S-adenosyl-L-methionine is a carbon donor in the conversion of benzo[ a]pyrene to 6-hydroxymethylbenzo[ a]pyrene by rat liver S-9

In earlier studies we reported that 6-hydroxymethylbenzo[ a]pyrene is a metabolite of benzo[ a]pyrene and of 6-methylbenzo[ a]pyrene when these substrates are incubated with homogenates or microsomal preparations of liver and microsomal preparations of subcutaneous tissue from Sprague-Dawley rats. However, the origin of the carbon donor was not established. We now report that S-adenosyl- l-methionine (SAM) can serve as a carbon donor in the metabolic formation of 6-hydroxymethylbenzo[ a]pyrene from benzo[ a]-pyrene by the S-9 fraction of rat liver.