Characterization of new sweet triterpene saponins from Albizia myriophylla.

Five new oleanane-type triterpene saponins, albiziasaponins A-E (1-5), were isolated from the stems of Albizia myriophylla collected in Thailand, together with two known triterpene saponins, licorice-saponin F3 and yunganoside B(1). The structures of the new compounds were elucidated on the basis of chemical and physicochemical evidence. In addition, when sensory tests were performed on sweetness, albiziasaponin B (2), with a carbonyl group at the C-30 position, was found to show a potent sweetness intensity relative to sucrose (600 times).