Three new metabolites from marine-derived fungi of the genera Coniothyriumand Microsphaeropsis

The marine sponges Ectyplasia perox and Myxilla incrustans were investigate d for associated fungal strains. Among others, a Coniothyrium sp., from E. perox, and a Microsphaeropsis sp., from M. incrustans, were isolated, cultu red, and investigated for their biologically active secondary metabolite co ntents. The new compound microsphaeropsisin (1) together with the known com pounds (R)-mellein (4), (3R,4S)-hydroxymellein (5), (3R,4R)-hydroxymellein (6), and 4,8-dihydroxy-3,4-dihydro-2H-naphthalen-1-one (7) were isolated fr om the Microsphaeropsis sp. From culture extracts of the Coniothyrium sp., the new compounds (3S)-(3',5'-dihydroxyphenyl)butan-2-one (2) and 2-(1'(E)- propenyl)-octa-4(E), 6(Z)-diene-1,2-diol (3), together with the six known m etabolites (3R)-6-methoxymellein (8), (3R)-6-methoxy-7-chloromellein (9), c ryptosporiopsinol (10), phenylethanol, (p-hydroxyphenyl)ethanol, and 2-(hyd roxymethyl)furan, were obtained. All structures were determined using spect roscopic methods. With the exception of 3, all compounds were tested for th eir antimicrobial properties, and all but 10 demonstrated significant antim icrobial activity in agar diffusion assays.