Targeting Chikungunya Virus Replication by Benzoannulene Inhibitors

J Med Chem. 2021 Apr 22;64(8):4762-4786. doi: 10.1021/acs.jmedchem.0c02183. Epub 2021 Apr 9.

Abstract

A benzo[6]annulene, 4-(tert-butyl)-N-(3-methoxy-5,6,7,8-tetrahydronaphthalen-2-yl) benzamide (1a), was identified as an inhibitor against Chikungunya virus (CHIKV) with antiviral activity EC90 = 1.45 μM and viral titer reduction (VTR) of 2.5 log at 10 μM with no observed cytotoxicity (CC50 = 169 μM) in normal human dermal fibroblast cells. Chemistry efforts to improve potency, efficacy, and drug-like properties of 1a resulted in a novel lead compound 8q, which possessed excellent cellular antiviral activity (EC90 = 270 nM and VTR of 4.5 log at 10 μM) and improved liver microsomal stability. CHIKV resistance to an analog of 1a, compound 1c, tracked to a mutation in the nsP3 macrodomain. Further mechanism of action studies showed compounds working through inhibition of human dihydroorotate dehydrogenase in addition to CHIKV nsP3 macrodomain. Moderate efficacy was observed in an in vivo CHIKV challenge mouse model for compound 8q as viral replication was rescued from the pyrimidine salvage pathway.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Antiviral Agents / chemistry
  • Antiviral Agents / pharmacokinetics
  • Antiviral Agents / pharmacology*
  • Antiviral Agents / therapeutic use
  • Benzene Derivatives / chemistry*
  • Benzene Derivatives / metabolism
  • Benzene Derivatives / pharmacology
  • Benzene Derivatives / therapeutic use
  • Binding Sites
  • Cell Line
  • Cell Survival / drug effects
  • Chikungunya Fever / drug therapy
  • Chikungunya virus / physiology*
  • Dihydroorotate Dehydrogenase
  • Disease Models, Animal
  • Female
  • Half-Life
  • Humans
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Microsomes, Liver / metabolism
  • Molecular Docking Simulation
  • Oxidoreductases Acting on CH-CH Group Donors / antagonists & inhibitors
  • Oxidoreductases Acting on CH-CH Group Donors / metabolism
  • Structure-Activity Relationship
  • Virus Replication / drug effects*

Substances

  • Antiviral Agents
  • Benzene Derivatives
  • Dihydroorotate Dehydrogenase
  • Oxidoreductases Acting on CH-CH Group Donors