Two new pyrrolo-2-aminoimidazoles from a Myanmarese marine sponge, Clathria prolifera

AbstractMarine organisms such as marine sponges and soft corals are valuable sources of pharmacologically active secondary metabolites. In our ongoing research on the discovery of new secondary metabolites from marine organisms, two new pyrrolo-2-aminoimidazoles, clathriroles A (1) and B (2), were isolated from the water-soluble portion prepared from the methanol and acetone (2:1) extract of the marine sponge,Clathria prolifera, collected in Myanmar. The chemical structures of the isolated compounds were determined using extensive spectroscopic techniques, including NMR, HRESIMS, IR, and optical rotation, and comparisons with the reported literature. The spectroscopic analyses of1 and2 suggested that1 is an enantiomer of antifungalN-methylmanzacidin C isolated from the marine spongeAxinella brevistyla, whereas2 is a diastereomer of manzacidin D at C-11 isolated from the marine spongeAstrosclera willeyana. To the best of our knowledge, this is the first report of the isolation of the pyrrolo-2-aminoimidazole compounds fromC. prolifera. Furthermore, in contrast to the potency ofN-methylmanzacidin C againstSaccharomyces cerevisiae, the antifungal assay revealed that1 and2 lack any activity against this strain. Thus, these observations may suggest that the absolute configurations at both C-9 and C-11 play an important role in controlling the antifungal activity of this type of compound.
Source: Journal of Natural Medicines - Category: Drugs & Pharmacology Source Type: research