Preparation and Characterization of a Novel Extrac

Authors: YanLi Chen WenJun Mao HongWen Tao WeiMing Zhu MengXia Yan Xue Liu TianTian Guo Tao Guo

Publish Date: 2015/01/28

Volume: 17, Issue: 2, Pages: 219-228

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Abstract

Marine fungi are recognized as an abundant source of extracellular polysaccharides with novel structures Mangrove fungi constitute the second largest ecological group of the marine fungi and many of them are new or inadequately described species and may produce extracellular polysaccharides with novel functions and structures that could be explored as a source of useful polymers The mangroveassociated fungus Fusarium oxysporum produces an extracellular polysaccharide Fw1 when grown in potato dextroseagar medium The homogeneous Fw1 was isolated from the fermented broth by a combination of ethanol precipitation ionexchange and gel filtration chromatography Chemical and spectroscopic analyses including one and twodimensional nuclear magnetic resonance spectroscopies showed that Fw1 consisted of galactose glucose and mannose in a molar ratio of 133133100 and its molecular weight was about 612 kDa The structure of Fw1 contains a backbone of 1 → 6linked βdgalactofuranose residues with multiple side chains The branches consist of terminal αdglucopyranose residues or short chains containing 1 → 2linked αdglucopyranose 1 → 2linked βdmannopyranose and terminal βdmannopyranose residues The side chains are connected to C2 of galactofuranose residues of backbone The antioxidant activity of Fw1 was evaluated with the scavenging abilities on hydroxyl superoxide and 11diphenyl2picrylhydrazyl radicals in vitro and the results indicated that Fw1 possessed good antioxidant activity especially the scavenging ability on hydroxyl radicals The investigation demonstrated that Fw1 is a novel galactofuranosecontaining polysaccharide with different structural characteristics from extracellular polysaccharides from other marine microorganisms and could be a potential source of antioxidant

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