New naphthyl derivatives from Aspergillus californicus

Two new naphthyl-products calinaphthyltriol A ( 1 ) and calinaphthalenone A ( 2 ) were isolated from Aspergillus californicus IBT 16748 together with one known compound ophiobolin X ( 3 ). Their structures were elucidated by extensive spectroscopic analyses. The absolute configuration of 2 was solved by comparing its optical rotation with data for the known compounds 4 , 5 , and 6 as well as theoretical calculations. The antibacterial and cytotoxic activities of 1 and 3 were evaluated. Both compounds did not show antibacterial activity (MIC > 96 µg·ml −1 ) against a few selected clinically relevant Gram positive and Gram negative bacterial strains. However, they showed moderate cytotoxicity against HL-60 cell line with IC 50 values of 18 and 24 µg·ml −1 , respectively.