Structural characterization and immunomodulatory activity of a new polysaccharide from jellyfish

A new polysaccharide (JSP-11) with a molecular weight of 1.25 × 106 Da was extracted and purified from jellyfish. Monosaccharide analysis showed that JSP-11 was composed of mannose, galactose and glucuronic acid with a molar ratio of 2.18:1.00:1.94. According to the analysis of fourier transform-infrared spectroscopy, methylation analysis, and NMR spectroscopy, JSP-11 was determined to contain a linear backbone which consisted of (1 → 3,6)-linked β-d-Manp and (1 → 6)-linked β-d-Galp. The branch of (1→)-linked α-d-GlcpA was attached to the C-3 position of (1 → 3,6)-linked β-d-Manp in the backbone. The immunomodulatory assay exhibited that JSP-11 could significantly enhance the viability of RAW 264.7 macrophage cells, and promote the release of NO, TNF-α, and IL-1β via activating NF-κB, MAPKs and PI3K/Akt signal pathways.