/t .... References * EC 2.3.1 Enzymes of unknown structur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glucuronidation
Glucuronidation is often involved in drug metabolism of substances such as drugs, pollutants, bilirubin, androgens, estrogens, mineralocorticoids, glucocorticoids, fatty acid derivatives, retinoids, and bile acids. These linkages involve glycosidic bonds. Mechanism Glucuronidation consists of transfer of the glucuronic acid component of uridine diphosphate glucuronic acid to a substrate by any of several types of UDP-glucuronosyltransferase. UDP-glucuronic acid (glucuronic acid linked via a glycosidic bond to uridine diphosphate) is an intermediate in the process and is formed in the liver. One example is the N-glucuronidation of an aromatic amine, 4-aminobiphenyl, by UGT1A4 or UGT1A9 from human, rat, or mouse liver. : The substances resulting from glucuronidation are known as glucuronides (or glucuronosides) and are typically much more water-soluble than the non-glucuronic acid-containing substances from which they were originally synthesised. The human body uses gl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trans-stilbene
(''E'')-Stilbene, commonly known as ''trans''-stilbene, is an organic compound represented by the condensed structural formula CHCH=CHCH. Classified as a diarylethene, it features a central ethylene moiety with one phenyl group substituent on each end of the carbon–carbon double bond. It has an (''E'') stereochemistry, meaning that the phenyl groups are located on opposite sides of the double bond, the opposite of its geometric isomer, ''cis''-stilbene. ''Trans''-stilbene occurs as a white crystalline solid at room temperature and is highly soluble in organic solvents. It can be converted to ''cis''-stilbene photochemically, and further reacted to produce phenanthrene. Stilbene was discovered in 1843 by the French chemist Auguste Laurent. The name "stilbene" is derived from the Greek word ''στίλβω'' (''stilbo''), which means "I shine", on account of the lustrous appearance of the compound. Isomers Stilbene exists as two possible stereoisomers. One is ''trans ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gnetum Cleistostachyum
''Gnetum cleistostachyum'' is a liana species in the ''Sessiles'' subsection of the genus ''Gnetum'' described from South East Yunnan. The name is still invalid and efloras states it is advisable to postpone validating it until more complete collections, particularly with seeds, can be studied. The stilbene derivatives, gnetucleistol A, B and C, gnetifolin A, p-hydroxycinnamic acid, piceatannol, resveratrol, bisisorhapontigenin A, gnetuhainin P, gnetulin, the stilbenolignans, gnetucleistol F, gnetofuran A, lehmbachol D, gnetifolin F and gnetumontanin, gnetucleistol D (2-methoxyoxyresveratrol), gnetucleistol E (3-methoxy-isorhapontigenin), rhapontigenin, isorhapontigenin, 4-methoxyresveratrol and pinosylvin Pinosylvin is an organic compound with the formula C6H5CH=CHC6H3(OH)2. A white solid, it is related to trans-stilbene, but with two hydroxy groups on one of the phenyl substituents. It is very soluble in many organic solvents, such as acetone. O ... can ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pinaceae
The Pinaceae, or pine family, are conifer trees or shrubs, including many of the well-known conifers of commercial importance such as cedars, firs, hemlocks, larches, pines and spruces. The family is included in the order Pinales, formerly known as Coniferales. Pinaceae are supported as monophyletic by their protein-type sieve cell plastids, pattern of proembryogeny, and lack of bioflavonoids. They are the largest extant conifer family in species diversity, with between 220 and 250 species (depending on taxonomic opinion) in 11 genera, and the second-largest (after Cupressaceae) in geographical range, found in most of the Northern Hemisphere, with the majority of the species in temperate climates, but ranging from subarctic to tropical. The family often forms the dominant component of boreal, coastal, and montane forests. One species, ''Pinus merkusii'', grows just south of the equator in Southeast Asia. Major centres of diversity are found in the mountains of southwest ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
