ABSTRACT
A series of benzo[d]isothiazole-1,1-dioxides were designed and evaluated as inhibitors of HCV polymerase NS5B. Structure-based design led to the incorporation of a high affinity methyl sulfonamide group. Structure-activity relationship (SAR) studies of this series revealed analogues with submicromolar potencies in the HCV replicon assay and moderate pharmacokinetic properties. SAR studies combined with structure based drug design focused on the sulfonamide region led to a novel and potent cyclic analogue.
Subject(s)
Antiviral Agents/chemical synthesis , Hepacivirus/drug effects , Thiazoles/chemistry , Viral Nonstructural Proteins/antagonists & inhibitors , Animals , Antiviral Agents/chemistry , Antiviral Agents/pharmacokinetics , Binding Sites , Crystallography, X-Ray , Haplorhini , Rats , Structure-Activity Relationship , Thiazoles/chemical synthesis , Thiazoles/pharmacokinetics , Viral Nonstructural Proteins/metabolismABSTRACT
Benzothiazine-substituted tetramic acids were discovered as highly potent non-nucleoside inhibitors of HCV NS5B polymerase. X-ray crystallography studies confirmed the binding mode of these inhibitors with HCV NS5B polymerase. Rational optimization of time dependent inactivation of CYP 3A4 and clearance was accomplished by incorporation of electron-withdrawing groups to the benzothiazine core.
Subject(s)
Antiviral Agents/chemical synthesis , Hepacivirus/drug effects , Pyrrolidinones/chemistry , Thiazines/chemistry , Viral Nonstructural Proteins/antagonists & inhibitors , Animals , Antiviral Agents/chemistry , Antiviral Agents/pharmacokinetics , Binding Sites , Crystallography, X-Ray , Pyrrolidinones/chemical synthesis , Pyrrolidinones/pharmacokinetics , Rats , Structure-Activity Relationship , Viral Nonstructural Proteins/metabolismABSTRACT
A new series of benzothiazine-substituted quinolinediones were evaluated as inhibitors of HCV polymerase NS5B. SAR studies on this series revealed a methyl sulfonamide group as a high affinity feature. Analogues with this group showed submicromolar potencies in the HCV cell based replicon assay. Pharmacokinetic and toxicology studies were also performed on a selected compound (34) to evaluate in vivo properties of this new class of inhibitors of HCV NS5B polymerase.