Niacin, Nicotinamide, and Nicotinic Acid

Abstract The history of the discovery of nicotinic acid and nicotinamide is unusual in that these compounds were first synthesized and later their biological significance was elucidated. In the early part of the twentieth century, the importance of nicotinamide in the treatment of pellagra was determined. Specifically, nicotinic acid and nicotinic amide are constituents of the cofactors NAD and NADH which are required for many enzymatic reactions and the particular role of these cofactors is discussed. The key intermediate in the industrial synthesis of these compounds are alkyl pyridines. Methods of preparation of these intermediates as well as methods to functionalize the side chain are reviewed. Both biological and chemical approaches have found utility in this application. A review of analytical methodology is presented. An overview of the biological effects of these substances is presented. Despite their structural similarities, the safety and toxicity of these compounds are quite different and these consequences are highlighted.