Hepatitis C virus (HCV) is a major cause of chronic liver disease, leading to hepatic steatosis, fibrosis, cirrhosis and hepatocellular carcinoma. A vaccine is currently not available, while the standard of care is effective in only 50% of treated patients. The first specific anti-HCV drugs have been recently approved, and new classes of targeted agents are under clinical trials/investigation. Nevertheless, improved treatment strategies are needed, in order to bypass the rapid emergence of resistance. All the viral non-structural proteins are a possible target for the identification of novel and selective antivirals. Among them, the NS3 helicase is still underexploited, with no known inhibitor under pre-clinical or clinical development. This enzyme plays a crucial role in the virus life cycle: it catalyses the separation of double-stranded RNA strands, which is necessary for genome amplification and translation. Due to its essential function, the NS3 helicase was chosen as a target for the identification of new, specific anti-HCV compounds. Different computer-aided techniques were employed to identify potential smallmolecule inhibitors of the enzyme. Two structure-based virtual screenings of commercially available compounds were performed on the main nucleic acid binding site. A series of candidate inhibitors was evaluated in the HCV replicon assay, yielding two primary hits with low μM activity. Secondly, the model of the one known inhibitor co-crystallised with the enzyme was used as a starting point for a shape-comparison screening of small molecule libraries. A new series of compounds was selected and evaluated for anti-HCV activity, and one of them was found to inhibit the viral replication at a low μM concentration. Several new derivatives of the initial hits were synthesised, belonging to four main structural families: bis-aromatic piperazine derivatives, symmetrical phenylendiamine compounds, differently substituted thieno-pyrimidines, and triphenyl-pyrrolone analogues. Inhibition of HCV replication in the replicon assay was evaluated for the new compounds prepared and several structures showed a range of activity from low-μM to nM.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:590348 |
| Date | January 2013 |
| Creators | Bassetto, Marcella |
| Publisher | Cardiff University |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://orca.cf.ac.uk/57024/ |
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