FIGURE 11.

Overlays of HMQC and HMBC heteronuclear NMR spectra (A) and HMQC and H2BC heteronuclear NMR spectra (B) of the V. fischeri O-antigen oligosaccharide. These data illustrate the assignments of the spin systems for the sugar residues A and E of 8-epi-legionaminic acids, as well as for the sugar residues B, D, F, and G. In both A and B, the HMQC spectra are shown in black for the positive peaks and blue for the folded negative peaks. The HMBC spectrum in A and the H2BC spectrum in B are shown in red. A, some of the cross-peaks belonging to the spin systems of the residues A and E are labeled, and the observed inter-glycosidic cross-peaks are also indicated by green circles. The dotted lines indicate the spin connectivities. The 1st letter in the labels refers to sugar subunit, and the rest in the labels refers to the position on that sugar residue.