A novel bromopyrrole alkaloid from the sponge Agelas longissima with antiserotonergic activity

Agelongine (1), a novel bromopyrrole alkaloid containing a pyridinium ring in place of the imidazole nucleus, usually found in Agelas alkaloids, has been isolated from the Caribbean sponge Agelas longissima, and its structure established by spectroscopic analysis and chemical degradation. Agelongine exhibited an antiserotonergic activity tested in vitro on the rat stomach fundus strip.