Antitumor agents, 79. Cytotoxic antileukemic alkaloids from Brucea antidysenterica

Two cytotoxic antileukemic alkaloids, the new 1,11-dimethoxycanthin-6-one (3) and the known 11-hydroxycanthin-6-one (1), as well as the known canthin-6-one (2) were isolated from the stem of Brucea antidysenterica. The structures of 1-3 were determined from their spectral data and X-ray analysis of the o-bromobenzoate of 1.