New Furanone Derivatives and Alkaloids from the Co-Culture of Marine-Derived Fungi Aspergillus sclerotiorum and Penicillium citrinum.

Six new compounds including two furanone derivatives sclerotiorumins A and B (1 and 2), one novel oxadiazin derivative sclerotiorumin C (3), one pyrrole derivative 1-(4-benzyl-1H-pyrrol-3-yl)ethanone (4), and two complexes of neoaspergillic acid aluminiumneohydroxyaspergillin (5) and ferrineohydroxyaspergillin (6) were isolated from the co-culture of marine-derived fungi Aspergillus sclerotiorum and Penicillium citrinum. Compound 3 was the first natural 1,2,4-oxadiazin-6-one. Compound 5 showed significant and selective cytotoxicity against human histiocytic lymphoma U937 cell line (IC50  = 4.2 μm) and strong toxicity towards brine shrimp (LC50  = 6.1 μm), and oppositely increased the growth and biofilm formation of Staphylococcus aureus.