Rapid high-resolution four-dimensional NMR spectroscopy using the filter diagonalization method and its advantages for detailed structural elucidation of oligosaccharides.
Four-dimensional nuclear magnetic resonance spectroscopy with high resolution of signals in the indirect dimensions is reported as an implementation of the filter diagonalization method (FDM). Using an oligosaccharide derivatized with 13C-labeled acetyl isotags, a four-dimensional constant-time pulse sequence was tailored for conjoint use with the FDM. Results demonstrate that high resolution in all dimensions can be achieved using a relatively short experimental time period (19 h), even though the spectrum is highly congested in the direct and all three indirect dimensions. The combined use of isotags, constant-time pulse sequences, and FDM permits rapid isolation of sugar ring proton spin systems in multiple dimensions and enables all endocyclic J-couplings to be simply measured, the key goal to assigning sugar stereochemistry and anomeric configuration. A general method for rapid, unambiguous elucidation of spin systems in oligosaccharides has been a long-sought goal of carbohydrate NMR, and isotags combined with the FDM now enable this to be easily performed. Additional general advantages of the FDM program for generating high-resolution 2D slices in any dimension from a 4D spectrum are emphasized.
Armstrong
Geoffrey S
GS
Department of Cell and Developmental Biology and Biomolecular Structure Program, University of Colorado Health Sciences Center, Mail Stop 8108, P.O. Box 6511, Aurora, CO 80045, USA.
Mandelshtam
Vladimir A
VA
Shaka
A J
AJ
Bendiak
Brad
B
D002247:Carbon Isotopes; D005936:Glucans / Q000737:chemistry*; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods*; D009844:Oligosaccharides / Q000737:chemistry*; D012815:Signal Processing, Computer-Assisted
D002247:Carbon Isotopes; D005936:Glucans; D009844:Oligosaccharides; C001290:glucan nigeran