Evidence for the multiplicity of products from acid-treated reduced nicotinamide adenine dinucleotide (NADH).

Treatment of NADH with acid gives rise to as many as 10 products derived from breakdown of the dihydropyridine ring. These substances are neutral or cationic in character, and one or more may be carbonyls. They have been separated on a column of Dowex 1-formate and characterized spectrophotometrically. No evidence was obtained to indicate that acidification of NADH leads to formation of a dinucleotide containing a modified dihydronicotinamide moiety.