Isolation and partial characterization of a neutral polysaccharide from Mosla chinensis Maxim. cv. Jiangxiangru and its antioxidant and immunomodulatory activities

A neutral polysaccharide MP-1 was isolated and purified from Mosla chinensis Maxim. cv. Jiangxiangru. The average molecular weight was 587.53 kDa and it was composed of glucose, galactose, arabinose, mannose and rhamnose in a molar ratio of 16.02:10.01:4.92:4.62:2.23, and trace of fucose. Partial characterization of MP-1 was elucidated by methylation analysis. MP-1 was composed of 1,4-Glcp (31.76%), followed by 1,2-Rhap (17.11%), 1,2,4-Rhap (6.47%), 1,3,4-Galp (5.05%), 1,4-Manp (3.61%), 1,2,4-Manp (2.55%), 1,5-Araf (3.10%) and 1,4,6-Glcp (1.53%). The branching points were located at O-2, O-4 or O-6 with α-Araf (4.01%), α-Rhap (4.31%), α-Fucp (2.39%), β-Galp (11.02%) and β-Glcp (4.04%) as terminal residues. MP-1 exhibited a dose-dependent enhancement in antioxidant assays in this study. Immunomodulatory effects of MP-1 were assessed by splenocyte proliferation test and nitric oxide production of mouse peritoneal macrophages.