Characterization of the Oxidative Behavior of Cyclic Nucleotides Using Electrochemistry-Mass Spectrometry

The oxidative behavior of cyclic nucleotides, important intracellular second messengers, was investigated. Guanosine-3',5'-cyclic monophosphate, adenosine-3',5'-cyclic monophosphate and cytidine-3',5'-cyclic monophosphate were subjected to electrochemical oxidation at different pH using boron doped diamond (BDD) and screen-printed carbon (SPC) electrodes. While oxidation on SPC electrodes proceeds only via direct analyte-electrode electron transfer, BDD involves in addition the action of hydroxyl radicals, formed at the electrode surface. Generated oxidation products were analyzed by liquid chromatography coupled to high resolution mass spectrometry (LC-MS). As an alternative electrochemically assisted injection-capillary electrophoresis-mass spectrometry was used as a means for product generation and identification. The results obtained indicate that experimental conditions as well as the presence of the cyclic phosphate group influence the oxidative pathway of cyclic nucleotides. Simplicity of the experiment and the absence of complex biological matrices are the main advantages of electrochemistry over other techniques, employed for investigation of oxidative stress. Elucidation of oxidation products and reaction mechanism is an important aspect of therapeutic strategies of numerous severe diseases.