Collect. Czech. Chem. Commun. 1988, 53, 479-486

Kinetic study of permanganate oxidation of L-leucine in neutral aqueous solution

Enrique Brillas, José A. Garrido, Joaquin F. Perez-Benito, Rosa M. Rodriguez and Jaime de Andres

Department of Physical Chemistry University of Barcelona, 08028-Barcelona, Spain


The permanganate oxidation of L-leucine in aqueous phosphate buffers over the pH range 6.1 – 7.6 is autocatalyzed by the manganese reduction product, a soluble form of colloidal manganese dioxide. The kinetic data for both the non-catalytic and autocatalytic reaction pathways have been obtained, and mechanism in agreement with them proposed. The non-catalytic pathway takes place by reaction between either the anionic or the zwitterionic form of the amino acid and permanganate ion, whereas the autocatalytic pathway is realized by the permanganate oxidation of the amino acid previously adsorbed on the colloid surface.