Tyrokeradines C–F, New Bromotyrosine Alkaloids from the Verongid Sponges

Abstract

Four new bromotyrosine alkaloids, tyrokeradines C–F (1–4), have been isolated from Okinawan marine sponges of the order Verongidae. The structures of 1–4 were elucidated on the basis of spectroscopic data. Tyrokeradines C (1) and D (2) are new bromotyrosine alkaloids possesing an imidazole ring, while tyrokeradines E (3) and F (4) are new bromotyrosine alkaloids possesing a cyano group.