ANTIFUNGAL ACTIVITY OF A NEW TRITERPENOID GLYCOSIDE FROM PITHECELLOBIUM-RACEMOSUM (M)

Purpose. In a continuation of our search for novel antifungal compound s from higher plants, the standard extract of the bark of Pithecellobi um racemosum was found to have good activity against important AIDS-re lated opportunistic yeasts. Methods. The extract was subjected to biog uided fractionation using silica gel column chromatography which led t o purification of triterpene glycosides. The structures of these compo unds were determined by a combination of spectroscopic (IR, NMR, HRMS) and chemical methods. Results. Compound 1 is a new glycoside, 3-O[alp ha-L-arabinopyranosyl (1-2)][alpha-L arabinopyranosyl (1-6)]2-acetoami do-2-deoxy-beta-D-glucopyranosyl oleanolic acid and Compound 2 was ide ntified as the known compound ha-L-arabinopyranosyl(1-2)alpha-L-arabin opyranoysl (1-6)] 2-acetamido-2-deoxy-beta-D-glucopyranosyl echinocyst ic acid. Conclusions. Compound 1 is a new glycoside, 3-O-[alpha-L-arab inopyranosyl (1-2)]alpha-L-arabinopyranosyl (1-6)]-2-acetoamido-2-deox y-beta-D-glucopyranosyl oleanolic acid and exhibits moderate antifunga l activity against T. mentogrophytes, C. albicans and S. cerevisiae wi th MIC values of 6.25, 12.5 and 12.5 mu g/ml respectively.