FORMATION OF THIAMINE DISULFIDE BY FERRICYANIDE AND ITS DEPENDENCY ON PH OF THE REACTION MEDIA

Abstract

Thiamine disulfide produced from thiamine in an alkaline medium immediately after adding ferricyanide solution or after allowing to stand for some time was determined by adsorption on and elution from Amberlite IRC-50. The formation was maximal at pH around 11.6, decreasing at other pH levels. Addition of ferricyanide after the solution was left standing for some time in an alkaline medium, resulted in production of less thiochrome and more thiamine disulfide with the lapse of minutes. The oxidation of thiamine with ferricyanide produces both thiochrome and thiamine disulfide simultaneously, but at pH 11 to 12, thiamine disulfide was predominantly produced and the reaction can be used as a practical synthetic method of the disulfide.