Bis-Indolyl Benzenoids, Hydroxypyrrolidine Derivatives and Other Constituents from Cultures of the Marine Sponge-Associated Fungus Aspergillus candidus KUFA0062.

A previously unreported -indolyl benzenoid, candidusin D () and a new hydroxypyrrolidine alkaloid, preussin C () were isolated together with fourteen previously described compounds: palmitic acid, clionasterol, ergosterol 5,8-endoperoxides, chrysophanic acid (), emodin (), six -indolyl benzenoids including asterriquinol D dimethyl ether (), petromurin C (), kumbicin B (), kumbicin A (), 2″-oxoasterriquinol D methyl ether (), kumbicin D (), the hydroxypyrrolidine alkaloid preussin (), (3, 6)-3,6-dibenzylpiperazine-2,5-dione () and 4-(acetylamino) benzoic acid (), from the cultures of the marine sponge-associated fungus KUFA 0062. Compounds , , , , , and were tested for their antibacterial activity against Gram-positive and Gram-negative reference and multidrug-resistant strains isolated from the environment. Only exhibited an inhibitory effect against ATCC 29213 and ATCC29212 as well as both methicillin-resistant (MRSA) and vancomycin-resistant enterococci (VRE) strains. Both and also reduced significant biofilm formation in ATCC 25922. Moreover, and revealed a synergistic effect with oxacillin against MRSA 66/1 while exhibited a strong synergistic effect with the antibiotic colistin against 1410/1. Compound , , , , , and were also tested, together with the crude extract, for cytotoxic effect against eight cancer cell lines: HepG2, HT29, HCT116, A549, A 375, MCF-7, U-251, and T98G. Except for , , , and , all the compounds showed cytotoxicity against all the cancer cell lines tested.