title: Sulfated modification of the polysaccharide from Sphallerocarpus gracilis and its antioxidant activities.
abstract: Sphallerocarpus gracilis (S. gracilis) is a little-investigated edible plant and used as traditional Chinese medicine. In this study, polysaccharide extracted from S. gracilis,deproteined and purified. The polysaccharide (SGP) was chemically modified to obtain its sulfated derivatives (S-SGP) using the method of chlorosulfonic acid/pyridine (CSA/Pyr). In order to acquire the derivative with the highest degree of substitution (DS), the optimum conditions of the sulfation were obtained based on response surface design (RSD), and the structural characterizations and antioxidant properties of the S-SGP were comparatively investigated by Fourier transform infrared spectrometry (FT-IR), GC-MS analysis, size exclusion chromatography (SEC), and DPPH radical assay, hydroxyl radical assay, superoxide radical assay, and reducing power assay, respectively. Results showed that the modification was successful, and obtained the optimum combination of conditions. Compared with SGP, the sulfated polysaccharide with relatively the decreased degree of molecular weight (Mw) but the same composition of monosaccharides exhibited better antioxidant activities in DPPH, hydroxyl, superoxide radical and reducing power assay. These results indicated that the antioxidant activities in vitro of the S-SGP from S. gracilis may be related to combined effects of Mw, monosaccharide composition, and sulfate content.
authors.affiliation: College of Life Science, Northwest Normal University, Lanzhou 730070, China; Bioactive Products Engineering Research Center for Gansu Distinctive Plants, Lanzhou 730070, China.
authors.forename: Yunfei
authors.initials: Y
authors.lastname: Xu
authors.affiliation: College of Life Science, Northwest Normal University, Lanzhou 730070, China.
authors.forename: Shen
authors.initials: S
authors.lastname: Song
authors.affiliation: College of Life Science, Northwest Normal University, Lanzhou 730070, China; Bioactive Products Engineering Research Center for Gansu Distinctive Plants, Lanzhou 730070, China.
authors.forename: Yanxia
authors.initials: Y
authors.lastname: Wei
authors.affiliation: Bioactive Products Engineering Research Center for Gansu Distinctive Plants, Lanzhou 730070, China; Institute of Polymers, College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070, China.
authors.forename: Fengxia
authors.initials: F
authors.lastname: Wang
authors.affiliation: College of Life Science, Northwest Normal University, Lanzhou 730070, China.
authors.forename: Min
authors.initials: M
authors.lastname: Zhao
authors.affiliation: College of Life Science, Northwest Normal University, Lanzhou 730070, China; Bioactive Products Engineering Research Center for Gansu Distinctive Plants, Lanzhou 730070, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Guo
authors.affiliation: College of Life Science, Northwest Normal University, Lanzhou 730070, China; Bioactive Products Engineering Research Center for Gansu Distinctive Plants, Lanzhou 730070, China; Institute of Polymers, College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070, China. Electronic address: zhangj@nwnu.edu.cn.
authors.forename: Ji
authors.initials: J
authors.lastname: Zhang
mesh_terms: D000975:Antioxidants / Q000737:chemistry* / Q000302:isolation & purification; D019661:Apiaceae / Q000737:chemistry*; D005609:Free Radicals / Q000737:chemistry; D008970:Molecular Weight; D009005:Monosaccharides / Q000032:analysis; D010084:Oxidation-Reduction; D011134:Polysaccharides / Q000737:chemistry* / Q000302:isolation & purification; D012044:Regression Analysis; D013431:Sulfates / Q000737:chemistry*
chemical_list: D000975:Antioxidants; D005609:Free Radicals; D009005:Monosaccharides; D011134:Polysaccharides; D013431:Sulfates
keywords: Antioxidant activity; Chemical structure; Sulfated modification