Mutagenic activity of 2,4.6-trinitrotoluene (2,4,6-TNT) and one of its
derivatives, 2,4-diamino-6-nitrotoluene (2,4-DA-6-NT) was studied in
the Ames test using the Salmonella typhimurium tester strains TA98, TA
100, TA100NR (deficient in classical nitroreductases), and TA100/1,8DN
P (deficient in 0-acetyltransferase). The number of revertants was sig
nificantly increased by 2,4,6-TNT, in comparison with that of spontane
ous revertants. Base pair substitutions were preferentially induced by
2,4,6-TNT. The mutagenic effect of this compound was virtually altere
d by in vitro metabolic activation with the S9 fraction of human place
nta. Neither 2,4,6-TNT nor 2,4-DA-6-NT exhibited mutagenic activity in
the strains TA100NR and TA100/1,8DNP. Based on the results obtained,
it is concluded that the mutagenic potential of 2,4,6-TNT is determine
d by its metabolites that form during bacterial metabolism. Bacterial
nitroreductases and 0-acetyltransferases are the key activators of thi
s compound to form the ultimate mutagens.