scholarly journals Possible Mechanisms of Fullerene C60Antioxidant Action

2013 ◽  
Vol 2013 ◽  
pp. 1-4 ◽  
Author(s):  
V. A. Chistyakov ◽  
Yu. O. Smirnova ◽  
E. V. Prazdnova ◽  
A. V. Soldatov
Keyword(s):  
Reactive Oxygen Species ◽  
Density Functional Theory ◽  
Antioxidant Activity ◽  
Mitochondrial Respiration ◽  
Density Functional ◽  
Positive Charge ◽  
Ros Production ◽  
Oxygen Species ◽  
Functional Theory ◽  
Mild Uncoupling

Novel mechanism of antioxidant activity of buckminsterfullerene C60based on protons absorbing and mild uncoupling of mitochondrial respiration and phosphorylation was postulated. In the present study we confirm this hypothesis using computer modeling based on Density Functional Theory. Fullerene's geroprotective activity is sufficiently higher than those of the most powerful reactive oxygen species scavengers. We propose here that C60has an ability to acquire positive charge by absorbing inside several protons and this complex could penetrate into mitochondria. Such a process allows for mild uncoupling of respiration and phosphorylation. This, in turn, leads to the decrease in ROS production.

scholarly journals Photosensitization Mechanisms of Triplet Excited State β-Lapachone. A Density Functional Theory Study

2011 ◽  
Vol 6 (11) ◽  
pp. 1934578X1100601
Author(s):  
Liang Shen
Keyword(s):  
Reactive Oxygen Species ◽  
Density Functional Theory ◽  
Excited State ◽  
Density Functional ◽  
Oxygen Species ◽  
Density Functional Theory Study ◽  
Triplet Excited State ◽  
Mechanistic Studies ◽  
Pharmacological Activities ◽  
Functional Theory

β-Lapachone is a natural product with multiple pharmacological activities and mechanistic studies indicated that reactive oxygen species (ROS) generated by β-lapachone play significant roles in its pharmacological actions. As photosensitization is an important ROS-generating pathway, in the present work, the photosensitization mechanisms of β-lapachone are explored on the basis of density functional theory estimated triplet excited state characters. Starting from triplet excited state β-lapachone, the possible generating pathways of 1O2 and O2·– are elucidated and the solvent effects on the photosensitizing reactions are also discussed.

The Theory Investigation for the Antioxidant Activity of Phloretin: A Comparation with Naringenin

2014 ◽  
Vol 513-517 ◽  
pp. 359-362
Author(s):  
Ming Xun Yan ◽  
Jin Dong Gong ◽  
Ping Shen ◽  
Chang Ying Yang
Keyword(s):  
Density Functional Theory ◽  
Antioxidant Activity ◽  
Density Functional ◽  
Radical Scavenging ◽  
Basis Set ◽  
Hydroxyl Groups ◽  
Bond Dissociation Energies ◽  
Functional Theory ◽  
Dissociation Energies ◽  
Radical Scavenging Properties

Density functional theory (DFT) calculations, based on B3LYP/6-311G (d, p) basis set, were performed to evaluate the OH bond dissociation energies (BDEs) for phloretin, compared with naringenin, in order to assess the contribution of hydroxyl groups at different position to the radical-scavenging properties. It is indicated clearly that A6 OH is determined as the weakest O-H bond, give rise to the smallest BDE, 73.98 kcal/mol. BDE of B4 OH decreases 2.5 kcal/mol in benzene, very close to that of A6OH, indicated that B4 OH group is also mainly contributed to the reaction with free radicals, especially in non-polar environments.

Ab initio and density functional theory studies for the explanation of the antioxidant activity of certain phenolic acids

Lipids ◽  
2001 ◽  
Vol 36 (2) ◽  
pp. 181-191 ◽  
Author(s):  
Evangelos G. Bakalbassis ◽  
Argero Chatzopoulou ◽  
Vasilios S. Melissas ◽  
Maria Tsimidou ◽  
Matina Tsolaki ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Antioxidant Activity ◽  
Ab Initio ◽  
Phenolic Acids ◽  
Density Functional ◽  
Functional Theory

Diffusion of Fluorine-Silicon Interstitial Complex in Crystalline Silicon

2005 ◽  
Vol 864 ◽  
Author(s):  
Scott A. Harrison ◽  
Thomas F. Edgar ◽  
Gyeong S. Hwang
Keyword(s):  
Density Functional Theory ◽  
Binding Energy ◽  
Charge State ◽  
First Principles ◽  
Density Functional ◽  
Positive Charge ◽  
Crystalline Silicon ◽  
Density Functional Theory Calculations ◽  
Functional Theory ◽  
And Diffusion

AbstractBased on first principles density functional theory calculations, we identify the structure and diffusion pathway for a fluorine-silicon interstitial complex (F-Sii). We find the F-Sii complex to be most stable in the singly positive charge state at all Fermi leVels. At mid-gap, the complex is found to have a binding energy of 1.08 eV relative to bond-centered F+ and (110)-split Sii. We find the F-Sii complex has an overall migration barrier of 0.76 eV, which suggests that this complex may play an important role in fluorine diffusion. Our results should lead to more accurate models that describe the behavior of fluorine co-implants crystalline silicon.

scholarly journals Synthesis, antioxidant activity, and density functional theory study of catechin derivatives

RSC Advances ◽  
2017 ◽  
Vol 7 (85) ◽  
pp. 54136-54141 ◽  
Author(s):  
Jing Wang ◽  
Han Tang ◽  
Bo Hou ◽  
Pan Zhang ◽  
Qi Wang ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Density Functional Theory ◽  
Antioxidant Activity ◽  
Density Functional ◽  
Density Functional Theory Study ◽  
Functional Theory ◽  
H Nmr ◽  
C Nmr

Catechin derivatives were synthesized, and their structures were characterized by 1H-NMR, 13C-NMR, and mass spectrometry.

scholarly journals Computational Framework for a Systematic Investigation of Anionic Redox Process in Li-Rich Compounds

2019 ◽  
Author(s):  
Alexander Tygesen ◽  
Jinhyun Chang ◽  
Tejs Vegge ◽  
Juan Maria García Lastra
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Computational Study ◽  
Systematic Investigation ◽  
Redox Processes ◽  
Oxygen Species ◽  
Computational Framework ◽  
Functional Theory ◽  
Redox Species ◽  
Formation And Evolution

Computational study of anionic redox processes in Li2MnO3, and newly developed methods for identifying and studying the evolution of anionic redox using density functional theory (DFT). A method for identifying localized anionic redox species is applied to a set of structures relaxed using the VASP software. A preconditioning scheme is presented to promote the formation of peroxo-like oxygen species, and study the formation and evolution of anionic redox.

Antioxidant activity of fraxetin and its regeneration in aqueous media. A density functional theory study

RSC Advances ◽  
2014 ◽  
Vol 4 (95) ◽  
pp. 52920-52932 ◽  
Author(s):  
M. E. Medina ◽  
C. Iuga ◽  
J. R. Álvarez-Idaboy
Keyword(s):  
Density Functional Theory ◽  
Antioxidant Activity ◽  
Density Functional ◽  
Aqueous Media ◽  
Density Functional Theory Study ◽  
Functional Theory

Fraxetin is an excellent and versatile antioxidant in aqueous media. In addition it regenerates, scavenging two radical equivalents per cycle.

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