Development of isoquinolinone derivatives as immunoproteasome inhibitors

Bioorg Med Chem Lett. 2022 Jan 1:55:128478. doi: 10.1016/j.bmcl.2021.128478. Epub 2021 Nov 24.

Abstract

The inhibition of immunoproteasome is considered nowadays a promising strategy for the treatment of hematologic malignancies. In this paper we report the design, synthesis, and biological evaluation as immunoproteasome inhibitors of a new series of isoquinolinone derivatives characterized by a (E)-prop-1-ene fragment that connects the heterocycle to a distal amide functionality. Among all the synthesized compounds, we identified an inhibitor with Ki values in the low micromolar or submicromolar range towards the chymotrypsin-like activities of both proteasome and immunoproteasome (β5c, β5i and β1i subunits). Molecular modeling studies suggest that the most potent compound of the series may act a single-site binder. In particular, through its isopentyl group, it might dock into P1 site in the case of the β1i catalytic subunit, while in the case of β5c and β5i subunits, the P3 site might be the preferred binding site.

Keywords: Immunoproteasome inhibition; Isoquinoline derivatives; Molecular dynamics simulation.

MeSH terms

  • Binding Sites / drug effects
  • Dose-Response Relationship, Drug
  • Drug Development*
  • Humans
  • Models, Molecular
  • Molecular Structure
  • Proteasome Endopeptidase Complex / immunology*
  • Proteasome Inhibitors / chemical synthesis
  • Proteasome Inhibitors / chemistry
  • Proteasome Inhibitors / pharmacology*
  • Quinolones / chemical synthesis
  • Quinolones / chemistry
  • Quinolones / pharmacology*
  • Structure-Activity Relationship

Substances

  • Proteasome Inhibitors
  • Quinolones
  • Proteasome Endopeptidase Complex