Electrochemical oxidation of 2',3'-dideoxyadenosine at pyrolytic graphite electrode

The oxidation chemistry of 2',3'-dideoxyadenosine (I) has been studied at a pyrolytic graphite electrode (PGE) in the pH range 2.4-10.9 and a well defined oxidation peak was noticed. The peak potential of the peak was linearly dependent on pH with dE(p)/dpH as 42 mV/pH. Voltammetric, coulometric, spectral studies and product analysis indicate that the oxidation of (I) occurs in an EC reaction involving 6e(-), 6H(+) process at pH 7.2 to give allantoin, C-C dimer and dideoxyribose as the major products and a C-O-O-C linked dimer as a minor product. Tentative mechanisms for the formation of the products have also been suggested. A comparison of peak potential value of 2',3'-dideoxyadenosine with adenosine and 2'-deoxyadensoine indicated that the difference is insignificant which has further been supported by the calculations of difference of energies of lowest unoccupied and highest occupied molecular orbitals. (c) 2008 Elsevier Ltd. All rights reserved.