scholarly journals Isolation, identification, thermal analysis, DFT calculations and antioxidant activity studies of lichen metabolites norstictic acid and evernic acid Abstract

2020 ◽  
Vol 0 (0) ◽  
pp. 0-0
Author(s):  
mohamed Zayed ◽  
Nedeljko Manojlovic
Keyword(s):  
Thermal Analysis ◽  
Antioxidant Activity ◽  
Dft Calculations ◽  
Lichen Metabolites

scholarly journals Delocalization of the Unpaired Electron in the Quercetin Radical: Comparison of Experimental ESR Data with DFT Calculations

2020 ◽  
Vol 21 (6) ◽  
pp. 2033 ◽  
Author(s):  
Zhengwen Li ◽  
Mohamed Moalin ◽  
Ming Zhang ◽  
Lily Vervoort ◽  
Alex Mommers ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Dft Calculations ◽  
Unpaired Electron ◽  
Density Functional ◽  
Dft Calculation ◽  
High Energy ◽  
Resonance Spectroscopy ◽  
Spin Resonance ◽  
Oxygen Groups ◽  
Ac Ring

In the antioxidant activity of quercetin (Q), stabilization of the energy in the quercetin radical (Q•) by delocalization of the unpaired electron (UE) in Q• is pivotal. The aim of this study is to further examine the delocalization of the UE in Q•, and to elucidate the importance of the functional groups of Q for the stabilization of the UE by combining experimentally obtained spin resonance spectroscopy (ESR) measurements with theoretical density functional theory (DFT) calculations. The ESR spectrum and DFT calculation of Q• and structurally related radicals both suggest that the UE of Q• is mostly delocalized in the B ring and partly on the AC ring. The negatively charged oxygen groups in the B ring (3′ and 4′) of Q• have an electron-donating effect that attract and stabilize the UE in the B ring. Radicals structurally related to Q• indicate that the negatively charged oxygen at 4′ has more of an effect on concentrating the UE in ring B than the negatively charged oxygen at 3′. The DFT calculation showed that an OH group at the 3-position of the AC ring is essential for concentrating the radical on the C2–C3 double bond. All these effects help to explain how the high energy of the UE is captured and a stable Q• is generated, which is pivotal in the antioxidant activity of Q.

Thermal analysis and antioxidant activity of oil extracted from pulp of ripe avocados

2017 ◽  
Vol 130 (2) ◽  
pp. 959-966 ◽  
Author(s):  
Oscar Forero-Doria ◽  
Marcos Flores García ◽  
Claudia E. Vergara ◽  
Luis Guzman
Keyword(s):  
Thermal Analysis ◽  
Antioxidant Activity

A novel 3-acetoxy-2-methyl-N-(4-methoxyphenyl)benzamide: Molecular structural describe, antioxidant activity with use X-ray diffractions and DFT calculations

2015 ◽  
Vol 1100 ◽  
pp. 582-591 ◽  
Author(s):  
Sibel Demir ◽  
Sukriye Cakmak ◽  
Necmi Dege ◽  
Halil Kutuk ◽  
Mustafa Odabasoglu ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Dft Calculations ◽  
X Ray

DFT calculations, spectroscopy and antioxidant activity studies on (E)-2-nitro-4-[(phenylimino)methyl]phenol

2015 ◽  
Vol 136 ◽  
pp. 534-546 ◽  
Author(s):  
Ersin Temel ◽  
Can Alaşalvar ◽  
Halil Gökçe ◽  
Aytaç Güder ◽  
Çiğdem Albayrak ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Dft Calculations
Sign in / Sign up

Export Citation Format

Share Document