1966 年 86 巻 10 号 p. 900-905
The stability of thiamine in the presence of sulpyrin in buffered aqueous solutions was examined over a pH range of 3.5 to 6.0. The apparent first-order rate constants at various pH and various sulpyrin concentrations were determined. The influence of ionic strength and acetate ion concentration was also investigated. By the addition of sulpyrin decomposition product, 4-methylaminoantipyrine, bis(4-methylaminoantipyrinyl)methane, aminopyrine, or formaldehyde sodium bisulfite, the hydrolysis of thiamine in the presence of sulpyrin appears to be catalyzed by bisulfite ion formed as a result of hydrolytic cleavage of sulpyrin. Decomposition of thiamine with sulpyrin yielded a substance (VIII) of m.p. 183∼184°, which was found to be N-methyl-N-[(2-methyl-4-amino-5-pyrimidyl)methyl]-4-aminoantipyrine from its ultraviolet and infrared spectra, color reaction, and elementary analysis. Further, 4-methyl-5-thiazoleethanol and 2-methyl-4-amino-5-pyrimidinemethanol were identified as the decomposition products of thiamine.