Relationship between the radical-scavenging activity of selected flavonols and thermodynamic parameters calculated by density functional theory

The structural and electronic properties of alkannin and its derivatives and their radicals were investigated at density functional level. It turned out that the presence of the dihydroxy functionality increases the radical stability through hydrogen bond formation. The hydrogen atom transfer for alkannin derivatives is difficult to occur compared with zero compound phenol. However, alkannin derivatives appear to be good candidates for the one-electron-transfer, particularly for alkannin derivatives with –OCOCH=CH(CH3)2 and –OCOCH2CH(CH3)2 groups. It suggests that 1–7 are expected to be the promising candidates for radical scavenging activity compounds because The ionization potential (IP) values of 1–7 are lower than that of the zero compound phenol.

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COMBINED EXPERIMENTAL AND COMPUTATIONAL STUDY OF THE RADICAL SCAVENGING ACTIVITY OF LUTEOLIN

Journal of Theoretical and Computational Chemistry ◽

10.1142/s0219633613500211 ◽

2013 ◽

Vol 12 (05) ◽

pp. 1350021 ◽

Cited By ~ 3

Author(s):

ABDULLAH G. AL-SEHEMI ◽

AHMAD IRFAN ◽

SALHA MANA ALJUBIRI ◽

KAMEL HUSSEIN SHAKER

Keyword(s):

Density Functional Theory ◽

Absorption Spectra ◽

Density Functional ◽

Computational Study ◽

Radical Scavenging Activity ◽

Radical Scavenging ◽

2D Nmr ◽

Hydrogen Atom Transfer ◽

Functional Theory ◽

Polarized Continuum Model

The luteolin has been extracted from Euphorbia schimperiana then 1H NMR, 13C NMR and 2D NMR spectra were measured. The ground-state geometries have been computed by using density functional theory (DFT) at B3LYP/6-31G* and M06/6-31++G** level of theories. The time dependent density functional theory (TD-DFT) has been applied to compute the absorption spectra with and without solvent. The absorption spectra have been computed in methanol to check the effect of solvent using the polarized continuum model (PCM). On the basis of bond dissociation enthalpy (BDE) and the adiabatic ionization potential (IP), we have explained the antioxidant activity of luteolin and its rotamer/positional isomer. Two mechanisms have been explained for the radical scavenging processes, i.e. hydrogen atom transfer and one-electron transfer.

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Predicting Notable Radical Scavenging Sites of Gnetin C Using Density Functional Theory

Materials Science Forum ◽

10.4028/www.scientific.net/msf.966.229 ◽

2019 ◽

Vol 966 ◽

pp. 229-233

Author(s):

Vera Khoirunisa ◽

Lusia Silfia Pulo Boli ◽

Rizka Nur Fadilla ◽

Adhitya Gandaryus Saputro ◽

Heni Rachmawati ◽

...

Keyword(s):

Density Functional ◽

Radical Scavenging Activity ◽

Radical Scavenging ◽

Heterocyclic Ring ◽

Polarizable Continuum Model ◽

Hydroxyl Groups ◽

Scavenging Activity ◽

Functional Theory ◽

Water Solvent ◽

Polarizable Continuum

We have been investigating the scavenging activity of gnetin C theoretically in the molecular level. In this work, we perform density functional based calculations to predict the possible site of gnetin C for free radical scavenging activity. The water solvent effect is considered as polarizable continuum model. All possible scavenging sites have been evaluated by obtaining the bond dissociation enthalpy (BDE) for one hydrogen atom abstraction. The results demonstrate that O-H bonds generally have lower BDE relative to C-H bonds of gnetin C. We also find that C-H bonds in 5-membered heterocyclic ring have exceptionally lower BDE. This could be additional possible sites for gnetin C to scavenge more free radicals in addition to hydroxyl groups.

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Sorbicillasins A–B and Scirpyrone K from a Deep-Sea-Derived Fungus, Phialocephala sp. FL30r

Marine Drugs ◽

10.3390/md16070245 ◽

2018 ◽

Vol 16 (7) ◽

pp. 245 ◽

Cited By ~ 6

Author(s):

Zhenzhen Zhang ◽

Xueqian He ◽

Qian Che ◽

Guojian Zhang ◽

Tianjiao Zhu ◽

...

Keyword(s):

Deep Sea ◽

Density Functional ◽

Radical Scavenging Activity ◽

Radical Scavenging ◽

Time Dependent ◽

Scavenging Activity ◽

Functional Theory ◽

Ic50 Value ◽

Td Dft ◽

Dependent Density

Two new nitrogen-containing sorbicillinoids named sorbicillasins A and B (1 and 2) and a new 3,4,6-trisubstituted α-pyrone derivative, scirpyrone K (3), together with two known biosynthetically related polyketides (4–5), were isolated from the deep-sea-derived fungus Phialocephala sp. FL30r by using the OSMAC (one strain-many compounds) method. The structures of 1–3, including absolute configurations, were deduced based on MS, NMR, and time-dependent density functional theory (TD-DFT) calculations of specific ECD (electronic circular dichroism) spectra. Compounds 1 and 2 possessed a novel hexahydropyrimido[2,1-a] isoindole moiety, and compound 3 exhibited weak radical scavenging activity against DPPH (2,2-diphenyl-1-picrylhydrazyl) with an IC50 value of 27.9 μM.

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Thermodynamic Parameters of PbTe Crystals: DFT-Calculations

Фізика і хімія твердого тіла ◽

10.15330/pcss.16.1.28-33 ◽

2015 ◽

Vol 16 (1) ◽

pp. 28-33

Author(s):

D. M. Freik ◽

B. P. Volochanska ◽

T. O. Parashchuk

Keyword(s):

Density Functional Theory ◽

Free Energy ◽

Electronic Structure ◽

Thermodynamic Parameters ◽

Quantum Chemical ◽

Density Functional ◽

Cubic Phase ◽

Functional Theory ◽

Temperature Dependences ◽

Analytical Expressions

Based on the analysis of the crystal NaCl type and electronic structure of cubic phase CdS crystals the cluster models have been built for calculation of the geometric and thermodynamic parameters. According to density functional theory (DFT) and using the hybrid valence base set B3LYP the temperature dependence of the energy ΔE and the enthalpy ΔH of formation, Gibbs free energy ΔG, entropy ΔS, specific heat at constant volume CV and pressure CP of the crystals have been found. The analytical expressions of the temperature dependences of presented thermodynamic parameters which was approximated from the quantum- chemical calculations data and with using mathematical package Maple 14 have been received.

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