title: An acetylated galactomannoglucan from the stems of Dendrobium nobile Lindl.
abstract: A water-soluble polysaccharide DNP-W2 composed of glucose, mannose, and galactose in the molar ratio of 6.1:2.9:2.0 had been isolated from the stems of Dendrobium nobile. Its molecular weight was 1.8 x 10(4) Da determined by HPGPC. Structural features of DNP-W2 were investigated by a combination of chemical and instrumental analysis, including FTIR, GC, GC-MS, periodate oxidation-Smith degradation, methylation analysis, partial acid hydrolysis, and NMR spectroscopy. The results showed that DNP-W2 is a 2-O-acetylgalactomannoglucan and has a backbone consisting of (1-->4)-linked beta-D-Glcp, (1-->6)-linked beta-D-Glcp, and (1-->4)-linked beta-D-Manp, with branches at O-6 of (1-->4)-linked beta-D-Glcp and beta-D-Manp. The branches are composed of alpha-D-Galp. The acetyl groups are substituted at O-2 of (1-->4)-linked Manp. Preliminary tests in vitro reveals that DNP-W2 can stimulate ConA- and LPS-induced T and B lymphocyte proliferation.
authors.affiliation: School of Biotechnology and Food Engineering, Hefei University of Technology, Tunxi Road 193#, Hefei 230009, People's Republic of China.
authors.forename: Jun-Hui
authors.initials: JH
authors.lastname: Wang
authors.forename: Xue-Qiang
authors.initials: XQ
authors.lastname: Zha
authors.forename: Jian-Ping
authors.initials: JP
authors.lastname: Luo
authors.forename: Xue-Fei
authors.initials: XF
authors.lastname: Yang
mesh_terms: D000818:Animals; D031667:Dendrobium / Q000737:chemistry*; D005690:Galactose / Q000737:chemistry*; D005947:Glucose / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008358:Mannose / Q000737:chemistry*; D051379:Mice; D008807:Mice, Inbred BALB C; D008970:Molecular Weight; D018547:Plant Stems / Q000737:chemistry*; D011134:Polysaccharides / Q000737:chemistry* / Q000276:immunology*
chemical_list: D011134:Polysaccharides; D005947:Glucose; D008358:Mannose; D005690:Galactose