Cytotoxic and antimicrobial metabolites from the marine-derived fungus Aspergillus sp. OPR23-FS01

Chemical investigation of a marine-derived fungus Aspergillus sp. OPR23-FS01 resulted in the isolation of a new unsaturated fatty acid featuring a terminal olefin, 10-methoxy-2-methylene-10-oxodecanoic acid (1), two new natural compounds, 2-carboxy-2 '-methyl-azobenzene (2) and 1,3,9-trimethyluric acid (3), and 11 previously described metabolites, pantheric acid C (4), pantheric acid D (5), 2-furoic acid (6), 5-(hydroxymethyl)-2-furancarboxylic acid (7), sporogen-AO 1 (8), gliocladic acid (9), hydroheptelidic acid (10), ditryptophenaline (11), emodin (12), uridine (13), and thymidine (14). Their structures were identified by comprehensive analyses of the spectroscopic methods, including NMR and HRESI mass spectra. Compound 2 possesses a rare diazenyl group among the previously reported fungal metabolites. Compound 8 showed significant cytotoxicity against both HepG2 and MCF-7 cell lines in a dose-dependent manner, with IC50 values of 4.66 +/- 0.24 and 5.54 +/- 0.28 mu M, respectively. Compounds 1-5 and 8-11 displayed antimicrobial effect against Enterococcus faecalis ATCC299212, with MIC values ranging from 32 to 128 mu M, whereas 1, 4, 5, and 8-11 inhibited Candida albicans ATCC10231 growth, with MIC values in a range of 32-256 mu M.