5-Fluoroimidazo[4,5-b]pyridine Is a Privileged Fragment That Conveys Bioavailability to Potent Trypanosomal Methionyl-tRNA Synthetase Inhibitors

ACS Infect Dis. 2016 Jun 10;2(6):399-404. doi: 10.1021/acsinfecdis.6b00036. Epub 2016 Apr 11.

Abstract

Fluorination is a well-known strategy for improving the bioavailability of drug molecules. However, its impact on efficacy is not easily predicted. On the basis of inhibitor-bound protein crystal structures, we found a beneficial fluorination spot for inhibitors targeting methionyl-tRNA synthetase of Trypanosoma brucei. In particular, incorporating 5-fluoroimidazo[4,5-b]pyridine into inhibitors leads to central nervous system bioavailability and maintained or even improved efficacy.

Keywords: bioavailability; brain penetration; fluorination; human African trypanosomiasis; methionyl-tRNA synthetase.

Publication types

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

MeSH terms

  • Animals
  • Enzyme Inhibitors / chemistry*
  • Enzyme Inhibitors / pharmacology
  • Female
  • Humans
  • Methionine-tRNA Ligase / antagonists & inhibitors*
  • Methionine-tRNA Ligase / genetics
  • Methionine-tRNA Ligase / metabolism
  • Mice
  • Molecular Structure
  • Protozoan Proteins / antagonists & inhibitors*
  • Protozoan Proteins / genetics
  • Protozoan Proteins / metabolism
  • Pyridines / chemistry
  • Trypanocidal Agents / chemistry*
  • Trypanocidal Agents / pharmacology
  • Trypanosoma brucei brucei / drug effects*
  • Trypanosoma brucei brucei / enzymology
  • Trypanosoma brucei brucei / genetics
  • Trypanosomiasis, African / parasitology*

Substances

  • Enzyme Inhibitors
  • Protozoan Proteins
  • Pyridines
  • Trypanocidal Agents
  • Methionine-tRNA Ligase
  • pyridine