Investigations of electron-transfer reactions and the redox mechanism of 2′-deoxyguanosine-5′-monophosphate using electrochemical techniques

摘要: Electron-transfer reactions of 2′-deoxyguanosine-5′-monophosphate (dGMP) have been investigated in phosphate buffers different pH at a pyrolytic graphite electrode (PGE). In cyclic voltammetry, two well-defined oxidation peaks, Ia (pH 1.9–10.6) and IIa ≥ 5.8), were noticed. The peak potentials shifted towards less positive potential when was increased. Concentration sweep rate studies established the adsorption dGMP on surface. UV-vis spectral analysis 2.9 7.1 indicated formation UV-absorbing intermediate, which decayed pseudo first-order reaction (k = ∼5.05 × 10−4 s−1). Coulometric, voltammetric UV revealed 4H+,4e− by an EC (electrode followed chemical reactions) mechanism. characterization products achieved converting them to their trimethylsilyl derivatives. At 7.1, 5-hydroxyhydantoin-5-carboxamide (9) N–O–C8 linked trimer (18) and, 2.9, monohydrated alloxan (12), deoxyriboside urea (11), C8O–OC8 one C8–C8 bridged dimers (13, 14 15, respectively) formed as major products. A tentative redox mechanism has suggested for electrooxidation dGMP.