3.6.5.  Interaction energy
The interaction energy is the measure of the interaction strength of the protein–ligand complex. In order to validate the results of molecular docking studies, the analysis of the interaction free energies from MD simulation was performed. The average interaction energy takes the contribution from the average short-range Lennard-Jones and van der Waals energy. The average interaction energies of RBD Spro-Piperine and Mpro-Piperine are found to be − 41.401 ± 17.843 kJ/mol and −143.162 ± 23.043 kJ/mol, respectively. These interaction energy values suggest that Piperine binds to the RBD Spro and Mpro with good affinity and hence supports the docking results, which in turn helps for the favourable use of Piperine as a drug candidate for SARS-CoV-2.