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Phenylpropanoid Metabolic Pathway
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/tyrosine ammonia-lyase) is an enzyme that transforms L-phenylalanine and tyrosine into trans-cinnamic acid and ''p''-coumaric acid, respectively. Trans-cinnamate 4-monooxygenase (cinnamate 4-hydroxylase) is the enzyme that transforms trans-cinnamate into 4-hydroxycinnamate (''p''-coumaric acid). 4-Coumarate-CoA ligase is the enzyme that transforms 4-coumarate (''p''-coumaric acid) into 4-coumaroyl-CoA. Enzymes associated with biosynthesis of hydroxycinnamic acids * Cinnamyl-alcohol dehydrogenase (CAD), an enzyme that transforms cinnamyl alcohol into cinnamaldehyde * Sinapine esterase, an enzyme that transforms sinapoylcholine into sinapate (sinapic acid) and choline * Trans-cinnamate 2-monooxygenase, an enzyme that transforms trans-ci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biosynthesis
Biosynthesis is a multi-step, enzyme-catalyzed process where substrates are converted into more complex products in living organisms. In biosynthesis, simple compounds are modified, converted into other compounds, or joined to form macromolecules. This process often consists of metabolic pathways. Some of these biosynthetic pathways are located within a single cellular organelle, while others involve enzymes that are located within multiple cellular organelles. Examples of these biosynthetic pathways include the production of lipid membrane components and nucleotides. Biosynthesis is usually synonymous with anabolism. The prerequisite elements for biosynthesis include: precursor compounds, chemical energy (e.g. ATP), and catalytic enzymes which may require coenzymes (e.g.NADH, NADPH). These elements create monomers, the building blocks for macromolecules. Some important biological macromolecules include: proteins, which are composed of amino acid monomers joined via peptide bon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Choline
Choline is an essential nutrient for humans and many other animals. Choline occurs as a cation that forms various salts (X− in the depicted formula is an undefined counteranion). Humans are capable of some ''de novo synthesis'' of choline but require additional choline in the diet to maintain health. Dietary requirements can be met by choline per se or in the form of choline phospholipids, such as phosphatidylcholine. Choline is not formally classified as a vitamin despite being an essential nutrient with an amino acid–like structure and metabolism. In most animals, choline phospholipids are necessary components in cell membranes, in the membranes of cell organelles, and in very low-density lipoproteins. Choline is required to produce acetylcholine – a neurotransmitter – and ''S''-adenosylmethionine (SAM), a universal methyl donor. Upon methylation SAM is transformed into homocysteine. Symptomatic choline deficiency causes non-alcoholic fatty liver disease and muscle dama ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sinapoylglucose—choline O-sinapoyltransferase
In enzymology, a sinapoylglucose---choline O-sinapoyltransferase () is an enzyme that catalysis, catalyzes the chemical reaction :1-O-sinapoyl-beta-D-glucose + choline \rightleftharpoons D-glucose + sinapoylcholine Thus, the two substrate (biochemistry), substrates of this enzyme are 1-O-sinapoyl-beta-D-glucose and choline, whereas its two product (chemistry), products are D-glucose and sinapoylcholine (sinapine). This enzyme belongs to the family of transferases, specifically those acyltransferases transferring groups other than aminoacyl groups. The List of enzymes, systematic name of this enzyme class is 1-O-(4-hydroxy-3,5-dimethoxycinnamoyl)-beta-D-glucose:choline 1-O-(4-hydroxy-3,5-dimethoxycinnamoyl)transferase. This enzyme is also called sinapine synthase. This enzyme participates in phenylpropanoid biosynthesis. References * EC 2.3.1 Enzymes of unknown structure {{2.3-enzyme-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
5-O-(4-coumaroyl)-D-quinate 3'-monooxygenase
