Figure 4.

Predicted complexes of flavonoids in the catalytic site of SARS-CoV 3CLpro. Docking poses of (A) herbacetin, kaempferol and morin and (B) rhoifolin and pectolinarin were depicted on the electrostatic surface potential of SARS-CoV 3CLpro (red, negative; blue, positive; white, uncharged). Flavonoids were predicted to occupy the active site of SARS-CoV 3CLpro. The 2D schematic representations of the interactions of five flavonoids were also drawn. Figures were created with Maestro v11.5.011. S1 represents the polar S1 site of SARS-CoV 3CLpro, S2 for the hydrophobic S2 site, and the S3′ site with no strong tendency. The pink arrows represent hydrogen bond interaction.