Structural characterization and antioxidant activity of a polysaccharide from the fruiting bodies of cultured Cordyceps militaris

• Published in: Carbohydrate polymers 2007-11, Vol.70 (4), p.430-436
• Main Authors: Yu, Rongmin, Yang, Wei, Song, Liyan, Yan, Chunyan, Zhang, Zhang, Zhao, Yu
• Format: Article
• Language: English
• Subjects: Antioxidant; antioxidant activity; antioxidants; Applied sciences; Biological and medical sciences; chemical composition; chemical structure; Cordyceps; Cordyceps militaris; Cultured Cordyceps militaris; Exact sciences and technology; free radical scavengers; Fruiting bodies; Fundamental and applied biological sciences. Psychology; fungi; HPAEC-PAD analysis; Microbiology; Morphology, structure, chemical composition; Mycology; Natural polymers; Physicochemistry of polymers; Polysaccharide structure; polysaccharides; Starch and polysaccharides
• ISSN: 0144-8617; 1879-1344
• DOI: 10.1016/j.carbpol.2007.05.005

The water-soluble crude polysaccharides were obtained from the fruiting bodies of cultured Cordyceps militaris by hot water extraction followed by ethanol precipitation. The polysaccharides were successively purified by chromatography on DEAE–cellulose-52 and Sephacryl S-100 HR columns, giving main three polysaccharide fractions termed P50-1, P70-1, and P70-2. Structural features of P70-1 were investigated by a combination of chemical and instrumental analysis, such as partial acid hydrolysis, methylation analysis, periodate oxidation – Smith degradation, GC–MS, 13C NMR, HPAEC-PAD, and FT-IR. The results indicated that P70-1 has a backbone of (1 → 6)-linked β- d-mannopyranosyl residues, which occasionally branches at O-3. The branches were mainly composed of (1 → 4)-linked α- d-glucopyranosyl and (1 → 6)-linked β- d-galactopyranosyl residues, and terminated with β- d-galactopyranosyl residues and α- d-glucopyranosyl residues. In the in vitro antioxidant assay, P70-1 was found to possess hydroxyl radical-scavenging activity with an IC 50 value of 0.548 mg/ml.