Kinetics and Mechanism of Transamination of Thiamine in the Presence of Bisulfite

Abstract

The transamination reaction of thiazole moiety of thiamine (PyTh) by aromatic amine (A) in the presence of bisulfite (S) was studied kinetically. The reaction between PyTh and A was found to be second order with respect to PyTh and A, whereas the concentration of S was independent to the reaction rate. The reaction rate was linearly correlated to the pK_a value of A. The transamination product (PyA) was also degradated by S in second order as well as PyTh. The complexation between PyTh and A was also investigated as a possible proceeding process of the transamination reaction.