African trypanosomiasis: Synthesis & SAR enabling novel drug discovery of ubiquinol mimics for trypanosome alternative oxidase

Eur J Med Chem. 2017 Dec 1:141:676-689. doi: 10.1016/j.ejmech.2017.09.067. Epub 2017 Oct 6.

Abstract

African trypanosomiasis is a parasitic disease affecting 5000 humans and millions of livestock animals in sub-Saharan Africa every year. Current treatments are limited, difficult to administer and often toxic causing long term injury or death in many patients. Trypanosome alternative oxidase is a parasite specific enzyme whose inhibition by the natural product ascofuranone (AF) has been shown to be curative in murine models. Until now synthetic methods to AF analogues have been limited, this has restricted both understanding of the key structural features required for binding and also how this chemotype could be developed to an effective therapeutic agent. The development of 3 amenable novel synthetic routes to ascofuranone-like compounds is described. The SAR generated around the AF chemotype is reported with correlation to the inhibition of T. b. brucei growth and corresponding selectivity in cytotoxic assessment in mammalian HepG2 cell lines. These methods allow access to greater synthetic diversification and have enabled the synthesis of compounds that have and will continue to facilitate further optimisation of the AF chemotype into a drug-like lead.

Keywords: Antiprotozoal agents; Medicinal chemistry; Oxidoreductase; Synthesis design.

MeSH terms

  • Dose-Response Relationship, Drug
  • Drug Discovery*
  • Enzyme Inhibitors / chemical synthesis
  • Enzyme Inhibitors / chemistry
  • Enzyme Inhibitors / pharmacology*
  • Humans
  • Mitochondrial Proteins / antagonists & inhibitors*
  • Mitochondrial Proteins / metabolism
  • Molecular Structure
  • Oxidoreductases / antagonists & inhibitors*
  • Oxidoreductases / metabolism
  • Plant Proteins / antagonists & inhibitors*
  • Plant Proteins / metabolism
  • Structure-Activity Relationship
  • Trypanocidal Agents / chemical synthesis
  • Trypanocidal Agents / chemistry
  • Trypanocidal Agents / pharmacology*
  • Trypanosoma / drug effects*
  • Trypanosoma / enzymology
  • Trypanosoma brucei brucei / drug effects*
  • Trypanosoma brucei brucei / growth & development
  • Trypanosomiasis, African / drug therapy*
  • Trypanosomiasis, African / parasitology
  • Ubiquinone / analogs & derivatives*
  • Ubiquinone / chemical synthesis
  • Ubiquinone / chemistry
  • Ubiquinone / pharmacology

Substances

  • Enzyme Inhibitors
  • Mitochondrial Proteins
  • Plant Proteins
  • Trypanocidal Agents
  • Ubiquinone
  • Oxidoreductases
  • alternative oxidase
  • ubiquinol