Naturally Occurring Anthraquinones as Potential Inhibitors of SARS-CoV-2 Main Protease: A Molecular Docking Study

Background: The novel coronavirus (COVID-19) has quickly spread throughout the globe, affecting millions of people. The World Health Organization (WHO) has recently declared this infectious disease as a pandemic. At present, several clinical trials are going on to identify possible drugs for treating this infection. SARS-CoV-2 M^pro is one of the most critical drug targets for the blockage of viral replication. Method: The blind molecular docking analyses of natural anthraquinones with SARS-CoV-2 M^pro were carried out in an online server, SWISSDOCK, which is based on EADock DSS docking software. Results: Blind molecular docking studies indicated that several natural antiviral anthraquinones could prove to be effective inhibitors for SARS-CoV-2 M^pro of COVID-19 as they bind near the active site having the catalytic dyad, HIS41 and CYS145 through non-covalent forces. The anthraquinones showed less inhibitory potential as compared to the FDA approved drug, remdesivir.

Conclusion: Among the natural anthraquinones, alterporriol Q could be the most potential inhibitor of SARS-CoV-2 M^pro among the natural anthraquinones studied here, as its ∆G value differed from that of remdesivir only by 0.51 kcal/ mol. The uses of these alternate compounds might be favorable for the treatment of the COVID-19.