a potent hepatotoxic and hepatocarcinogenic mycotoxin produced by the aspergillus flavus group of fungi. it is also mutagenic, teratogenic, and causes immunosuppression in animals. it is found as a contaminant in peanuts, cottonseed meal, corn, and other grains. the mycotoxin requires epoxidation to aflatoxin b1 2,3-oxide for activation. microsomal monooxygenases biotransform the toxin to the less toxic metabolites aflatoxin m1 and q1. Prod. by Aspergillus flavus and Aspergillus parasiticus. Toxin causing Turkey X disease. One of the most potent carcinogens known in animals. Potential food contaminant esp. in grains and nuts Aflatoxins are naturally occurring mycotoxins that are produced by many species of Aspergillus, a fungus, most notably Aspergillus flavus and Aspergillus parasiticus. At least 13 different types of aflatoxin are produced in nature. Aflatoxin B1 is considered the most toxic and is produced by both Aspergillus flavus and Aspergillus parasiticus. The native habitat of Aspergillus is in soil, decaying vegetation, hay, and grains undergoing microbiological deterioration and it invades all types of organic substrates whenever conditions are favorable for its growth. Favorable conditions include high moisture content (at least 7%) and high temperature. Aflatoxins B1 (AFB1) are contaminants of improperly stored foods; they are potent genotoxic and carcinogenic compounds, exerting their effects through damage to DNA. They can also induce mutations that increase oxidative damage. (PMID: 17214555). Crops which are frequently affected by Aspergillus contamination include cereals (maize, sorghum, pearl millet, rice, wheat), oilseeds (peanut, soybean, sunflower, cotton), spices (chile peppers, black pepper, coriander, turmeric, ginger), and tree nuts (almond, pistachio, walnut, coconut, brazil nut).