A detailed DFT-based study of the free radical scavenging activity and mechanism of daphnetin in physiological environments. (September 2021)

• Record Type: Journal Article
• Authors: Boulebd, Houssem; Amine Khodja, Imene
• Is Part Of: Phytochemistry. Volume 189(2021)
• Publication Date: 2021-09
• Subjects: Daphnetin -- DFT calculations -- Antiradical activity -- Kinetic study -- Antioxidant mechanisms; Botanical chemistry -- Periodicals; Biochemistry -- Periodicals; Botany -- Periodicals; Chimie végétale -- Périodiques; 572.2
• DOI: 10.1016/j.phytochem.2021.112831
• Languages: English
• ISSNs: 0031-9422

Abstract

Abstract: Daphnetin, a biologically active coumarin derivative found in plants of the genus Daphne, is a potent antioxidant phenolic compound. The present work describes the mechanisms and kinetics of the HO, NO, HOO, and NO2 scavenging activities of daphnetin in physiological environments using quantum chemistry calculations. The main antiradical mechanisms have been studied: formal hydrogen transfer (FHT), sequential electron transfer proton transfer (SETPT), sequential proton loss electron transfer (SPLET), and radical adduct formation (RAF). Besides its good HO scavenging activity in physiological environments, daphnetin is expected to exhibit good HOO and NO2 scavenging activities in water with k overall = 1.51 × 10 7 and 4.79 × 10 8 M −1 s −1, respectively. The FHT mechanism decides the HO scavenging activity in aqueous solution, as well as HO, HOO, and NO2 scavenging activities in lipid media, while SPLET is the primary mechanism in water for HOO and NO2 scavenging activities. The theoretical predictions were found to be in good agreement with the available experimental data, which supports the reliability of the calculations. Graphical abstract: Daphnetin is a good scavenger of hydroxyl radicals in physiological environments as well as a good scavenger of hydroperoxyl radicals and nitric dioxide in polar environments. Image 1 Highlights: The free radical scavenging activity and mechanism of daphnetin have been examined. Daphnetin is good HO scavenger in both polar and lipid media. The HOO and NO2 scavenging activity is higher in polar media than lipid media. The formal hydrogen transfer is the main mechanism for scavenging HO radical. The HOO and NO2 scavenging mechanism varies depending on the environment.