Background: COVID-19 is not fully known and causes severe inflammation and cytokine storm. It has many symptoms, such as: fever, sore throat, headache, dyspnoea, and diarrhoea. Arbidol was used in the treatment of COVID19, which was the most critical health problem in the world. However, the desired recovery was not achieved with Arbidol. Many countries still use this drug in the treatment of COVID19.

Aim: We aimed to determine whether Arbidol, the hemagglutinin esterase inhibitor used in the treatment of COVID-19, was effective against SARS Cov-2 in silico.

Results and conclusion: The similarity between hemagglutinin and spike proteins were reported due to the fact that inhibition properties of Arbidol and its 39 analogues were examined in detail against hemagglutinin esterase and spike glycoproteins. CID 1070884 and CID 1207786 were found to be more active against hemagglutinin esterase than in Arbidol, while these compounds were inactive against spike glycoproteins. The interaction mechanism was clarified between arbidol and spike proteins. Phenylalanine, tyrosine, glycine, lysine, and aspartic acid were found to be the headliner amino acids in the interactions between Arbidol and binding domains of spike glycoproteins in the SARS-CoV2 (Tab. 3, Fig. 8, Ref. 28).

Keywords: SARS-CoV-2; arbidol in silico.; hemagglutinin esterase; spike glycoprotein.