Formation of N-Nitrosamines and N-Nitramines by the Reaction of Secondary Amines with Peroxynitrite and Other Reactive Nitrogen Species:  Comparison with Nitrotyrosine Formation

Reactive nitrogen species, including nitrogen oxides (N2O3 and N2O4), peroxynitrite (ONOO-), and nitryl chloride (NO2Cl), have been implicated as causes of inflammation and cancer. We studied reactions of secondary amines with peroxynitrite and found that both N-nitrosamines and N-nitramines were formed. Morpholine was more easily nitrosated by peroxynitrite at alkaline pH than at neutral pH, whereas its nitration by peroxynitrite was optimal at pH 8.5. The yield of nitrosomorpholine in this reaction was 3 times higher than that of nitromorpholine at alkaline pH, whereas 2 times more nitromorpholine than nitrosomorpholine was formed at pH