Studies on Chlorogenic Acid Biosynthesis in Sweet Potato Root Tissue in Special Reference to the Isolation of a Chlorogenic Acid Intermediate

Open Access
Publisher Website
Google Scholar
Abstract
Marked polyphenol production takes place in root tissue of sweet potato, Ipomoea batatas Lam. cv. Norin 1, in response to slicing. A possible intermediate, tentatively termed compound V, of chlorogenic acid biosynthesis was isolated from the root tissue administrated with t-cinnamic acid-2-14C. Compound V was proved to be an ester whose acid moiety was t-cinnamic acid, and the hydroxyl group-bearing moiety appeared to be a carbohydrate. Compound V was suggested to be the first intermediate after t-cinnamic acid involved in the chlorogenic acid biosynthetic pathway by the following three results. (a) label of t-cinnamic acid-2-14C was distributed in compound V first, then transferred to chlorogenic acid and isochlorogenic acid, isomers of dicaffeoylquinic acid; (b) specific radioactivity of compound V increased prior to that of the fraction containing chlorogenic acid and isochlorogenic acids and decreased prior to that of the latter; and (c) label of compound V was efficiently incorporated into chlorogenic acid and isochlorogenic acid.