Anthocephaline, a New Indole Alkaloid and Cadambine, a Potent Inhibitor of DNA Topoisomerase IB of Leishmania donovani (LdTOP1LS), Isolated from Anthocephalus cadamba

Chemical investigation of the stem bark of Anthocephalus cadamba has resulted in the isolation of anthocephaline (1), a new indole alkaloid, along with strictosamide (2), vincosamide (3) and cadambine (4). The structures of the isolated alkaloids (1-4) were established by detailed 2D NMR spectral analysis. Cadambine (4) exhibited potent DNA topoisomerase IB inhibitory activity.