Mutagenicity of XXXX photoproducts in the Ames Salmonella assay.

@entity1042 @entity2340 @entity3636
During the photolysis of @entity2340 a large number of products is formed. In this study, aqueous solutions of @entity2340 were irradiated by ultraviolet light during 5, 20 or 40 h. Each of the irradiated batches was divided into two aliquots, which were freeze-dried or extracted with @entity3636 . For each batch the latter extract was subsequently divided into a purified @entity3636 extract and a @entity1042 extract. Aliquots of the purified @entity3636 extracts were fractionated and pooled, peakwise, into seven fractions. A recombined sample was also constructed. All extracts and samples were tested for mutagenicity using the standard Ames Salmonella assay. The results indicate an exposure time dependent increase in mutagenicity of the extracts, as seen with tester strain TA100 both with and without metabolic activation. The mutagenicity of the freeze-dried extracts well approximated the mutagenicity of the @entity3636 extracts, indicating that most mutagenicity can be extracted with @entity3636 . With the fractions the highest mutagenic responses were seen in the late, i.e., less lipophilic fractions. This response pattern seen in TA98 and TA100, mainly with S9 activation, was in contrast to the response of TA102 without S9, which was highest to the more lipophilic fractions. On a fraction level, no general exposure dependent increase of mutagenicity was observed. The results also show that photooxidation of @entity2340 gives rise to a different spectrum of products compared to pyrolysis. Both processes result in compounds with strong biological effects. Photooxidation results in compounds with low genotoxicity and high Ah receptor affinity while pyrolysis generates compounds with high genotoxicity and low or no Ah receptor affinity.
