Bioisosteric ferrocenyl-containing quinolines with antiplasmodial and antitrichomonal properties

Dalton Trans. 2016 Nov 29;45(47):19086-19095. doi: 10.1039/c6dt03175g.

Abstract

Bioisosteric ferrocenyl-containing quinolines and ferrocenylamines containing organosilanes and their carbon analogues, were prepared and fully characterised. The molecular structures of two ferrocenyl-containing quinolines, determined using single-crystal X-ray diffraction, revealed that the compounds crystallise in a folded conformation. The compounds were screened for their antiplasmodial activity against the chloroquine-sensitive (NF54) and CQ-resistant (Dd2) strains of P. falciparum, as well as for their cytotoxicity against Chinese Hamster Ovarian (CHO) cells. The ferrocenyl-containing quinolines displayed activities in the low nanomolar range (6-36 nM), and showed selectivity towards parasites. β-Haematin inhibition assays suggest that the compounds may in part act via the inhibition of haemozoin formation, while microsomal metabolic stability studies reveal that the ferrocenyl-containing quinolines are rapidly metabolised in liver microsomes. Further, antitrichomonal screening against the metronidazole-sensitive (G3) strain of the mucosal pathogen T. vaginalis revealed that the quinoline-based compounds displayed superior parasite growth inhibition when compared to the ferrocenylamines. The library was also tested E. coli and on Lactobacilli spp. found as part of the normal flora of the human microbiome and no effect on growth in vitro was observed, supporting the observation that these compounds are specific for eukaryotic pathogens.

MeSH terms

  • Animals
  • Antimalarials / chemical synthesis*
  • Antimalarials / chemistry
  • Antimalarials / pharmacology
  • Antitrichomonal Agents / chemical synthesis*
  • Antitrichomonal Agents / chemistry
  • Antitrichomonal Agents / pharmacology
  • CHO Cells
  • Cell Survival / drug effects
  • Cricetulus
  • Drug Design
  • Ferrous Compounds / chemical synthesis*
  • Ferrous Compounds / chemistry
  • Ferrous Compounds / pharmacology
  • Plasmodium falciparum / drug effects
  • Quinolines / chemical synthesis*
  • Quinolines / chemistry
  • Quinolines / pharmacology
  • Trichomonas vaginalis / drug effects

Substances

  • Antimalarials
  • Antitrichomonal Agents
  • Ferrous Compounds
  • Quinolines