Fig. 1

Eriodictyol suppresses the membrane-binding mechanisms of the SARS-CoV-2 spike protein. FRET-based enzymatic activity assays A were performed to examine the activity of TMPRSS2 B and furin C in the presence of eriodictyol at the indicated concentrations. FRET-based protein interaction assays D were employed to test the inhibitory effect of eriodictyol on the protein interaction between S protein and ACE2 E. Camostat (CAM), naphthofluorescein (NAP), and cepharanthine (CEP) were used as the positive control for the inhibitions of TMPRSS2 and furin activities and the binding between S protein and ACE2, respectively. Data are shown as mean ± SEM from three independent experiments with triplicates. ** p < 0.01 and **** p < 0.0001