ELECTROCHEMICAL REDUCTION OF ALPHA-KETOGLUTARATE IN THE PRESENCE OF AMMONIA AS A MEANS OF ACHIEVING SELECTIVELY THE REDUCTIVE AMINATION TO GLUTAMATE - THERMODYNAMIC AND KINETIC CHARACTERISTICS OF THE KETO IMINE EQUILIBRIUM

The electrochemical reduction of alpha-keto glutarate at a mercury cat hode in the presence of ammonia produces glutamate through selective r eductive amination. The sole side-product (ca. 5%) is due to spontaneo us degradation of alpha-keto glutarate in the medium. The species whic h undergoes the actual electrochemical reduction is the alpha-imino gl utarate. The keto/imine transformation has been analyzed quantitativel y. Its thermodynamic and kinetic characteristics are K = 0.18 +/- 0.03 for the equilibrium constant and k(f) = 0.21 +/- 0.04 M-1 h-1 and k(b ) = 1.3 +/-0.3 h-1 for the forward and backward rate constants, respec tively.