Yalamanchili Gopichand

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 1H NMR and other spectroscopic data. The new metabolites are formally derived by combination of major segments of two known Aplysina metabolites 1a and 2.

Recent developments in research on metabolites from Caribbean marine invertebrates

As a consequence of earlier surveys1 of extracts of a broad spectrum of marine invertebrates for pharmacological activities, our natural products research has been focused over the years on the chemistry of sponges, gorgonians, and sea hares. Sponges and gorgonians offer the practical advantage that they are frequently abundant and hence trace metabolites can be pursued where high levels of activity indicate that the effort of large scale work is worthwhile. Sea hares offer the advantage that they are often rich sources of interesting metabo— lites, but at the same time they pose a problem of determining the identity of the ultimate source, usually algae2, of these new natural products. The problem is compounded by the fact that the sea hares algal diet presumably varies seasonally, and hence complicated mixtures accumulate. Nevertheless, as sources of diverse natural products, sea hare digestive glands are difficult to match.