NMR analysis of a methylated non-pectic polysaccharide from water soluble yellow mustard mucilage

Detailed structure information on non-pectic polysaccharides (NPP) from yellow mustard mucilage was investigated in the present study. Prior to Nuclear Magnetic Resonance (NMR) experiments, NPP was methylated in order to improve the resolution of NMR spectra by increasing the sample solubility. C, 1H–1H and 1H–13C NMR spectra revealed that NPP possessed a β-1,4 linked glucose backbone, with β-mannose 1,6 linked to the backbone chain, and the β-galactose 1,2 linked to the glycosidic backbone chain. The methyl groups were substituted to the 2, 3, 6 positions of the glucose residues and the 2, 3 positions of mannose and galactose residues. Ethyl group was also detected but no linkage was observed to the glucose residue.