title: Regioselective sulfation of Artemisia sphaerocephala polysaccharide: Solution conformation and antioxidant activities in vitro.
abstract: Regioselective modification is an effective approach to synthesize polysaccharides with different structure features and improved properties. In this study, regioselective sulfation of Artemisia sphaerocephala polysaccharide (SRSASP) was prepared by using triphenylchloromethane (TrCl) as protecting precursor. The decrease in fractal dimension (df) values (1.56-2.04) of SRSASP was observed in size-exclusion chromatography combined with multi angle laser light scattering (SEC-MALLS) analysis. Compared to sample substituted at C-6, SRSASP showed a more expanded conformation of random coil, which was attributed to the breakup of hydrogen bonds and elastic contributions. Circular dichroism (CD), methylene blue (MB) and congo red (CR) spectrophotometric method and atomic force microscopy (AFM) results confirmed the conformational transition and stiffness of the chains after sulfation. SRSASP exhibited enhanced antioxidant activities in the DPPH, superoxide and hydroxyl radical scavenging assay. Sulfation at C-2 or C-3 was favorable for the chelation which might prevent the generation of hydroxyl radicals. It concluded that the degree of substitution and substitution position were the factors influencing biological activities of sulfated polysaccharides.
authors.affiliation: College of Life Science, Northwest Normal University, Lanzhou 730070, People's Republic of China; Bioactive Products Engineering Research Center For Gansu Distinctive Plants, Northwest Normal University, Lanzhou 730070, People's Republic of China. Electronic address: nuno-vai@163.com.
authors.forename: Junlong
authors.initials: J
authors.lastname: Wang
authors.affiliation: College of Life Science, Northwest Normal University, Lanzhou 730070, People's Republic of China; Bioactive Products Engineering Research Center For Gansu Distinctive Plants, Northwest Normal University, Lanzhou 730070, People's Republic of China.
authors.forename: Wen
authors.initials: W
authors.lastname: Yang
authors.affiliation: College of Life Science, Northwest Normal University, Lanzhou 730070, People's Republic of China; Bioactive Products Engineering Research Center For Gansu Distinctive Plants, Northwest Normal University, Lanzhou 730070, People's Republic of China.
authors.forename: YinYing
authors.initials: Y
authors.lastname: Tang
authors.affiliation: College of Life Science, Northwest Normal University, Lanzhou 730070, People's Republic of China; Bioactive Products Engineering Research Center For Gansu Distinctive Plants, Northwest Normal University, Lanzhou 730070, People's Republic of China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Xu
authors.affiliation: College of Life Science, Northwest Normal University, Lanzhou 730070, People's Republic of China; Bioactive Products Engineering Research Center For Gansu Distinctive Plants, Northwest Normal University, Lanzhou 730070, People's Republic of China.
authors.forename: Shengli
authors.initials: S
authors.lastname: Huang
authors.affiliation: College of Life Science, Northwest Normal University, Lanzhou 730070, People's Republic of China; Bioactive Products Engineering Research Center For Gansu Distinctive Plants, Northwest Normal University, Lanzhou 730070, People's Republic of China.
authors.forename: Jian
authors.initials: J
authors.lastname: Yao
authors.affiliation: College of Life Science, Northwest Normal University, Lanzhou 730070, People's Republic of China; Bioactive Products Engineering Research Center For Gansu Distinctive Plants, Northwest Normal University, Lanzhou 730070, People's Republic of China; Key Laboratory of Eco-Environment-Related Polymer Materials Ministry of Education, College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070, People's Republic of China.
authors.forename: Ji
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Eco-Environment-Related Polymer Materials Ministry of Education, College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070, People's Republic of China.
authors.forename: Ziqiang
authors.initials: Z
authors.lastname: Lei
mesh_terms: D000975:Antioxidants / Q000737:chemistry*; D019306:Artemisia / Q000737:chemistry*; D002236:Carbohydrate Conformation; D010084:Oxidation-Reduction; D011134:Polysaccharides / Q000737:chemistry*; D013431:Sulfates / Q000737:chemistry
chemical_list: D000975:Antioxidants; D011134:Polysaccharides; D013431:Sulfates
keywords: Antioxidant activity; Artemisia sphaerocephala; Regioselective synthesis; Solution conformation; Sulfated polysaccharide