Two New Glycosides from the Roots of Cynanchum versicolor.

Two new glycosides named cynanversicoside-A and -B, together with glaucogenin-C as the aglycone, were isolated from the Chinese crude drug "Pai-Wei", CYNANCHUM VERSICOLOR Bunge (Asclepiadaceae). Their structures were determined on the basis of spectral and chemical evidence as glaucogenin-C 3- O-beta- D-cymaropyranosyl-(1-->4)-alpha- L-diginopyranosyl-(1-->4)-beta- D-thevetopyranoside and glaucogenin-C 3- O-beta- D-glucopyranosyl-(1-->4)-beta- D-cymaropyranosyl-(1-->4)-alpha- L-diginopyranosyl-(1-->4)-beta- D-thevetopyranoside.