Tetrapterosides A and B, two new oleanane-type saponins from Tetrapleura tetraptera

From the stem bark of Tetrapleura tetraptera, two new oleanane-type saponins, tetrapteroside A 3-O-{6-O-[(2E,6S)-2,6-dimethyl-6-hydroxyocta-2,7-dienoyl]-beta-D-glucopyranosyl-(1 -> 2)-beta-D-glucopyranosyl-(1 -> 3)-beta-D-glucopyranosyl-(1 -> 4)-[beta-D-glucopyranosyl-(1 -> 2)]-beta-D-glucopyranosyl}-3,27-dihydroxyoleanolic acid (1), and tetrapteroside B 3-O-(beta-D-glucopyranosyl-(1 -> 2)-6-O-[(E)-feruloyl]-beta-D-glucopyranosyl-(1 -> 3)-beta-D-glucopyranosyl-(1 -> 4)-[beta-D-glucopyranosyl-(1 -> 2)]-beta-D-glucopyranosyl)-3,27-dihydroxyoleanolic acid (2), were isolated. Further extractions from the roots led to the isolation of four known oleanane-type saponins. Their structures were elucidated by the combination of mass spectrometry (MS), one and two-dimensional NMR experiments. Copyright (C) 2009 John Wiley & Sons, Ltd.