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)-ROE SY experiments for the rapid and selective identification of alpha/beta 1,2 -glycosidic linkages in polysaccharides. The method assists in the identifi cation 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 sequ ence of the glycan under study. selection of solely the 1,2- Linkages is ac hieved 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.