In 2017, Park et al. 204  assessed the inhibitory activity of polyphenols isolated from B. Papyrifera against SARS‐CoV PLpro and MERS‐CoV PLpro. Two of them (176 and 177 Figure 37) displayed moderate inhibition at both SARS‐CoV‐1 PLpro and MERS‐CoV PLpro with a noncompetitive mechanism of action.