New triterpenoid saponin from the stems of Albizia adianthifolia (Schumach.) W.Wight

Abstract

As part of our continuing study of apoptosis-inducing saponins from CameroonianAlbiziagenus, one new triterpenoid saponin, named adianthifolioside J (1), together with the known gummiferaoside E (2), were isolated fromAlbizia adianthifoliastems. The structure of the new saponin (1), was established on the basis of extensive analysis of 1 D and 2 D NMR (H-1-,C-13-NMR, DEPT, COSY, TOCSY, NOESY, HSQC, HSQC-TOCSY and HMBC) and HRESIMS experiments, and by chemical evidence as 3-O-[beta-D-xylopyranosyl-(1 -> 2)-beta-D-fucopyranosyl-(1 -> 6)-beta-D-glucopyranosyl]-21-O-{(2E,6S)-2-(hydroxymethyl)-6-methyl-6-O-{4-O-[(2E,6S)-2,6-dimethyl-6-O-(beta-D-quinovopyranosyl)octa-2,7-dienoyl]-(beta-D-quinovopyranosyl)octa-2,7-dienoyl]}acacic acid-28-O-beta-D-glucopyranosyl-(1 -> 3)-[5-O-acetyl-alpha-L-arabinofuranosyl-(1 -> 4)]-alpha-L-rhamnopyranosyl-(1 -> 2)-beta-D-glucopyranosyl ester (1).The pro-apoptotic activity of the new isolated saponin1was evaluated, using Annexin V-FITC binding assay, on the A431 human epidermoid cancer cell. The result showed that adianthifolioside J (1) displayed weak pro-apoptotic activity