Computational insight of repurpose drug for treatment of COVID-19: a CDFT approach

The COVID-19 is recognized as one of the deadly disease in the history of human life. It is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Since its first case appeared in December 2019 in Wuhan, China, number of COVID-19 cases are still growing worldwide, till now number of confirmed COVID-19 cases reported globally are 594 million and number of fatalities are 6.29 million. It creates panic situation on every individual as well as put an extraordinary challenge on every country, especially on the health care system. The ruthlessness of the disease and its noxious complexities need development of suitable and effective drug on urgent basis to prevent as well as treat COVID-19. Though specific drug with proper efficacy is not yet found, a number of research and clinical trials are still going on to check the suitability and effectiveness of existing drug, i.e. repurposed drug to treat patients of COVID-19. In this article, repurposed drug—arbidol, baricitinib, favipiravir, galidesivir and ribavirin are reported by using Conceptual Density Functional Theory (CDFT) approach. Optimization energy, spin multiplicity, zero point energy correction, CDFT-based descriptors, optical and thermochemical properties of these repurposed drugs are computed and analysed. Result signify that favipiravir is the most reactive compound whereas ribavirin is found as the most stable among these molecular species. Favipiravir has the lowest thermal energy, heat capacity and entropy, whereas arbidol has the maximum thermal energy, heat capacity and entropy. There is an interesting correlation found between optimization energy, zero point energy correction, polarizability and thermochemical properties of these repurposed drugs.