Nicotine Niacin

The answer is a. (Murray, pp 627-661. Scriver, pp 3897-3964. Sack, pp 121—138. Wilson, pp 287-320.) The major contributor of electrons in reductive biosynthetic reactions is nicotinamide adenine dinucleotide phosphate (NADPH -I- H ), which is derived by reduction of NAD. NAD is formed from the vitamin niacin (also called nicotinate). Niacin can be formed from tryptophan in humans. In the synthesis of NAD, niacin reacts with 5-phosphoribosyl-l-pyrophosphate to form nicotinate ribonucleotide. Then, AMP is transferred from ATP to nicotinate ribonucleotide. Finally, the amide group of glutamate is transferred to the niacin carboxyl group to form the final product, NAD. NADP is derived from NAD by phosphorylation of the 2 -hydroxyl group of the adenine ribose moiety. The reduction of NADP to NADPH -I- H occurs primarily through the hexose monophosphate shunt. [Pg.261]

Schlitz, Kerbe, Brachstelle nickel (Ni) Nickel nicotinic acid (nicotinate)/ niacin... [Pg.464]

VITAT S - NIACINE,NICOTINAMIDEAND NICOTINIC ACID] (Vol25)... [Pg.23]

Vitamin B3. See Vitamins, Niacin, Nicotinamide, and Nicotinic acid. [Pg.1058]

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