R-1479 (4'-Azidocytidine) is an RdRp inhibitor with an IC50 value of 1.28 μM for HCV RNA replication in the HCV subgenomic replicon system.

HCV replication:1.28 μM

R-1479 inhibits HCV RNA replication and reduces Renillaluciferase activity of proliferating replicon cells in a dose-dependent manner[1]. R-1479 inhibits RNA synthesis mediated by NS5B with an IC50 value of 320 nM and the RNA polymerase encoded by HCV[2].

The membrane-associated, native HCV replicase complex is isolated from 2209-23 HCV replicon cells and a derived cell line carrying HCV replicon RNA with an S282T mutation in the NS5B coding sequence. The in vitro replicase assay contain 10 μL of cytoplasmic membrane fraction, 50 mM HEPES (pH 7.5), 10 mM KCl, 10 mM dithiothreitol, 5 mM MgCl2, 20 μg/mL actinomycin D, 1 mM ATP, 1 mM GTP, 1 mM UTP, 30 μCi of [α-33P]CTP (3000 Ci/mmol, 10 mCi/mL), 1 unit/μL SUPERase•In, 10 mM creatine phosphate, and 200 μg/mL creatine phosphokinase in a final volume of 25 μL [1].