Synthesis of the building blocks Nα-Fmoc-O-[α-D-Ac3GalN3p-(1→3)-α-D-Ac2GalN3p]-Thr-OPfp and Nα-Fmoc-O-[α-D-Ac3GalN3p-(1→6)-α-D-Ac2GalN3p]-Thr-OPfp and their application in the solid phase glycopeptide synthesis of core 5 and core 7 mucin O-glycopeptides

Abstract

The structures α-D-GalNAc-( 1→3)-α-D-GalNAc-( 1→O)-L-Thr and α-D-GalNAc-( 1→6)-α-D-GalNAc-( 1→O)-L-Thr are present as cores 5 and 7 of the mucin-type glycoproteins. The preparation of the corresponding building blocks 10 and 15 is described. Compounds 10 and 15 can be used directly in a multiple-column solid-phase glycopeptide peptide synthesis. In the resulting peptides the azido groups are reduced and acetylated on the solid support. The products are cleaved from the resin and the carbohydrate part is deprotected. A series of 20 O-glycopeptides has been prepared.