Can Antimalarial Phytochemicals be a Possible Cure for COVID-19? Molecular Docking Studies of Some Phytochemicals to SARS-CoV-2 3C-like Protease

Objective: To evaluate the efficacy of reported anti-malarial phytochemicals as lead compounds for possible drug development against COVID-19. Methods: An in silico approach was used in this study to determine through molecular docking the binding affinities and site of binding of these phytochemicals to the 3C-like protease of COVID-19 which is considered as the main protease of the virus. Results: A number of anti-malarial phytochemicals like apigenin-7-O-glucoside, decurvisine, luteolin- 7-O-glucoside, sargabolide J, and shizukaols A, B, F, and G showed predicted high binding energies with ΔG values of -8.0 kcal/mol or higher. Shizukaols F and B demonstrated the best binding energies of -9.5 and -9.8, respectively. The acridone alkaloid 5-hydroxynoracronycine also gave a predicted high binding energy of -7.9 kcal/mol. Conclusion: This is for the first time that decursivine and several shizukaols were reported as potential anti-viral agents. These compounds merit further studies to determine whether they can be effective drug candidates against COVID-19.