Your mention of the non-uniform peak intensity confirming the three different sugar units found. This is because the signal intensity of NMR peaks is related to an -H abundance. Different monomer ratios are responsible for this variation and support our findings. Also, the 10 H1/H2 cross peaks observed in the COSY spectra supported our findings of EPS heterogeneity, given the following facts: 1) We found 3 different types of sugars by HPLC. 2) We identified by NMR at least 2 types of linkages α 1-2 Man-Man and alfa 1-4 Man-Man monosaccharides. 3) There are other 2 sugars for which the β- type of linkage was identified but not the exact sugar position. 4) Anomeric protons shifts from units at the reducing end of polysaccharide differs from the one in another position. In conclusion, there are different linkage possibilities (plus already identified) to different monosaccharides in different ring positions. This gives rise to a multiplicity of signals (not fully identified in this work), which could produce different H1/H2 correlations.
Chemical shift similarity is not sufficient to identify monosaccharide and linkage in a polysaccharide repeating unit. The evidences for the partial structure given are not convincing. If the authors do not add methylation analysis and perform full NMR spectral analysis, the claims about structure determination should be removed from the manuscript. They deleted erroneous information about mannose residues, but came up with new conclusions about mannose identity and linkages based solely on chemical shift of anomeric proton/carbon.The information contained in the other 2D spectra was not exploited to provide structural information.