Fig. 1.
Screening of 29 flavonoids, docking score lower than -6, against SARS-CoV-2 Mpro using the FRET assay. A 40-μM compound (final concentration 20 μM) was pre-incubated with 0.3 μM SARS-CoV-2 M pro at 30 °C for 10 min, and then 200 μM FRET substrate was added to the reaction mixture to initiate the reaction. The excitation wavelength is 340 nm, and the emission wavelength is 490 nm for fluorescence measurement. Results: Inhibition rate (%) = (RFU100% enzyme activity control-RFU sample) / (RFU100% enzyme activity control-RFU blank control) × 100%. The results are average ± standard deviation of three repeats. B The inhibitory assay of ( −)-gallocatechin gallate, ( +)-gallocatechin, and baicalein show efficient inhibition for Mpro. Error bars: mean ± S.D. of three independent replicates.