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Title: Mutagenic activity of the 4,5- and 9,10-dihydrodiols of benzo[i]fluoranthene and their syn- and anti-dihydrodiol epoxides in Salmonella typhimurium

Journal Article · · Environmental and Molecular Mutagenesis; (United States)
 [1]; ; ; ;  [2]
  1. Park One Research Labs., Sugar Land, TX (United States)
  2. Rutgers Univ., Piscataway, NJ (United States)

The objective of this study was to determine the relative mutagenic activities of the major dihydrodiol metabolites of benzo[i]fluoranthene (B[i]F) and their corresponding syn- and anti-dihydrodiol epoxides. Salmonella typhimurium tester strains TA97a, TA98, and TA100 were used to evaluate the mutagenic potencies of the parent hydrocarbon and these suspect proximate and ultimate mutagenic metabolites. B[i]F and the trans-dihydrodiol metabolites were active only in the presence of an external metabolic activation system (S9) with the exception of the B[i]F-4,5-diol, which was weakly active in TA98 and TA100 in the absence of S9. The B[i]F-4,5-diol was more mutagenic than the B[i]F-9,10-diol in tester strains TA98 and TA100, whereas the opposite effect was observed in TA97a. In the absence of S9, the anti-B[i]F-4,5-diol epoxide was more mutagenic than the syn-B[i]F-4,5-diol epoxide and the syn- and anti-B[i]F-9,10-diol epoxides in tester strains TA97a and TA100. The exceptional mutagenic potency of the anti-B[i]F-4,5-diol epoxide in TA100 resembles that observed by epoxides located within a fjord, or by the anti-diol epoxides of bay region methylated polycyclic aromatic hydrocarbons. In contrast, the mutagenicity of the pseudo bay region dihydrodiol epoxides arising from the B[i]F-9,10-diol more closely resembles that observed with the classical bay region dihydrodiol epoxides of chrysene. In summary, both dihydrodiol metabolites of B[i]F are mutagenic in S. typhimurium, and the relative potency varies among the tester strains. The highest mutagenic response was achieved in tester strain TA100, which detects base-pair substitutions. The most potent direct-acting dihydrodiol epoxide in this tester strain was the anti-B[i]F-4,5-diol epoxide, which agrees with the results of mouse skin painting studies that indicate that the B[i]F-4,5-diol is more tumorigenic than the parent hydrocarbon or the B[i]F-9,10-diol. 34 refs., 7 figs., 2 tabs.

OSTI ID:
7074811
Journal Information:
Environmental and Molecular Mutagenesis; (United States), Vol. 22:1; ISSN 0893-6692
Country of Publication:
United States
Language:
English