PROS1 and viral infectious disease: In addition, Kobophenol A (127), a bioactive molecule from Caragana sinica (Buc’hoz) Rehder, was recently identified as a potential inhibitor that hinders the interaction between the ACE2 and the S protein in vitro with an IC50 of 1.81 μM and inhibits the viral infection of SARS-CoV-2 in cells with an EC50 of 71.60 μM (Gangadevi et al., 2021).