A Theoretical Study on the Antioxidant Activity of Piceatannol and Isorhapontigenin Scavenging Nitric Oxide and Nitrogen Dioxide Radicals.

Yang Lu,Aihua Wang,Peng Shi,Hui Zhang,Dennis Salahub

doi:10.1371/journal.pone.0169773

Yang Lu, Aihua Wang + Show 3 more

Open Access

https://doi.org/10.1371/journal.pone.0169773

Copy DOI

Journal: PloS one	Publication Date: Jan 9, 2017
Citations: 27	License type: CC BY 4.0

Affiliation: Harbin University of Science and Technology

Abstract

The antioxidant activity of naturally occurring stilbene compounds piceatannol (PIC) and isorhapontigenin (ISO) scavenging two free radicals (NO and NO2) were studied using density functional theory (DFT) method. Four reaction mechanisms have been considered: hydrogen atom transfer (HAT), radical adduct formation (RAF), single electron transfer (SET), and sequential proton loss electron transfer (SPLET). The reaction channels in water solution were traced independently, and the respective thermodynamic and kinetic parameters were obtained. We found PIC and ISO scavenge NO mainly through RAF mechanism, and scavenge NO2 through HAT mechanism. The capacity of PIC scavenging NO2 is much higher than ISO, but the reactivity of scavenging NO is lower than ISO.

Highlights

Reactive nitrogen species (RNS) are nitrogen-centered radicals and related species produced by normal cellular metabolism of human body
Solvent effects were introduced as single point calculations on the optimized gas-phase geometries in the framework of the continuum solvation model based on solute electron density (SMD), which is recommended by Gaussian Manual to compute solvation energy
At the M05-2X/6-311++G(d,p) level, the optimized conformers of piceatannol and isorhapontigenin are showed in Fig 1, together with the energies of them

Summary

Introduction

Reactive nitrogen species (RNS) are nitrogen-centered radicals and related species produced by normal cellular metabolism of human body. Nitric oxide radical (NO) is a highly RNS produced by the oxidation of the terminal guanido-nitrogen atoms of L-arginine in organism [1]. Nitric dioxide radical (NO2) is formed from the reaction of peroxyl radical and NO, polluted air or smoking [3]. Overproduction of RNS is called nitrosative stress [4,5]. Nitrosative stress may initiate the nitrosylation reaction that can change the structures of proteins and so inhibit their normal function. Nitrosative stress can cause damage to membrane fatty acids, DNA and its repair mechanism. It is significant to find natural antioxidants that can help in scavenging the excess RNS and avoid oxidative damage in humans

Objectives

Methods

Results

Conclusion