Studies on the constituents of Clematis species. V. On the saponins of the root Clematis chinensis Osbeck

Three triterpenoid prosapogenins tentatively named CP0 (I), CP2a (VI) and CP3a (VIII) have been isolated from the alkaline hydrolysate of the crude saponin obtained from the root of Clematis chinensis OSBECK. On the basis of chemical and physicochemical evidence, they were characterized as follows : I, hederagenin 23-O-α-L-arabinopyranoside ; VI, hederagenin 23-O-β-D-glucopyranoside ; VIII, olean-12-ene-28-oic acid-3β, 24-diol (4-epihederagenin) 3-O-α-L-rhamnopyranosyl-(1→2)-α-L-arabinopyranoside. I and VI are the first examples of 23-O-glycosides of oleanane-type triterpenes to be isolated from nature. Six less polar genuine saponins were isolated and they appeared to be identical with prosapogenins CP4, CP6, CP7, CP8, CP9 and CP10, 1, 4) on the basis of the results of high performance thin-layer chromatography (HPTLC).