A solution NMR approach to determine the chemical structures of carbohydrates using the hydroxyl groups as starting points

Brown, G. D., Bauer, J., Osborn, H. M. I. ORCID: https://orcid.org/0000-0002-0683-0457 and Kuemmerle, R. (2018) A solution NMR approach to determine the chemical structures of carbohydrates using the hydroxyl groups as starting points. ACS Omega, 3 (12). pp. 17957-17975. ISSN 2470-1343 doi: 10.1021/acsomega.8b02136

Abstract/Summary

An efficient NMR approach is described for determining the chemical structures of the monosaccharide glucose and four disaccharides, namely, nigerose, gentiobiose, leucrose and isomaltulose. This approach uses the 1H resonances of the −OH groups, which are observable in the NMR spectrum of a supercooled aqueous solution, as the starting point for further analysis. The 2D-NMR technique, HSQC-TOCSY, is then applied to fully define the covalent structure (i.e., the topological relationship between C–C, C–H, and O–H bonds) that must be established for a novel carbohydrate before proceeding to further conformational studies. This process also leads to complete assignment of all 1H and 13C resonances. The approach is exemplified by analyzing the monosaccharide glucose, which is treated as if it were an “unknown”, and also by fully assigning all the NMR resonances for the four disaccharides that contain glucose. It is proposed that this technique should be equally applicable to the determination of chemical structures for larger carbohydrates of unknown composition, including those that are only available in limited quantities from biological studies. The advantages of commencing the structure elucidation of a carbohydrate at the −OH groups are discussed with reference to the now well-established 2D-/3D-NMR strategy for investigation of peptides/proteins, which employs the −NH resonances as the starting point.

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/82103
Item Type	Article
Refereed	Yes
Divisions	Interdisciplinary centres and themes > Chemical Analysis Facility (CAF) Life Sciences > School of Chemistry, Food and Pharmacy > Department of Chemistry Life Sciences > School of Chemistry, Food and Pharmacy > School of Pharmacy > Medicinal Chemistry Research Group
Publisher	ACS
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