Polycitone B and Prepolycitrin A:  Two Novel Alkaloids from the Marine Ascidian <i>Polycitor africanus</i>

Abstract

Two novel compounds, polycitone B (4) and prepolycitrin A (3), were isolated from the marine ascidian Polycitor africanus. The structures of these new dibromotyrosine metabolites were established mainly on the basis of NMR spectroscopic data. Isolation of compound 3 supports the earlier suggestion that it is the bioprecursor of polycitrin A (2).