Acknowledgements
The authors are thankful to the Ministry of Human Resource Development (MHRD), New Delhi, for financial assistance (MHRD/(FDC)/2015–2016/438/INST) to establish the computational facility. We are also extremely grateful to Dr. Anand Kant Das, New York University, Abu Dhabi, for a fruitful scientific discussion.

Disclosure statement
The authors declare no conflict of interest.  Abbreviations
COVID-19 coronavirus disease 2019
SARS-CoV-2 severe acute respiratory syndrome coronavirus 2
RBD receptor-binding domain
Spro spike protein
Mpro main protease
MEP molecular electrostatic potential
PCA principal component analysis
ADME absorption, distribution, metabolism, excretion