Proton coupled electron transfer (PCET) is of outstanding importance in biochemistry, especially in the fields of photosynthesis and oxidative DNA damages.[1,2] Herein, as a first step toward the study of the adenosine:thymidine H-bonded complex, we report spectroelectrochemical measurements of the UV-vis and IR absorption spectra of oxidized adenosine (Ado) in dichloromethane, which unequivocally demonstrate the occurrence of a PCET in Ado oxidation [3, 4]. Spectroelectrochemical measurements indicate that in CH2Cl2 Ado oxidation at the electrode induce self-association, followed by PT from the exocyclic amine group of oxidized Ado to the N1 and in a lesser extent to N7 nitrogens of the neutral Ado partner. Understanding whether electron transfer can be coupled to PT in DNA is of outstanding importance, because PT processes can both affect nucleobase oxidation potential and inhibit long range hole transfer along DNA single strand or duplex. Spectroelectrochemistry appears to be a very powerful and promising tool for investigating PCET processes and more generally the reaction mechanisms of electrolyzed species.[5,6,7
PROTON COUPLED ELECTRON TRANSFER IN ADENOSINE SELFAGGREGATES
CAPOBIANCO, AMEDEO;CARUSO, Tonino;PELUSO, Andrea
2013-01-01
Abstract
Proton coupled electron transfer (PCET) is of outstanding importance in biochemistry, especially in the fields of photosynthesis and oxidative DNA damages.[1,2] Herein, as a first step toward the study of the adenosine:thymidine H-bonded complex, we report spectroelectrochemical measurements of the UV-vis and IR absorption spectra of oxidized adenosine (Ado) in dichloromethane, which unequivocally demonstrate the occurrence of a PCET in Ado oxidation [3, 4]. Spectroelectrochemical measurements indicate that in CH2Cl2 Ado oxidation at the electrode induce self-association, followed by PT from the exocyclic amine group of oxidized Ado to the N1 and in a lesser extent to N7 nitrogens of the neutral Ado partner. Understanding whether electron transfer can be coupled to PT in DNA is of outstanding importance, because PT processes can both affect nucleobase oxidation potential and inhibit long range hole transfer along DNA single strand or duplex. Spectroelectrochemistry appears to be a very powerful and promising tool for investigating PCET processes and more generally the reaction mechanisms of electrolyzed species.[5,6,7I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
