The Discovery of in Vivo Active Mitochondrial Branched-Chain Aminotransferase (BCATm) Inhibitors by Hybridizing Fragment and HTS Hits

J Med Chem. 2015 Sep 24;58(18):7140-63. doi: 10.1021/acs.jmedchem.5b00313. Epub 2015 Jul 2.

Abstract

The hybridization of hits, identified by complementary fragment and high throughput screens, enabled the discovery of the first series of potent inhibitors of mitochondrial branched-chain aminotransferase (BCATm) based on a 2-benzylamino-pyrazolo[1,5-a]pyrimidinone-3-carbonitrile template. Structure-guided growth enabled rapid optimization of potency with maintenance of ligand efficiency, while the focus on physicochemical properties delivered compounds with excellent pharmacokinetic exposure that enabled a proof of concept experiment in mice. Oral administration of 2-((4-chloro-2,6-difluorobenzyl)amino)-7-oxo-5-propyl-4,7-dihydropyrazolo[1,5-a]pyrimidine-3-carbonitrile 61 significantly raised the circulating levels of the branched-chain amino acids leucine, isoleucine, and valine in this acute study.

MeSH terms

  • Adipocytes / drug effects
  • Adipocytes / enzymology
  • Animals
  • Crystallography, X-Ray
  • Humans
  • Isoleucine / blood
  • Leucine / blood
  • Mice, Inbred BALB C
  • Mice, Inbred C57BL
  • Mitochondrial Proteins / antagonists & inhibitors*
  • Models, Molecular
  • Pyrazoles / chemical synthesis
  • Pyrazoles / chemistry*
  • Pyrazoles / pharmacology
  • Pyrimidinones / chemical synthesis
  • Pyrimidinones / chemistry*
  • Pyrimidinones / pharmacology
  • Structure-Activity Relationship
  • Transaminases / antagonists & inhibitors*
  • Transaminases / chemistry
  • Valine / blood

Substances

  • 2-((4-chloro-2,6-difluorobenzyl)amino)-7-oxo-5-propyl-4,7-dihydropyrazolo(1,5-a)pyrimidine-3-carbonitrile
  • Mitochondrial Proteins
  • Pyrazoles
  • Pyrimidinones
  • Isoleucine
  • BCAT1 protein, human
  • Bcat1 protein, mouse
  • Transaminases
  • Leucine
  • Valine

Associated data

  • PDB/5BWR
  • PDB/5BWT
  • PDB/5BWU
  • PDB/5BWV
  • PDB/5BWW
  • PDB/5BWX