Synthesis and biological evaluation of fluorescent leishmanicidal analogues of hexadecylphosphocholine (miltefosine) as probes of antiparasite mechanisms

J Med Chem. 2007 Nov 29;50(24):5994-6003. doi: 10.1021/jm070595+. Epub 2007 Oct 31.

Abstract

The leishmanicidal mechanism of miltefosine (hexadecylphosphocholine, MT) is not clearly understood. Valuable insights into its mode of action could be obtained by fluorescence techniques, given suitably emitting analogues. In this regard, the synthesis and biological characterization of two fully competent MT fluorescent analogues is reported here: all-(E)-13-phenyltrideca-6,8,10,12-tetraenylphosphocholine (PTE-MT) and all-(E)-13-phenyltrideca-8,10,12-trien-6-ynylphosphocholine (PTRI-MT). Both compounds show large absorption coefficients and a modest, but usable, fluorescence yield. Their activities were very similar to that of MT and were recognized by the MT uptake system of Leishmania. Their localization in living L. donovani promastigotes by confocal microscopy show a homogeneous intracellular distribution of the fluorescence. The concentration of PTRI-MT within the parasites (ca. 1.7 mM) showed a 100-fold enrichment relative to its external concentration. These results are consistent with a multiple target leishmanicidal mechanism for MT and validate the application of these analogues for pharmacokinetic and diagnostic studies concerning the chemotherapy of leishmaniasis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Drug Resistance
  • Fluorescent Dyes / chemical synthesis*
  • Fluorescent Dyes / metabolism
  • Fluorescent Dyes / pharmacology
  • Leishmania donovani / drug effects*
  • Leishmania donovani / metabolism
  • Microscopy, Confocal
  • Phosphorylcholine / analogs & derivatives*
  • Phosphorylcholine / chemical synthesis
  • Phosphorylcholine / metabolism
  • Phosphorylcholine / pharmacology
  • Stereoisomerism
  • Structure-Activity Relationship
  • Trypanocidal Agents / chemical synthesis*
  • Trypanocidal Agents / metabolism
  • Trypanocidal Agents / pharmacology

Substances

  • 13-phenyltrideca-6,8,10,12-tetraenylphosphocholine
  • 13-phenyltrideca-8,10,12-trien-6-ynylphosphocholine
  • Fluorescent Dyes
  • Trypanocidal Agents
  • Phosphorylcholine
  • miltefosine