Other Notes Coenzymes and Cofactors, vol. 2: Pyridine Nucleotide Coenzymes1,2 Biochem/physiol Actions Nicotinamide (Niacinamide) (Nam) is a building block (active component) of coenzymes nicotinamide adenine dinucleotide (NAD) and nicotinamide adenine dinucleotide phopshate (NADP). Nicotinamide may be used as a substrate of nicotinamide phosphoribosyltransferase (NAMPT, EC 2.4.2.12), the rate-limiting enzyme for NAD(+) biosynthesis and an important signaling molecule. Nicotinamide is an amide derivative of vitamin B3 and a PARP inhibitor |