Occurence and Reactivity of Nitrite Ion in Human Environments

Abstract

Nitrite ion in the biological fluids of man chiefly originates from i) nitrates which are widespread in environments and ingested as vegetable-components followed by reduction by microorganisms in alimentary tracts, and ii) nitrites which are added in foods, especially cured meat products, as a preservative or coloring agent. Besides being toxic itself, nitrite ion is well known as an active species which reacts with amines in foods under gastro-intestinal conditions to form hepatotoxic as well as carcinogenic nitrosamines. In this review, we show the fate and biological activities of nitrites in environments, foods and humans. Then we discuss, from the standpoint of bioorganic chemistry, the reactions between nitrite ion and various amines, which yield different biologically active substances-nitrosamines, triazenes, cyclization products derived from azide intermediates, or deaminated products.