Effects of methyl linoleate hydroperoxide and hydrogen peroxide on N-nitrosation of dimethylamine.

The effects of methyl linoleate hydroperoxide and hydrogen peroxide on the N-nitrosation of dimethylamine were investigated. Hydrogen peroxide inhibited the formation of N-nitrosodimethylamine by the reaction of dimethylamine and nitrite in citrate buffer (pH 3-5). The inhibitory effect was due to the loss of available nitrite by quantitative conversion into nitrate. The formation of N-nitrosodimethylamine from the reaction of dimethylamine and nitrous acid in chloroform was effectively inhibited by methyl linoleate hydroperoxide. The inhibitory effect of the hydroperoxide was much greater than that of methyl linoleate. The loss of nitrous acid from the reaction mixture was due to the conversion of nitrous acid into nitric acid and the formation of two adducts, both of which contained nitrogen and had peroxide and carbonyl or carbonyl-liberating functions. It is suggested that unsaturated fatty acids and lipid hydroperoxides are effective inhibitors of nitrosamine formation.