THIAMINE 



693 



Table 45. The Activity of Antagonists Related to Thiamine. 



Analogue 



l-(2'-Methyl-4'-amino-5'-pyrimidylmethyl)- 

 2-methyl-3-(/3-hydroxyethyl)pyridinium 

 chloride (pyrithiamine) 



3-(2'-Methyl-4'-hydroxy-5'-pyrimidyl- 

 methyl)-4-methyl-5-(S-hydroxyethyl) 

 thiazolium chloride (oxythiamine) 



3-(2'-Butyl-4'-amino-5'-pyrimidylmethyl)- 

 4-methyl-5-(/3-hydroxyethyl)thiazolium 

 chloride 



2-Methyl-4-amino-5-bromoethylpyrimidine 



2-Methyl-4-amino-5-bromomethylpyrimidine 



2-Methyl-4-amino-5-chloromethylpyrimidine 

 2-Methyl-4-amino-5-hydroxymethylpyrimidine 

 2-Methyl-4-amino-5-aminomethylpyrimidine 

 2- Methyl-4-aminopy rimidine 



2-Methyl-4-amino-5-ethoxymethylpyrimidine 



4-Methyl-5-(/3-hydroxyethyl)thiazole 



pyrophosphate 

 Sulfathiazole 



Organism 



Mouse 

 Rat 



Ceratostomella 



fimbriata 

 Ceratostomella 



pennicillata 

 Phytophthora 



cinnamoni 

 Chalaropsis 



thielavioides 

 Lactobacillus 



fermenti 

 Endomyces vernalis 

 Penicillium 



digitatum 

 Mucor ramannianus 

 Saccharomyces 



cerevisiae 

 Staphylococcus 



aureus 

 Staphylococcus 



aureus 

 Salmonella 



gallinarum 

 Lactobacillus 



acidophilus 

 Neurospora crassa 

 Lactobacillus 



arabinosus 

 Escherichia coli 

 Escherichia coli 

 Mouse 



Inhibition 

 Index" 



ca20 6 

 ca 20 b 



7, 19 



10 



12 



11 

 50 

 10 c 



130 

 160 

 80° 



800 



800 

 2000 



700 



1000 



1900 

 400,000 



Rat 



Rat 



Rat 



Mouse 



Rat, mouse 



Rat, mouse 



Rat, mouse 



Lactobacillus 



fermentum 

 Lactobacillus 



fermentum 

 Yeast 



carboxylase 

 Yeast carboxylase 



40,000 

 2,000,000 d 

 20,000 

 Not 

 greater 

 than 25 

 ca 20 b 



f 

 i 

 f 

 > 20,000 

 3000 c 



20,000" 



10 c 

 ca 160 c ' * 



° For half-maximum growth. 



b Approximately 40 moles of the inhibitor nullified the effect of one mole of thiamine. 



c Using thiamine pyrophosphate as the growth factor. 



d For Clostridium butylicum, Lactobacillus casei, Lactobacillus delbruckii, Lactobacillus pcntoaceticus. 

 Streptococcus lactis R, Propionibacterium pentosaceum and hemolytic streptococcus H69D, the pyrithiamine 

 inhibition index is greater than 2X10 6 . 



e Quantitative data not available. 



I Subcutaneous administration of the inhibitor (7-9 mg to rats or 1-1.5 mg to mice) to animals main- 

 tained on a diet which appeared adequate for growth caused severe cramps and often death. 



a If thiamine pyrophosphate is used as the growth factor, 90% inhibition occurs when the inhibitor/ 

 growth factor ratio is 5000. 



* One mole of cocarboxylase was reported to prevent the union of 322 moles of sulfathiazole with the 

 carboxylase protein of yeast washed with alkaline phosphate buffer solution. 



