Antioxidant and spectral properties of chalcones and analogous aurones: Theoretical insights. Issue 3 (9th October 2018)

• Record Type: Journal Article
• Authors: Xue, Yunsheng; Liu, Yunping; Zhang, Ling; Wang, Han; Luo, Qingquan; Chen, Ran; Liu, Yin; Li, Ya
• Is Part Of: International journal of quantum chemistry. Volume 119:Issue 3(2019)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2018-10-09
• Subjects: aurones -- chalcones -- density functional theory -- mechanism -- radical scavenging activity; Quantum chemistry -- Periodicals; 541.28
• DOI: 10.1002/qua.25808
• Languages: English
• ISSNs: 0020-7608

Abstract

Abstract: Density functional theory (DFT) and time‐dependent DFT (TD‐DFT) have been employed to elucidate the radical scavenging capacity and the UV–Vis spectral property of several chalcones and analogous aurones. Three main antioxidant mechanisms, hydrogen atom transfer (HAT), electron transfer followed by proton transfer (SET‐PT) and sequential proton loss electron transfer (SPLET) were investigated. The results indicate that all the studied compounds adopt a fully planar conformation in their neutral, radical, cationic as well as anionic forms. 2′‐OH plays important role in the stabilization of phenolic radicals due to the formation of intramolecular hydrogen bonds (IHBs). Introduction of electron‐donating substituent on B‐ring is helpful for improving the activity. For the considered compounds, HAT is proposed as the thermodynamically favored mechanism in gas phase and nonpolar environment, while SPLET is preferred in polar media. The results confirmed the crucial role of hydroxyl group on A‐ring, especially on position 5′/5, in terms of the radical scavenging ability. The absorption spectra of title compounds were successfully simulated and the lowest energy transitions predominantly correspond to the π‐π* transitions from HOMO to LUMO with charge transfer (CT) character. Abstract : Chalcones and aurones are important subgroups of flavonoids, which have attracted much attention in recent times due to their antioxidant activities and other biologically relevant properties. DFT and TD‐DFT calculations are used to elucidate the antioxidant mechanism and the spectral properties of chalcones and analogous aurones.