Structure-guided lead optimization of triazolopyrimidine-ring substituents identifies potent Plasmodium falciparum dihydroorotate dehydrogenase inhibitors with clinical candidate potential

J Med Chem. 2011 Aug 11;54(15):5540-61. doi: 10.1021/jm200592f. Epub 2011 Jul 14.

Abstract

Drug therapy is the mainstay of antimalarial therapy, yet current drugs are threatened by the development of resistance. In an effort to identify new potential antimalarials, we have undertaken a lead optimization program around our previously identified triazolopyrimidine-based series of Plasmodium falciparum dihydroorotate dehydrogenase (PfDHODH) inhibitors. The X-ray structure of PfDHODH was used to inform the medicinal chemistry program allowing the identification of a potent and selective inhibitor (DSM265) that acts through DHODH inhibition to kill both sensitive and drug resistant strains of the parasite. This compound has similar potency to chloroquine in the humanized SCID mouse P. falciparum model, can be synthesized by a simple route, and rodent pharmacokinetic studies demonstrated it has excellent oral bioavailability, a long half-life and low clearance. These studies have identified the first candidate in the triazolopyrimidine series to meet previously established progression criteria for efficacy and ADME properties, justifying further development of this compound toward clinical candidate status.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antimalarials / chemical synthesis
  • Antimalarials / pharmacology
  • Chemical Phenomena
  • Crystallography, X-Ray
  • Drug Resistance
  • Humans
  • Mice
  • Oxidoreductases Acting on CH-CH Group Donors / antagonists & inhibitors*
  • Plasmodium falciparum / enzymology
  • Pyrimidines / chemical synthesis
  • Pyrimidines / chemistry*
  • Pyrimidines / pharmacokinetics
  • Pyrimidines / pharmacology
  • Rats
  • Structure-Activity Relationship
  • Triazoles / chemical synthesis
  • Triazoles / chemistry*
  • Triazoles / pharmacokinetics
  • Triazoles / pharmacology

Substances

  • Antimalarials
  • Pyrimidines
  • Triazoles
  • Oxidoreductases Acting on CH-CH Group Donors
  • dihydroorotate dehydrogenase

Associated data

  • PDB/3SFK