Flow and Microwave-Assisted Synthesis of N-(Triethylene glycol)glycine Oligomers and Their Remarkable Cellular Transporter Activities

Bioconjug Chem. 2015 Aug 19;26(8):1759-65. doi: 10.1021/acs.bioconjchem.5b00307. Epub 2015 Jul 23.

Abstract

Peptidomimetics, such as oligo-N-alkylglycines (peptoids), are attractive alternatives to traditional cationic cell-penetrating peptides (such as R9) due to their robust proteolytic stability and reduced cellular toxicity. Here, monomeric N-alkylglycines, incorporating amino-functionalized hexyl or triethylene glycol (TEG) side chains, were synthesized via a three-step continuous-flow reaction sequence, giving the monomers N-Fmoc-(6-Boc-aminohexyl)glycine and N-Fmoc-((2-(2-Boc-aminoethoxy)ethoxy)ethyl)glycine in 49% and 41% overall yields, respectively. These were converted into oligomers (5, 7, and 9-mers) using an Fmoc-based solid-phase protocol and evaluated as cellular transporters. Hybrid oligomers, constructed of alternating units of the aminohexyl and amino-TEG monomers, were non-cytotoxic and exhibited remarkable cellular uptake activity compared to the analogous fully TEG or lysine-like compounds.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biological Transport
  • Cell-Penetrating Peptides / chemistry*
  • Cell-Penetrating Peptides / pharmacokinetics
  • Cells, Cultured
  • Drug Design
  • Glycine / chemistry*
  • HEK293 Cells
  • HeLa Cells
  • Humans
  • Lysine / chemistry*
  • Microwaves*
  • Peptidomimetics / chemistry
  • Peptoids / chemistry*
  • Peptoids / pharmacokinetics*
  • Polyethylene Glycols / chemistry*
  • Tissue Distribution

Substances

  • Cell-Penetrating Peptides
  • Peptidomimetics
  • Peptoids
  • triethylene glycol
  • Polyethylene Glycols
  • Lysine
  • Glycine