Kinetics of oxidation of monosaccharides with cerium(IV)

✍ Scribed by Pentti O.I. Virtanen; Raija Lindroos; Eija Oikarinen; Juhani Vaskuri

• Publisher: Elsevier Science
• Year: 1987
• Tongue: English
• Weight: 539 KB
• Volume: 167
• Category: Article
• ISSN: 0008-6215
• DOI: 10.1016/0008-6215(87)80265-3

✦ Synopsis

The kinetics of the oxidation of n-galactose, D-glucose, o-mannose, D-fructose, L-sorbose, L-arabinose, D-ribose, and rr-xylose with cerium(IV) in perchloric acid were studied. Two complexes were found to form in each case. The first complex forms in a pre-equilibrium reaction during mixing in the stopped-flow apparatus. Michaelis-Menten kinetics were observed for this oxid'ation. The values of the complex-formation and dissociation rate-constants were determined in 1 .OM HClO,. The dissociation partly involves the oxidation of the first complex and partly, the formation of a second, more-stable complex. This second complex is oxidized much more slowly than the first, and the values of the pseudo-first-order rate-constant were again determined in 1.0~ HCIO,. The values proved to be almost constant in the range of 0.1~ to 1.0~ [Sugar], from which it was concluded that practically all of the Ce(IV) was complexed.