2-((4-Arylpiperazin-1-yl)methyl)benzonitrile Derivatives as Orally Available Inhibitors of Hepatitis C Virus with a Novel Mechanism of Action.

Although the direct-acting antivirals revolutionized the hepatitis C virus (HCV) infection treatment in the last decade, more efforts are needed to reach the elimination of HCV in the absence of a vaccine. 4-(Piperazin-1-yl)-2-((p-tolylamino)methyl)-benzonitrile (1) is a modest HCV inhibitor identified from an in-house screening using a HCV-infected Huh7.5 cell culture. Starting from it, the chemical optimization afforded a new 2-((4-arylpiperazin-1-yl)methyl)benzonitrile scaffold with significantly increased antiviral activity against HCV. A highly effective HCV inhibitor, 35 (L0909, EC50 = 0.022 µM, SI > 600), was identified by the structure-activity relationship study. The biological study revealed that L0909 could block HCV replication by acting on the HCV entry stage. The high sensitivity to clinical resistant HCV mutants and synergistic effect with clinical drugs were observed for this compound. The further pharmaceutical studies demonstrated that L0909 is long-lasting, is orally available, and has low toxicity in vivo. These results show L0909 as a promising HCV entry inhibitor for single or combinational therapeutic potential.

Synthesis and Broad Antiviral Activity of Novel 2-aryl-isoindolin-1-ones towards Diverse Enterovirus A71 Clinical Isolates.

Enterovirus 71 (EV-A71) is the main causative pathogen of childhood hand, foot and mouth disease. Effective medicine is currently unavailable for the treatment of this viral disease. Using the fragment-hopping strategy, a series of 2-aryl-isoindolin-1-one compounds were designed, synthesized and investigated for their in vitro antiviral activity towards multiple EV-A71 clinical isolates (H, BrCr, Shenzhen98, Jiangsu52) in Vero cell culture in this study. The structure⁻activity relationship (SAR) studies identified 2-phenyl-isoindolin-1-ones as a new potent chemotype with potent antiviral activity against EV-A71. Ten out of the 24 tested compounds showed significant antiviral activity (EC50 < 10 µM) towards four EV-A71 strains. Compounds A3 and A4 exhibited broad and potent antiviral activity with the 50% effective concentration (EC50) values in the range of 1.23⁻1.76 µM. Moreover, the selectivity indices of A3 and A4 were significantly higher than those of the reference compound, pirodavir. The western blotting experiment indicated that the viral VP1 was significantly decreased at both the protein and RNA level in a dose-dependent manner following treatment with compound A3. Moreover, compound A3 inhibited the viral replication by acting on the virus entry stage. In summary, this study led to the discovery of 2-aryl-isoindolin-1-ones as a promising scaffold with potent anti-EV-A71 activities, which deserves further in-depth studies.

[Synthesis and biological activity of substituted xanthines as DPP-â £ inhibitors].

In order to find more potential DPP-IV inhibitor, a series of xanthine-scaffold analogs of linagliptin, an approved antidiabetes drug, were designed and synthesized for SAR study. All compounds with a concentration of 50 nmol·L(-1) showed the inhibitory activity against DPP-IV enzyme in vitro, and the inhibition rate of compounds 1a, 1d and 1f was over 50%. Virtual docking was also performed to facilitate the SAR analysis of these substituted xanthines.

[Research progress of HCV NS5A complex inhibitors].

Direct acting antivirals against the hepatitis C virus (HCV) have been developed and the field has been under a rapid progress in recent years. Especially, HCV inhibitors targeting nonstructural 5A (NS5A) protein are attracting much attention due to the potent antiviral activity, fast viral clearance and broad antiviral spectrum. This article is prepared to cover the main progress of HCV NS5 A complex inhibitors in the market since 2010. The pharmaceutical characteristics of diverse compounds are described and summarized according to their different chemotypes.