Highly efficient synthesis of bioactive oleanane-type saponins.

Leveraging on Schmidt glycosylation method, a highly efficient approach to obtain oleanane-type triterpene saponins was fixed, whereby oleanyl mono-, disaccharide (guaianin N), trisaccharide (elatoside E), as well as tetrasaccharide (elatoside F) were obtained efficiently. The synthetic investigation has resulted in the discovery of the effect of branch-sugar incorporation sequence on the overall synthetic efficiency. Moreover, through bioactivity investigation, the cytotoxic activity of the obtained triterpenoid saponins was evaluated, and the preliminary structure-activity relationship was deduced.