Steroidal saponins from Tribulus terrestris

Three new steroidal saponins were isolated from the fruits of Tribulus terrestris, and their structures were elucidated as (25R,S)-5 alpha -spirostane-12-one-3 beta -ol-3-O-beta -xylopyranosyl(1 -->2)-[beta -xylopyranosyl(1 -->3)]-beta -glucopyranoside;26-O-beta -glucopyranosyl(25S)-5 alpha -furostane-1 2-one-3 beta ,22 alpha ,26-triol-3-O-beta -glucopyrano syl(1 -->2)-beta -galactopyranoside; 26-O-beta -glucopyranosyl-(25S)-5 alpha -furostane-12-one-3 beta ,22 alpha ,26-triol-3-O-beta -glucopyranosyl(1 -->4)-[alpha -rhamnopyranosyl(1 -->2)]-beta -galactopyranoside, respectively, by spectroscopic analysis and color reaction.