FIGURE 5.

Compounds inhibit spike and ACE2 interaction as well as cell fusion. A, Spike protein was incubated with the indicated concentrations of compounds or buffer for 1 hour and added to human ACE2‐coated plates for an additional 2 hours. Bound spike protein was detected with streptactin‐HRP by measuring absorbance. B‐D, HEK239T were transfected with spike, iRFP^NLS and split GFP_(1‐10):N7 or ACE2, BFP^NLS and split 3x(N8:GFP₁₁) plasmids. Spike‐expressing cells were incubated for 30 minutes with the indicated concentrations of compounds. ACE2‐expressing cells were added, mixed, and seeded. After 3 hours, cell fusion was detected using flow cytometer. Percentage of double‐positive cells (C) and syncytia (D) normalized to untreated cells (control) is shown. Combined means from two (A) and pooled data from four (C, D) independent experiments are shown as mean ± SEM P values of <.05 (*), <.01 (**) are indicated; n.s.‐not significant. (B) is representative of four independent experiments. See also Figure S4