Solid state NMR and X-ray diffraction studies of alpha-D-galacturonic acid monohydrate.
Crystalline alpha-D-galacturonic acid monohydrate has been studied by 13C CPMAS NMR and X-ray crystallography. The molecular dynamics were investigated by evaluating 13C spin-lattice relaxation in the rotating frame (T1rho) and chemical-shift-anisotropy properties of each carbon. Only limited molecular motions can be detected in the low frequency (< 10(4) Hz) range by 13C relaxation time measurements (T1rho) and changes of chemical shift anisotropy properties as a function of temperature. X-ray analysis (at both ambient temperature and 150 K) shows that the acid has the usual chair-shaped, pyranose ring conformation, and that the acid and water molecules are linked, through all their O-H groups, in an extensively hydrogen-bonded lattice.
Institute of Food Research, Norwich Laboratory, Norwich Research Park, Colney, UK.
H R
HR
Tang
P S
PS
Belton
S C
SC
Davies
D L
DL
Hughes
D002236:Carbohydrate Conformation; D018360:Crystallography, X-Ray / Q000379:methods; D006603:Hexuronic Acids / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008745:Methylation; D008958:Models, Molecular; D014867:Water
D006603:Hexuronic Acids; D014867:Water; C007819:galacturonic acid