In enzymology, a 5-O-(4-coumaroyl)-D-quinate 3'-monooxygenase () is an enzyme that catalyzes the chemical reaction :trans-5-O-(4-coumaroyl)-D-quinate + NADPH + H+ + O2 \rightleftharpoons trans-5-O-caffeoyl-D-quinate + NADP+ + H2O The 4 substrates of this enzyme are trans-5-O-(4-coumaroyl)-D-quinate, NADPH, H+, and O2, whereas its 3 products are trans-5-O-caffeoyl-D-quinate, NADP+, and H2O. This enzyme belongs to the family of oxidoreductases, specifically those acting on paired donors, with O2 as oxidant and incorporation or reduction of oxygen. The oxygen incorporated need not be derived from O2 with NADH or NADPH as one donor, and incorporation of one atom o oxygen into the other donor. The systematic name of this enzyme class is trans-5-O-(4-coumaroyl)-D-quinate,NADPH:oxygen oxidoreductase (3'-hydroxylating). Other names in common use include 5-O-(4-coumaroyl)-D-quinate/shikimate 3'-hydroxylase, and coumaroylquinate(coumaroylshikimate) 3'-monooxygenase. This enzyme p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caffeoyl-CoA O-methyltransferase
In enzymology, a caffeoyl-CoA O-methyltransferase () is an enzyme that catalyzes the chemical reaction :S-adenosyl-L-methionine + caffeoyl-CoA \rightleftharpoons S-adenosyl-L-homocysteine + feruloyl-CoA Thus, the two substrates of this enzyme are S-adenosyl methionine and caffeoyl-CoA, whereas its two products are S-adenosylhomocysteine and feruloyl-CoA. A large number of natural products are generated via a step involving this enzyme.Wout Boerjan, John Ralph, Marie Baucher "Lignin Biosynthesis" Annu. Rev. Plant Biol. 2003, vol. 54, pp. 519–46. This enzyme is classified to the family of transferases, specifically those transferring one-carbon group methyltransferases. The systematic name of this enzyme class is S-adenosyl-L-methionine:caffeoyl-CoA 3-O-methyltransferase. Other names in common use include caffeoyl coenzyme A methyltransferase, caffeoyl-CoA 3-O-methyltransferase, and trans-caffeoyl-CoA 3-O-methyltransferase. This enzyme participates in phenylpropanoid biosynthe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ferulic Acid
Ferulic acid is a hydroxycinnamic acid, an organic compound with the formula (CH3O)HOC6H3CH=CHCO2H. The name is derived from the genus ''Ferula'', referring to the giant fennel (''Ferula communis''). Classified as a phenolic phytochemical, ferulic acid is an amber colored solid. Esters of ferulic acid are found in plant cell walls, covalently bonded to hemicellulose such as arabinoxylans. Occurrence in nature As a building block of lignocelluloses, such as pectin and lignin, ferulic acid is ubiquitous in the plant kingdom, including a number of vegetable sources. It occurs in particularly high concentrations in popcorn and bamboo shoots. It is a major metabolite of chlorogenic acids in humans along with caffeic and isoferulic acid, and is absorbed in the small intestine, whereas other metabolites such as dihydroferulic acid, feruloylglycine and dihydroferulic acid sulfate are produced from chlorogenic acid in the large intestine by the action of gut flora. In cereals, f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caffeic Acid
Caffeic acid is an organic compound that is classified as a hydroxycinnamic acid. This yellow solid consists of both phenolic and acrylic functional groups. It is found in all plants because it is an intermediate in the biosynthesis of lignin, one of the principal components of woody plant biomass and its residues. Natural occurrences Caffeic acid can be found in the bark of ''Eucalyptus globulus'' the barley grain ''Hordeum vulgare'' and the herb ''Dipsacus asperoides''. It can also be found in the freshwater fern ''Salvinia molesta'' and in the mushroom ''Phellinus linteus''. Occurrences in food Free caffeic acid can be found in a variety of beverages, including brewed coffee at 0.13 mg per 100 ml and red wine at 2 mg per 100 ml. It is found at relatively high levels in herbs of the mint family, especially thyme, sage and spearmint (at about 20 mg per 100 g), and in spices, such as Ceylon cinnamon and star anise (at about 22 mg per 100 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
