The structure was elucidated in this paper NCBI PubMed ID:10877094 Journal NLM ID:0043535 Publisher: Elsevier Correspondence: gw+AEA-organ.su.se Institutions: Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University, S-106 91 Stockholm, Sweden, Department of Food Technology, 00014, University of Helsinki, Helsinki, Finland
A viscous extracellular polysaccharide produced by Lactobacillus helveticus Lb161 isolated from raw milk has been investigated. Sugar and methylation analysis, and 1H and 13C NMR spectroscopy revealed that the polysaccharide is composed of a heptasaccharide repeating unit. The sequence of sugar residues was determined by use of two-dimensional nuclear Overhauser effect spectroscopy and heteronuclear multiple bond connectivity experiments. The structure of the repeating unit of the exopolysaccharide from L. helveticus Lb161 is as follows: carbohydrate structure [see text]. The polysaccharide contains approximately 0.6 equivalents of O-acetyl group per repeating unit (not located).