A METHOD FOR THE DETERMINATION OF NICOTINIC ACID, NICOTINAMIDE, AND POSSIBLY OTHER PYRIDINE-LIKE SUBSTANCES IN HUMAN URINE

Abstract

The discovery of nicotinic acid in rice bran (1) and in yeast (2, 3) directed attention of biochemists to the natural occurrence of this pyridinecarboxylic acid.Funk suggested that it had some relation to vitamin B, but subsequent investigation showed that it made no part of vitamin B1 or Bz.The discovery by Warburg and associates (4) that it was present as the amide in coenzyme and by von Euler et al. ( 5) that it was a part of cozymase revived interest in it and indicated that it was playing an important part in the respiratory metabolism of both animal and plant cells.Following these clues, Elvehjem and his associates (6) discovered that its administration would cure the disease of black tongue in dogs, and Spies, Cooper, and Blankenhorn (7) reported its favorable action in the treatment of human pellagra, an action confirmed by others (8).Since there is no evidence that pyridine can be formed in the human body, it is evident that nicotinic acid or its amide must be an important article of human diet and that it is apparently necessary for the normal health of the mucosa of the mouth and intestine, nervous system, and skin, since these all are impaired in pellagra and improved by the ingestion of nicotinic acid or the amide.It must be necessary for the muscles also, and probably for the liver and some other organs, since it is an essential * A preliminary report was published (J.Am.Chem.Xoc.