Structural studies of the exocellular polysaccharide from Sphingomonas paucimobilis strain I-886

Abstract The exocellular polysaccharide from Sphingomonas paucimobilis strain 1-886 has been studied using methylation analysis, Smith degradation, partial acid hydrolysis, NMR spectroscopy, and mass spectrometry as the principal methods. It is concluded that the repeating unit has the following structure: The absolute configuration of the uronic acid was deduced from 1 H NMR chemical shifts and is most likely d . Some preparations of the polysaccharide also contain phosphate and O -acyl groups which have not been identified or localised.