Synthetically modified L-histidine-rich peptidomimetics exhibit potent activity against Cryptococcus neoformans

Bioorg Med Chem Lett. 2014 Jul 15;24(14):3150-4. doi: 10.1016/j.bmcl.2014.04.120. Epub 2014 May 10.

Abstract

We describe the synthesis and antimicrobial evaluation of structurally new peptidomimetics, rich in synthetically modified L-histidine. Two series of tripeptidomimetics were synthesized by varying lipophilicity at the C-2 position of L-histidine and at the N- and C-terminus. The data indicates that peptides (5f, 6f, 9f and 10f) possessing highly lipophilic adamantan-1-yl group displayed strong inhibition of Cryptococcus neoformans. Peptide 6f is the most potent of all with IC50 and MFC values of 0.60 and 0.63 μg/mL, respectively, compared to the commercial drug amphotericin B (IC50=0.69 and MFC=1.25 μg/mL). The selectivity of these peptides to microbial pathogen was examined by a tryptophan fluorescence quenching study and transmission electron microscopy. These studies indicate that the peptides plausibly interact with the mimic membrane of pathogen by direct insertion, and results in disruption of membrane of pathogen.

Keywords: Alkylation; Antifungal peptides; C. neoformans; Ecofriendly peptide synthesis; Microwave.

Publication types

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

MeSH terms

  • Antifungal Agents / chemical synthesis*
  • Antifungal Agents / chemistry
  • Antifungal Agents / pharmacology*
  • Cryptococcus neoformans / drug effects*
  • Dose-Response Relationship, Drug
  • Histidine / chemistry*
  • Microbial Sensitivity Tests
  • Molecular Conformation
  • Peptidomimetics / chemical synthesis*
  • Peptidomimetics / chemistry
  • Peptidomimetics / pharmacology*
  • Structure-Activity Relationship

Substances

  • Antifungal Agents
  • Peptidomimetics
  • Histidine