Abstract
Adenosine-Y-phosphate monohydrate was crystallized in the orthorhombic space group P212121, with a=22"997 (2), b=9.406 (1), c=6.599 (1)A,, Z=4. The structure was solved by direct methods and refined to a final Rw of 0.0639 for 1320 significant reflexions measured on an automatic diffractometer. The conformation of the molecule differs significantly from that previously reported for the monoclinic monohydrate [Kraut & Jensen, Acta Cryst. (1963), 16, 79-88]. The sugar conformation, for example, is here C(2)'-endo, and the glycosidic torsion angle has altered by almost 50 °.