Abstract
Twenty kinds of pyrimidine compounds, structually related to thiamine were examined for the growth inhibition of the thiamine requiring microorganisms ; Lactobacillus fermenti 36 and Kloeckera apiculata IFO No. 0630. The results indicated that only pyrimidine compounds similar to the pyrimidine moiety of thiamine were inhibitory to the growth of both microorganisms. Among the compounds shown in Table 1,2-methyl-4-aminopyrimidine (No.8), 2-methyl-4-amino-5-methylpyrimidine (No.7) and other derived compounds (No.2〜6) from No.7 were inhibitory in each concentration of 10^<-4> mole/tube, while such derived compounds as 5-carboxylic or 5-methanesulfonic were proved to be non-inhibitory. Compounds No.1 and 3 were the most inhibitory ; the compound having a -CH_2N= substitution in the 5-position is more antagonistic to thiamine than that having -CH_2- in 5. Inhibition by other compounds having different substitutions in 2 or 4 position of the pyrimidine moiety was negligible ; all the compounds showed practically no inhibition.
