Studies on the Constituents of Aster tataricus L. f. III. : Structures of Aster Saponins E and F Isolated from the Root

Abstract

Two new oleanane-type triterpene glycosides, aster saponins E and F, were isolated from the less polar saponin fraction of the root of Aster tataricus L. f. (Compositae), and their structures were elucidated on the basis of spectral evidence and by correlation to the other aster saponins reported earlier. Aster saponin E is 3-O-[O-α-L-arabinopyranosyl-(1→6)-β-D-glucopyranosyl]-2β, 3β, 16α-trihydroxyolean-12-en-28-oic acid (asterogenic acid) 28-[O-β-D-xylopyranosyl-(1→3)-O-α-L-arabinopyranosyl-(1→4)-O-α-L-rhamnopyranosyl-(1→2)-β-D-xylopyranosyl] ester. Aster saponin F is a 3β, 16α-dihydroxyolean-12-en-28-oic acid (echinocystic acid) glycoside, the sugar moiety of which is the same as that of aster saponin E.