A new cytotoxic steroidal saponin from the rhizomes and roots of Smilax scobinicaulis

Abstract

A phytochemical investigation of the EtOH extract from the rhizomes and roots of Smilax scobinicaulis resulted in the isolation of a new isospirostanol-type steroidal saponin, namely (25 R)-5α-spirostan-3β,6β-diol 3-O-β-D-glucopyranosyl-(1 → 4)-[α-L-arabinopyranosyl-(1 → 6)]-β-D-glucopyranoside (1), along with four known steroidal saponins (2–5). The structures of these compounds were determined by 1D- and 2D-NMR spectroscopic analysis, FABMS and HR–ESI–MS as well as chemical degradation. The isolated saponins were evaluated for their in vitro cytotoxicity against A549, LAC and Hela human cancer cell lines, which demonstrated that only compound 1 possessed significant cytotoxic activity with IC50 values of 3.70, 5.70 and 3.64 µM, respectively.