In plants, all phenylpropanoids are derived from the amino acids phenylalanine and tyrosine.
4-Coumarate-CoA ligase is the enzyme that transforms 4-coumarate (p-coumaric acid) into 4-coumaroyl-CoA.
An alternative bacterial ketosynthase-directed stilbenoids biosynthesis pathway exists in Photorhabdus bacterial symbionts of Heterorhabditis nematodes, producing 3,5-dihydroxy-4-isopropyl-trans-stilbene for antibiotic purposes.
[2] 4-Coumaroyl-CoA can be combined with malonyl-CoA to yield the true backbone of flavonoids, a group of compounds called chalconoids, which contain two phenyl rings.
Naringenin-chalcone synthase is an enzyme that catalyzes the following conversion: Conjugate ring-closure of chalcones results in the familiar form of flavonoids, the three-ringed structure of a flavone.