C-13 RELAXATION STUDY OF MOTIONAL PROPERTIES OF LACTO-N-NEOTETRAOSE IN SOLUTION

Carbon-13 spin-lattice relaxation times and NOE factors are reported for a tetrasaccharide, lacto-N-neotetraose, in solution as a function of temperature and magnetic field. The data that are outside the extreme narrowing regime are analysed using the 'model-free' approach of Lipari and Szabo. The global reorientation is assumed to be isotropic. The experimental data for the inner rings can be fitted very well using a simplified version of the equations, neglecting the local motion term in the spectral densities. The complete expression for the spectral densities is required for the outer rings, and three different fitting procedures are compared.