Development of Chemical Entities Endowed with Potent Fast-Killing Properties against Plasmodium falciparum Malaria Parasites

J Med Chem. 2019 Oct 24;62(20):9217-9235. doi: 10.1021/acs.jmedchem.9b01099. Epub 2019 Oct 14.

Abstract

One of the attractive properties of artemisinins is their extremely fast-killing capability, quickly relieving malaria symptoms. Nevertheless, the unique benefits of these medicines are now compromised by the prolonged parasite clearance times and the increasing frequency of treatment failures, attributed to the increased tolerance of Plasmodium falciparum to artemisinin. This emerging artemisinin resistance threatens to undermine the effectiveness of antimalarial combination therapies. Herein, we describe the medicinal chemistry efforts focused on a cGMP-dependent protein kinase (PKG) inhibitor scaffold, leading to the identification of novel chemical entities with very potent, similar to artemisinins, fast-killing potency against asexual blood stages that cause disease, and activity against gametocyte activation that is required for transmission. Furthermore, we confirm that selective PKG inhibitors have a slow speed of kill, while chemoproteomic analysis suggests for the first time serine/arginine protein kinase 2 (SRPK2) targeting as a novel strategy for developing antimalarial compounds with extremely fast-killing properties.

MeSH terms

  • Antimalarials / chemistry
  • Antimalarials / metabolism
  • Antimalarials / pharmacology*
  • Artemisinins / chemistry*
  • Artemisinins / metabolism
  • Artemisinins / pharmacology
  • Cyclic GMP-Dependent Protein Kinases / antagonists & inhibitors
  • Cyclic GMP-Dependent Protein Kinases / genetics
  • Cyclic GMP-Dependent Protein Kinases / metabolism
  • ERG1 Potassium Channel / antagonists & inhibitors
  • ERG1 Potassium Channel / metabolism
  • Humans
  • Inhibitory Concentration 50
  • Mutagenesis, Site-Directed
  • Plasmodium falciparum / drug effects*
  • Plasmodium falciparum / growth & development
  • Protozoan Proteins / antagonists & inhibitors
  • Protozoan Proteins / genetics
  • Protozoan Proteins / metabolism
  • Solubility
  • Structure-Activity Relationship
  • Thiazoles / chemistry

Substances

  • Antimalarials
  • Artemisinins
  • ERG1 Potassium Channel
  • KCNH2 protein, human
  • Protozoan Proteins
  • Thiazoles
  • artemisinine
  • Cyclic GMP-Dependent Protein Kinases