Computational Method on Hydroxychloroquine and Azithromycin for SARS-CoV-2: Binding Affinity Studies

World is facing a new pandemic called covid-19SARS-CoV-2) since a year ago. Unfortunately there is no treatment for Covid 19 nowadays as well as no potential therapies has been developed to overcome from coronavirus pandemic. Some potential drug molecules with combination have ability to respond for covid19 virus. From the research it was found that the reduction of viral load can be treated with hydroxychloroquine and azithromycin combination. We evaluate the mode of interactions of hydroxychloroquine and azithromycin with the dynamic site of SARS-CoV-2 coronavirus main protease. Molecular Structure-based computational approach viz. molecular docking simulations were performed to scale up their affinity and binding fitness of the docked complex of novel SARS-CoV-2 coronavirus protease and hydroxychloroquine and azithromycin. The natural inhibitor N3 of novel SARS-CoV-2 coronavirus protease were exhibited highest affinity in terms of MolDock score (-167.203Kcal/mol), and hydroxychloroquine was found with lowest target affinity (-55.917 Kcal/mol).The amino acid residue cysteine 145 and histidine 41 is bound covalently and formed hydrogen bond interaction with SARS-CoV-2 inhibitor known as inhibitor N3 as such, hydroxychloroquine and azithromycin also formed hydrogen bond interaction. The binding patterns of the inhibitor N3 of SARS-CoV-2 coronavirus main protease could be used as a guideline for medicinal chemist to explore their SARS-CoV-2 inhibitory potential.