Rivularinin, a new saponin from Anemone rivularis

Abstract A new saponin, rivularinin, has been isolated from the ethanolic extract of Anemone rivularis (Ranunculaceae). The saponin was shown to be [α- l -arabinofuranosyl(1→2)-α- l -rhamnopyranosyl (1→4)-β- d -glucopyranosyl(1→4)-β- d -glucuronopyranosyl(1→3)]-3β-hydroxy-olean-12-en-28-oic acid.