Nagelamides Q and R, novel dimeric bromopyrrole alkaloids from sponges Agelas sp.

Two new dimeric bromopyrrole alkaloids, nagelamides Q (1) and R (2), have been isolated from Okinawan marine sponges of the genus Agelas (SS-1134 and SS-956, respectively), and the structures and stereochemistry were elucidated from spectroscopic data. Nagelamide Q (1) is a rare dimeric bromopyrrole alkaloid possessing a pyrrolidine ring, while nagelamide R (2) is the first bromopyrrole alkaloid having an oxazoline ring. Nagelamides Q (1) and R (2) showed antimicrobial activity.