Carbon coupling constants, oligosaccharides

Conformational analysis of oligosaccharides in solution by NMR spectroscopy is based on the study of chemical shifts, n.O.e. s, and three-bond, proton-carbon coupling constants. Generally, the experimental NMR parameters P. . , (such as n.O.e. s or... 

Until now, the determination of three-dimensional structures of oligosaccharides in solution was based primarily on proton-proton distance information obtained from n.O.e. data. Here, we discuss the application of three-bond proton-carbon coupling constants. 

Interglycosidic Carbon-Proton Coupling Constants for Oligosaccharides ... 

M. Hricovini and I. Tvaroska, Conformational dependence of the one-bond carbon-proton coupling constants in oligosaccharides, Magn. Reson. Chem., 28 (1990) 862-866. 

I. Tvaroska and F. R. Taravel, One-bond carbon-proton coupling constants Angular dependence in a-linked oligosaccharides, Carbohydr. Res., 221 (1991) 83-94. 

B. Mulloy, T. A. Frenkiel, and D. B. Davies, Long-range carbon-proton coupling constants. Application of conformational studies of oligosaccharides, Carbohydr. Res., 184 (1988) 39 -6. 

In oligosaccharides the two trawr-glycosidic 3/hcoc spin-spin coupling constants provide a direct measure of the torsion angles phi ((f>) and psi ( torsion angle is defined as 05 —CT—0 —C , where n is the linkage carbon number, while the q> angle is related to CT-0 -C -C( -l) (Scheme 1). 

T.N. Pham, T. Liptaj, K. Bromek, D. Uhrin, Measmement of small one-bond proton-carbon residual dipolar coupling constants in partially oriented C natmal abundance oligosaccharide samples. Analysis of heteronuclear JcH-modulated spectra with the BIRD inversion pulse, J. Magn. Reson. 157 (2002) 200—209. 

L.D. Hall and G.A. Morris, Measurement of carbon-13 proton coupling constants in oligosaccharides by two-dimensional carbon-13 NMR spectroscopy, Carbohyd. Res. 82, 175 (1980). 

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