Thermochemical Parameters of Ergothioneine: A DFT Study Using M06, Wb97xd and TPSSTPSS Methods

Abstract

Antioxidant properties of ergothioneine (ESH) have been investigated via hydrogen atom transfer (HAT), single electron transfer-proton transfer (SET-PT) and sequential proton loss electron transfer (SPLET) mechanisms. Three new DFT methods including M06, WB97XD and TPSSTPSS at the 6-311++G(2df,2p) basis set were used to compute the thermochemical parameters of ESH in the gas phase. Based on these methods, bond dissociation enthalpy (BDE), ionization energy (IE), proton dissociation enthalpy (PDE), proton affinity (PA) and electron transfer enthalpy (ETE) were calculated. The results were also compared with the values obtained by B3LYP method. The calculated results show that ergothioneine plays a role as a potential antioxidant via HAT mechanism.