Glycopeptides in solution

Synthesis of glycopeptides in solution has been successfully applied in the preparation of glycopeptides of moderate lengths (see Sections 6.3.2 and 6.3.3). However, yields in solution synthesis are often only modest and isolation of intermediates makes the approach inconvenient. 

The improved availability of glycosyltransferases has led to increased use of che-moenzymatic synthesis, where chemical synthesis is combined with the use of glycosyltransferases to build up saccharides on a parent glycopeptide in solution or on solid phase (Section 6.3.3.6).1200"2061... 

Scheme 27 Synthesis of Glycosylated Hydroxylysine Building Blocks and Glycopeptide in Solution Using the Glycosyl Halide as Donorl74 ...

H Kunz, W Kosch, J Maerz, M Ciommer, W Guenther, C Unverzagt. Synthesis of glycopeptides in solution and on solid phase. Proceedings of Innovation and Perspectives in Solid Phase Synthesis. Second International Symposium, Canterbury, 1991, pp 171-178. 

In contrast with the construction of glycopeptides in solution, automated assembly on solid supports promises rapid access to the desired target compounds [87-89]. 

The step-by-step assembly of glycopeptides in solution is still the method of choice if larger quantities of the target compounds (>1 mmol) are required. The synthesis of glycopeptides containing important but complex saccharide residues remains a major task of glycopeptide chemistry. The introduction of sialic acid residues—considered to be a limitation in the past—can now be achieved efficiently. 

To quantify their binding to WGA in solution, glycopeptides 16, 18, and 22 were re-synthesized as single compounds. IC50 values for inhibition of the binding of porcine stomach mucin to peroxidase-labeled WGA (Table 2.7.1) were determined by an enzyme-linked lectin assay (ELLA) as described by Zanini and Roy [21]. The IC50 values shown in Table 2.7.1 confirm that the binding behavior of 16, 18, and... 

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