Radical Scavenging Activity of Puerarin: A Theoretical Study
School of Materials Science and Engineering, Central South University of Forestry and Technology, Changsha 410004, China
College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China
State Key Laboratory of Chemical Oncogenomics, Peking University Shenzhen Graduate School, Shenzhen 518055, China
Author to whom correspondence should be addressed.
Antioxidants 2019, 8(12), 590; https://doi.org/10.3390/antiox8120590
Received: 28 October 2019 / Revised: 18 November 2019 / Accepted: 24 November 2019 / Published: 26 November 2019
(This article belongs to the Section Natural and Synthetic Antioxidants)
Puerarin is a C-glycoside of daidzein, one of the major bioactive ingredients isolated from the root of Pueraria lobata, which has a wide spectrum of pharmacological effects. Although puerarin is well-known for its effective antioxidant activity, there is seldom a systematic theoretical study on its radical scavenging activity. Herein, the free radical scavenging ability of puerarin was investigated systematically by density functional theory (DFT) calculations. The reaction activity was compared with daidzein as well. Three reaction pathways: hydrogen atom transfer (HAT), single electron transfer followed by proton transfer (SET-PT), and sequential proton loss electron transfer (SPLET) were discussed and compared by thermodynamic parameters such as bond dissociation enthalpy (BDE), ionization potential (IP), proton dissociation enthalpy (PDE), proton affinity (PA), and electron transfer enthalpy (ETE). The reaction kinetics of puerarin with special radicals •OH and •OOH were also studied. The results obtained may be of great significance for better understanding the relationship between the antioxidant properties and structural design of puerarin, as well as other antioxidants.