Biosynthetic Pathways of Gallic Acid

Abstract

In this review, the gallic acid content of tea leaves is described, and the potential biosynthetic pathways of the acid and the enzymes involved in these pathways are illustrated. Three pathways have been proposed as follows: (a) β-oxydation of 3,4,5-trihydroxycinnamic acid, (b) hydroxylation of protocatechuic acid, and (c) dehydrogenation of 3-dehydroshikimic acid. Of these three pathways, the last one is currently considered to be the most probable pathway of gallic acid synthesis.