A Comparison of the Electronic Properties of Selected Antioxidants Vitamin C, Uric Acid, NAC and Melatonin with Guanosine Derivatives: A Theoretical Study.

Publisher: MDPI Country of Publication: Switzerland NLM ID: 100964009 Publication Model: Electronic Cited Medium: Internet ISSN: 1420-3049 (Electronic) Linking ISSN: 14203049 NLM ISO Abbreviation: Molecules Subsets: MEDLINE

Original Publication: Basel, Switzerland : MDPI, c1995-

Melatonin*/chemistry ; Melatonin*/pharmacology ; Antioxidants*/chemistry ; Antioxidants*/pharmacology ; Ascorbic Acid*/chemistry ; Ascorbic Acid*/pharmacology ; Uric Acid*/chemistry ; Acetylcysteine*/chemistry ; Acetylcysteine*/pharmacology ; Guanosine*/chemistry; Electrons ; Humans ; Oxidation-Reduction ; Models, Theoretical

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. The vertical ionisation potential and electron affinity are discussed in terms of non-equilibrated and equilibrated solvent-solute interactions. Additionally, at the same theoretical level, the electronic properties of canonical and oxidised derivatives of guanine were analysed. The presented results indicate that the selected antioxidants for this study (Vitamin C, Uric Acid, NAC, and Melatonin) exhibit the highest adiabatic electron affinity, while guanine derivatives (Gua, ^OXO Gua, Guo, dGuo, ^OXO Guo, ^OXO dGuo) are more prone to adiabatic radical cation formation. A red-ox balance (redox homeostasis) is crucial for intracellular signalling pathways that are reactive oxygen and nitrogen species (RO/NS)-dependent. Should this gentle balance be disrupted, either by an overload or deficit of species, physiological consequences may result, which in turn lead to pathological outcomes. On the other hand, maintaining the stability of the above balance of antioxidants/radicals may result in the improved effectiveness and safety of anticancer radiotherapy/chemotherapy or combined therapies with a subsequent increase in a patient's quality of life.

503/3-045-02/503-31-002 Medical University of Lodz

Keywords: antioxidants; electron affinity; guanine derivatives; ionisation potential; second-or-der Møller-Plesset perturbation theory

JL5DK93RCL (Melatonin)
0 (Antioxidants)
PQ6CK8PD0R (Ascorbic Acid)
268B43MJ25 (Uric Acid)
WYQ7N0BPYC (Acetylcysteine)
12133JR80S (Guanosine)

Date Created: 20250108 Date Completed: 20250108 Latest Revision: 20250108

20250114

10.3390/molecules29245944

39770034