Structures of Yadanziosides K, M, N, and O, New Quassinoid Glycosides from Brucea javanica (L.) Merr

Abstract
Four new bitter quassinoid glycosides, yadanziosides K, M, N, and O were isolated from Brucea javanica (L.) Merr and their structures were determined by spectral measurement and chemical means. The aglycone of yadanzioside O was found to exhibit a significant antitumor activity against the murine P388 lymphocytic leukemia and this aglycone could be prepared from brusatol.