Agelamadin F and tauroacidin E, bromopyrrole alkaloids from an Okinawan marine sponge Agelas sp.

A new structurally unique bromopyrrole alkaloid, agelamadin F (1), comprising oroidin and 3-hydroxypyridinium was isolated from an Okinawan marine sponge Agelas sp. together with tauroacidin E (2), a new bromopyrrole alkaloid possessing a taurine moiety. Six known bromopyrrole alkaloids, oroidin, tauroacidin A, sceptrin, ageliferin, nagelamide E, and agelongine were also isolated and identified. The structures of 1 and 2 were elucidated on the basis of spectroscopic evidences, while chiral HPLC analysis suggested tauroacidin E (2) to be a racemate. (C) 2015 Elsevier Ltd. All rights reserved.