A new anthraquinone derivative from the marine fish-derived fungus Alternaria sp. X112.

A new anthraquinone, altermodinacid A ( 1 ), and five known derivatives, pachybasic acid ( 2 ), emodic acid ( 3 ), emodin ( 4 ), phomarin ( 5 ), and 1,7-dihydroxy-3-methylanthracene-9,10-dione ( 6 ), were discovered from a halotolerant fungus Alternaria sp. X112 isolated from a marine fish Gadus macrocephalus . Their structures were determined by analysing MS and NMR data. The cytotoxic effect, antiagricultural pathogens activity, antibacterial activity and quorum sensing inhibitory potential of new compound 1 were evaluated.