Author(s): Rajendra N Goyal and Aikta Dhawan
Journal: International Journal of Electrochemical Science
ISSN 1452-3981
Volume: 1;
Issue: 6;
Start page: 304;
Date: 2006;
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Original page
Keywords: Adenosine | electrooxidation | purine nucleosides
ABSTRACT
The oxidation chemistry of adenosine (1) has been studied in Britton-Robinson buffers of pH range 2.2-10.1 at pyrolytic graphite (PGE) and glassy carbon (GCE) electrodes. The oxidation occurred in a single, well-defined peak (Ia) at about 200-250 mV less positive potential in comparison to phosphate medium. The peak potential of peak Ia was dependent on pH and shifted to less positive potential with increase in pH. Under cyclic voltammetric conditions oxidation occurred in Britton Robinson buffer in a 6e, 6H+ process in contrast to 5e, 5H+ process in phosphate medium and the nature of mechanism is found to be EC in which charge transfer is followed by chemical reactions. The major products of oxidation were found as allantoin, hydroxylated C-O-O-C and C-C dimers and ribose. A comparison of the observed behaviour in B.R. buffers with that observed in phosphate medium has also been presented Tentative mechanism for the formation of products has also been suggested.
Journal: International Journal of Electrochemical Science
ISSN 1452-3981
Volume: 1;
Issue: 6;
Start page: 304;
Date: 2006;
VIEW PDF
DOWNLOAD PDF Original pageKeywords: Adenosine | electrooxidation | purine nucleosides
ABSTRACT
The oxidation chemistry of adenosine (1) has been studied in Britton-Robinson buffers of pH range 2.2-10.1 at pyrolytic graphite (PGE) and glassy carbon (GCE) electrodes. The oxidation occurred in a single, well-defined peak (Ia) at about 200-250 mV less positive potential in comparison to phosphate medium. The peak potential of peak Ia was dependent on pH and shifted to less positive potential with increase in pH. Under cyclic voltammetric conditions oxidation occurred in Britton Robinson buffer in a 6e, 6H+ process in contrast to 5e, 5H+ process in phosphate medium and the nature of mechanism is found to be EC in which charge transfer is followed by chemical reactions. The major products of oxidation were found as allantoin, hydroxylated C-O-O-C and C-C dimers and ribose. A comparison of the observed behaviour in B.R. buffers with that observed in phosphate medium has also been presented Tentative mechanism for the formation of products has also been suggested.
