Triterpenoid saponins from the stem barks of Chytranthus klaineanus Radlk. ex Engl

In our continuing studies on saponins from Cameroonian medicinal plants, phytochemical investigation of Chytranthus klaineanus stem barks led to the isolation of three new oleanane-type saponins, named Klaineanosides A-C(1-3). Their structures were established by extensive analysis of their spectral data, mainly 1D(H-1, C-13 NMR, and DEPT) and 2D (COSY, HSQC, NOESY, HSQC-TOCSY, and HMBC) NMR experiments, and mass spectrometry as 3-O-beta-D-glucopyranosyl-(1 -> 3)-beta-D-xylopyranosyl-(1 -> 4)[-beta-D-xylopyranosyl(1 -> 3)-beta-D-xylopyranosyl(1 -> 3)-alpha-L-rhamnopyranosyl-(1 -> 2)]-alpha-L-arabinopyranosylhederagenin(1), 3-O-beta-D-glucopyr-anosyl-(1 -> 3)-beta-D-xylopyranosyl-(1 -> 4)[ beta-D-xylopyranosyl(1 -> 3)-alpha-L-rhamnopyranosyl-(1 -> 2)]-alpha-L-arabinopyr-anosylhederagenin(2), and 3-O-beta-D-xylopyranosyl(1 -> 4)-beta-D-glucopyranosyl-(1 -> 3)-alpha-L-rhamnopyranosyl-(1 -> 2)-alpha-L-arabinopyranosylhederagenin(3). These triterpene saponins 1-3 have hederagenin as aglycone with a-(3)Rha-(2)Ara-(3)hederagenin oligosaccharidic sequence usually found in Sapindaceae family.