Enzymatic synthesis of the sugar esters of hydroxy-aromatic acids.

Abstract

GLUCOSE esters (1-O-acyl derivatives) of hydroxycinnamic acids have recently been shown to be widely distributed among higher plants1. They are also the most common derivatives produced when the free acids are fed to a wide variety of plants even in cases where the species examined contained either a different derivative of the acid in question or no trace of it at all2. In spite of this, however, comparatively little is known of the way in which these glucose esters are synthesized. Although 1-O-anthraniloyl glucose has been shown to be formed from anthranilic acid and uridine diphosphoglucose (UDPG) in the presence of an enzyme preparation from Lens esculentum3 it has been suggested that esters of phenolic acids are more probably synthesized from free glucose and the acyl coenzyme A derivative4. This hypothesis was presumably put forward because it has already been shown that many phenols form O-glucosides with UDPG in the presence of suitable enzyme systems5.