Background:

S119-8 is a broad spectrum inhibitor of influenza A and B viruses.

S119-8 is an analog of S119. S119-8 has acquired enhanced broad-spectrum activity with improved calculated physical properties, while maintaining significant potency (IC50=1.43 μM) at non-toxic (CC50=66.10 μM) concentrations, albeit somewhat higher (7-fold) than that of the parent S119 against influenza A/WSN/33 H1N1 (WSN) virus. S119-8 also shows activity against multiple influenza B viruses and an oseltamivir-resistant influenza A virus, but does not inhibit a non-influenza virus, vesicular stomatitis nirus (VSV). S119-8 has increased breadth of inhibition against influenza A and B viruses accompanied by only a small loss in potency. S119-8 inhibits influenza viruses A/Puerto Rico/8/1934 (H1N1) (PR8) with an IC50 of 6.05 μM. S119-8 inhibits influenza A/Vietnam/1203/2004 (H5N1) with an IC50 of 8.42 μM[1].

[1]. White KM, et al. Broad Spectrum Inhibitor of Influenza A and B Viruses Targeting the Viral Nucleoprotein. ACS Infect Dis. 2018 Feb 9;4(2):146-157.