Peptides neoglycopeptides

As illustrated above, peptides have been used as tethering elements for the suitable positioning of carbohydrate moieties. Since the chemistry of glycopeptides is well under control, the approach may appear valuable, at least a priori. This is likely to be true for research investigations. However, as neoglycopeptides should eventually developed into useful therapeutics, the synthesis of novel and metabolically stable neoglycopeptidomitics was undertaken [110-113]. The approach chosen was commensurate to that used for the synthesis of peptoids. 

An A -methyl-amino-oxy amino acid has also been incorporated into peptides using standard SPPS procedures. Reaction of these peptides with native reducing sugars yields neoglycopeptides via a chemoselective reaction with the amino-oxy side chains, maintaining the linked sugars in their cyclic conformations and... 

I. Shin, H.-J. Jung, and M.-R. Lee, Chemoselective ligation of maleimidosugars to peptides/ protein for the preparation of neoglycopeptides/neoglycoprotein, Tetrahedron Lett., 42 (2001) 1325-1328. 

Lee et al. subsequently S3mthesized similar neoglycopeptides using a one-pot strategy in which two propargyl peptides were coupled via NCL subsequent 1,3-dipolar cycloaddition afforded the glycosylated peptide (Fig. 22) [139]. 

Neoglycopeptides and -proteins" differ from naturally occurring structures by replacement of the natural carbohydrate-peptide linkage with a non-natural one. This not only allows studying the influence of distinct structural elements on biological activity, but has many practical applications as well. Use of chemoselective ligation reactions such as... 

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