ANEURINE (thiamine) 



absence of pyridoxine. The effect of the pyridoxine was, however, 

 enormously enhanced, within certain limits of concentration, by the 

 presence of aneurine ; with high concentrations of pyridoxine, aneurine 

 had an antagonistic effect. Of sixteen fungi, chiefly Ceratostomella 

 spp., examined by W. J, Robbins and R. Ma,^^ four required aneurine 

 as such and were unable to utilise its intermediates, five others grew 

 with a mixture of the pyrimidine and thiazole halves and six grew 

 well with aneurine, or a mixture of the pyrimidine and thiazole com- 

 pounds or of the pyrimidine compound alone. None of the organisms 

 responded to the thiazole half only. Aneurine is a supplementary, 

 though not an essential, growth factor for Eremothecium Ashbyii.^'^ 



According to M. N. Musil,^^ cocarboxylase, aneurine, a mixture of 

 the thiazole and pyrimidine moieties or the thiazole moiety alone 

 produced what he terms " fermentative rearrangement " of the cells 

 of Endomyces magnusii, characterised by large cell nuclei poor in 

 thymonucleic acid. The pyrimidine moiety alone was without effect. 

 On addition of the thiazole compound, aneurine was synthesised, and 

 accumulated in the cells. 



Aneurine or a related substance appears to be S5nithesised by 

 several species of Actinomyces, since extracts prepared from cultures 

 stimulated the growth of Phy corny ces Blakesleeanus.^^ 



Pyruvic acid accumulates in cultures of Phycomyces Blakesleeanus 

 containing inadequate amounts of aneurine, though not in the total 

 absence of aneurine. ^^ The formation of pyruvic acid was prevented 

 by the addition of aneurine or of cocarboxylase or of a mixture of the 

 pyrimidine and thiazole halves of the molecule. 



The growth of Pityrosporum ovale was also increased by aneurine, 

 especially in the presence of asparagine.^^ The addition of oxalo- 

 acetate instead of aneurine caused an equal increase, however, and 

 the subsequent addition of aneurine did not augment the increase 

 further. This observation supports Kreb's hypothesis (page g6) 

 that aneurine catalyses the formation of oxaloacetic acid, but 

 objections have been made to this hypothesis on other grounds 

 (page 98). 



Bacteria 



Comparatively few bacteria have been shown to require aneurine, 

 in striking contrast to the widespread requirement for this factor 

 among yeasts and moulds. Indeed, great difficulty has been experi- 

 enced in devising a satisfactory assay method analogous to those now 

 in widespread use for ribofiavine, nicotinic acid and other members of 

 the \4tamin B complex. Only Lactobacillus fermenti appears to be 

 sufficiently exacting in its requirements to be of value for this purpose,^^ 



no 



