Direct NMR analysis of sugars from glycosides

The structural identification of glycosides often poses great challenges. NMR is a powerful method, but overlapping signals complicate 2D NMR approaches. To identify the sugars in a glycoside, often a small sample is hydrolyzed and analyzed by GC after derivatizing the free sugars. We have developed a direct¹H-NMR approach to sugar identification based on the anomeric signals that does not require derivatization. The chemical shifts of the anomeric signals and their α/β ratios will be presented for all C₆H₁₂O₆ aldoses as well as common pentoses and modified sugars. An approach to determine linkage patterns will be presented.