Isolation and purification of the polysaccharides

Crude MLPs (200 mg) were dissolved in 10 mL of distilled water, and the solution was filtered through a 0.45 μm membrane. The filtrate was passed through an anion exchange column (2.6 cm×50 cm) of DEAE-52 cellulose. The eluents were 0.1, 0.3, and 0.5 mol/L NaCl at a flow rate of 1 mL/min. The total sugar content of the eluate was determined by the phenol-sulfuric acid method [16]. The fractions eluted with different concentrations of NaCl were pooled, desalted and further purified on a Sephadex G-100 column eluted with distilled water at 0.5 mL/min. The major polysaccharide fractions were pooled, concentrated and lyophilized. This process afforded the purified polysaccharides, which were further characterized.