Isolation, purification and structural characterization of Bletilla striata polysaccharides and its antitumor activity / 中草药

ABSTRACT

Objective: Bletilla striata polysaccharide (BSP-1) extracted from the stem tubers of B. striata was purified to study the structural properties and antitumor activity. Methods: The crude polysaccharide was fractionated by DEAE-cellulose column chromatography, and three fractions were obtained including BP-1, BP-2, and BP-3, respectively, BP-1 was further purified by SephadexG-200 column chromatography, and a sub-fraction named BSP-1 was obtained. Subsequently, HPGPC, IR spectroscopy, gas chromatography (GC), GC coupled to mass spectrometry (GC-MS) and methylation analysis, and 1H- and 13C-NMR were employed to characterize the structural properties of the polysaccharide fractions. Moreover, the anticancer activity was investigated in vivo. Results: The results showed that the molecular weight of BSP-1 were 4.72 × 105. BSP-1 was consisted of mannose (Man) and glucose (Glc) residues. The backbone of BSP-1 was composed of β-1,4-linked Man and Glc residues at the end with a molar ratio of 81. BSP-1 could inhibit the tumor proliferation of HepG2-bearing mice. The tumor weight of mice was significantly inhibited by BSP-1 with inhibitory rate of 66.42%. Conclusion: Structural characterization of BSP-1 provides the significant reference for the further development and elucidation of polysaccharides from B. striata as new drugs.