Chapter VI 



PANTOTHENIC ACID 



I. HISTORICAL 



The story of pantothenic acid is closely bound up with that of pyri- 

 doxine. Both factors occur together in yeast and liver, and were 

 separated from one another by treatment with fuller's earth ; pyri- 

 doxine (the " eluate factor ") was retained on the adsorbent, whilst 

 pantothenic acid (the " filtrate factor ") remained in the filtrate. 

 The first concentrate of pantothenic acid substantially free from other 

 factors was prepared from liver by C. A. Elvehjem and C. J. Koehn/ 

 and by S. Lepkovsky and T. H. Jukes. ^ As the factor was found to 

 be effective in preventing and curing dermatitis in chicks, but not in 

 rats, it became known as the " chick antidermatitis factor ", and 

 chicks were used for assaying it. 



Edgar et al.^ prepared a yeast concentrate with properties similar 

 to those of Lepkovsky and Jukes' " factor 2 ", and showed that it 

 stimulated the growth of rats ; a method of assaying the factor was 

 devised, based on this property. 



Progress in the purification of the new vitamin was slow, partly 

 because it did not readily give rise to derivatives of a type that might 

 facilitate its isolation and characterisation, and partly because it was 

 present in admixture with other substances difficult to separate from it. 



The concentrates prepared by S. Lepkovsky and T, H. Jukes ^ and 

 by C. E. Edgar and T. F. Macrae ^ resembled one another in most 

 respects ; * thus, the active fraction could be extracted from acid 

 aqueous solutions by ether, butyl alcohol or amyl alcohol, it could 

 be precipitated from alcoholic solution by barium hydroxide and it 

 could be adsorbed on norit. Woolley et al.^ prepared the barium salt, 

 and purified it by extraction with absolute alcohol, most of the activity 

 passing into the soluble fraction. They also made an inactive acetyl 

 derivative, from which the activity was regenerated by hydrolysis. 

 This acetyl compound could be purified by high-vacuum distillation. 

 From this evidence it was concluded that the factor was an acid con- 

 taining one or more hydroxyl groups. G. H. Hitchings and Y. 

 SubbaRow ^ also prepared a concentrate of the substance and showed 

 that it was a growth factor for rats. 



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