Steroidal saponins from the rhizomes of Smilax menispermoidea.

Four steroidal saponins were isolated from the dried rhizomes of Smilax menispermoidea. One of them is new and its structure was established as (25S)spirost-5-en-3 beta,17 alpha-triol-3-O-[alpha-L-rhamnopyranosyl(1----2)] [alhpa-L-rhamnopyranosyl(1----4)]-beta-D-glucopyranoside using spectrometry and chemical methods, as well as comparison with three known steroidal saponins, dioscin, methyl protodioscin and pseudoprotodioscin.