Molecular structures, chemical properties and biological activities of polysaccharide from Smilax glabra rhizome

The water-soluble crude polysaccharides, extracted from the rhizome of Smilax glabra, were fractionated using an anion exchange chromatography, yielding two fractions, F-1 and F-2. The crude and fractions (F-1 and F-2) mainly consisted of carbohydrates (66.7%-91.1%), proteins (7.30%-23.9%) and minor amount of sulfates (1.60%-9.40%). Glucose was the major monosaccharide unit of the polysaccharides with different levels of sugar constituents including galactose, arabinose, rhamnose and mannose. The molecular weight (M-w) of crude and fractions ranged from 32,102-63 x 10(3) g/mol. The crude and fractions could stimulate RAW264.7 cells to release nitric oxide and cytokines via up-regulation of their mRNA expression by the activation of NF-kappa B and MAPKs pathways. The related pattern recognition receptors (PRRs) on the surface of the cells appeared to be TLR2 and CR3. The GC-MS analysis revealed that the main backbone of the most immune-enhancing F-2 was (1 -> 4)-linked glucose and galactose chain with minor linkages of (1 -> 6)-galactose, (1 -> 3)-mannose, (1 -> 2)-rhamnose and (1 -> 5)-arabinose with some branches at C-3 and C-4 rhamnose, or C-6 galactose. (C) 2018 Elsevier B.V. All rights resered.