ARS | Publication request: Stable Isotope-Enhanced Two- and Three-Dimensional Diffusion Ordered 13C-NMR Spectroscopy (SIE-DOSY 13C-NMR)

Submitted to: Journal of Magnetic Resonance
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: February 20, 2009
Publication Date: N/A

Interpretive Summary: This research identified a potential new timesaving method for scientists who characterize sugars and carbohydrates as well as for those involved in metabolic research. For the development of uses for agricultural-derived materials, techniques like nuclear magnetic resonance (NMR) spectroscopy are used to identify molecules. The different components of a mixed material often have different physical properties, such as the rate of diffusion. In this experiment, a new method based on diffusion was developed for NMR to help identify different sugars in mixtures. The examples tested were mixed carbohydrates of potential agricultural importance. By increasing the small amount of one type of carbon (carbon-13) naturally found in the sugars, the experiments were completed quickly, often within minutes.

Technical Abstract: Stable Isotope-Enhanced Diffusion Ordered (SIE-DOSY) 13C-NMR has been applied to 13C-enriched carbohydrates and has been used to determine diffusion coefficients for pentose and hexose monosaccharides, a disaccharide and a trisaccharide. These 2D spectra were obtained with as little as 8 min of acquisition time. Fully resolved 3D DOSY-HMQC NMR spectra of [U-13C]xylose, [U-13C]glucose and [1-13Cgal]lactose were obtained in 5 hr. Sample derivatization with [carbonyl-13C]acetate (peracetylation) extends the usefulness of the technique to include non-labeled sugars; the 13C carbonyl¿carbohydrate ring proton 1H-13C correlations also provide additional structural information, as shown for the 3-D DOSY-HMQC analysis of a mixture of maltotriose and lactose per-[carbonyl-13C]acetates.