Reducing the overlap problem in the proton NMR spectra of oligosaccharides by application of pseudo-four-dimensional homonuclear HOHAHA-HOHAHA-COSY.
A new homonuclear NMR experiment is described for the assignment of the proton NMR spectra of oligosaccharides, namely HOHAHA-HOHAHA-COSY (where HOHAHA is homonuclear Hartmann-Hahn spectroscopy and COSY is correlated spectroscopy). While this technique may formally be thought of as a four-dimensional NMR experiment, by use of selective pulses it is demonstrated that the analogous pseudo-four-dimensional experiment is a valuable improvement over conventional three-dimensional HOHAHA-COSY, in that the degree of resonance overlap is markedly reduced by the dispersion of resonances into a fourth effective dimension. The technique is demonstrated by application to the biantennary nonasaccharide Gal beta 1-4-GlcNAc beta 1-2Man alpha 1-6(Gal beta 1-4GlcNAc beta 1-2Man alpha 1-3)Man-beta 1-4GlcNAc beta 1-4GlcNAc.
Rutherford
T J
TJ
Department of Biochemistry, University of Dundee, UK.
Homans
S W
SW
D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008969:Molecular Sequence Data; D009844:Oligosaccharides / Q000737:chemistry*
D009844:Oligosaccharides