10 - The Synthesis of Glycosyl Amino Acids

Abstract

Most naturally occuring proteins display O-linked glycopeptides and N-linked glycopeptides, and have immense biological significance. Several reviews and texts cover the most recent progress in glycopeptide synthesis. Since the isolation of glycopeptides from natural sources is difficult, they are often prepared by chemical synthesis, employing a combination of both carbohydrate and peptide chemistry. This chapter details the synthesis of glycosyl amino acids of use in glycopeptide synthesis. The development of selective synthetic methodologies has allowed the field of glycopeptide chemistry to constantly expand and diversify, providing access to highly complex structures on preparative scales. Biological investigations into the roles of glycopeptides demand better and cleaner synthetic methods. Future efforts in glycopeptide chemistry will particularly focus on improved synthesis of glycosylation building blocks either in solution or solid phase using chemical or enzymic methods. Indeed, new S-linked glycosides with enhanced stability to chemical and enzymic degradation have recently been prepared by solid phase synthesis.