ANEURINE (thiamine) 



also appears to be present in raw clams. ^^ According to L. O. Krampitz 

 and D. W. WooUey/^ the enzyme consists of a heat-labile, non- 

 dialysable portion and a heat-stable dialysable portion. It appears 

 to effect a hydrolytic cleavage of the aneurine molecule into the 

 thiazole and pyrimidine halves : ^^ 



I I /C==C . CH2 . CH2OH __ I I 

 CH3— C C— CHg— n/ I CH3 . C C . CH2OH 



II II /XcH-S II II 

 N— CH CI N— CH 



CH3 



X:=C . CHa . CHjOH 



+ N^ I 



^CH— S 



+ HCl 



The presence of thiaminase in raw carp tissues and blood was 

 confirmed by K. Bhagvat and P. Devi/^ who also demonstrated the 

 existence of another anti-aneurine factor in certain cereals and oil 

 seeds. This second factor was soluble in water, but not in salt solu- 

 tions, and could be extracted from cereals by means of a water- 

 chloroform mixture. It was stated not to be enz5miic in nature, but 

 it could be separated by dialysis into a heat-labile, non -dialysable 

 part and a heat-stable, dialysable part, both of which inactivated 

 aneurine. The inactivated aneurine could be utilised by mosquito 

 larvae, but not by rats or pigeons. 



Thiaminase is also present in the tissues of shrimps and some 

 mussels, but it appears to be absent from crabs and some salt-water 

 fish.2o 



The existence of another natural product capable of producing 

 vitamin B^ deficiency on a vitamin B^ rich diet was reported by Weswig 

 et al.,^^ who showed that bracken, which causes " fern -poisoning " in 

 cattle, also poisons rats when given to the extent of 40 % of the diet ; 

 the animals died after twenty days with symptoms of vitamin B^ 

 deficiency. Animals given aneurine recovered. Bracken inactivated 

 aneurine in vitro and so to a smaller extent did the faeces of rats fed 

 on a diet containing bracken.^^" 



Stability of Cocarboxylase 



Aneurine pyrophosphate, or cocarboxylase (see page 93) is the 

 form in which aneurine functions as a co-enzyme. It is somewhat 

 more stable than aneurine when the two are compared at the same 



26 



