Abstract
The effect of hydroxymethylpyrimidine analogues on the thiamine biosynthesis from hydroxymethylpyrimidine and thiazole by baker's yeast was examined. Among various pyrimidine compounds including vitamin B_6,2-nor-4-amino-5-hydroxymethylpyimidine (2-nor-OMP), 2-methyl-4-amino-5-methylpyrimidine (5-CH_3-OMP), 2-methyl-4-amino-5-nor-pyrimidine (5-nor-OMP) were inhibitory in this order in the thiamine synthesizing system containing ATP and Mg^<2+> in the extract, while they were less inhibitory in the suspension of the cells. The growth inhibition of these compounds for a thiamine requiring mutant of E. coli (OMP-less strain. 70-17) was not observed. The structural analogy of these compounds were discussed comparing with the toxopyrimidine groups which were inhibitory on pyridoxal kinase of rat brain investigated by K. Makino, et al.
