Mutagenicity and antibacterial activity of mycotoxins produced by Penicillium islandicum Sopp and Penicillium rugulosum.

Twelve mycotoxins produced by Penicillium islandicum Sopp and Penicillium rugulosum in solid-state fermentation on grains were purified and tested for mutagenicity and antibacterial activity in Salmonella/mammalian microsome assays. The mutations studied were reversions of histidine auxotrophs to prototrophy in strains TA98 and TA100 and forward mutations to 8-azaguanine resistance (8AGR) in strain TM677. Rubroskyrin, (+)rugulosin, lumiluteoskyrin [a photoproduct of (-)luteoskyrin], and simatoxin [a new water-soluble metabolite of unknown structure] induced 8AGR mutations in strain TM677 but not histidine reversions in strains TA98 and TA100. Mutagenic potency was reduced by rat-liver microsomes. The carcinogens (-)luteoskyrin and cyclochlorotine were antibacterial but not mutagenic. (+)Rugulosin, rubroskyrin, lumiluteoskyrin, and high concentrations of simotoxin were also antibacterial. Antibacterial activity but not mutagenicity was observed with pibasterol and skyrin. Chrysophanol, islandicin, iridoskyrin, and emodin were inactive as mutagens or as antibacterial agents.