The molecule is made up of a head and a flexible carbon-based tail, connected via a β-keto-amide linker. The plan was to incorporate a switch into the tail.

Westvac Biopharma Co. Ltd. has described keto amide derivatives acting as 3C-like proteinase (3CLpro; Mpro; nsp5) (SARS-CoV-2; COVID-19 virus) inhibitors reported to be useful for the treatment of ...