Two-dimensional relayed-rotating-frame overhauser spectroscopy H-1 NMR experiments for the selective identification of 1,2-glycosidic linkages in polysaccharides
This communication describes the use of two-dimensional relayed (TOCSY)-ROESY experiments for the rapid and selective identification of alpha/beta 1,2-glycosidic linkages in polysaccharides. The method assists in the identification of cross-peaks in crowded regions of ROESY spectra by moving them to less congested areas. In addition, the appearance of the spectra provides information relating the location of the glycosidic linkage within the sequence of the glycan under study. selection of solely the 1,2- Linkages is achieved by appropriately tuning the duration of the TOCSY mixing period. The method is demonstrated both theoretically and experimentally for a variety of test case polysaccharides. (C) 2000 Academic Press.