Executive Summary : | Novel human Corona Virus SARS-CoV-2, responsible for COVID-19, has come across as a significant worldwide threat to the human population. It is reported to cause a huge number of mortality and morbidity globally. In fact, the catastrophic outbreak of COVID-19 has claimed the life of more than 5.4 million people. Moreover, the spread of the disease has affected human health, social life, economy, and education sector, etc. Unfortunately, very few oral antiviral drugs are approved by US Food and Drug Administration (FDA) for the treatment of COVID-19 patients. Many strategies have been developed worldwide in unmatched time-line to fight this infectious disease. So far, WHO approved vaccines like COVAXIN, COVISHIELDTM, Moderna: mRNA-1273, Ad26.COV2.S (Janssen COVID-19), BNT162b2 (Tozinameran / Comirnaty) developed by Bharat Biotech International Limited, Oxford University and British-Swedish company AstraZeneca (manufactured by Serum Institute of India Pvt. Limited), Moderna, Johnson & Johnson, Pfizer-BioNTech, respectively, are available as prophylactic measures of COVID-19. Intravenous therapeutics like remdesivir, sotrovimab, tocilizumab, tixagevimab, etc, were found to be effective to treat the infection caused by the deadly virus. The need of oral drugs has now become imperative, as it is believed that oral drugs can significantly reduce hospitalization and death. Oral antiviral drugs such as Molnupiravir (RNA dependent RNA polymerase inhibitor), Paxlovid (Nirmatrelvir co-packaged with ritonavir) and AT-527 are currently under clinical trials. Usually, in Chemical Graph Theory (CGT), a molecular or chemical graph is used to narrate a molecule of a chemical compound where the atoms and the chemical bonds between the atoms are furnished respectively by the vertices and the edges of the chemical graph. In the area of CGT and molecular topology, a topological index which is also known as a graph theoretic index is a kind of molecular descriptor, that is, the mathematical representation of a molecule. Essentially, a topological index is a numerical parameter of a chemical molecular structure, which helps us for a better understanding of the biological activity, physical features and chemical reactivity such as the energy of the molecule, its molecular branching, structural fragments, and its electronic structures, etc. The current study involves the topological characterizations of the antiviral medication Nirmatrelvir (other familiar names are PF-07321332, UNII-7R9A5P7H32), Molnupiravir, remdesivir (GS-5734), Hydroxy-chloroquine, etc., which are being used as the clinical candidates in treating COVID-19 patients. |