1-O-TRANS-CINNAMOYL-BETA-D-GLUCOPYRANOSE - ALCOHOL CINNAMOYLTRANSFERASE ACTIVITY IN FRUITS OF CAPE GOOSEBERRY (PHYSALIS-PERUVIANA L.)

Methyl and ethyl cinnamate are aroma volatiles frequently occurring in fruits. Evidence was obtained that the enzymatic transfer of cinnamic acid to endogenous alcohols present in fruits (methanol, ethanol, 1-p ropanol) depended on energy-rich 1-O-glycosyl esters of cinnamic acid which served as acyl donor molecules. A putative 1-O-trans-cinnamoyl-b eta-D-glucopyranose: alcohol cinnamoyltransferase from cape gooseberry (Physalis peruviana L.) was active towards 1-O-trans-cinnamoyl-beta-D -glucopyranose and 1-O-trans-cinnamoyl-beta-D-gentiobiose. The enzyme was purified 290-fold by a protocol including ammonium sulphate precip itation. solubilization by Triton X-100, gel permeation and affinity c hromatography on concanavalin A. The acidic glycoprotein (pI = 4.8) mo st probably is membrane bound. The distribution of alcohol cinnamoyltr ansferase activity in gel chromatography fractions suggests a native M -r of 75,000. For 1-O-trans-cinnamoyl-beta-D-glucopyranose, an apparen t K-m of 69 mu M was determined. At pH > 6.0, non-enzymatic transester ification superposes the enzymatic transformation.