Table 3.

Binding energy components comparison for SARS-CoV-2 M^pro protein in complex with X77 (control) and most stable inhibitor molecules 22, 26 as obtained from in silico investigation.

Complex	ΔEvdwa	ΔEelec	ΔEMM	ΔGpolar	ΔGnon-polar	ΔGbinding
Control	−168.312 ± 13.357	−7.801 ± 4.448	−176.113 ± 11.457	61.034 ± 4.082	−14.934 ± 0.054	−130.014 ± 9.977
Mpro-22	−123.792 ± 7.327	−151.609 ± 9.399	−275.402 ± 15.326	102.911 ± 7.036	−11.370 ± 0.993	−183.860 ± 9.106
Mpro-26	−113.942 ± 7.049	−245.111 ± 13.287	−359.053 ± 19.781	219.180 ± 13.912	−12.099 ± 0.602	−171.972 ± 8.757

^aΔE_vdw, ΔE_elec, ΔE_MM, ΔG_polar and ΔG_non-polar are binding energy components of van der Waals, electrostatic, molecular mechanics, polar and non-polar solvation (SASA) energies, respectively. ΔG_binding is the total binding energy. The unit of energy is kJ/mol.