102 BACTERIOLOGICAL CHEMISTRY 



Aneurin. — ch, 



N==C.NH, CI I 



I 1 «| ! /C = C.CH.X^HaOH. 



CH3.C2 50 CH2— N/Sg* 6,1 



II3 4 1! ^CH— S 



N CH 



Pyriniidirie Thiazole 



Vitamin B^, aneurin or thiamine was shown to be a con- 

 stituent of bios by Williams in 1940. It was shown by 

 Knight that the substance required by Stajyhylococcus 

 aureus, in addition to nicotinic acid, and supplied by a 

 gelatin hydrolysate, meat extract or " marmite " (an auto- 

 lysed yeast preparation) was aneurin. It is active in con- 

 centrations of 0-003 jLtg./ml. It can be replaced by a mix- 

 ture of the corresponding 2-methyl-6-amino-5-amino- 



N = C.NH2 



methyl pyrimidine, CH3.C C— CH2NH2 and 4-methyl- 



N— CH 

 N - C.CH3 

 5- p -hydro xyethyl thiazole, |ljj ^l ^^jj qjj fragments but 



not by differently substituted fragments nor by differently 

 substituted aneurins. It was shown that the pyrimidine 

 moiety attached to an inactive thiazole as in thiochrome 

 (an oxidation jDroduct of aneurin) can act as a source of 

 the pyrimidine and that the thiazole moiety attached 

 to an inactive pyrimidine can serve as a source of thiazole. 

 Aneurin, or a mixture of the two components, has also 

 been shown to be essential for the growth of Phyccmiyces 

 blakesleeanus, of lactic acid bacteria and of propionic 

 acid bacteria. Some protozoa and some parasitic fungi 

 need intact aneurin and will not grow if the separate 

 components are supplied instead. Some organisms 

 need only one component and can synthesise the other. 

 Thus Mucor rammanianus can sjnithesise the pyrimidine 

 but not the thiazole whilst the red yeast, Rhodotorula 



