1,2,3-Triazolium-Based Cationic Amphipathic Peptoid Oligomers Mimicking Antimicrobial Helical Peptides

Amphipathic cationic peptoids (N-substituted glycine oligomers) represent a promising class of antimicrobial peptide mimics. The aim of this study is to explore the potential of the triazolium group as a cationic moiety and helix inducer to develop potent antimicrobial helical peptoids. Herein we report the first solid-phase synthesis of peptoid oligomers incorporating 1,2,3-triazolium-type side chains and their evaluation against Escherichia coli, Enterococcus faecalis, and Staphylococcus aureus. Several triazolium-based oligomers, even of short length, selectively kill bacteria over mammalian cells. SEM visualization of S. aureus cells treated with a dodecamer and a hexamer reveals severe cell membrane damage and suggests that the longer oligomer acts by pore formation.