Further saponins from Taverniera aegyptiaca

From the saponin fraction of the total methanolic extract of the dried root and stem barks of Taverniera aegyptiaca Boiss, six new triterpenoidal saponins of oleanane type were isolated and identified as 28-methyl serratagenate-3-beta-O-beta-xylopyranosyl (1-->2)-beta-glucopyranoside (2), 28-methyl serratagenate 3-beta-O-alpha-rhamnopyranosyl (1-->2)-beta-glucopyranoside (3), 3beta-O-alpha-rhamnopyranosyl (1-->2) beta-glucopyranosyl-olean-11,13(18)-dien-1beta, 3beta, 22beta-triol (4), 3beta-O-beta-glucopyranosyl (1-->2)-beta-glucuronopyranosylolean-11,13(18)-dien-1beta,3beta,22beta-triol (5), 3beta-O-beta-xylopyranosyl(1-->2)-beta-glucuronopyranosylolean-11,13(18)-dien-1beta,3beta,22beta-triol (6), 3beta-O-alpha-rhamnopyranosyl (1-->2)-beta-glucuronopyranosylolean-11,13(18)-dien-1beta, 3beta, 22beta-triol (7) together with the known oleanolic acid 3-beta-O-beta-glucoside (1). The identification of the isolated compounds was done on the basis of chemical and spectral evidences.