ANEURINE (thiamine) 



adoption of measures that allowed sudden mobilisation of the reserve 

 vitamins from organs and tissues. He therefore postulated that a 

 substance with true vitamin activity should be able {a) to cure re- 

 peatedly beriberi spasm occurring several times in the same animal ; 

 {b) to keep the animal alive after cure ; and (c) prevent the appear- 

 ance of symptoms of vitamin Bj deficiency. Tested in this way, the 

 2'-ethyl-4-methyl-, 2 '-fi-propyl-4-ethyl- and 4-ethyl analogues of 

 aneurine (compounds i, 4 and 6 above) had a true curative effect on 

 pigeons, and moreover the substances appeared to act directly and 

 not by conversion into aneurine. 

 The substances : 



Br 



-N 'C . CH3 



11 II 

 / Vr CH C . CH2 . CH2OH 

 H H ^^/ 



and CH3— C N 



II II 



CH C S\ 



I I >H 



CO— N— CH^ 



which had previously been shown to have a pseudo-antineuritic action 

 failed to achieve a second cure. 



The superior activity of compound i over aneurine was confirmed 

 by W. H. Schopfer,^^ using Phycomyces Blakesleeanus. Other com- 

 pounds tested at the same time were less active, with the sole exception 

 of cocarboxylase. 



W. Huber ^^ prepared 3-{2' : 4'-diamino-5'-pyrimidyl-methyl)-5- 

 ^-hydroxyethyl-4-methyl-thiazolium chloride hydrochloride, and found 

 it to be devoid of vitamin B^ activity on rats at a level of 25 fig. 

 This compound differs from aneurine in the presence of a second 

 amino group in the pyrimidine ring in place of the methyl group. 



Other compounds related to aneurine were prepared by E. R. 

 Buchman and E. M. Richardson.^ ^ In these the ^-hydroxyethyl 

 group of aneurine hydrobromide was replaced by a hydrogen atom or 

 an ethyl, vinyl, hydroxym ethyl, a-hydroxyethyl or a-, p- or y-hydroxy- 

 M-propyl group. None of the compoimds exhibited antineuritic 

 activity when fed to rats at a level of 0-5 mg. 



The 2-w-butylpyrimidine homologue of aneurine hydrobromide 

 was prepared by G. A. Emerson and P. L. Southwick,^^ and found to 

 inhibit growth and produce polyneuritis in rats fed a subnormal 

 amount of aneurine. The effects were prevented by feeding excess 



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