摘要:
Glycopeptide (1), Neu5Aca2-3Gal beta 1-4GlcNAc beta 1-2Man alpha 1-Ser, was synthesized using a chemoenzymatic strategy. Gal beta 1-4GlcNA beta 1-2Man trisaccharide was prepared using glycosidase assisted oligosaccharide synthesis. After coupling of this trisaccharide with a serine derivative by chemical glycosylation, sialic add was introduced using sialyltransferase to produce a tetrasaccharide serine derivative. Removal of protecting group afforded glycopeptide (1). Use of a chemoenzymatic strategy allowed for the elimination of numerous synthetic steps and efficient preparation of the target compound. (C) 1999 Elsevier Science Ltd. All rights reserved.