Abstract:

The structure of a bioactive fructan RCP isolated from the traditional Chinese medicinal herb Cyathula officinalis Kuan was determined by NMR, methylation, reductive-cleavage and GC-MS analyses. It was a highly branched fructan possessing a (2→1)-linked b-D-fructofuranosyl (Fruf ) backbone with (2→6)-linked b-D-Fruf side chains, belonging to neokestose family. Of the 93.17% b-D-Fruf residues, 24.15% was terminal, 26.24% was 1-linked, 20.46% was 6-linked, and 22.32% was 1,6-linked. Of the 6.83% a-D-glucopyranosyl (Glcp) residues, 2.14% was terminal and 4.69% was 6-linked. A structural model was postulated for a degree of polymerization (DP) of 15.

Key words: Cyathula officinalis , reductive cleavage, NMR, fructan, structure