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Beta-D-glucose, or β-D-glucose, is the beta anomer of D-glucose, a common aldohexose. Like other forms of glucose, it has the molecular formula C6H12O6 and exists primarily in cyclic pyranose forms in solution. In the beta anomer, the anomeric hydroxyl group at carbon 1 is oriented above the plane of the ring (equatorial in the β-D-glucopyranose chair).

In solution, glucose undergoes mutarotation, interconverting between alpha and beta pyranose forms and a small amount of open-chain form. At neutral pH, the equilibrium mixture is about 64% beta and 36% alpha, with the exact proportions influenced by temperature and solvent conditions.

Biologically, β-D-glucose is a central building block in many carbohydrates. It is the monomeric unit in polysaccharides such as cellulose, where glucose units are linked by β-1,4-glycosidic bonds. In contrast, starch and glycogen are composed of α-D-glucose units linked by α-1,4 and α-1,6 bonds. In humans, free glucose is absorbed and metabolized via glycolysis, providing a primary source of cellular energy regardless of its anomeric form in the open-chain state.

In chemistry, beta-D-glucose is a reducing sugar and participates in glycosidic bond formation and mutarotation. Its distinction from alpha-D-glucose lies in the orientation of the C1 hydroxyl group, which has implications for the properties and digestibility of polysaccharides formed from glucose units.