Elatumic Acid: A New Ursolic Acid Congener from Omphalocarpum elatum Miers (Sapotaceae)

A new triterpene diastereomer, 1, of the previously reported 3 beta,6 beta,19 alpha-trihydroxy-urs-12-en-28-oic acid-24-carboxylic acid methyl ester was obtained from the stem bark of Omphalocarpum elatum Miers (Sapotaceae) along with alpha-amyrin acetate (2), spinasterol (3), spinasterol 3-O-beta-D-glucopyranoside (4), and tormentic acid (5). The structures of the isolates were established on the basis of NMR and mass spectrometric data and by comparison with those previously reported in the literature. Compound 1 showed weak antibacterial activity against E. aerogenes ATCC13048 and EA3, K pneumoniae ATCC29916, and P. aeruginosa; it also displayed moderate cytotoxicity against CCRF-CEM, CEM/ADR5000, and MDA-MB231 cells.