Synthesis of Chondroitin Sulfate A Bearing Syndecan-1 Glycopeptide

Abstract

Syndecan-1 chondroitin sulfate glycopeptide was synthesized for the first time using the cassette approach. The sequence of glycosylation to form the octasaccharide serine cassette was critical. The glycopeptide was successfully assembled via a 2+ (3 + 3) glycosylation strategy followed by peptide chain elongation.

Chemical Synthesis of the Repeating Unit of Type II Group B Streptococcus Capsular Polysaccharide

“…The stereochemistry of the new glycosidic bond was confirmed by 1 H NMR spectrometry ( J H1‴,2‴ = 8.4 Hz). This result further indicated that the failed glycosylation reactions in Schemes and were probably because of the low reactivity of trisaccharide 4 . It was worth noting that the glycosylation reaction of 16 with a 4- O -Fmoc derivative of diol 7 gave a pentasaccharide byproduct, which could be avoided by using donor 24 .…”

“…This result further indicated that the failed glycosylation reactions in Schemes 4 and 5 were probably because of the low reactivity of trisaccharide 4. 21 It was worth noting that the glycosylation reaction of 16 with a 4-O-Fmoc derivative of diol 7 gave a pentasaccharide byproduct, which could be avoided by using donor 24. Subsequently, 26 was glycosylated with sialodisaccharide 6 under the promotion of NIS and TfOH to provide 27 (J H1⁗,2⁗ = 8.4 Hz) smoothly, which was eventually desilylated with 3HF•Et 3 N to furnish 14.…”

Chemical synthesis of human syndecan-4 glycopeptide bearing O-, N-sulfation and multiple aspartic acids for probing impacts of the glycan chain and the core peptide on biological functions

“…In turn, 3 can be generated using a cassette approach from glycosyl serine-glycine 4 building block followed by peptide chain elongation (Scheme 1). While previous synthesis utilized glycosyl serine as the cassette for peptide synthesis, 26,48 we found that the glycosylated serine was prone to base promoted glycan elimination (Fig. 2c) during coupling with peptides more than ve amino acids long.…”

Long-Range Stereodirecting Participation across a Glycosidic Linkage in Glycosylation Reactions

“…Our work originated from the efforts toward the synthesis of heparan sulfate/chondroitin sulfate proteoglycan glycopeptides, − which contain a tetrasaccharide linker of glucuronic acid (GlcA)-β-1,3-galactose (Gal)-β-1,3-Gal-β-1,4-xylose (Xyl). To form this linkage region, we first synthesized the Gal-Gal disaccharide donor 3 bearing two levuniloyl (Lev) groups by the glycosylation of the bifunctional acceptor 2 with thiogalactosyl donor 1 followed by benzoylation (Scheme ).…”