Submission Details

Design Rationale:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7114332/ 3.3. Emodin inhibits the interaction between S protein and ACE2 As emodin (1,3,8-trihydroxy-6-methylanthraquinone), rhein (1,8-dihydroxy-3-carboxyl-9,10-anthraquinone), and chrysin (5,7-dihydroxyflavone) are produced in high levels in genus Rheum and Polygonum (Koyama et al., 2003, Nonaka et al., 1977), we investigated whether these compounds were responsible for blocking the binding of S protein to ACE2. Emodin and rhein belong to anthraquinone compounds, while chrysin belongs to a flavonoid compound (Fig. 4 ). As shown in Fig. 5A, emodin blocked the binding of S protein to ACE2 in a dose-dependent manner. The IC50 value of emodin is 200 μM. Preincubation of rhein with biotinylated S protein slightly inhibited the S protein and ACE2 interaction (Fig. 5B). Chrysin exhibited a weak inhibition on the S protein and ACE2 interaction at 400 μM; however, it significantly stimulated the binding of S protein to ACE2 at 50 μM (Fig. 5C). These results suggested that emodin was the likely active constituent of Rheum and Polygonum responsible for blocking the binding of S protein to ACE2.