Drug repurposing is the process of finding the new uses of existing drugs. It is one of the emerging methods involved in selecting a molecule for diseases which are communicable and can spread in the general population at a faster pace. The method is selected over conventional drug discovery methods because it is a faster way to bring an existing molecule for a different disease. Ever since COVID-19 pandemic has emerged worldwide use of repurposed drugs has become an important toll to tackle this viral disease. This review is a study of the varous stargegies of drug reprposing for the treatment of COVID19.

Leishmaniasis is one of the most dreadful diseases as a leading cause of death in most of the developed countries. In the given study molecular docking study was performed on the library of coumarin analogues as anti-leishmaniasis agents. Total 300 coumarins analogues were taken from Pubmed and were studied using a molecular docking study on trypanothione reductase from Leishmania infantum (PDB code: 2JK6 and 2P18) and Leishmania mexicana (PDB code: 3PP7). Molecular docking result revealed that most active compound COU-130 and COU-220 bind to the active site of the protein with amino acids present in the various proteins. In PDB 2JK6 the active compound binds to the amino acid thr-51 and ser-14 were binding to the active site, and in PDB 3PP7 the active compound binds amino acid thr-26 and in PDB 2P18 the active compound binds to the amino acid phe-219 and try-212. Further in vitro and in vivo study of selected coumarin analogues can be studied for their therapeutic potential in treating leishmaniasis.