Thioglucosides

Thioglucosides are a class of glycosides in which the glycosidic bond between glucose and the aglycone is a thio-glycosidic linkage, i.e., the anomeric carbon of glucose is bound to the aglycone through sulfur rather than oxygen. This C–S linkage classifies them as thioglycosides, distinct from the more common O-glycosides found in most natural glycosides. The term can refer to glucose-derived thioglycosides used as building blocks in carbohydrate chemistry as well as to natural products containing sulfur-linked glucose motifs.

Preparation commonly involves coupling a thiol with a protected glucosyl donor, such as a glycosyl halide or a trichloroacetimidate, to form a thioglycoside with a glucose moiety. Thioglycosides are widely used as glycosyl donors in oligosaccharide synthesis because they can be selectively activated under mild, controlled conditions to release the sugar and form glycosidic bonds with various acceptors. The sulfur bridge alters the electronic and steric properties of the linkage, often conferring greater chemical stability toward acid hydrolysis and enabling different activation pathways compared with O-glycosides.

Biochemically, thioglucoside analogs are employed to study glycosidase and glycosyltransferase activity and substrate specificity. Their altered linkage can affect enzyme recognition and reaction rates, providing tools for mechanistic studies and inhibitor design. In some contexts, thioglucoside motifs are found in natural products as components of sulfur-containing glucoside derivatives.