Structural Analysis and Immuno-Stimulating Activity of an Acidic Polysaccharide from the Stems of Dendrobium nobile Lindl

• Published in: Molecules (Basel, Switzerland) Vol. 22; no. 4; p. 611
• Main Authors: Wang, Jun-Hui, Zuo, Shu-Rong, Luo, Jian-Ping
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 10.04.2017; MDPI
• Subjects: Acids; Animals; Antioxidants; Cataracts; Chromatography; Dendrobium - chemistry; Dendrobium nobile; Food; Galactose; Glucose; Herbal medicine; Immunologic Factors - chemistry; Immunologic Factors - isolation & purification; Immunologic Factors - pharmacology; Immunology; Lymphocyte Activation - drug effects; Lymphocytes - drug effects; Lymphocytes - immunology; Lymphocytes - metabolism; Male; Mannose; Methylation; Mice; NMR; Nuclear magnetic resonance; Pectin lyase; Plant Extracts - chemistry; Plant Extracts - isolation & purification; Plant Extracts - pharmacology; Plant Stems - chemistry; Polysaccharides; Polysaccharides - chemistry; Polysaccharides - isolation & purification; Polysaccharides - pharmacology; Rhamnose; Spectrum Analysis; Structural analysis; Structure-Activity Relationship; Xylose; polysaccharide; immunological activities; Dendrobium nobile Lindl; acidic polysaccharide
• ISSN: 1420-3049; 1420-3049
• DOI: 10.3390/molecules22040611

Lindl., an epiphytic herb distributed in the Southeast Asia, is used as a tonic and antipyretic herbal medicine in China. In this study, a water-soluble acidic heteropolysaccharide, DNP-W4, containing mannose, glucose, galactose, xylose, rhamnose, and galacturonic acid, in the molar ratios of 1.0:4.9:2.5:0.5:1.0:0.9, was obtained from the stems of Lindl. Using methylation analysis, partial acid hydrolysis, pectolyase treatment, NMR, and ESI-MS, the structure of DNP-W4 was elucidated. The obtained data indicated that DNP-W4 was a complex heteropolysaccharide and possessed a backbone composed of (1→4)-linked β-d-Glcp, (1→6)-linked β-d-Glcp, and (1→6)-linked β-d-Galp, with substitutes at O-4/6 of Glcp residues and O-3 of Galp. The branches of DNP-W4 were composed of terminal Manp, (1→6)-linked β-d-Manp, (1→3)-linked β-d-Glcp, β-d-Glcp, β-d-Galp, (1→4)-linked α-d-GalAp, (1→2)-linked α-L-Rhap, and Xylp. DNP-W4 had little immunological activities, but its derivatives had immuno-stimulating activities to some extent.