o-Coumaric acid is a hydroxycinnamic acid, an organic compound that is a hydroxy derivative of cinnamic acid. There are three isomers of coumaric acids — o-coumaric acid, m-coumaric acid, and p-coumaric acid — that differ by the position of the hydroxy substitution of the phenyl group.
Natural occurrence o-Coumaric acid can be found in vinegar. Biosynthesis In some plants such as Melilotus species, o-coumaric acid is produced directly from cinnamic acid by the enzyme trans-cinnamate 2-monooxygenase.
Metabolism 2-Coumarate reductase is an enzyme that converts o-coumaric acid to melilotic acid using reduced nicotinamide adenine dinucleotide (NADH). This enzyme participates in phenylalanine metabolism.
2-coumarate O-beta-glucosyltransferase forms a glucoside by transferring glucose from UDP-glucose:
This occurs in Melilotus alba and gives uridine diphosphate (UDP) as byproduct.
References
External links o-Coumaric acid at www.phenol-explorer.eu