Main Reaction: trans-Cinnamic acid >> p-Coumaric acid

Reference: PubMed ID: 19342120
Authors: Sircar D, Mitra A
Title: Accumulation of p-hydroxybenzoic acid in hairy roots of Daucus carota 2: confirming biosynthetic steps through feeding of inhibitors and precursors.
Published: 2009 Sep 1

trans-Cinnamic acid --> p-Coumaric acid