Simulation of oxidative stress of guanosine and 8-oxo-7,8-dihydroguanosine by electrochemically assisted injection-capillary electrophoresis-mass spectrometry

Scholz, Rebekka and Palatzky, Peter and Matysik, Frank-Michael (2014) Simulation of oxidative stress of guanosine and 8-oxo-7,8-dihydroguanosine by electrochemically assisted injection-capillary electrophoresis-mass spectrometry. ANALYTICAL AND BIOANALYTICAL CHEMISTRY, 406 (3). pp. 687-694. ISSN 1618-2642, 1618-2650

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Abstract

Oxidative stress plays a crucial role in DNA and RNA damage within biological cells. As a consequence, mutations of DNA can occur, leading to disorders like cancer and neurodegenerative and cardiovascular diseases. The oxidative attack of guanosine and 8-oxo-7,8-dihydroguanosine is simulated by electrochemistry coupled to capillary electrophoresis-mass spectrometry. The electrochemical conversion of the compound of interest is implemented in the injection protocol termed electrochemically assisted injection (EAI). In this way, oxidation products of guanosine can be generated electrochemically, separated by capillary electrophoresis, and detected by electrospray ionization time-of-flight mass spectrometry (EAI-CE-MS). A fully automated laboratory-made EAI cell with an integrated buffer reservoir and a compartment holding screen-printed electrodes is used for the injection. In this study, parameters like pH of the sample solution and the redox potential applied during the injection were investigated in terms of corresponding formation of well-known markers of DNA damage. The important product species, 8-oxo-7,8-dihydroguanosine, was investigated in a separate study to distinguish between primary and secondary oxidation products. A comparison of product species formed under alkaline, neutral, and acidic conditions is presented. To compare real biological systems with an analytical approach for simulation of oxidative stress, it is desirable to have a well-defined control over the redox potential and to use solutions, which are close to physiological conditions. In contrast to typical HPLC-MS protocols, the hyphenation of EAI, CE, and MS enables the generation and separation of species involved without the use of organic solvents. Thus, information of the electrochemical behavior of the nucleoside guanosine as well as the primary oxidation product 8-oxo-7,8-dihydroguanosine can be characterized under conditions close to the physiological situation. In addition, the migration behavior found in CE separations of product species can be used to identify compounds if several possible species have the same mass-to-charge values determined by MS detection.

Item Type: Article
Uncontrolled Keywords: TEMPERATURE PHOTOSENSITIZED OXIDATION; ELECTRON-TRANSFER; GUANINE OXIDATION; NUCLEIC-ACIDS; EC/ESI-MS; DNA; PRODUCTS; SPIROIMINODIHYDANTOIN; REDUCTION; 8-OXO-7,8-DIHYDRO-2'-DEOXYGUANOSINE; Nucleoside oxidation; Electrochemistry; Capillary electrophoresis; Mass spectrometry; Electrochemically assisted injection; Guanosine; Oxidative stress
Subjects: 500 Science > 540 Chemistry & allied sciences
Divisions: Chemistry and Pharmacy > Institut für Analytische Chemie, Chemo- und Biosensorik > Instrumentelle Analytik (Prof. Frank-Michael Matysik)
Depositing User: Dr. Gernot Deinzer
Date Deposited: 02 Dec 2019 10:04
Last Modified: 02 Dec 2019 10:04
URI: https://pred.uni-regensburg.de/id/eprint/11063

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