Fig. 6.

Inhibitory effects of emodin and emodin-like compounds on the SARS-CoV S protein and ACE2 interaction. Biotin-labeled S protein (0.05 μg) was mixed with various amounts of emodin, promazine, anthraquinone or 1,4-bis-(1-anthraquinonylamino)-anthraquinone, and the mixtures were added to wells, which were coated with 1 ng of ACE2. The biotinylated ELISA was performed as described in Section 2. Results are expressed as inhibition (%) described in Section 2. Values are mean ± standard error of six independent assays.