Synthesis of C-terminal glycopeptides from resin-bound glycosyl azides via a modified Staudinger reaction

J Org Chem. 2000 Aug 25;65(17):5249-52. doi: 10.1021/jo000381z.

Abstract

The solid-phase synthesis of glycopeptides containing the sugar at the C-terminus is reported. The method is demonstrated on a model, the endogenous antinociceptive peptide Leu-enkephalin. 2,3,4-Tri-O-acetyl-1-azido-1-deoxy-beta-D-glucopyranuronic acid was synthesized and immobilized onto a variety of derivatized resins. Conjugation of the first amino acid was accomplished by reaction of the resin-bound glycosyl azide with an activated amino acid, in one step, via a modified Staudinger reaction. Standard solid-phase peptide synthesis then resulted in the desired amide-linked glycopeptide. Reaction conditions and reagents for the glycosylation were varied to optimize the yield and purity of the product. The optimum conditions were found to be the use of a 4-fold molar excess of activated amino acid and 3-fold excess of tri-n-butylphosphine in tetrahydrofuran. This methodology is generally applicable to most peptide sequences and is compatible with both Boc- and Fmoc- synthetic strategies on a variety of resins.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Azides / chemistry*
  • Glycopeptides / chemical synthesis*
  • Glycopeptides / chemistry
  • Magnetic Resonance Spectroscopy
  • Spectrometry, Mass, Fast Atom Bombardment

Substances

  • Azides
  • Glycopeptides