Steroid and triterpenoid saponins from the rhizomes of Paris polyphylla var. stenophylla

Five new saponins, including three steroid saponins, paristenoids A−C ( 1 − 3 ), and two triterpenoid saponins, paristenoids D−E ( 4 − 5 ), along with four known ones ( 6 − 9 ) were isolated from the rhizomes of Paris polyphylla var. stenophylla. The structures of the isolated compounds were identified mainly by detailed spectroscopic analysis, including extensive 1D and 2D NMR, MS, as well as chemical methods. Compound 3 is a new cyclocholestanol-type steroidal saponin with a rare 6/6/6/5/5 fused-rings cholestanol skeleton, and this skeleton has been first found from the genus Paris. The cytotoxicities of the isolated compounds against three human three glioma cell lines (U87MG, U251MG and SHG44) were evaluated, and compound 7 displayed certain inhibitory effect with IC₅₀ values of 15.22 ± 1.73, 18.87 ± 1.81 and 17.64 ± 1.69 μmol·L⁻¹, respectively.