title: Structure Characterization and Immunomodulating Effects of Polysaccharides Isolated from Dendrobium officinale.
abstract: A crude polysaccharide fraction (cDOP) has been determined to be the characteristic marker of Dendrobium officinale, an expensive tea material in Asia, but its chemistry and bioactivity have not been studied. In work reported here, cDOP was destarched (DOP, 90% yield) and separated into two subfraction polysaccharides, DOPa and DOPb, which were characterized by monosaccharide composition and methylation analyses and spectral analyses (FT-IR and (1)H and (13)C NMR). Both are composed of mannose and glucose at similar ratios and have a similar structure with a backbone of 1,4-linked β-D-mannopyranosyl and β-D-glucopyranosyl residues. Significant differences were observed only in their molecular weights. Bioassay using mouse macrophage cell line RAW264.7 indicated that DOP and its two subfractions enhance cell proliferation, TNF-α secretion, and phagocytosis in a dose-dependent manner. They also induced the proliferation of lymphocytes alone and with mitogens. DOPa and DOPb are thus proven to be major, active polysaccharide markers of D. officinale.
authors.affiliation: School of Chinese Medicine, Hong Kong Baptist University , Hong Kong, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Wei
authors.affiliation: School of Chinese Medicine, Hong Kong Baptist University , Hong Kong, China.|State Key Laboratory of Food Science and Technology, Nanchang University , Nanchang, Jiangxi, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Feng
authors.affiliation: School of Chinese Medicine, Hong Kong Baptist University , Hong Kong, China.
authors.forename: Wan-Rong
authors.initials: WR
authors.lastname: Bao
authors.affiliation: State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau , Macao, China.
authors.forename: Dik-Lung
authors.initials: DL
authors.lastname: Ma
authors.affiliation: Department of Chemistry, Hong Kong Baptist University , Hong Kong, China.
authors.forename: Chung-Hang
authors.initials: CH
authors.lastname: Leung
authors.affiliation: State Key Laboratory of Food Science and Technology, Nanchang University , Nanchang, Jiangxi, China.
authors.forename: Shao-Ping
authors.initials: SP
authors.lastname: Nie
authors.affiliation: School of Chinese Medicine, Hong Kong Baptist University , Hong Kong, China.
authors.forename: Quan-Bin
authors.initials: QB
authors.lastname: Han
mesh_terms: D000818:Animals; D049109:Cell Proliferation / Q000187:drug effects; D031667:Dendrobium / Q000737:chemistry*; D007155:Immunologic Factors / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D008264:Macrophages / Q000166:cytology / Q000187:drug effects / Q000276:immunology; D051379:Mice; D010587:Phagocytosis / Q000187:drug effects; D010936:Plant Extracts / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D011134:Polysaccharides / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D000067996:RAW 264.7 Cells; D014409:Tumor Necrosis Factor-alpha / Q000276:immunology
chemical_list: D007155:Immunologic Factors; D010936:Plant Extracts; D011134:Polysaccharides; D014409:Tumor Necrosis Factor-alpha
keywords: Dendrobium officinale; RAW264.7 cells; chemical structure; lymphocytes; polysaccharides