Cytotoxic alkaloids of Annona montana

Abstract The leaves of Annona montana afforded one novel cytotoxic phenanthrene alkaloid, annoretine [3-hydroxy-4-methoxy- N -methyl-tetrahydropyrido(4,3-a)phenanthrene], together with two cytotoxic alkaloids, argentinine and liriodenine, as well as a new oxoaporphine alkaloid, annolatine, and one steroid, sitosterol-β- d -glucoside, which are inactive. The structures of annoretine and annolatine were elucidated from spectral data and chemical evidence.