Isolation and structural identification of a novel fructan from Radix Codonopsis

Fructans are generally divided into two different types:beta-D-fructofuranosyl-(2 -> 1)-linked inulin and beta-D-fructofuranosyl-(2 -> 6)-linked levan. Previously, Radix Codonopsis was found to be rich in inulin type of fructans with low molecular weight (<5000 Da). In this study, a novel macromolecular fructan with a molecular weight of 1.70 x 10(3)KD was isolated from Radix Codonopsis, and its homogeneity was shown to be a single peak by high performance gel permeation chromatography (HPGPC), and its structure was confirmed to contain a new type of linkage,alpha-D-fructofuranosyl-(2 -> 3)-beta-D-fructofuranosyl linkage, by 1D- and 2D-nuclear magnetic resonance (NMR).