Abstract
The production of aflatoxin (AF) groups (B1, B2, G1, G2, M1, M2, P1 and Q1) and aflatoxicol (AFL) groups (A and B) by AF-producing Aspergillus flavus and A. parasiticus isolated from various foods, and the metabolism of AF B1 to AF M1, AF P1, AF Q1, AFL-A and AFL-B by AF-non-producing A. flavus also isolated from various foods, were studied. A simple and rapid method for the analysis of the 10 kinds of toxins was developed. Toxins produced in culture were extracted with chloroform, separated into AF and AFL fractions by a silica gel cartridge column, then assayed by high performance liquid chromatography (HPLC). AF M1, AF M2, AFL-A and AFL-B were detected in addition to AF B1 and AF B2 in nearly all of the cultures inoculated with AF-producing A. flavus. The same groups were detected in addition to AF B1, AF B2, AF G1 and AF G2 in the cultures inoculated with A. parasiticus. The time courses of AF M1 and AF M2 production were almost the same as those of AF B1, AF B2, AF G1 and AF G2. AFLs tended to appear after AFs had accumulated in the cultures. AF P1 and AF Q1 were not detected at all. AF B1 added to the cultures was metabolized by all strains of non-AF-producing A. flavus. AFL-A and AFL-B were the common metabolites in all of the cultures. However, no strains which converted AF B1 to AF M1, AF P1 and AF Q1 were observed.
