title: Structural characterization and antioxidant activity of a novel heteropolysaccharide from the submerged fermentation mycelia of Ganoderma capense.
abstract: A novel heteropolysaccharide (GCPB-2) with a molecular mass of 1.03×10(5)Da was isolated from the submerged fermentation culturing mycelia powder of Lingzhi, Ganoderma capense, by DEAE-52 cellulose, DEAE Sepharose CL-6B, and Sephadex G-75 column chromatography. Its chemical structure was characterized for the first time. The antioxidant activity was evaluated by two antioxidant assay methods. The result of this study introduced G. capense as a possible valuable source that helped to exhibit some antioxidant properties. The homogeneous polysaccharide was composed of xylose and arabinose in the molar ratio of 1:1, and showed a specific optical rotation of [α]D(25)=+161° (c 1.0, H2O). Monosaccharide analysis, partial acid hydrolysis, periodic acid oxidation, methylation analysis, gas chromatography-mass spectrometry (GC-MS), Fourier transform-infrared spectroscopy (FT-IR), and nuclear magnetic resonance (NMR) spectroscopy ((1)H, (13)C, HMQC and HMBC) were conducted to elucidate its structure. The backbone of GCPB-2 was composed of (1 → 4)-linked-β-D-xylopyranose residues which branched at O-3. The two branches consisted of (1 → 3)-linked-β-L-arabinopyranose terminated with β-D-xylopyranose residues, and (1 → 4)-linked-β-L-arabinopyranose terminated with β-D-arabinopyranose residues. In the in vitro antioxidant assay, GCPB-2 was found to possess 1-diphenyl-2-picryl-hydrazyl (DPPH) radical-scavenging activity with an EC50 value of 0.379 μM. The findings of this study indicated that GCPB-2 possesses the hydroxyl radical-scavenging activity, which provided an experimental evidence to support the G. capense as functional foods in some Asian countries. To understand better the bioactivity of GCPB-2, the antioxidant activity should be further investigated to find out its mechanism in future work.
authors.affiliation: College of Pharmacy, Guangdong Pharmaceutical University, Guangzhou 510006, PR China; Key Laboratory of Digital Quality Evaluation of Chinese Materia Medica of State Administration of TCM, PR China; Engineering & Technology Research Center for Chinese Materia Medica Quality of the Universities of Guangdong Province, PR China.
authors.forename: Yating
authors.initials: Y
authors.lastname: Huang
authors.affiliation: College of Pharmacy, Guangdong Pharmaceutical University, Guangzhou 510006, PR China.
authors.forename: Naisheng
authors.initials: N
authors.lastname: Li
authors.affiliation: State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao, PR China.
authors.forename: Jian-Bo
authors.initials: JB
authors.lastname: Wan
authors.affiliation: College of Pharmacy, Guangdong Pharmaceutical University, Guangzhou 510006, PR China.
authors.forename: Dezhi
authors.initials: D
authors.lastname: Zhang
authors.affiliation: College of Pharmacy, Guangdong Pharmaceutical University, Guangzhou 510006, PR China; Key Laboratory of Digital Quality Evaluation of Chinese Materia Medica of State Administration of TCM, PR China; Engineering & Technology Research Center for Chinese Materia Medica Quality of the Universities of Guangdong Province, PR China. Electronic address: ycybridge@163.com.
authors.forename: Chunyan
authors.initials: C
authors.lastname: Yan
mesh_terms: D005285:Fermentation; D016166:Free Radical Scavengers / Q000737:chemistry* / Q000378:metabolism; D062610:Fungal Polysaccharides / Q000096:biosynthesis / Q000737:chemistry*; D032902:Ganoderma / Q000378:metabolism*; D017665:Hydroxyl Radical / Q000737:chemistry; D008970:Molecular Weight; D009005:Monosaccharides / Q000032:analysis; D025282:Mycelium / Q000378:metabolism*; D010084:Oxidation-Reduction; D012995:Solubility; D014867:Water / Q000737:chemistry
chemical_list: D016166:Free Radical Scavengers; D062610:Fungal Polysaccharides; D009005:Monosaccharides; D014867:Water; D017665:Hydroxyl Radical
keywords: Antioxidant activity; Ganoderma capense; Lingzhi; Polysaccharide; Structural characterization