Theoretical insights into the antioxidant activity of moracin T

Moracin T is a natural product isolated from Morus mesozygia (Moraceae), which acts as potent antioxidant agent. In this study, density functional theory-based computational methods have been performed to evaluate systematically the radical scavenging behaviour of this compound. Structural characteristics such as frontier molecular orbitals and molecular electrostatic potential mapping have been investigated. Thermodynamic parameters related to the three main antiradical mechanisms, hydrogen atom transfer (HAT), sequential electron transfer proton transfer (SETPT), and sequential proton loss electron transfer (SPLET) have been studied. In addition, two variants of SPLET mechanism namely sequential proton loss hydrogen atom transfer (SPLHAT) and double sequential proton loss electron transfer (D-SPLET) have been investigated. The reaction of moracin T with hydroperoxyl radical (HOO center dot), as representative reactive oxygen species, was also studied. The obtained results are of great significance in better understanding the chemical mechanism of the radical-scavenging action and open new perspectives for the design of new potent antioxidant agents.