Novel orally active inhibitors of β-1,3-glucan synthesis derived from enfumafungin

Bioorg Med Chem Lett. 2015 Dec 15;25(24):5813-8. doi: 10.1016/j.bmcl.2015.10.011. Epub 2015 Oct 9.

Abstract

The clinical success of the echinocandins, which can only be administered parentally, has validated β-1,3-glucan synthase (GS) as an antifungal target. Semi-synthetic modification of enfumafungin, a triterpene glycoside natural product, was performed with the aim of producing a new class of orally active GS inhibitors. Replacement of the C2 acetoxy moiety with various heterocycles did not improve GS or antifungal potency. However, replacement of the C3 glycoside with an aminoether moiety dramatically improved oral pharmacokinetic (PK) properties while maintaining GS and antifungal potency. Installing an aminotetrazole at C2 in conjunction with an N-alkylated aminoether at C3 produced derivatives with significantly improved GS and antifungal potency that exhibited robust oral efficacy in a murine model of disseminated candidiasis.

Keywords: Antifungal; Candidiasis; Enfumafungin; Oral bioavailability; β-1,3-Glucan synthesis inhibitor.

MeSH terms

  • Administration, Oral
  • Animals
  • Antifungal Agents / chemistry*
  • Antifungal Agents / pharmacokinetics
  • Antifungal Agents / therapeutic use
  • Aspergillus fumigatus / drug effects
  • Candida albicans / drug effects
  • Candidiasis / drug therapy
  • Candidiasis / veterinary
  • Glucosyltransferases / antagonists & inhibitors
  • Glucosyltransferases / metabolism
  • Glycosides / chemistry*
  • Half-Life
  • Mice
  • Microbial Sensitivity Tests
  • Structure-Activity Relationship
  • Terpenes / chemistry
  • Triterpenes / chemistry*
  • beta-Glucans / chemistry*
  • beta-Glucans / pharmacokinetics
  • beta-Glucans / therapeutic use

Substances

  • Antifungal Agents
  • Glycosides
  • Terpenes
  • Triterpenes
  • beta-Glucans
  • enfumafungin
  • beta-1,3-glucan
  • Glucosyltransferases
  • glucan synthase