NICOTINIC ACID (NIACIN) 



acid and nicotinic acid diethylamide and this was not accompanied by 

 changes in the coenzyme I content of the blood or tissue. 



The behaviour of nicotinic acid diethylamide was apparently 

 much the same in pellagra and blacktongue, and the compound had 

 I /14th and i/7th the activity of nicotinic acid respectively in the two 

 conditions ; ^*^^' ^^' it had no effect on the coenzyme I content of 

 erythrocytes.^^ 



Huber et al^^ attempted to prepare derivatives of aneurine and nico- 

 tinic acid that could be added to cereals without being lost on sub- 

 sequent washing with water. Nicotinic acid and its amide, in contrast 

 to aneurine, failed to form satisfactory salts with methylene-bis-(2- 

 hydroxy-3-naphthoic acid) or 2-ethylhexyl-sulphuric acid, the basicity 

 of the ring-nitrogen being apparently reduced by the presence of the 

 carboxyl group. A series of w-alkyl esters of nicotinic acid was pre- 

 pared, the properties of which agreed with those reported earlier by 

 Badgett et al. These esters had too pronounced an odour for use in 

 the enrichment of cereals, but they formed salts with methylene-bis- 

 (2-hydroxy-3-naphthoic acid), and both the ethyl and butyl ester salts 

 were sparingly soluble in water. After treatment with dilute alkali, 

 both stimulated the growth of L. arabinosus. 



N-{^-Carboxyphenyl)-nicotinamide, N-(phenylcarbamyl) -nicotin- 

 amide and N-(6-methoxy-8-quinolyl)-nicotinainide were sparingly 

 soluble in water. The first two showed activity after standing in 

 dilute alkali, but the last was inactive after standing in dilute sulphuric 

 acid. 



Effect on IViicro-organisms 



The requirements of micro-organisms for nicotinic acid are even 

 more specific than are those of animals, and B. C. J. G. Knight and 

 H. Mcllwain 22 found that quinolinic acid, picolinic acid and isonico- 

 tinic acid, trigonelline, nicotinic acid diethylamide, nicotine, pyridine- 

 j3-sulphonic acid, 3-cyano-pyridine, jS-picoline, 2 : 4-dimethyl-pyridine- 

 3 : 5-dicarboxylic acid and 2:4: 6-trimethylpyridine-3 : 5-dicarboxylic 

 acid could not replace nicotinic acid as a growth factor for Staphylo- 

 coccus aureus. 



The requirements of Proteus vulgaris were just as specific, with two 

 exceptions ; for, whereas both organisms grew in presence of nicotinic 

 acid, and its sodium and ammonium salts, ethyl nicotinate, nicotin- 

 amide and nicotinuric acid, Pr. vulgaris also grew in presence of nico- 

 tinic acid mono- and diethylamides, whilst 5. aureus did not .22. 24 

 2- and 4-Methylpyridines were also inactive for S. aureus ^^. Accord- 

 ing to E. F. Moller and L. Birkofer,^^ nicotinic acid and its analogues 

 stimulated the growth o^ Pr. vulgaris in the following molar concentra- 



290 



