title: Isolation and structural characterization of a neutral polysaccharide from the stems of Dendrobium densiflorum.
abstract: A novel neutral heteropolysaccharide (DDP-1-D) was purified from hot water extracts of dried stem of Dendrobium densiflorum by DEAE-52 and Sephacryl S-200 High-Resolution Chromatography. The heteropolysaccharide had an average molecular weight about 9440 Da. It was composed mainly of glucose and mannose in the ratio of 3.01:1. Structural features of DDP-1-D were elucidated by a combination of chemical and instrumental techniques, including FT-IR, GC-MS, periodate oxidation-Smith degradation, (1)H and (13)C NMR spectroscopies (including COSY, TOCSY, HSQC, and HMBC spectra). The results indicated that DDP-1-D is a mannoglucan and has a backbone consisting of (1→4)-linked α-D-Glcp, (1→6)-linked α-D-Glcp, (1→2)-linked α-D-Manp and (1→4)-linked β-Manp. This is the first study to provide clear evidence for the structure of the polysaccharide in D. densiflorum.
authors.affiliation: School of Pharmaceutical Sciences, Southern Medical University, Guangzhou 510515, People's Republic of China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Li
authors.forename: Yang
authors.initials: Y
authors.lastname: Xie
authors.forename: Jianwei
authors.initials: J
authors.lastname: Su
authors.forename: Qingsheng
authors.initials: Q
authors.lastname: Ye
authors.forename: Zhimin
authors.initials: Z
authors.lastname: Jia
mesh_terms: D031667:Dendrobium / Q000737:chemistry*; D008970:Molecular Weight; D019906:Nuclear Magnetic Resonance, Biomolecular; D010084:Oxidation-Reduction; D018547:Plant Stems / Q000737:chemistry*; D011134:Polysaccharides / Q000737:chemistry* / Q000302:isolation & purification
chemical_list: D011134:Polysaccharides