beta-glucosyltransferase in cell cultures of Verbesina caracasana

(E)-3,4-Dimethoxycinnamic acid, inoculated in cell cultures of Verbesina ca racasana, was converted to the corresponding beta-glucopyranoside ester, re vealing the presence of an exoglucosyltransferase. An extensive study on ot her cinnamic acid derivatives showed that the aromatic ring must contain at least one methoxy substituent, but no hydroxy group, for the esterificatio n to be performed. Moreover, the presence of the double bond was shown to h ave no influence. The glucosylation reaction may involve also the hydroxyl of benzyl alcohols, with the same specificity towards the substitution of t he aromatic ring as shown by the cinnamic acids.