Cytidylic Acid "a" Trihydrate: Structure and Conformation

Science  02 Feb 1973:
Vol. 179, Issue 4072, pp. 495-496
DOI: 10.1126/science.179.4072.495


Cytidylic acid "a" (cytidine 2'-monophosphate) crystallizes in the triclinic space group P1 with two molecules of cytidine monophosphate (C9H14O8N3P) and six molecules of water in the unit cell. X-ray analysis of this crystal shows that in both molecules, the base is in the anti conformation, the ribose ring is C(2')-endo puckered, and the hydroxyl O(5') is gauche-gauche. The two molecules are linked by a short hydrogen bond through the phosphate oxygens.