Structure analysis of a bioactive heteropolysaccharide from Schisandra chinensis (Turcz.) Baill.

Our previous study revealed that Schisandra polysaccharide (SCPP11) exerted excellent antitumor and immunomodulatory activities. In this investigation, the structure of SCPP11 was elucidated. The results indicated that SCPP11 has a backbone that is composed of 1,4-disubstituted-β-gal, 1,4-disubstituted-α-glu,1,6-disubstituted-β-man and 1,4,6-disubstituted-α-gal. The branches was composed of 1,4-disubstituted-α-glu and 1-substituted-β-glu. The Mw and (r(g)(2))(z)(1/2) of the polymer molecules in 0.1 M NaCl were 1.793 × 10(4) Da and 11 nm, respectively. The exponent of (r(g)(2))(z)(1/2) versus Mw(0.39) suggested SCPP11 adopted a globular conformation with seldom random coil. Circular dichroism analysis revealed the presence of ordered structures in SCPP11. AFM and TEM further confirmed the agglomerated morphologies of SCPP11. In addition, it inferred the agglomerated conformation, branching structure and flexibility of chain are beneficial for exerting excellent activities. This information will be helpful in the recognition of biological systems for polysaccharides and the selection of active polysaccharide.