Cytotoxic oleanane-type saponins from Albizia inundata.

ABSTRACT: Bioassay-guided fractionation of a CH(2)Cl(2)-MeOH extract of the aerial parts of Albizia inundata resulted in the isolation of two new natural oleanane-type triterpene saponins {3-O-[?-L-arabinopyranosyl(1?6)]-2-acetamido-2-deoxy-?-D-glucopyranosyl oleanolic acid (1) and 3-O-[?-L-arabinopyranosyl(1?2)-?-L-arabinopyranosyl(1?6)]-2-acetamido-2-deoxy-?-D-glucopyranosyl acacic acid lactone (2)} along with seven known saponins {3-O-[?-L-arabinopyranosyl(1?6)]-2-acetamido-2-deoxy-?-D-glucopyranosyl echinocystic acid (3), 3-O-[?-D-xylopyranosyl (l?2)-?-L-arabinopyranosyl(l?6)]-2-acetamido-2-deoxy-?-D-glucopyranosyl acacic acid lactone (concinnoside D) (4), 3-O-[?-D-glucopyranosyl(l?2)]-?-D-glucopyranosyl oleanolic acid (5), 3-O-[?-L-arabinopyranosyl(1?2)-?-L-arabinopyranosyl(l?6)]-?-D-glucopyranosyl oleanolic acid (6), 3-O-[?-D-xylopyranosyl(1?2)-?-L-arabinopyranosyl(l?6)]-?-D-glucopyranosyl oleanolic acid (7), 3-O-[?-L-arabinopyranosyl(l?2)-?-L-arabinopyranosyl(1?6)-[?-D-glucopyranosyl(l?2)]-?-D-glucopyranoside echinocystic acid (8), and 3-O-[?-D-xylopyranosyl(l?2)-?-L-arabinopyranosyl(1?6)-[?-D-glucopyranosyl(l?2)]-?-D-glucopyranoside echinocystic acid (9)}. The structures of 1 and 2 were established on the basis of extensive 2D NMR ((1)H-(1)H COSY or DQF-COSY, HSQC, HMBC, TOCSY, and HSQC-TOCSY) spectroscopic, ESIMS, and chemical methods. Saponins 1, 3, 6, and 7 showed cytotoxicity against human head and neck squamous cells (JMAR, MDA1986) and melanoma cells (B16F10, SKMEL28) with IC(50) values in the range 1.8-12.4 ?M, using the MTS assay.

SUBMITTER: Zhang H 

PROVIDER: S-EPMC3090140 | biostudies-literature | 2011 Mar

REPOSITORIES: biostudies-literature