Lead Optimization of Benzoxazolone Carboxamides as Orally Bioavailable and CNS Penetrant Acid Ceramidase Inhibitors

J Med Chem. 2020 Apr 9;63(7):3634-3664. doi: 10.1021/acs.jmedchem.9b02004. Epub 2020 Mar 26.

Abstract

Sphingolipids (SphLs) are a diverse class of molecules that are regulated by a complex network of enzymatic pathways. A disturbance in these pathways leads to lipid accumulation and initiation of several SphL-related disorders. Acid ceramidase is one of the key enzymes that regulate the metabolism of ceramides and glycosphingolipids, which are important members of the SphL family. Herein, we describe the lead optimization studies of benzoxazolone carboxamides resulting in piperidine 22m, where we demonstrated target engagement in two animal models of neuropathic lysosomal storage diseases (LSDs), Gaucher's and Krabbe's diseases. After daily intraperitoneal administration at 90 mg kg-1, 22m significantly reduced the brain levels of the toxic lipids glucosylsphingosine (GluSph) in 4L;C* mice and galactosylsphingosine (GalSph) in Twitcher mice. We believe that 22m is a lead molecule that can be further developed for the correction of severe neurological LSDs where GluSph or GalSph play a significant role in disease pathogenesis.

MeSH terms

  • Acid Ceramidase / antagonists & inhibitors*
  • Administration, Oral
  • Animals
  • Benzoxazoles / administration & dosage
  • Benzoxazoles / chemical synthesis
  • Benzoxazoles / pharmacokinetics
  • Benzoxazoles / pharmacology*
  • Brain / metabolism
  • Cell Line, Tumor
  • Enzyme Inhibitors / administration & dosage
  • Enzyme Inhibitors / chemical synthesis
  • Enzyme Inhibitors / pharmacokinetics
  • Enzyme Inhibitors / pharmacology*
  • Female
  • Gaucher Disease / enzymology
  • Gaucher Disease / metabolism
  • Humans
  • Leukodystrophy, Globoid Cell / enzymology
  • Leukodystrophy, Globoid Cell / metabolism
  • Male
  • Mice
  • Molecular Structure
  • Psychosine / analogs & derivatives
  • Psychosine / metabolism
  • Structure-Activity Relationship

Substances

  • Benzoxazoles
  • Enzyme Inhibitors
  • Psychosine
  • benzoxazolone
  • sphingosyl beta-glucoside
  • Acid Ceramidase