Synthesis and evaluation of α-thymidine analogues as novel antimalarials

J Med Chem. 2012 Dec 27;55(24):10948-57. doi: 10.1021/jm301328h. Epub 2012 Dec 14.

Abstract

Plasmodium falciparum thymidylate kinase (PfTMPK) is a key enzyme in pyrimidine nucleotide biosynthesis. 3-Trifluoromethyl-4-chloro-phenyl-urea-α-thymidine has been reported as an inhibitor of Mycobacterium tuberculosis TMPK (MtTMPK). Starting from this point, we designed, synthesized and evaluated a number of thymidine analogues as antimalarials. Both 5'-urea-α- and β-thymidine derivatives were moderate inhibitors of PfTMPK and furthermore showed moderate inhibition of parasite growth. The structure of several enzyme-inhibitor complexes provides a basis for improved inhibitor design. However, we found that certain 5'-urea-α-thymidine analogues had antimalarial activity where inhibition of PfTMPK is not the major mode of action. Optimization of this series resulted in a compound with potent antimalarial activity (EC(50) = 28 nM; CC(50) = 29 μM).

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antimalarials / chemical synthesis*
  • Antimalarials / chemistry
  • Antimalarials / pharmacology
  • Blood Proteins / metabolism
  • Cell Line
  • Crystallography, X-Ray
  • Humans
  • Ligands
  • Microsomes, Liver / metabolism
  • Models, Molecular
  • Molecular Structure
  • Nucleoside-Phosphate Kinase / antagonists & inhibitors
  • Nucleoside-Phosphate Kinase / chemistry
  • Plasmodium falciparum / drug effects
  • Plasmodium falciparum / enzymology
  • Protein Binding
  • Protozoan Proteins / antagonists & inhibitors
  • Protozoan Proteins / chemistry
  • Recombinant Proteins / antagonists & inhibitors
  • Recombinant Proteins / chemistry
  • Structure-Activity Relationship
  • Thiourea / analogs & derivatives*
  • Thiourea / chemical synthesis*
  • Thiourea / pharmacology
  • Thymidine / analogs & derivatives*
  • Thymidine / chemical synthesis*
  • Thymidine / pharmacology
  • Urea / analogs & derivatives*
  • Urea / chemical synthesis*
  • Urea / pharmacology

Substances

  • Antimalarials
  • Blood Proteins
  • Ligands
  • Protozoan Proteins
  • Recombinant Proteins
  • Urea
  • Nucleoside-Phosphate Kinase
  • dTMP kinase
  • Thiourea
  • Thymidine