Triterpenoid saponins from Sesbania vesicaria

Nine oleanane saponins including three new and six known were isolated from the seeds of Sesbania vesicaria. The new saponins were established as 3-O-[alpha-L-rhamnopyranosyl-(1 -> 3)]-beta-D-glucuronopyranosyl-3 beta,29-dihydroxy-olean-12-en-28-oic acid, 3-O-alpha-L-rhamnopyranosyl-28-O-beta-D-glucopyransoyl-3 beta-hydroxy-olean-12-en-23-al-28-oate, and 3-O-alpha-L-rhamnopyranosyl-28-O-beta-Dglucopyransoyl-3 beta,23-dihydroxy-olean-12-en-28-oate. All isolated saponins were assayed for their DNA topoisomerase I inhibition ability and cytotoxicity against A549 human lung adenocarcinoma epithelial cells with no positive activity detected (IC50 > 312 mu M and GI(50) > 25 mu M, respectively). (C) 2013 Published by Elsevier B. V. on behalf of Phytochemical Society of Europe.