Structure and immunobiological activity of a new polysaccharide from Bletilla striata

• Published in: Carbohydrate polymers 2014-07, Vol.107, p.119-123
• Main Authors: Peng, Qiang, Li, Ming, Xue, Feng, Liu, Huajing
• Format: Article
• Language: English
• Subjects: Adjuvants, Immunologic - chemistry; Adjuvants, Immunologic - pharmacology; Animals; Applied sciences; Biological and medical sciences; Bletilla striata; Carbohydrate Sequence; Cell Proliferation - drug effects; Exact sciences and technology; Glucomannan; Hydrolysis; Immunobiological activity; Immunomodulators; Medical sciences; Methylation; Mice; Molecular Sequence Data; Natural polymers; Orchidaceae - chemistry; Oxidation-Reduction; Pharmacology. Drug treatments; Physicochemistry of polymers; Polysaccharide; Polysaccharides - chemistry; Polysaccharides - pharmacology; Spleen - immunology; Starch and polysaccharides; Structure; Tuber
• ISSN: 0144-8617; 1879-1344
• DOI: 10.1016/j.carbpol.2014.02.042

•A novel glucomannan (BSPF2) was isolated from Bletilla striata.•BSPF2 was composed of Man, Glc and Gal in a molar ratio of 9.4:2.6:1.0.•The backbone was (1→4)-linked Man and Glc, substituted at O-6 with side chains.•BSPF2 could induce the spleen cell proliferation in mice. A new polysaccharide (designated BSPF2), with a molecular weight of 2.35×105Da, was isolated from the tubers of Bletilla striata. It contained mannose, glucose, and galactose in a molar ratio of 9.4:2.6:1.0. The acetyl content of BSPF2 was estimated to be 2.9%, and acetyl groups were located in positions 3 and 6 of mannosyl residues. The structural features were elucidated by a combination of monosaccharide composition analysis, periodate oxidation, partial acid hydrolysis, acetolysis, and methylation analysis. The results indicated that the backbone of BSPF2 consisted of (1→4)-linked mannosyl residues and (1→4)-linked glucosyl residues in a molar ratio of 2:1. About three fifths of glucosyl residues in the backbone were branched at O-6 position, and the terminal sugar residues were composed of mannosyl residues. Immunological assay results demonstrated that BSPF2 significantly induced the spleen cell proliferation in a dose-dependent manner.