Two new dihydroisocoumarins from the endophytic fungus Aspergillus sp collected from the south china sea

Two new dihydroisocoumarin derivatives, aspergillumarins A and B (1 and 2), were isolated from the culture broth of a marine-derived fungus Aspergillus sp., which was isolated from the fresh leaf of the mangrove tree Bruguiera gymnorrhiza collected from the South China Sea. The structures of compounds 1 and 2 were established by comprehensive analysis of the spectral data, especially 2D NMR spectra results. Compounds 1 and 2 showed weak antibacterial activity against Staphylococcus aureus and Bacillus subtilis at a concentration of 50 mu g/mL.