Physiological oxidized nitrosamines

Most of the C-diazeniumdiolates are not NO donors since they hydrolyze to produce nitrous oxide directly [174]. However, it has been found that carefully selected compounds can serve as NO donors under physiological conditions via alternative reaction pathways. Many cupferron analogs release NO via enzymatic oxidation [175] as do Oi-alkylated diazeniumdiolates [176]. Several novel types of NO-releasing N-hydroxy-N-nitrosamines have been prepared. These new preparative methods have been described in earlier sections. The precursors are enamines (Scheme 3.10), phenolates (Scheme 3.12), nitriles, and N-hydroxyguanidines (Scheme 3.9). 

Nitrates and nitrites are spread within environmental, food, industrial, and physiological systems. Nitrate may be reduced by bacteria to nitrite, and nitrite produces carcinogenic nitrosamines. Nitrite is also commonly employed in cured meat products to provide antimicrobial action, color fixation, and preservation. Nitrite can oxidize hemoglobin iron(II) to iron(III) resulting in methemoglobin, leading to a condition known as methemoglobinemia in children mainly. In excess, nitrates and nitrites may be toxic. 

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