Inasmuch as therapeutic options against coronavirus have been focused mainly on blocking the interaction between its spike protein and the ACE2 receptor on host cells, SARS-CoV-2 has several additional critical proteins that could potentially be targeted with drugs that have already been approved for use against other viruses. One of these viral proteins is the main protease (Mpro) that is needed to separate newly minted polypeptides into their functional component parts.