Nicotinic Acid and Amide

Vitamin Ba (pyridoxine, pyridoxal, pyridoxamine) like nicotinic acid is a pyridine derivative. Its phosphorylated form is the coenzyme in enzymes that decarboxylate amino acids, e.g., tyrosine, arginine, glycine, glutamic acid, and dihydroxyphenylalanine. Vitamin B participates as coenzyme in various transaminations. It also functions in the conversion of tryptophan to nicotinic acid and amide. It is generally concerned with protein metabolism, e.g., the vitamin B8 requirement is increased in rats during increased protein intake. Vitamin B6 is also involved in the formation of unsaturated fatty acids. 

For more specific analysis, chromatographic methods have been developed. Using reverse-phase columns and uv detection, hplc methods have been appHed to the analysis of nicotinic acid and nicotinamide in biological fluids such as blood and urine and in foods such as coffee and meat. Derivatization techniques have also been employed to improve sensitivity (55). For example, the reaction of nicotinic amide with DCCI (AT-dicyclohexyl-0-methoxycoumarin-4-yl)methyl isourea to yield the fluorescent coumarin ester has been reported (56). After separation on a reversed-phase column, detection limits of 10 pmol for nicotinic acid have been reported (57). 

Owing to poor volatihty, derivatization of nicotinic acid and nicotinamide are important techniques in the gc analysis of these substances. For example, a gc procedure has been reported for nicotinamide using a flame ionisation detector at detection limits of - 0.2 fig (58). The nonvolatile amide was converted to the nitrile by reaction with heptafluorobutryic anhydride (56). For a related molecule, quinolinic acid, fmol detection limits were claimed for a gc procedure using either packed or capillary columns after derivatization to its hexafluoroisopropyl ester (58). 

Both nicotinic acid and nicotinamide have been used in the enrichment of bread, flour, and other grain-derived products. Animal feed is routinely supplemented with nicotinic acid and nicotinamide. Nicotinamide is also used in multivitamin preparations. Nicotinic acid is rarely used in this appHcation. The amide and carboxyHc acid have been used as a hrightener in electroplating baths and as stabili2er for pigmentation in cured meats. 

The vitamins niacin (nicotinic acid, and its amide niacin amide are... 

Early investigators assumed that human erythrocytes could convert nicotinic acid, but not the amide, into NAD (H3, H8). There are later reports to the contrary, i.e., that nicotinamide, but not the acid, produced increased synthesis of NAD-active material (L3). To resolve these discrepancies, standards for assaying nicotinic acid activity were prepared by mixing equal weights of the acid and amide, because these... 

We have developed a direct assay for vitamin Be in blood, serum, urine, cerebrospinal fluid, and tissue, based on the ciliate, Tetrahymena pyriformvs. The techniques are essentially those described for nicotinic acid (see Section 4.1), except that vitamin Be is omitted from the basal medium both nicotinic acid and its amide are added each at 0.1 mg/100 ml of basal medium. The method for blood, serum, urine, cerebrospinal fluid, and tissues is given below. 

The usable range for T. pyriformis is from 0.3-300 mug/ml. The organism utilizes pyridoxal, pyridoxamine pyridoxine, and pyridoxal-5-phosphate. Pyridoxamine + pyridoxal yielded the best growth approximately 120 times more pyridoxine is required to yield the same growth as pyridoxamine (Fig. 4). As with nicotinic acid and its amide, when these compounds are added together in the same concentration, the increment of growth is less than the sum of the individual increments. Upon an intramuscular load dose of 100 mg of pyridoxine, peak vitamin Bs levels are reached 2 hours after injection. The curves for 4 normal individuals are illustrated in Fig. 5. 

Pharmacology Niacinamide is synonymous with nicotinamide, 3-pyridine carboxamide, and nicotinic acid amide. Niacinamide is the amide of nicotinic acid (niacin, vitamin B3). Although nicotinic acid and nicotinamide function identically as vitamins, their pharmacologic effects differ. Nicotinamide does not have the hypolipidemic or vasodilating effects characteristic of niacin (nicotinic acid). 

Values of the dissociation constant due to N in the ring of nicotinic acid and the amide were found to be 3.55 x 10-11 and 2.24 x 10 n (from ultraviolet absorption spectra), whereas the value for the dissociation of amide groups is generally much smaller (acetamide, 3.1 x 10"15). It is, therefore, reasonable to assume that Kt and K4 are large compared with K2 and K3. Using these assumptions, the observed rate, v, is given by... 

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

An important characteristic is the considerable increase in the band in 0.1 M acid (for example pheniramine maleate [308], nicotine [3003]). Some of these characteristics persist in the presence of functional groups, as in nicotinic acid and nicotinic acid amide [1802, 2805]. The narrow bands disappear in isonicotinic acid [2907]. In hydroxy-pyridine compounds [2806] the character of the spectrum changes completely, similar in some respects to the phenols (e. g. -> shift in alkaline solution). 

Use Solvent in synthesis of pharmaceuticals, resins, dyestuffs, rubber accelerators, insecticides, preparation of nicotinic acid and nicotinic acid amide, waterproofing agents, laboratory reagent. 

Chemically, 3-picoline is the ideal starting-material for nicotinic acid or amide the methyl group can be selectively and readily oxidized to the carboxyl derivative with few by-products or pollutants. High selectivity coupled with the low molecular weight ratio (1 1.3) compared to the end-products make picoline an attractive industrial starting-material for the production of nicotinic derivatives. 

Nicotinic acid (pyridine-3-carboxylic acid), mp 236°C, was first obtained by oxidation of the alkaloid nicotine by KMn04. It is produced commercially from 5-ethyl-2-methylpyridine (see p 291). Nicotinic acid and its amide belong to the B group of vitamins (vitamin B5). The daily requirement of an adult is ca. 20 mg. Deficiency of nicotinic acid causes pellagra, a skin disease. 

Nicotinic acid was first identified as an essential dietary supplement in 1937. It can be found in an active form as either free nicotinic acid, the amide derivative or bound to the pyridine-containing nucleotides (nicotinamide adenine dinucleotide (NAD) and the corresponding phosphate ester (NADP)). 

Relation of nicotinic acid and nicotinic acid amide to canine black tongue. J. Amer. chem. Soc. 59, 1767 (1937). 

Beta-picoline is similar to the olpho compound. It is soluble in water with which it forms o constant-boiling mixture it is also soluble in ethyl olcohol and ethyl ether. Suggested uses for it are in the manufacture of alkaloids, pharmaceuticals and rubber occeleratars. It is also o starting moterial for the production of nicotinic acid and nicotinic acid amide. 

Treatment of nicotinic acid and isonicotinic acid, or their corresponding amides, with sodamide followed by oxidation with concentrated nitric acid affords 2,6-diaminopyridine. ... 

As a simple indole derivative, the aromatic amino acid tryptophan (2-amino-3-(3-indolyl)-propionic acid) plays an important part in animal and plant metabolism. Its degradation via kynurenine leads, e. g., to formation of nicotinic acid and its amide or of ommochromes which have been found as pigments especially in crustaceans and insects. Observations made on mutant strains of insects and of the mould Neurospora crassa, in which the biosynthetic routes mentioned are blocked, have given a profound insight into the physiology of gene activity [6]. 

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. 

Nicotinic acid and nicotinamide are pyridine-3-carboxylic acid and its amide respectively their structural formulas are ... 

Both nicotinic acid and its amide can be determined by the above methods. If the determination of either one alone is desired, the two compounds can be separated by extracting the amide derivative with ether from an aqueous solution. 

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