Discovering novel anti-HCV compounds with inhibitory activities toward HCV NS3/4A protease

Aim: To discover novel hepatitis C virus (HCV) inhibitors and elucidate the mechanism of action of the active compounds.

Methods: HCV subgenomic replicon-based luciferase reporter cell line was used to screen 1200 synthetic compounds with novel structures. Huh7.5.1 cell line stably transfected with HCV NS3/4A protease reporter was established to investigate the anti-HCV mechanism of the active compounds. The active compounds were further examined in an in vitro HCV Infection assay to confirm their anti-HCV activity.

Results: After two-round screening in the anti-HCV replicon assay, some 2,4-diaminoquinazoline derivatives and carboxamide analogues were found to possess anti-HCV replicon activities (the IC50 values were less than 5 μmol/L). Among them, two representative compounds HZ-1157 and LZ-110618-6 inhibited HCV NS3/4A protease with IC50 values of 1.0 and 0.68 μmol/L, respectively. Furthermore, HZ-1157 and LZ-110618-6 inhibited HCV Infection in vitro with IC50 values of 0.82 and 0.11 μmol/L, respectively.

Conclusion: Some 2,4-diaminoquinazoline derivatives and carboxamide analogues have been identified as novel anti-HCV compounds.