Sulfotransferase-mediated mutagenicity of 1-hydroxymethylpyrene and 4H-cyclopenta[def]chrysen-4-ol and its enhancement by chloride anions.

Abstract

1-Hydroxymethylpyrene (HMP), a primary benzylic alcohol, and 4H-cyclopenta[def]chrysen-4-ol (OH-CPC), a secondary benzylic alcohol, were investigated for mutagenicity in Salmonella typhimurium (reversion of the his- strain TA98) in the presence of various xenobiotic-metabolizing systems. In the direct test, HMP was inactive and OH-CPC was very weakly active. In the presence of NADPH-fortified postmitochondrial fraction from rat liver (S9/NADPH), no activation of OH-CPC was observed, whereas strong mutagenic effects were elicited by HMP. In the presence of cytosol and 3'-phosphoadenosine-5'-phosphosulfate (PAPS), both alcohols were activated to potent mutagens. For equal mutagenic effects, approximately 650-fold lower concentrations of HMP were required in the cytosol/PAPS-mediated assay than in the S9/NADPH-mediated assay. The cytosol/PAPS-mediated mutagenicity of both alcohols was 3- to 4-fold enhanced, when KCl (125 mM) was present during the exposure. The authentic chloromethylarenes, 1-chloromethylpyrene and 4-chloro-4H-cyclopenta[def]chrysene, showed very strong direct mutagenicity. These results, taken together with previous findings, indicate that both primary and secondary benzylic alcohols derived from polycyclic aromatic hydrocarbons may be activated by sulfotransferases to electrophilic sulfuric acid esters, and by subsequent substitution reaction to further active species such as benzylic chlorides.