The primary antioxidant activity and the non-covalent inhibition capacity of M^pro from SARS-CoV-2 of miquelianin, a derivative of quercetin, were investigated in the mean of DFT calculations and MD simulations respectively. From computations, dual activity of miquelianin resulted, since promising inhibition of ⋅OOH in water environment was calculated and a potential suppression of M^pro enzyme from SARS-CoV-2 was highlighted.

Abstract

The antioxidant power of quercetin-3-O-glucuronide (miquelianin) has been studied, at the density functional level of theory, in both lipid-like and aqueous environments. In the aqueous phase, the computed pK _a equilibria allowed the identification of the neutral and charged species present in solution that can react with the ⋅OOH radical. The Hydrogen Atom Transfer (HAT), Single Electron Transfer (SET) and Radical Adduct Formation (RAF) mechanisms were considered, and the individual, total and fraction corrected rate constants were obtained. Potential non-covalent inhibition of M^pro from SARS-CoV-2 by miquelianin has been also evaluated.