K. Noguchi et al., Molecular and crystal structure of galactinol dihydrate [1-O-(alpha-D-galactopyranosyl)-myo-inositol dihydrate], CARBOHY RES, 328(2), 2000, pp. 241-248
The crystal structure of galactinol dihydrate has been determined by X-ray
diffraction. The crystal belongs to the orthorhombic system, space group P2
(1)2(1)2, a = 15.898(6), b = 19.357(5), c = 5.104(4) Angstrom, and Z = 4. T
he structure was refined to R = 0.044 for 1818 observed structure amplitude
s. The primary hydroxyl group exhibits twofold orientational disorder. The
linkage conformation is close to those of alpha-(1 --> 4) linkages in methy
l alpha-maltotrioside tetrahydrate and erlose trihydrate. Although there is
no interring hydrogen bond in galactinol, an indirect interring hydrogen b
ond including a water molecule is present. The observed conformation is add
itionally stabilized by the indirect interring hydrogen bond. The global mi
nimum in the relaxed-residue energy map based on the MM3(92) force-field is
close to the observed conformation in the crystal structure. All hydroxyl,
ring and water oxygen atoms are involved in a complex three-dimensional hy
drogen-bonding network. (C) 2000 Elsevier Science Ltd. All rights reserved.