Mixed alkyl/aryl phosphonates identify metabolic serine hydrolases as antimalarial targets

Cell Chem Biol. 2024 Sep 19;31(9):1714-1728.e10. doi: 10.1016/j.chembiol.2024.07.006. Epub 2024 Aug 12.

Abstract

Malaria, caused by Plasmodium falciparum, remains a significant health burden. One major barrier for developing antimalarial drugs is the ability of the parasite to rapidly generate resistance. We previously demonstrated that salinipostin A (SalA), a natural product, potently kills parasites by inhibiting multiple lipid metabolizing serine hydrolases, a mechanism that results in a low propensity for resistance. Given the difficulty of employing natural products as therapeutic agents, we synthesized a small library of lipidic mixed alkyl/aryl phosphonates as bioisosteres of SalA. Two constitutional isomers exhibited divergent antiparasitic potencies that enabled the identification of therapeutically relevant targets. The active compound kills parasites through a mechanism that is distinct from both SalA and the pan-lipase inhibitor orlistat and shows synergistic killing with orlistat. Our compound induces only weak resistance, attributable to mutations in a single protein involved in multidrug resistance. These data suggest that mixed alkyl/aryl phosphonates are promising, synthetically tractable antimalarials.

Keywords: Plasmodium falciparum; activity-based probes; alky/aryl phosphonates; covalent probes; drug resistance; lipid metabolism; serine hydrolases.

MeSH terms

  • Antimalarials* / chemical synthesis
  • Antimalarials* / chemistry
  • Antimalarials* / pharmacology
  • Humans
  • Molecular Structure
  • Organophosphonates* / chemical synthesis
  • Organophosphonates* / chemistry
  • Organophosphonates* / pharmacology
  • Parasitic Sensitivity Tests
  • Plasmodium falciparum* / drug effects
  • Plasmodium falciparum* / enzymology
  • Structure-Activity Relationship

Substances

  • Antimalarials
  • Organophosphonates