Guanine radical detection was carried out by a new convenient and efficient method coupling electron paramagnetic resonance spectroscopy and indirect electrooxidation of guanine in different biological environments, from the free nucleotide to several types of DNA substrates. Compared to the widely used photoirradiation method, this method appeared more selective in the choice of the electrochemical mediator. Carried out in presence of a ruthenium mediator and PBN as spin trap, this method revealed two types of EPR spectra depending of the environment of the guanine radical. Both EPR spectra show the trapping of the neutral guanine radical G(-H)(•) obtained after fast deprotonation of the radical cation G(•+). However, they differ by the atom where the trapped radical is centered. This difference highlights the structural dependency of the environment on the nature of the radical formed. This work gave the evidence of an innovative method to detect in situ the guanine radical.
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http://dx.doi.org/10.1021/jp500952q | DOI Listing |
Int J Mol Sci
January 2025
Institute for Information Technologies Kragujevac, Department of Science, University of Kragujevac, Jovana Cvijića bb, 34000 Kragujevac, Serbia.
In this study, the antioxidant and prooxidant potency of protocatechuic aldehyde (PCA) was evaluated using density functional theory (DFT). The potency of direct scavenging of hydroperoxyl (HOO) and lipid peroxyl radicals (modeled by vinyl peroxyl, HC=CHOO) involved in lipid peroxidation was estimated. The repair of oxidative damage in biomolecules (lipids, proteins and nucleic acids) and the prooxidant ability of PCA phenoxyl radicals were considered.
View Article and Find Full Text PDFMolecules
December 2024
DNA Damage Laboratory of the Food Science Department, Faculty of Pharmacy, Medical University of Lodz, ul. Muszynskiego 1, 90-151 Lodz, Poland.
Each cell in the human body is continually exposed to harmful external and internal factors. During evolution, cells have developed various defence systems, divided into enzymatic and non-enzymatic types, to which low-weight molecule antioxidants belong. In this article, the ionisation potential and electron affinity, as well as global reactivity descriptors of Vitamin C, Melatonin, Uric Acids, and N-acetyl-L-cysteine, were theoretically investigated at the MP-2/aug-cc-pVTZ level of theory in the condensed (aqueous) phase.
View Article and Find Full Text PDFBiomolecules
December 2024
Institut de Chimie Physique, CNRS-UMR8000, Université Paris-Saclay, 91405 Orsay, France.
There is compelling evidence that the absorption of low-energy UV radiation directly by DNA in solution generates guanine radicals with quantum yields that are strongly dependent on the secondary structure. Key players in this unexpected phenomenon are the photo-induced charge transfer () states, in which an electric charge has been transferred from one nucleobase to another. The present work examines the factors affecting the population of these states during electronic relaxation.
View Article and Find Full Text PDFJ Am Soc Mass Spectrom
January 2025
Suntory Institute for Bioorganic Research, Suntory Foundation for Life Sciences, 8-1-1 Seikadai, Seika-Cho, Soraku-Gun, Kyoto 619-0284 Japan.
In this study, we analyzed purine derivatives using multimatrix variation matrix-assisted laser desorption ionization mass spectrometry (MALDI MS) with α-cyano-4-hydroxycinnamic acid (CHCA), 1,5-diaminonaphtalene (DAN), 5-formylsalicylic acid (FSA), and 5-nitrosalicylic acid (NSA) as matrices. Further, we focused on the abstraction/attachment of hydrogen from/to analytes and detected [M - H], [M + 2H] and/or [M + 3H] in MALDI MS spectra of compounds containing nitrogen and/or carbonyl oxygen. Although [M - H] generation of purine compounds in MALDI MS with conventional matrices was challenging, NSA-MALDI MS effectively yielded the [M - H]species of purine derivatives compared with CHCA, FSA, and DAN, and the [M - H]/[M + H] ratios reflected their structures, such as the substituting groups and positions.
View Article and Find Full Text PDFBiomacromolecules
January 2025
Chemistry Department, Faculty of Science, Cairo University, Giza 12613, Egypt.
Acyclovir (ACV) is a potentially effective antiviral medication; however, it has a serious drawback, which is its poor solubility, bioavailability, and short half-life. The goal of this study is to improve its drawbacks through the synthesis of nanogels. In this study, the cross-linked hyaluronic acid-grafted poly(acrylamide--itaconic acid) nanogel is synthesized successfully through free radical polymerization and used as a safe pH-responsive carrier for ACV.
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