Ruthenate Ion Catalysed Oxidation of D-galactose and D-xylose by Alkaline Solution of Sodium Metaperiodate: A Kinetic Study

The kinetics of ruthenate ion (RuO₄^2–)-catalysed oxidation of D-galactose (Gal) and D-xylose (Xyl) by alkaline species of periodate, H₂IO₆^3–, in an aqueous solution at constant ionic strength shows zero order dependence on reducing sugar and first order dependence on RuO₄^2–. First-order dependence of the reaction on periodate and OH^- at their low concentrations tends to zero order in their higher concentration range. A slight increase in the rate of reaction with increase in ionic strength of the medium has also been observed. Various activation parameters have been computed. Lyxonic acid and threonic acid, along with formic acid, were identified as the main oxidation products for Gal and Xyl, respectively. A general mechanism involving bidentate interaction of a species of IO₄^– with a reactive species of sugar has been proposed.