Lead optimization of a pyrazole sulfonamide series of Trypanosoma brucei N-myristoyltransferase inhibitors: identification and evaluation of CNS penetrant compounds as potential treatments for stage 2 human African trypanosomiasis

J Med Chem. 2014 Dec 11;57(23):9855-69. doi: 10.1021/jm500809c. Epub 2014 Nov 20.

Abstract

Trypanosoma brucei N-myristoyltransferase (TbNMT) is an attractive therapeutic target for the treatment of human African trypanosomiasis (HAT). From previous studies, we identified pyrazole sulfonamide, DDD85646 (1), a potent inhibitor of TbNMT. Although this compound represents an excellent lead, poor central nervous system (CNS) exposure restricts its use to the hemolymphatic form (stage 1) of the disease. With a clear clinical need for new drug treatments for HAT that address both the hemolymphatic and CNS stages of the disease, a chemistry campaign was initiated to address the shortfalls of this series. This paper describes modifications to the pyrazole sulfonamides which markedly improved blood-brain barrier permeability, achieved by reducing polar surface area and capping the sulfonamide. Moreover, replacing the core aromatic with a flexible linker significantly improved selectivity. This led to the discovery of DDD100097 (40) which demonstrated partial efficacy in a stage 2 (CNS) mouse model of HAT.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acyltransferases / antagonists & inhibitors*
  • Aminopyridines / chemistry
  • Animals
  • Blood-Brain Barrier / drug effects
  • Central Nervous System / drug effects
  • Female
  • Humans
  • Inhibitory Concentration 50
  • Mice
  • Pyrazoles / chemical synthesis*
  • Pyrazoles / pharmacology
  • Pyrazoles / therapeutic use
  • Structure-Activity Relationship
  • Sulfonamides / chemical synthesis*
  • Sulfonamides / chemistry
  • Sulfonamides / pharmacology
  • Sulfonamides / therapeutic use
  • Trypanocidal Agents / chemical synthesis*
  • Trypanocidal Agents / pharmacology
  • Trypanosoma brucei brucei / drug effects
  • Trypanosomiasis, African / drug therapy*

Substances

  • 2,6-dichloro-N-(difluoromethyl)-4-(3-(1-methylpiperidin-4-yl)propyl)-N-(1,3,5-trimethyl-1H-pyrazol-4-yl)benzenesulfonamide
  • Aminopyridines
  • DDD 85646
  • Pyrazoles
  • Sulfonamides
  • Trypanocidal Agents
  • Acyltransferases
  • glycylpeptide N-tetradecanoyltransferase

Associated data

  • PDB/4UWI
  • PDB/4UWJ