II. CHEMISTRY 527 



Structure: 



O 



II 



c 



/ \ 



HN NH 



I I 



HC CH 



I I 



HjC CH(CHj)4C00H 



\ / 



S 



Biotin 



II. Chemistry 



PAUL GYORGY 

 A. ISOLATION 



The identification of biotin with the curative factor (vitamin H) for 

 egg white injury^ helped to merge the originally independent studies deal- 

 ing with a microbiological yeast factor (biotin) and a vitamin-like substance 

 (vitamin H). Furthermore, it has been suggested^ that biotin and vitamin H 

 are also identical with coenzyme R, a gro^vth and respiration factor for 

 many strains of legume nodule bacteria.^ The identity of biotin and coen- 

 zyme R had previously been indicated by other investigators.^ • ^ 



Biotin as growth factor for yeast has been isolated in the form of a crys- 

 talline methyl ester from egg yolk by Kogl and Tonnis.^ 



Vitamin H was first recognized as the curative factor for egg white in- 

 jury. The toxicity of egg white as a food constituent was first observed 

 by Bateman^ and confirmed, at least under special conditions, by several 

 other investigators in the past.'^-^- Rats fed a ration that was well bal- 



1 P. Gyorgy, D. B. Melville, D. Burk, and V. du Vigneaud, Science 91, 243 (1940). 



2 F. E. Allison, S. R. Hoover and D. Burk, Science, 78, 217 (1933). 



^ R. Nilsson, G. Bjalfoe, and D. Burstrom, Naturwissenschaften 27, 389 (1939). 



* P. M. West and P. W. Wilson, Science 89, 607 (1939). 



5 F. Kogl and B. Tonnis, Hoppe-Serjler's Z. physiol. Chem. 242, 43 (1936). 

 " W. G. Bateman, J. Biol. Chem. 26, 263 (1916). 

 'M. A. Boas, Biochem. J. 21, 712 (1927). 



* E. Friedberger and S. Seidenberg, Deitt. rned. Wochschr. 53, 1507 (1927). 

 9 F. Stenquist, Detd. nied. Wochschr. 54, 1920 (1928). 



»" P. Gyorgy, Z. arzil. Forhild. 28, 377, 417 (1931). 



1' II. T. Parsons and E. Kelly, J. Biol. Chem. 100, 645 (1933). 



*» n. T. Parsons and E. Kelly, Am. J. Physiol. 104, 150 (1933). 



