杏鲍菇多糖WPP2的结构表征及抗肿瘤活性

采用热水浸提法从杏鲍菇中提取粗多糖, 经纯化得到一种新的多糖WPP2.通过紫外光谱、色谱、质谱、核磁共振、红外光谱、环境扫描电子显微镜(ESEM)和原子力显微镜(AFM)等技术相结合的方法, 对WPP2结构进行了表征, 并对其体外抗氧化和抗肿瘤活性进行了初步探讨.结果表明, WPP2的平均分子量为4.499×10⁵, 主要由Glc组成, 每个重复单元存在2条支链,→1,2,3)-β-D-Manp和→1,2,6)-β-D-Manp位于支链位点, 支链由→1,6)-β-D-Glcp和→1,6)-β-D-Galp构成, 非还原末端基为→1)-β-D-Glcp, 主链主要由→1,3)-β-D-Glcp,→1,6)-β-D-Galp和→1,3)-β-D-Manp糖残基组成.刚果红实验结果表明其具有三螺旋结构; 用ESEM和AFM首次在纳米尺度观察到WPP2具有多分枝结构; 活性实验结果表明WPP2具有一定的抗氧化和抗肿瘤活性.

Structure Characterization and Antitumor Activity of Polysaccharide WPP2 from Pleurotus Eryngii

Polysaccharides are an important class of active components from Pleurotus eryngii with potential biological activities. Scince structure and functions are intimately related, an in-depth study of Pleurotus eryngii polysaccharides would be of interest. In this work, crude polysaccharides were extracted from Pleurotus eryngii by hot water and were further fractionated to give a new polysaccharide fraction termed WPP2. WPP2 was subjected to structural identification by means of UV, HPLC, GC, IR, GC-MS, NMR, ESEM and AFM. In addition, the antioxidant and antitumor activities of WPP2 were evaluated in vitro. The results revealed that WPP2 is rich in Glc with an average molecular weight of about 4.499×10⁵. The main chain of WPP2 was made up of→1,3)-β-D-Glcp,→1,6)-β-D-Galp, and→1,3)-β-D-Manp with two side chains.→1,6)-β-D-Glcp,→1,6)-β-D-Galp and terminal residue→1)-β-D-Glcp were linked to form side chains bearing→1,2,3)-β-D-Manp and→1,2,6)-β-D-Manp residues as branched points. Congo red reaction indicated that WPP2 has the triple-helical structure in aqueous solution. The multi-branched structure of WPP2 was detected at the nanometer scale by ESEM and AFM; the bioactivity analysis in vitro indicated that WPP2 possessed certain antioxidant activity and antitumor effect. The results suggested that the novel polysaccharide WPP2 could potentially be used as a new natural medicine, but the relation of structure and functions need further study.