碱提工艺对茶树菇多糖形貌特征和构象及其生物活性的影响

Morphology and conformation of polysaccharide from Agrocybe aegerita and its antioxidant activity

利用传统水提及碱提的方法得到茶树菇粗多糖S-ACP和J-ACP,经CTAB法和Sephadex G-150凝胶层析法对其分离纯化,分别得到S-ACP2-1和S-ACP2-2以及J-ACP2-1和J-ACP2-2两组主要组分,用扫描电子显微镜(SEM)和原子力显微镜(AFM)对多糖的形貌进行表征并测定其体外抗氧化活性和抗肿瘤活性;对多糖S-ACP2-2、J-ACP2-2进行刚果红实验测定及圆二色谱仪(CD)分析。SEM观测结果:S-ACP2-1为较粗的表面光滑的丝状,J-ACP2-1呈较细的有少量碎屑的丝状;S-ACP2-2为较大的片状,J-ACP2-2在大的片状周围有很多细小的碎屑。AFM观测结果:碱液可以使多糖分子部分断裂成小片段。刚果红实验:S-ACP2-2、J-ACP2-2在水溶液中为自由卷曲构型。CD分析:S-ACP2-2的空间构型中有序结构较少,J-ACP2-2在水溶液中为无序构型。对比4种多糖的活性,碱液作用的多糖J-ACP2-2活性高于S-ACP2-2。

A polysaccharide named S-ACP was extracted from Agrocybe aegerita by hot water extraction,after that, a polysaccharide named J-ACP was isolated from the dried leaf mustard with alkali. The crude polysaccharides were purified by CTAB and Sephadex G-150 in sequence, and the obtained ones were designated as S-ACP2-1, S-ACP2-2 ,J-ACP2-1 and J-ACP2-2 ,respectively. SEM and AFM were used in characterizing the morphology of the polysaccharide, and AFM was used to observe in vitro antioxidant and anti-tumor activities. Polysaccharide S-ACP2-2 and J-ACP2-2 were used for Congo red test and CD analysis. SEM showed that S-ACP2-1 and J-ACP2-1 existed in filamentous form, S-ACP2-2 and J-ACP2-2 existed in sheet form, S-ACP2-1 had stronger rigidity than J-ACP2-1, and the sheet of S-ACP2-2 was bigger than that of J-ACP2-2. AFM images showed that： the alkali could make a portion of the polysaccharide molecule break into small pieces. The conformations of S-ACP2-2 and J-ACP2-2 were studied by complex-formation with Congo red, result showed that the conformations were mainly in disorder coli in water solution. The CD spectrum showed that only a little of ACP2-2 was in ordered structure in the spatial configuration and J-ACP2-2 was in disordered conformation in aqueous solution. Comparison of activities of four kinds of polysaccharides, J-ACP2-2 treated with alkaline had stronger activity.