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.