New triterpene glycosides from the stems of Anomospermum grandifolium

Two new dammarane saponins identified as jujubogenin 3-O-alpha-l-arabinofuranosyl(1-->2)-[beta-d-glucopyranosyl(1-->6) beta-d-glucopyranosyl(1-->3)]-alpha-l-arabinopyranoside (2) and jujubogenin 3-O-alpha-l-arabinofuranosyl(1-->2)-[6-O-[3-hydroxy-3-methylglutaryl]-beta-d-glucopyranosyl(1-->3)]-alpha-l-arabinopyranoside (3) and a new lupane saponin, 3beta-hydroxylup-20(29)-en-27,28-dioic acid 28-O-beta-d-glucopyranosyl(1-->2)-[beta-d-xylopyranosyl(1-->3)]-beta-d-xylopyranosyl(1-->2)-beta-d-glucopyranoside ester (5), along with the known jujubogenin 3-O-alpha-l-arabinofuranosyl(1-->2)-[beta-d-glucopyranosyl(1-->3)]-alpha-l-arabinopyranoside (1) and 3beta-hydroxylup-20(29)-ene-27,28-dioic acid (4), were isolated from the methanol extract of the stems of Anomospermum grandifolium. The structures of the new compounds were established by spectral analysis. Antimicrobial activity screening of compounds 1-3 revealed antifungal properties against C. albicans ATCC 3153 for compounds 2 and 3. The antibacterial and antifungal activities of the petroleum ether, chloroform, and methanol extracts of A. grandifolium stems were also evaluated.