Controlled-potential electrosynthesis of glucosaminic acid from glucosamine at a gold electrode

The electrocatalytic oxidation of D-glucosamine (2-amino-2-deoxy-D-glucose) in alkaline and neutral solutions was examined using a carbon felt electrode modified with 2 nm core sized gold nanoparticles (Au-2 (nm) nanoparticles) and a gold plate electrode. The electrocatalytic voltammetric oxidation curves of D-glucosamine were obtained in both solutions. The voltammetric responses for the electrocatalytic oxidation at a Au-2 (nm) nanoparticle-modified electrode in both alkaline and neutral solutions were almost the same to those at a gold plate electrode. The oxidized product was identified to be D-glucosaminic acid (2-amino-2-deoxy-D-gluconic acid) generated by the 2-electron oxidation product of D-glucosamine by electrospray ionization time-of-flight mass spectra (ESI TOF-MS). The HPLC results also indicated that the oxidation product was D-glucosaminic acid. The controlled-potential electrolysis of D-glucosamine was performed at the Au-2 (nm) nanoparticle-modified carbon felt electrodes in both alkaline and neutral solutions. In the alkaline solution, at a potential of -0.2 V, D-glucosaminic acid was formed with a current efficiency of 100%. In the neutral solution, electrolysis at 0.4 V on D-glucosaminic acid was obtained with current efficiencies of 70%. (c) 2006 Elsevier B.V. All rights reserved.