Prenylterphenyllin and its dehydroxyl analogs, new cytotoxic substances from a marine-derived fungus Aspergillus candidus IF10

Three novel cytotoxic substances named prenylterphenyllin (1), 4 ''-deoxyprenylterphenyllin (2), and 4 ''-deoxyisoterprenin (3) were isolated from a cultured marine-derived fungus of Aspergillus candidus IF10 together with 4 ''-deoxyterprenin (4). Their chemical structures were elucidated on the basis of 2D NMR analysis. These compounds 1 similar to 4 showed cytotoxic activity against human epidermoid carcinoma KB cells (KB3-1) with IC50 of 8.5, 3.0, 2.5, and 4.5 mu g/ml, respectively.