| map01110 |
Biosynthesis of secondary metabolites |
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| map01100 |
Metabolic pathways |
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| map00945 |
Stilbenoid, diarylheptanoid and gingerol biosynthesis |
Stilbenoids are a group of phenolic compounds, biosynthetically interrelated through their common origin from a C6-C2-C6 intermediate, such as resveratol found in grapes. Stilbenoids can also exist as glycosides (e.g., piceid). Combretastatins are potentially useful stilbenoid natural products with known antitumor activity. Diarylheptanoid is a compound group having phenyl rings at 1,7 positions of n-heptane (C6-C7-C6), such as curcumin found in the ginger family. [6]-Gingerol is a major active component of ginger and has diverse pharmacologic effects. |
| map00941 |
Flavonoid biosynthesis |
Flavonoids are a major class of plant secondary metabolites that serves a multitude of functions including pigments and antioxidant activity. Flavonoids are synthesized from phenylpropanoid derivatives by condensation with malonyl-CoA. For example, condensation of p-coumaroyl-CoA (C6-C3) with three malonyl-CoA (C3) molecules results in naringenin chalcone with a diphenylpropane (C6-C3-C6) unit, which is converted to naringenin with the flavone (2-phenylchromen-4-one) backbone by conjugate ring closure. These and further modifications yield a variety of structural forms including chalcones, flavanones, dihyroflavonols, and flavans, anthocyanins, flavones and flavonols, and isoflavonoids. |
| map00940 |
Phenylpropanoid biosynthesis |
Phenylpropanoids are a group of plant secondary metabolites derived from phenylalanine and having a wide variety of functions both as structural and signaling molecules. Phenylalanine is first converted to cinnamic acid by deamination. It is followed by hydroxylation and frequent methylation to generate coumaric acid and other acids with a phenylpropane (C6-C3) unit. Reduction of the CoA-activated carboxyl groups of these acids results in the corresponding aldehydes and alcohols. The alcohols are called monolignols, the starting compounds for biosynthesis of lignin. |
| map00130 |
Ubiquinone and other terpenoid-quinone biosynthesis |
Ubiquinone (UQ), also called coenzyme Q, and plastoquinone (PQ) are electron carriers in oxidative phosphorylation and photosynthesis, respectively. The quinoid nucleus of ubiquinone is derived from the shikimate pathway; 4-hydroxybenzoate is directly formed from chorismate in bacteria, while it can be formed from either chorismate or tyrosine in yeast. The following biosynthesis of terpenoid moiety involves reactions of prenylation, decarboxylation, and three hydroxylations alternating with three methylations. The order of these reactions are somewhat different between bacteria and yeast. Phylloquinone (vitamin K1), menaquinone (vitamin K2), and tocopherol (vitamin E) are fat-soluble vitamins. Phylloquinone is a compound present in all photosynthetic plants serving as a cofactor for photosystem I-mediated electron transport. Menaquinone is an obligatory component of the electron-transfer pathway in bacteria. |
