Comparison of the scavenging capacities of phloroglucinol and 2,4,6-trihydroxypyridine towards HO˙ radical: a computational study

Milanović, Žiko; Tošović, Jelena; Marković, Svetlana; Marković, Zoran

doi:10.1039/d0ra08377a

Cited by 20 publications

(18 citation statements)

References 65 publications

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“…Based on our previous experience 42,43 and that of other research groups, 39,40,44–46 the following redox and non-redox pathways were explored:Hydrogen atom transfer (HAT): HX + R˙ → X˙ + RHSingle electron transfer (SET): HX + R˙ → HX + ˙ + R – Radical adduct formation (RAF): HX + R˙ → [HX−R]˙…”

Section: Resultsmentioning

confidence: 99%

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Antioxidant and copper-chelating power of new molecules suggested as multiple target agents against Alzheimer's disease. A theoretical comparative study

Spiegel

Marino

Prejanò

et al. 2022

Phys. Chem. Chem. Phys.

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Section: Resultsmentioning

confidence: 99%

“…Numerous previous studies have demonstrated, in fact, that this computational protocol gives reliable results for thermochemistry and kinetics parameters relative to reactions involving free radicals and metals. [37][38][39][40]…”

Section: Computational Detailsmentioning

confidence: 99%

Antioxidant and copper-chelating power of new molecules suggested as multiple target agents against Alzheimer's disease. A theoretical comparative study

Spiegel

Marino

Prejanò

et al. 2022

Phys. Chem. Chem. Phys.

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“…Results obtained using FRAP assay differ from the results obtained using DPPH assay, thus indicating that the chemical composition of obtained extracts is significant to the mode of action. The latest study shows that phloroglucinols exhibit different modes of action [ 54 ], similar to the polyphenols [ 55 ]. Also, SWV revealed that most of the area that is quantified from the voltammograms has a potential between 0.600 V and 0.900 V ( Figure 6 ).…”

Section: Discussionmentioning

confidence: 99%

Supercritical Carbon Dioxide Extraction of Four Medicinal Mediterranean Plants: Investigation of Chemical Composition and Antioxidant Activity

et al. 2021

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With everyday advances in the field of pharmaceuticals, medicinal plants have high priority regarding the introduction of novel synthetic compounds by the usage of environmentally friendly extraction technologies. Herein, a supercritical CO2 extraction method was implemented in the analysis of four plants (chamomile, St. John’s wort, yarrow, and curry plant) after which the non-targeted analysis of the chemical composition, phenolic content, and antioxidant activity was evaluated. The extraction yield was the highest for the chamomile (5%), while moderate yields were obtained for the other three plants. The chemical composition analyzed by gas chromatography-high-resolution mass spectrometry (GC-HRMS) and liquid chromatography-high-resolution mass spectrometry (LC-HRMS) demonstrated extraction of diverse compounds including terpenes and terpenoids, fatty acids, flavonoids and coumarins, functionalized phytosterols, and polyphenols. Voltammetry of microfilm immobilized on a glassy carbon electrode using square-wave voltammetry (SWV) was applied in the analysis of extracts. It was found that antioxidant activity obtained by SWV correlates well to 1,1-diphenyl-2-picrylhidrazine (DPPH) radical assay (R2 = 0.818) and ferric reducing antioxidant power (FRAP) assay (R2 = 0.640), but not to the total phenolic content (R2 = 0.092). Effective results were obtained in terms of activity showing the potential usage of supercritical CO2 extraction to acquire bioactive compounds of interest.

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“…Using sophisticated experimental (Electron Paramagnetic Resonance-EPR) and computational ((Density Functional Theory-DFT)/QM-ORSA (Quantum Mechanics-based test for Overall free Radical Scavenging Activity) protocol)) methods, the reactivity, and mechanism of radical scavenging activity of these compounds against HO • were analyzed in detail. The applied QM-ORSA protocol and the chosen theoretical model have proven to reproduce well the results of experimental studies of antioxidant capacity in the following references [30][31][32]. The acid-base equilibria of the obtained substances were included in the discussion, as the ability to remove reactive radial species depends on the pH of the reaction medium and the degree of deprotonation.…”

Section: Introductionmentioning

confidence: 94%

Mechanism of Antiradical Activity of Newly Synthesized 4,7-Dihydroxycoumarin Derivatives-Experimental and Kinetic DFT Study

Milanović

Dimić

Žižić

et al. 2021

IJMS

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Coumarin derivatives have proven beneficial biological activities, but the mechanism of their radical scavenging potency is not fully understood. In this study, the antiradical capacity of two newly synthesized 4,7-dihydroxycoumarin derivatives: (E)-3-(1-((3-hydroxy-4-methoxyphenyl)amino)-ethylidene)-2,4-dioxochroman-7-yl acetate (A-3OH) and (E)-3-(1-((4-hydroxy-3-methoxyphenyl)amino)ethylidene)-2,4-dioxochroman-7-yl acetate (A-4OH) towards HO• were examined by Electron Paramagnetic Resonance (EPR) Spectroscopy and Density Functional Theory (DFT). The compounds were fully characterized by the elemental microanalysis, IR, and NMR spectroscopies. The effect of pH on the acid–base equilibria is separately discussed and the predominant species at the physiological pH were determined. Several common mechanisms (Hydrogen Atom Transfer (HAT), Single-Electron Transfer followed by Proton Transfer (SET-PT), Sequential Proton Loss followed by Electron Transfer (SPLET), Radical Adduct Formation (RAF), and Intramolecular Hydrogen Atom Abstraction (iHAA)) of radical scavenging were investigated based on thermodynamic and kinetic parameters. EPR results indicated that both compounds significantly reduce the amount of present HO•. The results of the kinetic DFT study demonstrated that both compounds predominantly exhibit antiradical capacity through HAT and SPLET mechanisms. The estimated overall rate constants (koverall) proved that A-4OH shows better antioxidant capacity than A-3OH which is well-correlated with the results obtained by EPR measurement.

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Comparison of the scavenging capacities of phloroglucinol and 2,4,6-trihydroxypyridine towards HO˙ radical: a computational study

Abstract: The scavenging capacities of biologically active phloroglucinol (1,3,5-trihydroxybenzene, THB–OH) and structurally similar 2,4,6-trihydroxypyridine (THP–OH) towards HO˙ were elucidated.

Cited by 20 publications

References 65 publications

Antioxidant and copper-chelating power of new molecules suggested as multiple target agents against Alzheimer's disease. A theoretical comparative study

Antioxidant and copper-chelating power of new molecules suggested as multiple target agents against Alzheimer's disease. A theoretical comparative study

Supercritical Carbon Dioxide Extraction of Four Medicinal Mediterranean Plants: Investigation of Chemical Composition and Antioxidant Activity

Mechanism of Antiradical Activity of Newly Synthesized 4,7-Dihydroxycoumarin Derivatives-Experimental and Kinetic DFT Study

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