ChemInform Abstract: Marine Bacterial Inhibitors from the Sponge-Derived Fungus Aspergillus sp

Chromatographic separation of a crude extract obtained from the fungus Aspergillus sp., isolated from the Mediterranean sponge Tethya aurantium , yielded a new tryptophan derived alkaloid, 3-((1-hydroxy-3-(2-methylbut-3-en-2-yl)-2-oxoindolin-3-yl)methyl)-1-methyl-3,4-dihydrobenzo[ e ][1,4]diazepine-2,5-dione ( 1 ), and a new meroterpenoid, austalide R ( 2 ), together with three known compounds ( 3 – 5 ). The structures of the new compounds were unambiguously elucidated on the basis of extensive one and two-dimensional NMR ( 1 H, 13 C, COSY, HMBC, and ROESY) and mass spectral analysis. Interestingly, the compounds exhibited antibacterial activity when tested against a panel of marine bacteria, with 1 selectively inhibiting Vibrio species and 2 showing a broad spectrum of activity. In contrast, no significant activity was observed against terrestrial bacterial strains and the murine cancer cell line L5178Y.