Figure 3.

Dose–response curves of kite-shaped molecules in SARS-CoV-2-S inhibition. Mouse leukemia virus pseudotyped with spike protein (S) from severe acute respiratory syndrome coronavirus-2 was used to infect 293T-ACE2 cells in 96-well plates for 48 h in the presence of serial doses of the drug, as indicated, with 1 h pre-treatment. (a) Infectivity was measured as luciferase activity and expressed as % infectivity to infected, own solvent control (dimethyl sulfoxide, ethanol or water). Viability was measured by XTT assays in uninfected cells and expressed as % viability to un-infected solvent control (dimethyl sulfoxide, ethanol or water). Data are presented as mean ± SD of two to three repeats, as indicated. The square symbols are for cell viability (% of control) and the round symbols are for infectivity by the pseudovirus (% of control). (b) Summary of IC₅₀ values. * The IC₅₀ of E64d was obtained by interpolation from the dose–response curve.