title: Chemical properties and antioxidant activity of a water-soluble polysaccharide from Dendrobium officinale.
abstract: In this report, a water-soluble polysaccharide was obtained from the dried stems of Dendrobium officinale Kimura et Migo by hot-water (70-75°C) extraction and 85% ethanol precipitation, and successively purification by DEAE-cellulose anion-exchange chromatography and gel-permeation chromatography. The D. officinale polysaccharide (DOP) has a molecular weight of 8500Da. Monosaccharide composition analysis reveals that DOP is composed of mannose, glucose, and arabinose with a trace of galacturonic acid in a molar ratio of 6.2:2.3:2.1:0.1. Periodate oxidation-smith degradation and 1D and 2D NMR spectroscopy analysis suggest the predominance of mannose and glucose, and it contains a 2-O-acetylglucomannan and (1→4)-linked-β-d-mannopyranosyl and (1→4)-linked-β-d-glucopyranosyl residues. Atomic force microscope shows that DOP mainly exists as rod-shaped chains, supporting high degrees of polymerization. The antioxidant activities of the polysaccharide in vitro assay indicate that DOP has good scavenging activity of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, higher scavenging activity of hydroxyl radical, and metal chelating activities.
authors.affiliation: School of Chemistry and Chemical Engineering, Guangxi University, 100 Daxue Road, Nanning 530004, Guangxi, P. R. China.
authors.forename: Qiu-Lian
authors.initials: QL
authors.lastname: Luo
authors.affiliation: School of Chemistry and Chemical Engineering, Guangxi University, 100 Daxue Road, Nanning 530004, Guangxi, P. R. China.
authors.forename: Zhuan-Hui
authors.initials: ZH
authors.lastname: Tang
authors.affiliation: School of Chemistry and Chemical Engineering, Guangxi University, 100 Daxue Road, Nanning 530004, Guangxi, P. R. China.
authors.forename: Xue-Feng
authors.initials: XF
authors.lastname: Zhang
authors.affiliation: School of Chemistry and Chemical Engineering, Guangxi University, 100 Daxue Road, Nanning 530004, Guangxi, P. R. China.
authors.forename: Yong-Hong
authors.initials: YH
authors.lastname: Zhong
authors.affiliation: School of Chemistry and Chemical Engineering, Guangxi University, 100 Daxue Road, Nanning 530004, Guangxi, P. R. China.
authors.forename: Su-Zhi
authors.initials: SZ
authors.lastname: Yao
authors.affiliation: School of Chemistry and Chemical Engineering, Guangxi University, 100 Daxue Road, Nanning 530004, Guangxi, P. R. China; Guangxi Colleges and Universities Key Laboratory of Applied Chemistry Technology and Resource Development, Guangxi University, 100 Daxue Road, Nanning, Guangxi, P. R. China.
authors.forename: Li-Sheng
authors.initials: LS
authors.lastname: Wang
authors.affiliation: School of Chemistry and Chemical Engineering, Guangxi University, 100 Daxue Road, Nanning 530004, Guangxi, P. R. China; Guangxi Colleges and Universities Key Laboratory of Applied Chemistry Technology and Resource Development, Guangxi University, 100 Daxue Road, Nanning, Guangxi, P. R. China.
authors.forename: Cui-Wu
authors.initials: CW
authors.lastname: Lin
authors.affiliation: School of Chemistry and Chemical Engineering, Guangxi University, 100 Daxue Road, Nanning 530004, Guangxi, P. R. China; Guangxi Colleges and Universities Key Laboratory of Applied Chemistry Technology and Resource Development, Guangxi University, 100 Daxue Road, Nanning, Guangxi, P. R. China. Electronic address: luo-xuan625@hotmail.com.
authors.forename: Xuan
authors.initials: X
authors.lastname: Luo
mesh_terms: D000975:Antioxidants / Q000737:chemistry* / Q000302:isolation & purification; D001089:Arabinose / Q000737:chemistry; D001713:Biphenyl Compounds / Q000037:antagonists & inhibitors*; D002236:Carbohydrate Conformation; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D031667:Dendrobium / Q000737:chemistry*; D005947:Glucose / Q000737:chemistry; D006027:Glycosides / Q000737:chemistry; D006603:Hexuronic Acids / Q000737:chemistry; D008358:Mannose / Q000737:chemistry; D008970:Molecular Weight; D010851:Picrates / Q000037:antagonists & inhibitors*; D010936:Plant Extracts / Q000737:chemistry; D018547:Plant Stems / Q000737:chemistry; D011134:Polysaccharides / Q000737:chemistry* / Q000302:isolation & purification; D052616:Solid Phase Extraction
chemical_list: D000975:Antioxidants; D001713:Biphenyl Compounds; D006027:Glycosides; D006603:Hexuronic Acids; D010851:Picrates; D010936:Plant Extracts; D011134:Polysaccharides; C007819:galacturonic acid; D001089:Arabinose; C004931:1,1-diphenyl-2-picrylhydrazyl; D005947:Glucose; D008358:Mannose
keywords: Antioxidant activity; Dendrobium officinale polysaccharide; Structure characterization