Evaluation of Phytochemicals of Cassia occidentalis L. for their Binding Affinities to SARS-CoV-2 3C-Like Protease: An in Silico Approach

Aims: Corona virus SARS-CoV-2, otherwise known as COVID-19 has created a pandemic resulting in social and financial crisis throughout the world. The virus has no known drugs or vaccines for preventive or therapeutic purposes. The objective of the present study was to screen phytochemicals from Cassia occidentalis L. in virtual screening (in silico) studies to evaluate their potential of binding to the main 3C-like protease of the virus and so stop its replication.

Study Design: Molecular docking approach was used for virtual screening studies.

Place and Duration of Study: University of Development Alternative between April and July 2020.

Methodology: Molecular docking (blind) were done with the help of Autodock Vina. We have used the pdb file (6LU7) of the main protease of SARS-CoV-2 3C-like protease or SARS-CoV-2 3CLpro (monomeric form) to study binding of the phytochemicals.

Results: Of the nine phytochemicals studied, the C-glycosidic flavonoids, cassiaoccidentalins A-C demonstrated excellent binding affinities to the protease. The compounds bound to the active site of the protease with binding energy values of -8.2 to-8.4 kcal/mol.

Conclusion: The in silico studies suggest that the compounds merit actual COVID-19 inhibitory tests and have potential for anti-COVID-19 use.