Polysaccharide from Mesona chinensis: Extraction optimization, physicochemical characterizations and antioxidant activities

The optimization of extraction conditions, physicochemical characterizations and antioxidant activities of polysaccharide from Mesona chinensis (MCP) were investigated. Optimal extraction conditions of MCP with the highest yield of 7.05 +/- 0.12% was obtained by response surface methodology (RSM). The physicochemical characterizations of MCP obtained at the optimal extraction conditions were detected by TU-1900 spectrophotometer, high performance gel permeation chromatography (HPGPC), high-performance anion exchange chromatography (HPAEC) and fourier transform infrared spectroscopy (FT-IR) as well, revealing that MCP was a heteropolysaccharide containing uronic acid (29.3 +/- 11.3%) and protein (10.41 +/- 0.8%), with an average molecular weight (Mw) of 1.45 x 10(6) Da, which mainly consisted of galactose (Gal) and glucose (Glc) in a molar ratio of 1.00:1.38. Furthermore, MCP exhibited considerable antioxidant potential on scavenging hydroxyl (53.87 +/- 0.44%), superoxide anion (58.42 +/- 11.17%) and DPPH radicals (55.59 +/- 0.69%). Our results indicated that MCP might be a good candidate for further investigations of functional foods. (C) 2017 Elsevier B.V. All rights reserved.