PROS1 and viral infectious disease: Using frontal affinity chromatography-mass spectrometry (FAC/MS) and pseudotyped virus infection assay, Yi et al. screened 121 herbs used in traditional Chinese medicine and identified tetra-O-galloyl-β-d-glucose (TGG, 123) and luteolin (21), with significant affinity to the S2 protein (Asn733 to Gln1190 of the SARS-CoV S protein), as agents against SARS-CoV with EC50 values of 4.50 and 10.60 μM, respectively (Yi et al., 2004).