A solid-state NMR application of the anomeric effect in carbohydrates: galactosamine, glucosamine, and N-acetyl-glucosamine.
Simple 2D 13C/15N heteronuclear correlation solid-state NMR spectroscopy was implemented to resolve the 15N resonances of the alpha and beta anomers of three amino monosaccharides: galactosamine (GalN), glucosamine hydrochloride (GlcN), and N-acetyl-glucosamine (GlcNAc) labeled specifically with 13C1/15N spin pairs. Although the 15N resonances could not be distinguished in normal 1D spectra, they were well resolved in 2D double CP/MAS correlation spectra by taking advantage of the 13C spectral resolution. The alpha and beta resonances shifted apart by 3-5 ppm in their 13C chemical shifts, and differed by 1-2 ppm in the extended 15N dimension. Aside from this, the detection of other 13C/15N correlations over short distances was also achieved arising from the C2, C3 and CO carbons present in natural abundance. 2D double CP/MAS chemical shift correlation NMR spectroscopy is a simple and powerful technique to characterize the anomeric effect of amino monosaccharides. Applications of the 2D method reveal well-resolved 15N and 13C chemical shifts might be useful for structural determination on carbohydrates of biological significance, such as glycopeptide or glycolipids.
Tzou
Der-Lii M
DL
Institute of Chemistry, Academia Sinica, Nankang, Number 128, Yen-Chiu-Yuan Road, Taipei 11529, Taiwan, ROC. tzou@ccvax.sinica.edu.tw
D000117:Acetylglucosamine / Q000737:chemistry*; D002247:Carbon Isotopes; D005688:Galactosamine / Q000737:chemistry*; D005944:Glucosamine / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D009587:Nitrogen Isotopes
D002247:Carbon Isotopes; D009587:Nitrogen Isotopes; D005688:Galactosamine; D005944:Glucosamine; D000117:Acetylglucosamine