Nicotinic acid mononucleotide is an intermediate in the biosynthesis of nicotinamide-adenine dinucleotide (NAD) from nicotinic acid as well as from tryptophan (l-3). We previously presented evidence which suggests that nicotinic acid mononucleotide may be involved in the feedback regulation of nicotinic acid synthesis from tryptophan (4, 5). These studies required fairly large quantities of nicotinic acid mononucleotide.
This compound was previously prepared by two methods. The first method utilizes an exchange reaction between NAD and nicotinic acid catalyzed by spleen NAD (P) nucleosidase (7) to prepare nicotinic acid dinucleotide (desamido NAD). The desamido NAD is then isolated by column chromatography and cleaved with snake venom phosphodiesterase to form nicotinic acid mononucleotide and adenosine monophosphate (AMP)
(3). This method is laborious, time consuming, and inefficient. The over-all yield of nicotinic acid mononucleotide by this method, in our hands, ran from 5 to 20%. The second method, developed by Atkinson and Morton (S), is a direct chemical one which uses commercially available nicotinamide mononucleotide as the starting material (8). Nitrous anhydride is used to hydrolyze the amide group from nicotinamide mononucleotide.
This procedure involves the generation of nitrous anhydride in situ and requires a complex apparatus. In addition, Atkinson and Morton did not present data for the yield obtained by their method.
We have substituted the use of nitrosyl chloride for nitrous anhydride. Nitrosyl chloride is available commercially in small cylinders. With this reagent, the synthesis of nicotinic acid mononucleotide is rapid and efficient. Yields of 75-85s a.re regularly obtained.