Steroidal glycosides from Tribulus terrestris.

In addition to hecogenin 3-O-beta-D-glucopyranosyl(1--> 4)-beta-D-galactopyranoside, two new steroidal saponins were isolated from the aerial parts of Tribulus terrestris L. On the basis of chemical and spectroscopic evidence, especially 2D NMR spectroscopic techniques, the structures of the new saponins were established as 26-O-beta-D-glucopyranosyl-3-O-[-beta-D-xylopyranosyl(1--> 3)--beta-D-galactopyranosyl(1-->2)--beta-D-glucopyranosyl (1--> 4)-beta-D-glucopyranosyl]-5 alpha-furost-20(22)-en-12-one-3 beta,26-diol and 26-O-beta-D-glucopyranosyl-3-O-[{beta-D-xylopyranosyl (1-->3)--beta-D-galactopyranosyl(1-->2)--beta-D-glucopyranosyl(1 -->4)-beta-D-glucopyranosyl]-5 alpha-furostan-12-one-3 beta,22,26-triol.