Genotoxicity of nitrated polycyclic aromatic hydrocarbons and related structures on Escherichia coli PQ37 (SOS chromotest).

To determine the genotoxicity of nitrated polycyclic aromatic hydrocarbons and related molecules (nPAH) we examined 24 compounds representative of nitroanthracenes, nitrofluorenes, nitronaphthalenes, nitropyrenes, and nitroquinolines for genotoxicity in Escherichia coli PQ37 (SOS-chromotest). To enhance the sensitivity of the tester strain and optimize metabolic activation we used a modified test protocol and S9-mix composition. All chemicals with the exception of 9-nitroanthracene, 1- and 2-nitronaphthalene, 2-methyl-1-nitronaphthalene, and 5-, 6-, and 8-nitroquinoline induced the SOS system of E. coli PQ37. As expected from previously referred mutagenicity studies, the highest SOS inducing potencies (SOSIP) were exhibited by the dinitropyrenes (SOSIP = 151-416), 4-nitroquinoline-N-oxide (SOSIP = 62), and 3-nitrofluoranthese (SOSIP = 16). Except for some nitronaphthalenes, the nPAHs showed their highest genotoxicity in the absence of an exogeneous metabolic activation system. The results were compared to those reported for the bacterial mutagenicity of these substances in Salmonella typhimurium TA98.