Triterpenoid Saponins from Xanthoceras Sorbifolia Bunge and Their Inhibitory Activity on Human Cancer Cell Lines

Xanthoceras sorbifolia Bunge is widely used as healthy food material and folk medicine in China. Phytochemical investigation on its seeds oil leavings has led to the isolation and identification of seven new oleanane-type triterpenoid saponins named sorbifoliasides A-F (1-6) and bunkankasaponin F (7), along with five known ones (8-12). The structures of the new compounds were elucidated through spectroscopic analysis and chemical derivatization. Among the isolated compounds, 16-oxo-3, 28-O-bidesmosidic triterpenoid saponins (2, 3, 5) were isolated from this plant for the first time. The cytotoxicity of all compounds against the ten selected human cancer cell lines was assayed. Compounds 7 and 9 showed significant activity against all the ten cancer cell lines (IC(50) <10 μM), while compounds 8, 10 and 11 exhibited moderate activity against most of these cancer cell lines.