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. Short but sweet: In this study we used triazolium as a cationic pendant group and helix inducer to develop antimicrobial peptoids. Rapidly and efficiently synthesized on solid phase, amphipathic helical peptoid oligomers incorporating 1,2,3‐triazolium‐type side chains were evaluated against Escherichia coli, Enterococcus faecalis, and Staphylococcus aureus. These amphipathic oligomers, even of short length, selectively kill bacteria over mammalian cells.