Theoretical study on the structural and antioxidant properties of some recently synthesised 2, 4, 5-trimethoxy chalcones. (15th March 2015)

• Record Type: Journal Article
• Authors: Wang, Guirong; Xue, Yunsheng; An, Lin; Zheng, Youguang; Dou, Yunyan; Zhang, Ling; Liu, Yi
• Is Part Of: Food chemistry. Volume 171(2015)
• Page Start: 89
• Page End: 97
• Publication Date: 2015-03-15
• Subjects: Chalcones -- Radical scavenging activity -- DFT -- HAT -- SET-PT -- SPLET; Food -- Analysis -- Periodicals; Food -- Composition -- Periodicals; 664
• DOI: 10.1016/j.foodchem.2014.08.106
• Languages: English
• ISSNs: 0308-8146

Abstract

Highlights: Antioxidant activity of five 2, 4, 5-trimethoxy chalcones have been studied using DFT. The HAT, SET-PT and SPLET mechanisms have been elucidated. The calculated results are in line with experimental values. HAT is thermodynamically preferred mechanism in gas phase. SPLET represents the most probable reaction pathway in polar solvents. Abstract: The free radical scavenging activity of a series of 2, 4, 5-trimethoxy chalcones has been computationally explored using the density functional theory (DFT) method. Three potential working mechanisms, hydrogen atom transfer (HAT), stepwise electron transfer proton transfer (SET-PT) and sequential proton loss electron transfer (SPLET) have been investigated. The physiochemical parameters including O–H bond dissociation enthalpy (BDE), ionisation potential (IP), proton dissociation enthalpy (PDE), proton affinity (PA) and electron transfer enthalpy (ETE) have been calculated in gas phase and solvents. The order of antioxidant efficiencies predicted theoretically in this work is in good agreement with that reported by experimental results. The results obtained demonstrate that HAT would be the most favourable mechanism in the gas and benzene phases, whereas the SPLET mechanism is the thermodynamically preferred pathway in polar media. In addition, the importance of the A-ring on the radical scavenging capabilities of chalcones was also confirmed.