Nicotinamide
"Nicotinamide contains an amide instead of a carboxyl group" (Ferrier, 2014) as seen in Nicotinic Acid. Nicotinic Acid (Niacin) combines with Nicotinamide and tryptophan to form oxidised Nicotinamide adenine dinucleotide (NAD+) which can further be modified to Nicotinamide adenine dinucleotide phosphate (NADP+) via the hydrolysis of ATP.
References: D.Ferrier, Sixth Edition, (2014), Biochemistry, Lippincott Williams and Wilkins, (p379-380)