Nicotinic acid mixture with nicotinamide

A mixture of nicotinic acid, nicotinamide, trigonelline and tryptophan can be separated chromatographicaUy, using as solvent a 5 i mixture of n-butanol and concentrated hydrochloric acid, saturated with water. Tryptophan is revealed by ninhydrin, while nicotinic acid, nicotinamide and trigonelline are detected with phosphomolybdic acid reagent and the color developed with stannous chloride, which reduces the phosphomolybdic acid to give a blue spot. The Rf values for the butanol-HCl solvent are nicotinic acid, 0.37 nicotinamide, 0.28 trigonelline, 0.38 and tryptophan, 0.62. 

Gaseous ammonia was passed into nicotinic acid at a temperature between 200-235°C until the conversion to nicotinamide was 85%. The reaction mixture was colored light brown. The reaction mass was cooled and grounds to a fine powder. Fifty grams of this crude nicotinamide were boiled with 500 ml of anhydrous ethyl acetate until a dark solution was. obtained. A little solid... 

Benzonitrile acts in a similar way to form benzoic acid but requires sulfuric acid in the reacting mixture. Nicotinic acid amide (nicotinamide) has been prepared by the mild hydrolysis of 3-cyanopyridine, and acrylamide by the partial hydrolysis of acrylonitrile. Acrylonitrile may also be hydrolyzed to acrylic acid with mineral acids or with alkalies. Polyacrylonitrile is partially converted to the amide by nitric acid, and the nitrile oups of a number of polymers and copolymers have been hydrolyzed to amide and carboxylic acid groups to produce water-soluble polyelectrolytes. Isooyanides are stable toward alkalies but hydrolyze in the presence of acids to form an acid and an amine ... 

The first experiments were carried out with nicotinic acid (61), and it was found that mitochondrial oxidation of cholesterol was enhanced in rats fed this compound. It was later found (62) that addition of nicotinic acid (8 X 10 moles, 10 mg) to the incubation mixture enhanced oxidation of cholesterol. Of a large series of nicotinic acid and nicotinamide homologues tested, only 3-pyridylacetic acid also stimulated oxidation of cholesterol (62,63). This compound has also been shown to be hypocholesterolemic in man (64,65). Pyridinol carbamate, 2,6-bis(hydroxymethyl)pyridine-di-A -methylcarbamate, fed to rats as 1 % of their diet also enhanced in vitro oxidation of cholesterol by rat liver mitochondria (66). 

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