Back-Pocket Optimization of 2-Aminopyrimidine-Based Macrocycles Leads to Potent EPHA2/GAK Kinase Inhibitors

J Med Chem. 2024 Aug 8;67(15):12534-12552. doi: 10.1021/acs.jmedchem.4c00411. Epub 2024 Jul 19.

Abstract

Macrocyclization of acyclic compounds is a powerful strategy for improving inhibitor potency and selectivity. Here we have optimized 2-aminopyrimidine-based macrocycles to use these compounds as chemical tools for the ephrin kinase family. Starting with a promiscuous macrocyclic inhibitor, 6, we performed a structure-guided activity relationship and selectivity study using a panel of over 100 kinases. The crystal structure of EPHA2 in complex with the developed macrocycle 23 provided a basis for further optimization by specifically targeting the back pocket, resulting in compound 55, a potent inhibitor of EPHA2/A4 and GAK. Subsequent front-pocket derivatization resulted in an interesting in cellulo selectivity profile, favoring EPHA4 over the other ephrin receptor kinase family members. The dual EPHA2/A4 and GAK inhibitor 55 prevented dengue virus infection of Huh7 liver cells. However, further investigations are needed to determine whether this was a compound-specific effect or target-related.

MeSH terms

  • Cell Line, Tumor
  • Crystallography, X-Ray
  • Dengue Virus / drug effects
  • Humans
  • Intracellular Signaling Peptides and Proteins
  • Macrocyclic Compounds / chemical synthesis
  • Macrocyclic Compounds / chemistry
  • Macrocyclic Compounds / pharmacology
  • Models, Molecular
  • Morpholines
  • Protein Kinase Inhibitors* / chemical synthesis
  • Protein Kinase Inhibitors* / chemistry
  • Protein Kinase Inhibitors* / pharmacology
  • Protein Serine-Threonine Kinases
  • Pyrimidines* / chemical synthesis
  • Pyrimidines* / chemistry
  • Pyrimidines* / pharmacology
  • Receptor, EphA2* / antagonists & inhibitors
  • Receptor, EphA2* / metabolism
  • Structure-Activity Relationship

Substances

  • 2-aminopyrimidine
  • EPHA2 protein, human
  • GAK protein, human
  • Intracellular Signaling Peptides and Proteins
  • Macrocyclic Compounds
  • Protein Kinase Inhibitors
  • Protein Serine-Threonine Kinases
  • Pyrimidines
  • Receptor, EphA2
  • Morpholines