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.
In addition, the yeast mannan have β-(1→4) linkage and the one found in this work have α-linkage type.