ABSTRACT

This chapter gives an overview of scientific data regarding aflatoxin classification and chemical structure and the genes associated with aflatoxin synthesis. Aflatoxins are toxic metabolites generally produced by molds belonging to three different groups of Aspergilli: Aspergillus section Flavi, Aspergillus section Nidulantes, and Aspergillus section Ochraceorosei. Specifically, the principal aflatoxin producers are Aspergillus flavus and Aspergillus parasiticus, as well as Aspergillus nomius. These molds are distributed in air, soil, and both living and dead plants and animals. Aflatoxins are difurocoumarin derivatives with a chemical structure that consists of a bifuran ring attached to a coumarin with a pentenone ring or a six-membered lactone ring. The synthesis of aflatoxins occurs through a series of highly organized oxidation-reduction reactions. The syntheses of aflatoxins are increased at high water activity values. In 1974, a major outbreak of hepatitis due to aflatoxins was reported in India, causing about 106 deaths.