H. Garg, R. Jeanloz
1985
Citations
0
Influential Citations
56
Citations
Journal
Advances in Carbohydrate Chemistry and Biochemistry
Abstract
Publisher Summary This chapter describes the synthetic N - and O -glycosyl derivatives of l -asparagine, l -serine, and l -threonine. Glycoproteins' are macromolecules containing one carbohydrate chain covalently linked to a protein backbone. They include proteoglycans, N -glycoproteins, O -glycoproteins, and collagen or basal-membrane proteins. The chapter presents the method of forming an amide bond between the 4-carboxyl group of l -aspartic acid and a glycosylamine in the presence of dicyclohexylcarbodiirnide. A series of derivatives of l -alanine, l -glutamic acid, glycine, l -serine, and l -valine, required for determining the specificity of amidohydrolase enzymes, as well as for testing the growth-inhibitory activity, was synthesized by coupling amine 8 with protected amino acids. The synthesis of glycopeptides of l -asparagine by the solid-phase procedure required a derivative protected, for example, by the acid-labile N -( tert -butoxycarbonyl) group. The reaction of a glycosyl bromide with the sodium salt of a phenol was the first procedure for the preparation of an O -glycosyl derivative of an amino acid. It is found that the glycoproteins of animal origin have glycoside linkages involving the hydroxyl groups of l -serine and l -threonine, as treatment with alkali releases the sugar component simultaneously with the loss of an equimolecular amount of hydroxyamino acid.