US EPA

625777 

Journal Article 

Comparative metabolism and mutagenicity of azo and hydrazone dyes in the Ames test 

De France, BF; Carter, MH; Josephy, PD 

1986 

Yes 

Food and Chemical Toxicology
ISSN: 0278-6915
EISSN: 1873-6351 

24 

2 

165-169 

English 

3957165 

10.1016/0278-6915(86)90352-2 

WOS:A1986A746300014 

Enteric bacterial and hepatic azoreductase enzymes are capable of reducing azo dyes to yield the constituent aromatic amines. Azo dyes based on benzidine and benzidine congeners have received particular attention because of their widespread use and the known carcinogenicity of benzidine to humans. Azo dyes based on beta-diketone coupling components exist preferentially as the tautomeric hydrazones. A series of hydrazone dyes based on benzidine and benzidine congeners was prepared and characterized by NMR and UV-visible spectroscopy. These dyes were tested for mutagenicity using a modified Ames assay and, unlike the true azo dyes, showed no significant mutagenic activity. The hydrazone dyes were resistant to enzymatic reduction by FMN-supplemented hamster-liver post-mitochondrial supernatant (S-9); under identical conditions, azo dyes such as trypan blue were rapidly reduced.