Marine natural products: fistularin-1, -2 and -3 from the sponge Aplysina fistularis forma fulva

Three new high molecular weight bromotyrosine-related metabolites, 3a , 4a and 5a , were isolated from the sponge Aplysina ( Verongia ) fistularis forma fulva , and their structures were determined from high resolution 1 H NMR and other spectroscopic data. The new metabolites are formally derived by combination of major segments of two known Aplysina metabolites 1a and 2 .