Niacin and Niacinamide

Specifications for niacin and niacinamide for food use are given in the Vood Chemicals Codex (63) and for pharmaceutical use in the United States Pharmacopeia (64). The Codex also gives specifications for niacinamide ascorbate. 

U.S. manufacturers of niacin and niacinamide include Nepera, Inc. and Reilly Industries, Inc. U.S. suppliers include BASF Corporation, Hoffmann-La Roche Inc., and Rhc ne-Poulenc. Western European producers and suppHers include Degussa, Rhc ne-Poulenc, BASF, Hoffmann-La Roche, and Lon2a (71). In 1995, the prices for niacin and nicotinamide were 9.75/kg and 9.25/kg, respectively (72,73). 

S. P. Sood, D. P. Wittmer, S. A. Ismael, and W. G. Haney, Simultaneous high-performance liquid chromatographic determination of niacin and niacinamide multivitamin preparations reversed-phase, ion-pair approach, J. Pharm. Sci., 66 40 (1977). 

Nicotinic acid (melting point 236°C, density 1.473) and nicotinamide (melting point 129°C, density 1.400) are known as niacin and niacinamide in the food industry. Niacin is the most stable of all vitamins and is essential to humans and animals for growth and health. Niacin and niacinamide are nutritionally equivalent, and compete with one another. 

For production of niacinamide in the past, methylethylpyridine was oxidized with nitric acid to yield niacin, and P-picoline was treated with air and ammonia to produce the nitrile that was then hydrolyzed to niacinamide. A more modern process can produce both niacin and niacinamide from a single feedstock, either P-picoline or 2-methyl-5-ethylpyridine by oxidative ammonolysis, a combination of oxidation and animation. 

Procedure Chromatograph the Resolution Solution. The resolution, R, between the niacin and Niacinamide peaks is not less than 3.0. Chromatograph replicate injections of the Standard Preparation, record the chromatograms, and measure the responses for the major peaks. The relative standard deviation is not more than 2.0%. Separately inject equal volumes (about 20 p,L) of the Standard Preparation and the Assay Preparation into the chromatograph, record the chroma-... 

Niacin and niacinamide refer to nicotinic acid and its amide. Nicotinic acid is a pyridine derivative synthesized from tryptophan. 

Niacin and niacinamide (nicotinamide and nicotinic acid amide) are converted to the ubiquitous redox coenzymes nicotinamide-adenine dinucleotide (NAD)" and nicotinamide-adenine dinucleotide phosphate (NADP). ... 

The two commercial forms of the vitamin, niacin and niacinamide, are rapidly absorbed from both the stomach and intestine. As the dose increases, absorption decreases. It is not clear whether there is a feedback mechanism operating or the transport system becomes saturated. Conversion to the coenzyme forms occurs in the cells where NAD and NADP are needed. 

Since the human body produces neither nicotinic acid nor the amide, it is dependent on intake via foodstuffs. Although niacin is found in a bound form naturally in wheat, yeast and pork and beef liver, most niacin today is produced synthetically by chemical oxidation of alkyl pyridines. To demonstrate the economic significance of this, in 1995 worldwide a total of 22 000 metric tonnes of niacin and niacinamide were produced. Today between 35 000 and 40 000 tonnes are produced and the demand for nicotinates is rising. Thus, both economic and ecological factors play a significant role. 

USE Solvent intermediate in the dye and resins industries in the manuf OF insecticides, waterproofing agents, niacin, and niacinamide. 

Over 40 kinds of alkaloids from tobacco have been isolated and identified. The major alkaloids from tobacco are nicotine, cotinine, nornicotine, myosmine, nicotyrine, anabasine, and anatabine. The nicotine content is highest of most of the alkaloids and nicotine (Figure 8.3) has insecticidal, detoxifying, and refreshing activities. Nicotine is also commonly used to synthesize niacin and niacinamide (key intermediates). Niacinamide (Figure 8.3) is the amide of nicotinic acid (vitamin B3/niacin), a water-soluble... 

Figure 1.3 Niacin, Niacinamide, NAD, and NADP. Nicotinic acid and nicotinamide are now called niacin and niacinamide, in order to avoid confusion with nicotine. NAD niacinamide adenine dinucleotide NADP niacinamide adenine dinucleotide phosphate.

Niacin, also known as vitamin B3, nicotinic acid or vitamin PP, is a water-soluble B-complex vitamin (Table 7.1). This vitamin is the generic descriptor for two vitamers niacin and niacinamide. In the research literature the terms nicotinic acid/nicotinamide are most commonly used, while in medical practice niacin/niadnamide are preferred. The vitamin is obtained from the diet in the form of nicotinic acid, nicotinamide and tryptophan, which are transformed to nicotinamide adenine dinucleotides, NAD and NADP. These compounds participate in cellular oxidation-reduction reactions that are critical for energy production. NAD and NADP also participate in a wide variety of... 

Table 7.1 The chemistry of niacin and niacinamide. Vitamin B3 vitamers ...

Niacin in mature cereal grains, particularly in com, is largely bound and is poorly available alkali treatment of the grain increases the percentage absorbed. Meat and fish have the scarce free form of niacin and niacinamide but contain high levels of NAD/ NADP, which are available as niacinamide after digestion (Prousky et al. 2011). Fortification of flour and cereal products adds up to 20 mg of the free form of niacin per serving to items such as breakfast cereals (Food and Nutrition Board 1998). 

Niacin is also known as vitamin B3, nicotinic acid or vitamin PP. It is the generic descriptor for two vitamers niacin and niacinamide. 

Spector, R., 1979, Niacin and niacinamide transport In the central nervous system, J. Neurochem., 33 1285. 

The name niacin is often used for two compounds, namely pyridine-3-carboxylic acid and pyridine-3-carboxylic acid amide. This confusion occurs because there is no consistency in the empirical nomenclature used in nutrition literature. Harris 1 lists niacin and niacinamide as the terms preferred in the United States, and nicotinic acid and nicotinic acid amide in the British literature. A convenient solution to the problem would be to use the term niacin to refer generically to the two compounds of nutritional significance as anti-pellagra factor and adopt the names nicotinic acid and nicotinamide to refer specifically to each. Nicotinamide has been adopted by the Commission for the Reform of Nomenclature in Biological Chemistry of the International Union of Pure and Applied Chemistry, and nicotinic acid is already in current use in most British, United States and other scientific literature in English. 

Sherma, J., and Ervin, M. (1986). Quantification of niacin and niacinamide in vitamin preparations by densitometric thin layer chromatography. J. Liq. Chromatogr. 9 3423-3431. 

Hamano, T., Mitsuhashi, Y., Aoki, N., and Yamamoto, S., Simultaneous determination of niacin and niacinamide in meats by high-performance liquid chromatography, J. Chromatogr., 457, 403-408, 1988. 

Takatsuki, K., Suzuki, S., Sato, M., Sakai, K., and Usbizawa, I., Liquid cbromatograpbic determination of tree and added niacin and niacinamide in beef and pork, J. Assoc. Off. Anal. Chem., 70(4), 698 702, 1987. 

Niacin and niacinamide (also known as nicotinic acid and nicotinamide, respectively) or vitamin B3, chemically 3-pyridinecarboxylic acid and 3-pyridinecarboxamide, are able to form various cadmium complexes with known crystal and molecular structures. In order to rationalize the analysis, hereafter the complexes have been differentiated according to the ligand and, within each case, we have only considered the most relevant structures. 

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