THE VITAMIN B COMPLEX 



German occupation of Holland and suggested a formula which he 

 subsequently admitted, in the light of du Vigneaud's results, to be 

 erroneous. Actually, Kogl's biotin is probably different from, although 

 closely related to, du Vigneaud's, and what is believed to be the 

 correct formula for egg-yolk biotin was suggested by Kogl in 1944. 

 Folic acid was isolated in 1941 from spinach leaves by Prof. R. J. 

 Williams, of pantothenic acid fame, and Dr. E. E. Snell, who had 

 already carried out a large amount of microbiological work in connec- 

 tion with members of the vitamin B complex. Similar substances 

 were subsequently isolated from yeast and liver, and synthesised in 

 1946 by research chemists employed by the Lederle Labs. Inc., Pearl 

 River, New York, and the American Cyanamid Co., Bound Brook, 

 New Jersey. The latest member of the vitamin B complex to be 

 discovered, vitamin Bjg, was obtained in crystalline form in 1948 by 

 the Merck group already referred to and by Dr. E. Lester Smith of 

 Glaxo Laboratories Ltd., Greenford. 



This is the story in briefest outline of the vitamin B complex. In 

 the chapters that follow, details are given of the isolation, chemistry, 

 biological properties and functions of each vitamin in turn, and in a 

 final chapter an attempt is made to show the close biological relation- 

 ship that exists between these substances by indicating the different 

 stages of metabolism in which each participates. 



