鸡腿菇多糖WCP3a的抗氧化活性与空间结构的关系

摘要

研究鸡腿菇多糖WCP3a的体外抗氧化活性与空间结构的关系。邻苯三酚自氧化法检测结果表明,在实验质量浓度范围内,鸡腿菇多糖WCP3a对超氧阴离子自由基（O-2.）有一定的清除作用,并且当多糖质量浓度为0.6mg/mL时对O-2.的清除效果最明显;刚果红实验和原子力显微镜技术检测结果表明,鸡腿菇多糖WCP3a为单股螺旋结构;用不同浓度NaOH溶液处理WCP3a,产生不同空间构象的多糖样品WCP3a-0.2和WCP3a-0.4,检测两者清除O-2.的能力,与WCP3a对比发现,WCP3a-0.2和WCP3a-0.4对O-2.的清除效果均优于WCP3a,且WCP3a-0.4的清除能力最强;原子力显微镜观测结果发现,NaOH碱性环境使缠绕成股的多糖分子逐渐解聚,且不同浓度NaOH溶液对多糖裂解程度不同。鸡腿菇多糖WCP3a的体外抗氧化活性与其空间结构关系更密切。%The in vitro antioxidant activity and structure-antioxidant activity of polysaccharide WCP3a isolated from Coprinus comatus were explored in this study.The polysaccharide revealed an obvious scavenging effect against superoxide anion free radicals generated from pyrogallol self-oxidation.Meanwhile,the polysaccharide at the concentration of 0.6 mg/mL had the strongest scavenging activity against superoxide anion free radicals.The single-helix structure of the polysaccharide was determined by Congo red test and atomic force microscopy.Moreover,the polysaccharide WCP3a treated with NaOH at various concentrations could generate WCP3a-0.2 and WCP3a-0.4 with different spatial configurations.The scavenging capacity of WCP3a-0.2 and WCP3a-0.4 against superoxide anion free radicals was much stronger than that of WCP3a.The atomic force microscopy（AFM） revealed that NaOH treatment could damage the spatial structure of the polysaccharide.Therefore,the antioxidant activity of WCP3a in vitro is highly correlated with its spatial structure.