Discovery of Pyrrolo[2,3- b]pyridine (1,7-Dideazapurine) Nucleoside Analogues as Anti- Trypanosoma cruzi Agents

J Med Chem. 2019 Oct 10;62(19):8847-8865. doi: 10.1021/acs.jmedchem.9b01275. Epub 2019 Sep 20.

Abstract

Trypanosoma cruzi is the causative pathogen of Chagas disease and the main culprit for cardiac-related mortality in Latin-America triggered by an infective agent. Incapable of synthesizing purines de novo, this parasite depends on acquisition and processing of host-derived purines, making purine (nucleoside) analogues a potential source of antitrypanosomal agents. In this respect, hitherto 7-deazaadenosine (tubercidin) analogues attracted most attention. Here, we investigated analogues with an additional nitrogen (N1) removed. Structure-activity relationship investigation showed that C7 modification afforded analogues with potent antitrypanosomal activity. Halogens and small, linear carbon-based substituents were preferred. Compound 11 proved most potent in vitro, showed full suppression of parasitemia in a mouse model of acute infection, and elicited 100% animal survival after oral dosing at 25 mg/kg b.i.d. for 5 and 15 days. Cyclophosphamide-induced immunosuppression led to recrudescence. Washout experiments demonstrated a lack of complete clearance of infected cell cultures, potentially explaining the in vivo results.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Administration, Oral
  • Animals
  • Chagas Disease / drug therapy
  • Chagas Disease / mortality
  • Chagas Disease / parasitology
  • Crystallography, X-Ray
  • Disease Models, Animal
  • Male
  • Mice
  • Molecular Conformation
  • Nucleosides / analogs & derivatives*
  • Nucleosides / pharmacology
  • Nucleosides / therapeutic use
  • Pyridines / chemistry*
  • Pyridines / pharmacology
  • Pyridines / therapeutic use
  • Pyrroles / chemistry*
  • Pyrroles / pharmacology
  • Pyrroles / therapeutic use
  • Structure-Activity Relationship
  • Survival Rate
  • Trypanocidal Agents / chemistry*
  • Trypanocidal Agents / pharmacology
  • Trypanocidal Agents / therapeutic use
  • Trypanosoma cruzi / drug effects

Substances

  • Nucleosides
  • Pyridines
  • Pyrroles
  • Trypanocidal Agents
  • pyrrolo(2, 3-b)pyridine