Investigation of glucofructans from roots of two species of comfrey (Symphytum asperum Lepech. and Symphytum caucasicum bieb.)

Barbakadze, V.V.; Kemertelidze, E.P.; Dekanosidze, G.E.; Beruchashvili, T.G.; Usov, A.I.

Bioorganicheskaya Khimiya 18(5): 671-679


Neutral glucofructans were shown to be the principal watersoluble polysaccharides of Symphytum asperum and S. caucasicum roots. According to the methylation analysis and 13C-NMR spectral data, both polysaccharides consist of 2 .fwdarw. 1 and 2 .fwdarw. 6-linked .beta.-D-fructofuranose residues; 1,6-distributed residues of .beta.-D-fructofuranose serve as branching points of the polymeric molecules. A single residue of .alpha.-D-glucopyranose in each molecule occupies the terminal position and is linked to the .beta.-D-fructofuranose residue through an 1 .fwdarw. 2 linkage. Differences between the two polysaccharides are the average degree of polyermization (22 and 39 monosaccharide residues), the proportion of 2 .fwdarw. 1 and 2 .fwdarw. 6 linkages (3.4 : 1 and 3.8 : 1) and the degree of branching (4-5 and 7 branching points per molecule, respectively).