The structure of the capsular polysaccharide (CPS) produced by Leuconostoc mesenteroides ssp. cremoris PIA2 has been determined using component analysis and NMR spectroscopy. H-1 and C-13 resonances were assigned using 2D NMR experiments, and sequential information was obtained by H-1,H-1-NOESY and H-1, C-13-HMBC experiments. The CPS consists of linear pentasaccharide repeating units with the following structure: -> 3)-beta-D-Galf-(1 -> 6)-beta-D-Galf-(1 -> 2)beta-D-Galf-(1 -> 6)-beta-D-Galf-(1 -> 3)-beta-D-Galp-(1 ->, in which four out of the five sugar residues have the furanoid ring form, a structural entity found in bacteria but not in mammals. The analysis of the magnitude of the homonuclear three-bond coupling constants of the anomeric protons for the five-membered sugar rings indicates that the sugar residues substituted at a primary carbon atom show one kind of conformational preferences, whereas those substituted at a secondary carbon atom show another kind of conformational preferences.