α,β-Trehalose Monohydrate

The structure of α,β-trehalose (α-D-glucopyranosyl-β-D-glucopyranoside) monohydrate, C₁₂H₂₂O₁₁.H₂O, was determined in order to compare the molecular structures of other stereoisomers, α,α-trehalose and β,β-trehalose. Both hexopyranosyl rings have ⁴C₁ conformations. In the glycosidic linkage the torsion angles about the α-anomeric C—O bond are close to those observed in α,α-trehalose, but the torsion angles about the β-anomeric C—O bond deviate from those in β,β-trehalose and other β-pyranosides. This conformation is stabilized by an intramolecular hydrogen bond between the O(6) hydroxyl groups of the two glucopyranosyl residues. The hydrogen-bond system in the crystal structure consists of infinite and finite chains cross-linked by the water molecule.

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