Inhibition by diacylmethane derivatives of mutagenicity and nucleic acid binding of 2-aminofluorene derivatives.

The active methylene compounds acetylacetone, 1,1,1-trifluoroacetylacetone, benzoylacetone, dibenzoylmethane, and 1,3-indandione inhibited the mutagenicity of 2-nitrofluorene in Salmonella typhimurium. They also inhibited the N,O-acetyltransferase-catalyzed transfer RNA binding of N-hydroxy-2-acetylaminofluorene, but they did not inhibit N,O-acetyltransferase. However, only 1,3-indandione and 1,1,1-trifluoroacetylacetone significantly inhibited the binding of N-acetoxy-2-acetylaminofluorene to transfer RNA. Reaction of the trifluoro compound with the acetoxy compound yielded 1-(N-2-fluorenylacetamido)acetone. These results demonstrate that active methylene compounds can inhibit mutagenicity and nucleic acid binding of chemical carcinogens.