title: Nuclear spin relaxation study of aqueous raffinose solution in the presence of a gadolinium contrast agent.
abstract: Paramagnetic enhancement of nuclear spin-lattice relaxation rates (PREs) was measured in aqueous solution of the trisaccharide raffinose in the presence of a gadolinium(III) complex, GdDTPA-BMA, used as a magnetic resonance imaging contrast agent. The relaxation enhancement of aqueous protons was measured over a broad range of magnetic fields, using field-cycling apparatus in addition to conventional spectrometers. The nuclear magnetic relaxation dispersion profile thus obtained was interpreted with a recently developed model, allowing for both inner- and outer-sphere relaxation. The relaxation enhancement for the carbon-13 nuclei in raffinose was studied under high-resolution conditions at three magnetic fields, whereas the sugar proton PRE was measured at two fields. The PRE of the sugar nuclei could be interpreted in a consistent way, assuming that it was caused by the outer-sphere mechanism. The electron spin relaxation was found to be a less important source of modulation of the electron-nuclear dipole-dipole interaction than the mutual translational diffusion.
authors.affiliation: Physical Chemistry, Arrhenius Laboratory, Stockholm University, S-106 91 Stockholm, Sweden.
authors.forename: Leila
authors.initials: L
authors.lastname: Ghalebani
authors.forename: Danuta
authors.initials: D
authors.lastname: Kruk
authors.forename: Jozef
authors.initials: J
authors.lastname: Kowalewski
mesh_terms: D003287:Contrast Media / Q000032:analysis / Q000737:chemistry*; D019786:Gadolinium DTPA / Q000032:analysis / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D011887:Raffinose / Q000032:analysis / Q000737:chemistry*; D012996:Solutions; D013113:Spin Labels; D014867:Water / Q000032:analysis / Q000737:chemistry*
chemical_list: D003287:Contrast Media; D012996:Solutions; D013113:Spin Labels; D014867:Water; C064925:gadodiamide; D019786:Gadolinium DTPA; D011887:Raffinose