II. CHEMISTRY 457 



acetate. The N^-methylriicotinamide was adsorbed on a Decalso (Permutit) 

 column. After the column had been washed to remove impurities, the N'- 

 methylnicotinamide was eluted, using 25% potassium chloride solution. 

 The eluate was alternately evaporated and extracted with ethanol until 

 almost entirely free of potassium chloride. The characteristic picrate of 

 N^-methylnicotinamide was then formed, recrystalhzed, and decomposed 

 with hydrochloric acid to yield the free N^-methylnicotinamide which could 

 be crystallized from absolute ethanol. Other investigators have used meth- 

 ods differing but shghtly from that described above.^^- ^^ Beher*° has re- 

 ferred briefly to a method for isolating semimicro amounts of N^-methyl- 

 nicotinamide in which the compound is adsorbed on a cation exchange 

 resin and eluted with dilute hydrochloric acid which in turn is removed 

 with an anion exchange resin. The procedure was stated to give better 

 yields and was less time consuming than older methods. 



5. Isolation of 6-Pyridone of N^-Methylnicotin amide 



Knox and Grossman^^ isolated this substance from urine. The urine was 

 decolorized with basic lead acetate and the compound adsorbed on Lloyds' 

 reagent. After washing with 0.01 A'' hydrochloric acid, the compound was 

 eluted from the Lloyd's reagent with absolute ethanol. After evaporation, 

 the residue was dissolved in water and the compound extracted into iso- 

 butanol. This extract was dried with calcium sulfate, evaporated, and the 

 residue extracted with acetone. Crystals were obtained from the concen- 

 trated acetone extract. Recrystallization could be accomplished from either 

 acetone or water. 



6. Isolation of Other Nicotinic Acid Metabolites 



The isolation of dinicotinylornithine from chicken droppings has been 

 described by Dann and Huff.^^ Ackerman'*^ was apparently the first to 

 isolate nicotinuric acid. He administered nicotinic acid and isolated both 

 nicotinuric acid and trigonelline from urine. The nutritional significance of 

 nicotinic acid was not known at that time. Linneweh and Reinwein^^ also 

 isolated this substance from human urine. 



'*• M. Hochberg, D. Melnick, and B. L. Oser, J. Biol. Chem. 158, 265 (1945). 



39 J. M. Hundley and H. W. Bond, J. Biol. Chem. 173, 513 (1948). 



•"•VV. T. Beher, Absfr. 118th Meeting, Am. Chem. Soc, Chicago, p. 73C (September 



3-8, 1950). 

 " W. E. Knox and W. I. Grossman, J. Biol. Chem. 166, 391 (1946); 168, 363 (1947). 

 *^ W. J. Dann and J. W. Huff, ./. Biol. Chem. 168, 121 (1947). 

 « D. Ackerman, Z. Biol. 59, 17 (1912). 

 ^* W. Linneweh and H. Reinwein, Hoppe-Seyler's Z. physiol. Chem. 207, 48 (1932); 



209, 110 (1932). 



