Four new furostanol saponins from the rhizomes and roots of Smilax scobinicaulis and their cytotoxicity.

Four new furostanol saponins 1-4, along with two known furostanol saponins 5 and 6 and one known spirostanol saponin 7 were isolated from the rhizomes and roots of Smilax scobinicaulis. The structures of the new saponins were elucidated as 26-O-β-D-glucopyranoside-3β,26-dihydroxy-(25R)-5α-furostan-22-methoxyl-6-one-3-O-α-L-arabinopyranosyl-(1→6)-β-D-glucopyranoside (1), 26-O-β-D-glucopyranoside-3β,26-dihydroxy-(25R)-5α-furostan-22-methoxyl-6-one (2), 26-O-β-D-glucopyranoside-3β,26-dihydroxy-(25R)-5α-furostan-20(22)-en-6-one (3), 26-O-β-D-glucopyranoside-3β,23,26-trihydroxy-(23R, 25R)-5α-furostan-20(22)-en-6-one (4) on the basis of spectroscopic analysis. The isolated saponins were evaluated for cytotoxic activity against two human cancer cell lines including Hela (cervical carcinoma) and SMMC-7221 (hepatocellular carcinoma). Compounds 1 and 7 demonstrated cytotoxicity against the tested cell lines.