II. CHEMISTRY 595 



by these workers to \atamin B2 or G. By the use of a heat-treated ration 

 composed largely of yellow corn, middlings, and casein, Kline et alP de- 

 veloped a basal ration which regularly produced dermatitis in chicks and 

 was very useful in studies of a factor referred to as the chick antidermatitis 

 vitamin. Using this technique for the quantitative determination of this 

 vitamin, Woolley et alP obtained evidence that it was a hydroxy acid. 

 Further study indicated a close similarity between the properties of the 

 chick antidermatitis vitamin and those of pantothenic acid. Like panto- 

 thenic acid, the chick antidermatitis vitamin contained /3-alanine in its 

 molecule. Moreover, these workers succeeded in producing a partial syn- 

 thesis of physiologically active chick antidermatitis vitamin by coupling 

 /3-alanine with the acidic part of alkali-inactivated concentrates of the 

 chick antidermatitis vitamin. ^i - 22 



As a result of their investigations, Woolley et al.~^ • ^- suggested that the 

 chick antidermatitis vitamin was identical with pantothenic acid for the 

 following reasons. 



1. Both are acids composed of /3-alanine with an hydroxy acid in amide 

 linkage. 



2. Both are labile to hot acid and alkali. 



3. Both form heat-stable acetyl derivatives which distill at approxi- 

 mately the same temperature and pressure. 



4. The solubilities in various solvents of the free acids and salts of both 

 these vitamins are similar. 



Jukes^* fed a crude preparation of pantothenic acid, which he obtained 

 from Williams, to chicks with dermatitis and cured them. Although his 

 results are of limited significance because of impurity of the preparation, 

 they did serve to strengthen the evidence of Woolley and his coworkers. 

 In a later communication with a highly potent concentrate of pantothenic 

 acid, also obtained from Williams, Jukes^* was able to strengthen the evi- 

 dence still further for the identity of pantothenic acid and the chick anti- 

 dermatitis vitamin by the similarity in their dissociation constants and by 

 the constancy in the ration of chick activity to yeast growth activity of the 

 pantothenic acid preparations that he fed. Final proof of the identity of 



13 0. L. Kline, J. A. Keenan, C. A. Elvehjem, and E. B. Hart, /. Biol. Chem. 99, 295 

 (1932). 



20 D. W. Woolley, H. A. Waisman, 0. Mickelsen, and C. A. Elvehjem, /. Biol. Chem. 

 125, 715 (1938). 



21 D. W. Wooley, H. A. Waisman, and C. A. Elvehjem, J. Am. Chem. Soc. 61, 977 

 (1939). 



" D. W. Wooley, H. A. Waisman, and C. A. Elvehjem, J. Biol. Chem. 129, 673 (1939). 

 " T. H. Jukes, /. Am. Chem. Soc. 61, 975 (1939). 

 2* T. H. Jukes, J. Biol. Chem. 129, 225 (1939). 



