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.
Class
Metabolism; Biosynthesis of other secondary metabolites
Halbwirth H, Martens S, Wienand U, Forkmann G, Stich K.
Title
Synthesis of (14C)-labeled 5-deoxyflavonoids and their application in the study of dihydroflavonol/leucoanthocyanidin interconversion by dihydroflavonol 4-reductase.
Shimada N, Aoki T, Sato S, Nakamura Y, Tabata S, Ayabe S.
Title
A cluster of genes encodes the two types of chalcone isomerase involved in the biosynthesis of general flavonoids and legume-specific 5-deoxy(iso)flavonoids in Lotus japonicus.
Flavanone Glycoside Biosynthesis in Citrus: Chalcone Synthase, UDP-Glucose:Flavanone-7-O-Glucosyl-Transferase and -Rhamnosyl-Transferase Activities in Cell-Free Extracts.