Mechanistic Investigation of the Oxidation of Lysine by Oxone

Abstract

The kinetics and mechanism of oxidation of lysine, a basic α-amino acid, by oxone in an acetic acid/sodium acetate buffered medium (pH = 3.6–5.2) at 308 K has been investigated. The rate of disappearance of oxone at constant [lysine] and pH follows the equation: $$\frac{-\mathrm{d}[\mathrm{oxone}]}{\mathrm{d}t}=k_{1}[\mathrm{lysine}][\mathrm{oxone}]+k_{2}[\mathrm{acetate}][\mathrm{oxone}].$$ The experimental results rule out autocatalysis of the aldehyde product which was observed in other neutral α-amino acids reactions under the same kinetic conditions. The different behavior of lysine is due to the formation of the product, 6-amino-2-oxo hexanoic acid, which does not initiate the autocatalysis.