Computation of the bond dissociation enthalpies and free energies of hydroxylic antioxidants using the<i>ab initio</i>Hartree–Fock method

Woldu, Ameha Seyoum; Mai, Joachim

doi:10.1179/1351000212y.0000000030

Cited by 9 publications

(3 citation statements)

References 90 publications

(117 reference statements)

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“…The active OH groups determined by our method matched those generally accepted and reported in the literature [30,40,41], determined using the method based on O-H bond dissociation energy, BDE:…”

Section: Determination Of An Active Oh Groupsupporting

confidence: 67%

Flavonoid Oxidation Potentials and Antioxidant Activities-Theoretical Models Based on Oxidation Mechanisms and Related Changes in Electronic Structure

Miličević

2024

IJMS

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Herein, I will review our efforts to develop a comprehensive and robust model for the estimation of the first oxidation potential, Ep1, and antioxidant activity, AA, of flavonoids that would, besides enabling fast and cheap prediction of Ep1 and AA for a flavonoid of interest, help us explain the relationship between Ep1, AA and electronic structure. The model development went forward with enlarging the set of flavonoids and, that way, we had to learn how to deal with the structural peculiarities of some of the 35 flavonoids from the final calibration set, for which the Ep1 measurements were all made in our laboratory. The developed models were simple quadratic models based either on atomic spin densities or differences in the atomic charges of the species involved in any of the three main oxidation mechanisms. The best model takes into account all three mechanisms of oxidation, single electron transfer-proton transfer (SET-PT), sequential proton loss electron transfer (SPLET) and hydrogen atom transfer (HAT), yielding excellent statistics (R2 = 0.970, S.E. = 0.043).

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Section: Determination Of An Active Oh Groupsupporting

confidence: 67%

Flavonoid Oxidation Potentials and Antioxidant Activities-Theoretical Models Based on Oxidation Mechanisms and Related Changes in Electronic Structure

Miličević

2024

IJMS

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“…A reaction is possible if he antioxidant's BDE is lower than that of the reduced radical form. Therefore, the lower the BDE, the stronger the antioxidative potential of a given compound [87]. Mixed reaction mechanisms can also occur between radicals and antioxidants, e.g., involving proton-coupled electron transfer (PCET), sequential proton-loss electron transfer (SPLET), or electron transfer-proton transfer (ET-PT) reactions [88].…”

Section: The Inhibitory Effects Of Exogenous Antioxidants On the Procmentioning

confidence: 99%

The Role of Dietary Antioxidants in the Pathogenesis of Neurodegenerative Diseases and Their Impact on Cerebral Oxidoreductive Balance

et al. 2020

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Neurodegenerative diseases are progressive diseases of the nervous system that lead to neuron loss or functional disorders. Neurodegenerative diseases require long-term, sometimes life-long pharmacological treatment, which increases the risk of adverse effects and a negative impact of pharmaceuticals on the patients' general condition. One of the main problems related to the treatment of this type of condition is the limited ability to deliver drugs to the brain due to their poor solubility, low bioavailability, and the effects of the blood-brain barrier. Given the above, one of the main objectives of contemporary scientific research focuses on the prevention of neurodegenerative diseases. As disorders related to the competence of the antioxidative system are a marker in all diseases of this type, the primary prophylactics should entail the use of exogenous antioxidants, particularly ones that can be used over extended periods, regardless of the patient's age, and that are easily available, e.g., as part of a diet or as diet supplements. The paper analyzes the significance of the oxidoreductive balance in the pathogenesis of neurodegenerative diseases. Based on information published globally in the last 10 years, an analysis is also provided with regard to the impact of exogenous antioxidants on brain functions with respect to the prevention of this type of diseases.

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“…The higher defect estimated value of the Gibbs free energy is presented as a result of the anharmonicity at the defect sites with the transition at higher temperatures (>298 K). BDE ( Fukaya et al, 2001 ; Luo, 2007 ; Woldu and Mai, 2012 ) and BDFE ( Parr and Pearson, 1983 ; Moroz, 2011 ) are calculated for the chemical reaction, taking into account the ε 0 correction to electronic energy and the enthalpy and Gibbs free energy corrections H Corr and G Corr at 298.15K, obtaining the change in enthalpy (4) and Gibbs free energy (3) with the reaction.

…”

Section: Suitability Of Febid Of the Precursormentioning

confidence: 99%

Dissociative electron attachment to gold(I)-based compounds: 4,5-dichloro-1,3-diethyl-imidazolylidene trifluoromethyl gold(I)

et al. 2023

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With the use of proton-NMR and powder XRD (XRPD) studies, the suitability of specific Au-focused electron beam induced deposition (FEBID) precursors has been investigated with low electron energy, structure, excited states and resonances, structural crystal modifications, flexibility, and vaporization level. 4,5-Dichloro-1,3-diethyl-imidazolylidene trifluoromethyl gold(I) is a compound that is a uniquely designed precursor to meet the needs of focused electron beam-induced deposition at the nanostructure level, which proves its capability in creating high purity structures, and its growing importance in other AuImx and AuClnB (where x and n are the number of radicals, B = CH, CH3, or Br) compounds in the radiation cancer therapy increases the efforts to design more suitable bonds in processes of SEM (scanning electron microscopy) deposition and in gas-phase studies. The investigation performed of its powder shape using the XRPD XPERT3 panalytical diffractometer based on CoKα lines shows changes to its structure with change in temperature, level of vacuum, and light; the sensitivity of this compound makes it highly interesting in particular to the radiation research. Used in FEBID, though its smaller number of C, H, and O atoms has lower levels of C contamination in the structures and on the surface, it replaces these bonds with C–Cl and C–N bonds that have lower bond-breaking energy. However, it still needs an extra purification step in the deposition process, either H2O, O2, or H jets.

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Computation of the bond dissociation enthalpies and free energies of hydroxylic antioxidants using theab initioHartree–Fock method

Abstract: It was concluded that ab initio UHF was well suited for the estimation of gas phase BDE and BDFE. The method presented has a good potential for application across a range of hydroxylic antioxidants. Currently, work is underway to extend its application in other class of antioxidants.

Cited by 9 publications

References 90 publications

Flavonoid Oxidation Potentials and Antioxidant Activities-Theoretical Models Based on Oxidation Mechanisms and Related Changes in Electronic Structure

Flavonoid Oxidation Potentials and Antioxidant Activities-Theoretical Models Based on Oxidation Mechanisms and Related Changes in Electronic Structure

The Role of Dietary Antioxidants in the Pathogenesis of Neurodegenerative Diseases and Their Impact on Cerebral Oxidoreductive Balance

Dissociative electron attachment to gold(I)-based compounds: 4,5-dichloro-1,3-diethyl-imidazolylidene trifluoromethyl gold(I)

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