Abstract
The X-ray crystal structures of the glycosaminoglycan-related monosaccharides 2-deoxy-2-(sulfoamino)-α-
d-glucopyranose sodium salt dihydrate, 2-amino-2-deoxy-α,β-
d-glucopyranose 3-(hydrogen sulfate) monohydrate, and 2-amino-2-deoxy-α-
d-glucopyranose 6-(hydrogen sulfate) monohydrate have been determined at 173 K. In the solid state, the 3-sulfated and 6-sulfated compounds assume the expected zwitterionic form. The 2(N)- and 6-sulfate crystal structures contain only the α-anomers, but the 3-sulfate crystal structure includes both the α- and β-anomers, as well as two different orientations of the hydroxymethyl group. The sodium ion in the 2(N)-sulfate structure is sixfold coordinated, with two water molecules, a sulfate oxygen, a ring oxygen, and two hydroxyl oxygens serving as electron donors. The 2(N)-sulfate group makes direct contact with the sodium ion and also makes indirect contact with it through mediating water molecules. In the 3-sulfate structure, the sulfate group participates in a close intramolecular contact with the protonated amino group at C-2. In all three structures the sulfate oxygens engage in close intermolecular interactions with -NH
3
+ and -OH groups and with water molecules, although the sole sulfate-water approach in the 6-sulfate structure is exceptional in not being very close (> 3.0 Å). Selected IR and NMR data are presented.