Substituted Nicotinamide Analogues of Nicotinamide Adenine Dinucleotide*

A number of nicotinamide adenine dinucleotide analogues have been prepared in which the purine, pyridine, and ribose moieties have been modified (2-12). These analogues have proven to be valuable in studies dealing with the site of binding of the pyridine coenzyme to dehydrogenases, in elucidating the mechanism of dehydrogenases and the configuration of the pyridme coenzymes, and as indicators in demonstrating the heterogeneity of enzymes catalyzing the same function. Johnson and M&o11 (8) and Dietrich, Friedland, and Kaplan (9) have prepared the 6-aminonicotinamide analogue of NADl and studied some of the properties of this analogue. It appeared to us that a detailed investigation of substituted nicotinamide analogues might be of general interest in elucidating the catalytic and physical chemical properties of the pyridine coenzymes. The present communication deals with the preparation and properties of some substituted nicotinamide analogues. Data will be presented showing that these analogues are of particular value for an understanding of the structural relationships of NAD.