Purpose. In a continuation of our search for novel antifungal compounds from higher plants, the standard extract of the bark of Pithecellobium racemosum was found to have good activity against important AIDS-related opportunistic yeasts. Methods. The extract was subjected to bioguided fractionation using silica gel column chromatography which led to purification of triterpene glycosides. The structures of these compounds were determined by a combination of spectroscopic (IR, NMR, HRMS) and chemical methods. Results. Compound 1 is a new glycoside, 3-O[α-L-arabinopyranosyl (1-2)][α-L arabinopyranosyl (1-6)]2-acetoamido-2-deoxy-β-D-glucopyranosyl oleanolic acid and Compound 2 was identified as the known compound 3-O-[α-L-arabinopyranosyl(1-2)α-L-arabinopyranoysl (1-6)] 2-acetamido-2-deoxy-β-D-glucopyranosyl echinocystic acid. Conclusions. Compound 1 is a new glycoside, 3-O-[α-L-arabinopyranosyl (1-2)]α-L-arabinopyranosyl (1-6)]-2-acetoamido-2-deoxy-β-D-glucopyranosyl oleanolic acid and exhibits moderate antifungal activity against T. mentogrophytes, C. albicans and S. cerevisiae with MIC values of 6.25, 12.5 and 12.5 mu g/ml respectively.
antifungal, triterpene glycoside, oleanolic acid, Pithecellobium racemosum, carbon-13C NMR
NCBI PubMed ID: 9098881Publication DOI: 10.1023/A:1012010407824Journal NLM ID: 8406521Publisher: New York, NY: Kluwer Academic/Plenum Publishers
Institutions: National Center for Development of Natural Products, School of Pharmacy, University of Mississippi 38677, USA
Methods: 13C NMR, 1H NMR, IR, FAB-MS, GC-MS, sugar analysis, TLC, GC, chemical methods, biological assays, extraction
Found