CBS1194 is a novel specific fusion inhibitor for group 2 influenza viruses, inhibits IAVs bearing group 2 HAs (pseudo-H7, EC50=0.25 uM).CBS1194 displays no inhibition against both pseudo-H5 and pseudo-Lassa.CBS1194 exhibitss potency agianst group II influenza viruses influenza A/rhea/North Carolina/1993 (H7N1) and A/Hong Kong/1/1968 (H3N2) with EC59 of 3.17 and 1.60 uM, respectively.CBS1194 displays no inhibitory activity against group 1 influenza viruses, including A/Puerto Rico/8/1934 (H1N1) and A/Viet Nam/1203/04 (H5N1).CBS1194 acts at an early stage of viral infection, inhibits viral HA mediated hemolysis, and prevents the low pH-induced conformational change of HA.The substitutions K1172N and T301A but not D71N to confer resistance to CBS1194.
