Sontochin as a guide to the development of drugs against chloroquine-resistant malaria

Antimicrob Agents Chemother. 2012 Jul;56(7):3475-80. doi: 10.1128/AAC.00100-12. Epub 2012 Apr 16.

Abstract

Sontochin was the original chloroquine replacement drug, arising from research by Hans Andersag 2 years after chloroquine (known as "resochin" at the time) had been shelved due to the mistaken perception that it was too toxic for human use. We were surprised to find that sontochin, i.e., 3-methyl-chloroquine, retains significant activity against chloroquine-resistant strains of Plasmodium falciparum in vitro. We prepared derivatives of sontochin, "pharmachins," with alkyl or aryl substituents at the 3 position and with alterations to the 4-position side chain to enhance activity against drug-resistant strains. Modified with an aryl substituent in the 3 position of the 7-chloro-quinoline ring, Pharmachin 203 (PH-203) exhibits low-nanomolar 50% inhibitory concentrations (IC(50)s) against drug-sensitive and multidrug-resistant strains and in vivo efficacy against patent infections of Plasmodium yoelii in mice that is superior to chloroquine. Our findings suggest that novel 3-position aryl pharmachin derivatives have the potential for use in treating drug resistant malaria.

Publication types

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

MeSH terms

  • Animals
  • Antimalarials / chemical synthesis
  • Antimalarials / chemistry
  • Antimalarials / therapeutic use*
  • Chloroquine / therapeutic use*
  • Drug Resistance
  • Inhibitory Concentration 50
  • Malaria / drug therapy*
  • Mice
  • Molecular Structure
  • Plasmodium falciparum / drug effects
  • Plasmodium falciparum / pathogenicity
  • Plasmodium yoelii / drug effects
  • Plasmodium yoelii / pathogenicity

Substances

  • Antimalarials
  • Chloroquine