gentiobiose

Gentiobiose is a disaccharide composed of two glucose units linked by a β-1,6-glycosidic bond. Its commonly cited structural form is β-D-glucopyranosyl-(1→6)-β-D-glucopyranose, and it is a reducing sugar because the anomeric carbon of one glucose remains free after linkage.

Natural occurrence and production methods include occurrence in small amounts within certain plant polysaccharides and as a product of hydrolysis of β-glucan-containing materials. In laboratory settings, gentiobiose is encountered as a reference sugar or intermediate when studying glycosidic bond formation and cleavage, and it can be prepared or isolated from polysaccharide hydrolysates.

Physical and chemical properties are typical of many small glucose disaccharides: it is soluble in water and forms crystalline solids. The sweetness of gentiobiose is generally lower than that of sucrose, and its behavior in solution reflects its glucose-based structure. In enzymatic or chemical hydrolysis, the β-1,6 linkage can be cleaved by appropriate β-glucosidases or other glycosidases that act on β-1,6 bonds.

Uses and applications are primarily in carbohydrate chemistry and analytical contexts. Gentiobiose serves as a standard or reference compound for chromatographic methods and for studying the properties and reactivity of β-1,6 glycosidic linkages. It is not commonly used as a general sweetener or dietary sugar.

See also: disaccharides such as maltose, cellobiose, and lactose.