Novel alkylated azoles as potent antifungals

Eur J Med Chem. 2017 Jun 16:133:309-318. doi: 10.1016/j.ejmech.2017.03.075. Epub 2017 Mar 31.

Abstract

Fluconazole (FLC) is the drug of choice when it comes to treat fungal infections such as invasive candidiasis in humans. However, the widespread use of FLC has resulted in the development of resistance to this drug in various fungal strains and, simultaneously has occasioned the need for new antifungal agents. Herein, we report the synthesis of 27 new FLC derivatives along with their antifungal activity against a panel of 13 clinically relevant fungal strains. We also explore their toxicity against mammalian cells, their hemolytic activity, as well as their mechanism of action. Overall, many of our FLC derivatives exhibited broad-spectrum antifungal activity and all compounds displayed an MIC value of <0.03 μg/mL against at least one of the fungal strains tested. We also found them to be less hemolytic and less cytotoxic to mammalian cells than the FDA approved antifungal agent amphotericin B. Finally, we demonstrated with our best derivative that the mechanism of action of our compounds is the inhibition of the sterol 14α-demethylase enzyme involved in ergosterol biosynthesis.

Keywords: Cytotoxicity; Ergosterol; Fluconazole; Hemolysis; Time-kill curves.

MeSH terms

  • Alkylation
  • Animals
  • Antifungal Agents / adverse effects
  • Antifungal Agents / chemical synthesis
  • Antifungal Agents / chemistry*
  • Antifungal Agents / pharmacology*
  • Azoles / adverse effects
  • Azoles / chemical synthesis
  • Azoles / chemistry*
  • Azoles / pharmacology*
  • Candida albicans / drug effects
  • Candidiasis / drug therapy
  • Cell Line
  • Ergosterol / metabolism
  • Fungi / drug effects*
  • Fungi / enzymology
  • Fungi / metabolism
  • Hemolysis / drug effects
  • Humans
  • Mice
  • Microbial Sensitivity Tests
  • Mycoses / drug therapy*

Substances

  • Antifungal Agents
  • Azoles
  • Ergosterol