The structures of four new himbacine-like Galbulimima alkaloids

The structures of four new alkaloids isolated from the bark of the rain forest trees Galbulimima belgraveana and Galbulimima baccata have been determined. Two of the alkaloids are simple oxygenated derivatives of himbacine, while the remaining two are based on a novel 7,19-cyclo-himbacine skeleton.