III. INDUSTRIAL PREPARATION 409 



number of examples of the influence of modifications in the pyrimidine or in 

 the thiazole moiety of thiamine on the biological activity of these thiamine 

 analogs. They arrive at the following conclusion: "as a result of these tests 

 it is e\'ident that the thiamine molecule can undergo very Uttle modifica- 

 tion without extensive loss of vitamin Bi activity." 



Williams and Cline'^ were a])lo to establish that the synthetic thiamine 

 hydrochloride was identical with the natural in composition, ultraviolet ab- 

 sorption and antineuritic potency. Eckler and Chen'* in elaborate pharma- 

 cological studies compared the curative doses and the minimum lethal 

 doses of natural and synthetic thiamine. This work confirmed the identity 

 of both substances. 



In several microorganisms the thiamine may be replaced by one or both 

 of its pyrimidine and thiazole moieties.-'' Abderhalden-' has shown that 

 higher animals too could sustain on the thiazole + pyrimidine moieties 

 instead of thiamine itself. One would think that this might be brought about 

 by the phenomenon of "refection," i.e., the synthesis of thiamine by the 

 microorganisms in the gut, as was found by Fridericia et alP But E. 

 Abderhaldcn and R. Abderhalden-^ stated that tissue extracts are capable 

 of synthesizing thiamine from the pyrimidine and thiazole parts — only to a 

 very small extent, however, up to about 1 % of the theoretical amount. 



III. Industrial Preparation 



H. M. WUEST 



A. FROM NATURAL SOURCES 

 1. Low" Concentrates from Rice Bran or Polishings 



Effective thiamine preparations go back as far as 1910, when Robert R. 

 Williams under the direction of E. B. ^>dder prepared the first crude ex- 

 tracts from rice bran in Manila which were used in the treatment of beriberi 

 in the Philippine Islands.' The preparation, called tikitiki extract (or just 

 tikitiki, the Tagalog word for bran) is still used in the Philippines, and 

 similar preparations are sold in Japan. 



In this country preparations of this kind were first made about 1930 by 



'» R. R. William.s and J. K. Cline, /. Am. Chein. Soc. 59, 216 (1937). 



>9 C. R. Eckler and K. K. Chen, Proc. Soc. Exptl. Biol. Med. 35, 45S (1937). 



" W. II. Schopfer, Enjeb. Biol. 16, 1 (1939). 



2' R. Abderhalden, Pflugers Arch. ges. Physiol. 243, 762 (1940). 



" L. S. Fridericia, P. Freudenthal, S. Gudjonsson, G. Johansen, and N. Schoul)ye, 



J. Hug. 27, 70 (1928). 

 " E. Abderhalden and R. Abderhalden, Pflugers Arch. ges. Physiol. 243, 85 (1939). 

 ' E. B. Vedder, Beriberi, p. 405. William Wood & Co., New York, 1913. 



