Structure-activity relationships and blood distribution of antiplasmodial aminopeptidase-1 inhibitors

J Med Chem. 2012 Dec 27;55(24):10909-17. doi: 10.1021/jm301506h. Epub 2012 Dec 5.

Abstract

Malaria is a severe infectious disease that causes between 655,000 and 1.2 million deaths annually. To overcome the resistance to current drugs, new biological targets are needed for drug development. Aminopeptidase M1 (PfAM1), a zinc metalloprotease, has been proposed as a new drug target to fight malaria. Herein, we disclosed the structure-activity relationships of a selective family of hydroxamate PfAM1 inhibitors based on the malonic template. In particular, we performed a "fluoro-scanning" around hit 1 that enlightened the key positions of the halogen for activity. The docking of the best inhibitor 2 is consistent with in vitro results. The stability of 2 was evaluated in microsomes, in plasma, and toward glutathione. The in vivo distribution study performed with the nanomolar hydroxamate inhibitor 2 (BDM14471) revealed that it reaches its site of action. However, it fails to kill the parasite at concentrations relevant to the enzymatic inhibitory potency, suggesting that killing the parasite remains a challenge for potent and druglike catalytic-site binding PfAM1 inhibitors. In all, this study provides important insights for the design of inhibitors of PfAM1 and the validity of this target.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aminopeptidases / antagonists & inhibitors*
  • Animals
  • Antimalarials / blood
  • Antimalarials / chemical synthesis*
  • Antimalarials / pharmacology
  • Cell Line
  • Drug Resistance
  • Female
  • Humans
  • Malaria / drug therapy
  • Malonates / blood
  • Malonates / chemical synthesis*
  • Malonates / pharmacology
  • Metalloproteases / antagonists & inhibitors*
  • Mice
  • Molecular Docking Simulation
  • Plasmodium berghei
  • Plasmodium falciparum / drug effects
  • Plasmodium falciparum / enzymology*
  • Protein Binding
  • Protozoan Proteins / antagonists & inhibitors*
  • Rats
  • Solubility
  • Stereoisomerism
  • Structure-Activity Relationship
  • Tissue Distribution
  • Zinc

Substances

  • Antimalarials
  • Malonates
  • N-(4-fluorobenzyl)-N'-hydroxy-2-(1-phenylmeth-(Z)-ylidene)malonamide
  • Protozoan Proteins
  • Metalloproteases
  • Aminopeptidases
  • Zinc