In-vitro metabolism of fluorinated diakylnitrosamines

To elucidate differences in metabolism caused by fluorination of NDEA and NDBA, these compounds and their fluorinated analogs (NDEA-F3, NDEA-F6, NDBA-F3, NDBA-F6 and NDBA-F1 4) were incubated with rat liver microsomal fractions. Aldehydes, nitrite and unchanged nitrosamines were determined. Additionally, the mutagenicity was investigated with a Salmonella/mammalian microsome assay. NDEA-F6 and NDBA-F1 4 were not appreciably metabolized and were not mutagenic. NDEA, NDEA-F3, NDBA, NDBA-F3 and NDBA-F6 were dealkylated and, to a lesser extent, denitrosated. Dealkylation at the fluorinated alkyl group was inhibited, especially in the case of NDEA-F3. Whereas NDEA, NDBA, NDBA-F3 and NDBA-F6 were clearly mutagenic, mutagenicity of NDEA-F3 was only marginal.