36597-25-8Relevant articles and documents
Investigations of electron-transfer reactions and the redox mechanism of 2′-deoxyguanosine-5′-monophosphate using electrochemical techniques
Goyal, Rajendra N.,Sondhi, Sham M.,Lahoti, Anand M.
, p. 587 - 595 (2007/10/03)
Electron-transfer reactions of 2′-deoxyguanosine-5′- monophosphate (dGMP) have been investigated in phosphate buffers of different pH at a pyrolytic graphite electrode (PGE). In cyclic voltammetry, two well-defined oxidation peaks, 1a (pH 1.9-1
Electrochemical and peroxidase catalysed oxidation of 9-β-D-ribofuranosyluric acid 5′-monophosphate
Goyal, Rajendra N.,Rastogi, Arshi
, p. 2423 - 2429 (2007/10/03)
The electrochemical oxidation of 9-β-D-ribofuranosyluric acid 5′-monophosphate (UA-9R-5′-P) in aqueous solution has been studied in the pH range 2.10-10.0. The evidence strongly indicates that UA-9R-5′-P is oxidized in a 2e-, 2H+ reaction to give an unstable diimine which subsequently decomposes. A UV absorbing intermediate is observed during electrooxidation which decays in a pseudo first-order reaction to give alloxan, urea and ribosyl phosphate at pH 3.0. Controlled potential electrolysis results in the transfer of 2.0 ± 0.2 electrons per molecule and three major products are obtained at pH 7.0; allantoin, 5-hydroxyhydantoin-5-carboxamide and D-ribose. Tentative reaction schemes are proposed to explain the formation of these products. Oxidation of UA-9R-5′-P in the presence of peroxidase and H2O2 also generates an intermediate which has spectral and kinetic properties identical to those of the intermediate generated electrochemically. Thus, it is believed that electrochemical and enzymic oxidation of UA-9R-5′-P proceed by identical reaction mechanisms.
On-line electrochemistry/thermospray/tandem mass spectrometry as a new approach to the study of redox reactions: the oxidation of uric acid.
Volk,Yost,Brajter-Toth
, p. 1709 - 1717 (2007/10/02)
The electrochemical oxidation pathway of uric acid was determined by on-line electrochemistry/thermospray/tandem mass spectrometry. Intermediates and products formed as a result of electrooxidation were monitored as the electrode potential was varied. Several reaction intermediates have been identified and characterized by tandem mass spectrometry. The tandem mass spectrometric results provide convincing evidence that the primary intermediate produced during the electrooxidation of uric acid has a quinonoid diimine structure. The results indicate that once formed via electrooxidation, the primary intermediate can follow three distinct reaction pathways to produce the identified final products. The final electrochemical oxidation products observed in these studies were urea, CO2, alloxan, alloxan monohydrate, allantoin, 5-hydroxyhydantoin-5-carboxamide, and parabanic acid. The solution reactions that follow the initial electron transfer at the electrode are affected by the vaporizer tip temperature of the thermospray probe. In particular, it was found that at different tip temperatures either hydrolysis or ammonolysis reactions of the initial electrochemical oxidation products can occur. Most importantly, the results show that the on-line combination of electrochemistry with thermospray/tandem mass spectrometry provides otherwise difficult to obtain information about redox and associated chemical reactions of biological molecules such as the structure of reaction intermediates and products, as well as providing insight into reaction pathways.
