One electron rsix potental of thiamine

Abstract

The radiolytic degradation of thiamine in aqueous medium under reducing conditions has been employed to assess the extent of one electron transfer to this vitamin from various radicals of known reduction potential for oxidation. The graphical plot of these two quantities has the typical shape of redox titrational curves. Eo1 for the reduction of thiamine inferred from this plot is ∼−0.5 V. This is close to the Eo1 for the oxidation of reduced thiazole moiety of thiamine in cyclic voltammetric experiments. The reversible one electron redox potential of thiamine may therefore be taken as ∼−0.5 V.