Three New Oleanane Saponins from Zanha africana

Three new saponins, zanhasaponins, A, B, and C, were isolated from the MeOH extract of the root bark of Zanha africana and were, respectively, identified by spectroscopic methods as 3-O-beta-D-glucuronopyranosyl-2 beta,16 alpha-dihydroxyolean-12-ene-23,28- dioic acid 28-O-alpha-L-rhamnopyranosyl(1-->2)-alpha-L-rhamnopyranoside (1); 3-O-beta-D-glucuronopyranosyl-2 beta,16 alpha-dihydroxyolean-12-ene- 23,28-dioic acid 28-O-beta-D-xylopyranosyl(1-->2)-alpha-L-rhamnopyranosyl(1-->2)-alpha-L- rhamnopyranoside (2); and 3-O-beta-D-glucuronopyranosyl-2 beta,16 alpha-dihydroxyolean-12-ene- 23,28-dioic acid 28-O-beta-D-xylopyranosyl(1-->3)-beta-D-xylopyranosyl (1-->2)-alpha-L-rhamnopyranosyl(1-->2)-a…