title: Physicochemical properties and antioxidant activities of polysaccharides from Gynura procumbens leaves by fractional precipitation.
abstract: Four new polysaccharides (GPP-20, GPP-40, GPP-60 and GPP-80) were fractionated from Gynura procumbens leaves by 20%, 40%, 60% and 80% (v/v) ethanol, successively. Their physicochemical properties including the contents of neutral sugar, uronic acid and protein, as well as the monosaccharide composition were determined. In addition, the antioxidant activities of them were investigated via the reducing power assay and scavenging capacities of 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radicals and hydroxyl free radicals, respectively. The results indicated that apart from neutral sugar, they all contained uronic acids and proteins in their structures, which were further proved by the UV-vis and FT-IR spectra. Monosaccharide composition analysis implied that they all belonged to heteropolysaccharides consisted of arabinose, galactose, glucose, xylose and galacturonic acid with different types and ratios. What's more, GPP-20, GPP-40 and GPP-80 always exhibited better antioxidant activities than GPP-60 among these three antioxidant assays in vitro.
authors.affiliation: College of Food Science and Engineering, Jiangxi Agricultural University, Nanchang, 330045 Jiangxi Province, China. Electronic address: enen928@163.com.
authors.forename: Jing-En
authors.initials: JE
authors.lastname: Li
authors.affiliation: College of Food Science and Engineering, Jiangxi Agricultural University, Nanchang, 330045 Jiangxi Province, China.
authors.forename: Wen-Jun
authors.initials: WJ
authors.lastname: Wang
authors.affiliation: College of Food Science and Engineering, Jiangxi Agricultural University, Nanchang, 330045 Jiangxi Province, China.
authors.forename: Guo-Dong
authors.initials: GD
authors.lastname: Zheng
authors.affiliation: State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, 330047 Jiangxi Province, China.
authors.forename: Lin-Yan
authors.initials: LY
authors.lastname: Li
mesh_terms: D000975:Antioxidants / Q000737:chemistry* / Q000302:isolation & purification*; D019659:Asteraceae / Q000737:chemistry*; D001713:Biphenyl Compounds / Q000737:chemistry; D005590:Fractional Precipitation; D017665:Hydroxyl Radical / Q000737:chemistry; D009005:Monosaccharides / Q000032:analysis; D010851:Picrates / Q000737:chemistry; D018515:Plant Leaves / Q000737:chemistry*; D011134:Polysaccharides / Q000737:chemistry* / Q000302:isolation & purification*
chemical_list: D000975:Antioxidants; D001713:Biphenyl Compounds; D009005:Monosaccharides; D010851:Picrates; D011134:Polysaccharides; D017665:Hydroxyl Radical; C004931:1,1-diphenyl-2-picrylhydrazyl
keywords: Antioxidant activities; Gynura procumbens polysaccharides; Physicochemical properties