Structural elucidation of an exopolysaccharide from mycelial fermentation of a Tolypocladium sp. fungus isolated from wild Cordyceps sinensis
2009; Elsevier BV; Volume: 79; Issue: 1 Linguagem: Inglês
10.1016/j.carbpol.2009.07.047
ISSN1879-1344
AutoresJing‐Kun Yan, Lin Li, Zhao Mei Wang, Jian‐Yong Wu,
Tópico(s)Microbial Metabolites in Food Biotechnology
ResumoA novel polysaccharide designated EPS-1A with an average molecular weight around 40 kDa was fractionated and purified by anion-exchange and gel-filtration chromatography from the crude exopolysaccharide (EPS) isolated from fermentation broth of Cs-HK1, a Tolypocladium sp. fungus isolated from wild Cordyceps sinensis. The structural characteristics of EPS-1A were determined with various methods (e.g. GC, GC–MS, FT-IR, 1H NMR and 13C NMR) and through acid hydrolysis, methylation, periodate-oxidation and Smith degradation. The results suggested that EPS-1A was composed of glucose, mannose and galactose at 15.2:3.6:1.0 M ratio. EPS-1A was a slightly branched polysaccharide and its backbone was composed of (1 → 6)-α-d-glucose residues (∼77%) and (1 → 6)-α-d-mannose residues (∼23%). Branching occurred at O-3 position of (1 → 6)-α-d-mannose residues of the backbone with (1 → 6)-α-d-mannose residues and (1 → 6)-α-d-glucose residues, and terminated with β-d-galactose residues.
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