Biotransformation of p-, m-, and o-hydroxybenzoic acids by Panax ginseng hairy root cultures

The regioselective glycosylation of three isomers of hydroxybenzoic acids was observed in Panax ginseng hairy root Cultures. p-Hydroxybenzoic acid (1) and in-hydroxybenzoic acid (2) were converted into their corresponding glycosides (1a and 2a) and glycosyl esters (1b and 2b) while no metabolite of o-hydroxybenzoic acid (3) was detected. A new compound, m-hydroxybenzoic acid beta-D-xylopyranosyl (1 -> 6)-beta-D-glycopyranosyl ester (2c) was identified as a biotransformation product of 2. Further time-course Studies of the biotransformation reactions showed that the glycosides were major products in the latter stage. The addition of carbohydrates or antioxidants increased glycosyl esters formation. (c) 2008 Elsevier B.V. All rights reserved.