title: Structure and antioxidant activity study of sulfated acetamido-polysaccharide from Radix Hedysari.
abstract: A new sulfated acetamido-heteropolysaccharide, HPS4-2A, was obtained by aqueous extraction followed by precipitation with ethanol and fractionation with DEAE column chromatography from Radix Hedysari. It was composed of rhamnose, arabinose, glucose, galactose and 2-acetamido-2-deoxy-d-galactose in the molar ratio of 10.09%:25.90%:25.90%:25.0%:12.30%. Elemental analysis indicated that HPS4-2A was a sulfated polysaccharide containing small amount of sulfate groups (1.87%). Partial acid hydrolysis, GC, GC-MS, 1D and 2D NMR spectroscopy analysis of the HPS4-2A revealed a predominance of glucose, galactose and 2-acetamido-2-deoxy-D-galactose linked in a highly-branched structure. The molecular weight of HPS4-2A was determined by HPSEC and HPSEC-MALLS. AFM study indicated that HPS4-2A took a highly branched conformation, which in consistent with the result studied by SEC-MALLS. Structural features of HPS4-2A were also investigated by SEM and TEM. Antioxidant assays demonstrated that HPS4-2A possessed of strong DPPH and hydroxyl radicals scavenging activities, suggesting that HPS4-2A could potentially be used as natural antioxidant.
authors.affiliation: School of Pharmacy, Lanzhou University, Lanzhou 730000, PR China.
authors.forename: Zilong
authors.initials: Z
authors.lastname: Dang
authors.forename: Demei
authors.initials: D
authors.lastname: Feng
authors.forename: Xiaohua
authors.initials: X
authors.lastname: Liu
authors.forename: Tao
authors.initials: T
authors.lastname: Yang
authors.forename: Long
authors.initials: L
authors.lastname: Guo
authors.forename: Jin
authors.initials: J
authors.lastname: Liang
authors.forename: Jiandi
authors.initials: J
authors.lastname: Liang
authors.forename: Fangdi
authors.initials: F
authors.lastname: Hu
authors.forename: Fang
authors.initials: F
authors.lastname: Cui
authors.forename: Shilan
authors.initials: S
authors.lastname: Feng
mesh_terms: D000975:Antioxidants / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D001713:Biphenyl Compounds / Q000378:metabolism; D004365:Drugs, Chinese Herbal / Q000737:chemistry / Q000494:pharmacology*; D007887:Fabaceae / Q000737:chemistry*; D017665:Hydroxyl Radical / Q000378:metabolism; D015394:Molecular Structure; D008970:Molecular Weight; D010851:Picrates / Q000378:metabolism; D018517:Plant Roots / Q000737:chemistry; D011134:Polysaccharides / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*
chemical_list: D000975:Antioxidants; D001713:Biphenyl Compounds; D004365:Drugs, Chinese Herbal; C586575:HPS4-2A polysaccharide; D010851:Picrates; D011134:Polysaccharides; D017665:Hydroxyl Radical; C004931:1,1-diphenyl-2-picrylhydrazyl
keywords: 2D NMR; Atomic force microscopy; Electron microscopy; Polysaccharide; Radix Hedysari; Structure