Chemical and enzymatic synthesis of S-linked sugars and glycoconjugates

Abstract

Abstract S-Linked oligosaccharide/polysaccharide and glycoconjugates including glycolipid, glycoprotein, saponin and others, in which the glycosidic oxygen is replaced by a sulfur atom, have attracted considerable attention as probes in biological investigations, due to the higher metabolic stability compared to their natural saccharide counterparts. Furthermore, these resulting S-linked glycosides maintain or even show improved biological activity than their parent O-linked glycosides when bond to proteins and are tolerated in most biological systems. Therefore, this class of saccharides is widely used as valuable tools in various biological studies such as glycosidase inhibitors, antibacterial agents and antitumor drugs as well as ligands for the purification of proteins by affinity chromatography. However, to date, there are very limited reviews published about the summarization of the synthetic approaches towards S-linked sugars and glycoconjugates. In this review, we systematically examine the remarkable progress that has been made in the chemical and enzymatic synthesis of the thioglycosides in the past ten years, and discuss their pharmacological applications as well.