fructoside

Fructoside is a glycoside in which the sugar moiety is fructose. In glycosides, a sugar unit (the glycone) is bound via a glycosidic linkage to an aglycone. In a fructoside, this linkage involves the anomeric carbon of fructose (C2) and can be an O-glycosidic bond to various acceptors.

This term is used to distinguish fructosides from glucosides or galactosides; more precise terms such as 'fructosyl glycosides' or 'fructosides' appear in older or specialized literature. Fructose as glycone yields α- or β-fructosides depending on configuration at the anomeric center; hydrolysis yields free fructose and the aglycone.

Natural occurrence: Fructosides occur in plants and some microorganisms as parts of secondary metabolites or storage forms. They can serve to detoxify, store sugars, or modulate biological activity; the aglycone can be a phenolic, terpenoid, or flavonoid moiety.

Chemical properties: Fructosides are hydrolyzable glycosides; acid or enzymatic hydrolysis liberates fructose and the aglycone. Their stability depends on the type of aglycone and the glycosidic linkage. They are typically synthesized by glycosylation at the fructose anomeric center using enzymes (fructosyltransferases) or chemical glycosyl donors.

Related topics include glycoside, fructose, and glycosylation.