Assignment of 1H and 13C NMR spectra by a combination of homo- and heteronuclear shift correlated two-dimensional NMR. Application to oligosaccharides related to arabinoxylane

Abstract

It is shown that a combination of homo- and heteronuclear shift correlated 2 D NMR yields correct and complete assignment of 1H and 13C NMR spectra. The amount of the work necessary can be considerably reduced if some of the lines can be unambiguously assigned on the basis of other information or if suitable model compounds are available.The pattern of homonuclear cross-peaks is characteristic for molecular fragments and can be used with advantage to trace out the lines in the spectral regions with heavy overlap. The exactly assigned 13C chemical shifts of disaccharide and trisaccharide related to arabinoxylan agree satisfactorily with the shifts predicted according to the shifts found in the spectra of model mono- and disaccharides measured under the same conditions.