Mutagenic activity of the glutathione S-transferase substrate 1-chloro-2,4-dinitrobenzene (CDNB) in the Salmonella mutagenicity assay.
The mutagenicity of the commonly used glutathione S-transferase substrates 1-chloro-2,4-dinitrobenzene (CDNB) and 1,2-dichloro-4-nitrobenzene (DCNB) was investigated in the Salmonella mutagenicity assay. CDNB induced a concentration-dependent mutagenic response in Salmonella typhimurium strain TA98. Incorporation of an activation system derived from Aroclor 1254-induced rats did not influence mutagenic response. Under the same conditions DCNB failed to display mutagenic activity. The mutagenic activity of CDNB was attenuated in bacterial strains under-expressing nitroreductase or O-acetylase activity but, in contrast, it was exaggerated in an O-acetylase over-expressing strain. It is inferred that CDNB exhibits a mutagenic response following reduction of the nitro-group to the hydroxylamine, which is further acetylated to form the acetoxy derivative that presumably breaks down spontaneously to generate the nitrenium ion, the likely ultimate mutagen.
Catterall
Fenton
F
Molecular Toxicology Group, School of Biomedical and Life Sciences, University of Surrey, Surrey GU2 7XH, Guildford, UK.
King
Laurie J
LJ
Ioannides
Costas
C
D000818:Animals; D004137:Dinitrochlorobenzene / Q000633:toxicity*; D005982:Glutathione Transferase / Q000378:metabolism*; D007509:Irritants / Q000633:toxicity*; D008297:Male; D009152:Mutagenicity Tests; D009153:Mutagens; D010084:Oxidation-Reduction; D051381:Rats; D017208:Rats, Wistar; D012480:Salmonella Infections; D012486:Salmonella typhimurium / Q000187:drug effects*
D004137:Dinitrochlorobenzene; D007509:Irritants; D009153:Mutagens; D005982:Glutathione Transferase