不同部位鱼腥草多糖的结构表征与生物活性

Structure Characterization and Biological Activity of Polysaccharides from Different Parts of Houttuynia cordata Thunb

鱼腥草是我国传统的药食同源植物,其富含的多糖已被证明具有多种生物活性。目前,关于鱼腥草多糖的研究多集中在全株或地上部分,不同部位鱼腥草多糖结构与活性的差异鲜有报道。本研究对鱼腥草的地下茎、茎和叶3个部位的多糖分别进行提取分离,并测定其结构、体外抗氧化活性和α-葡萄糖苷酶抑制活性,旨在探究鱼腥草多糖结构与生物活性的关系。结果表明,鱼腥草3个部位的多糖均为酸性多糖,均由葡萄糖、半乳糖、阿拉伯糖、鼠李糖、半乳糖醛酸以及少量的岩藻糖、甘露糖、木糖和葡萄糖醛酸组成,但比例各不相同;分子质量范围是4.11×10^(4)~1.20×10^(6)u;红外结构基本相同;叶多糖具有较多的甲酯基和乙酰基基团,其含量分别为0.95%和1.05%;3种多糖的表面形态均为光滑平整的片状结构;叶多糖不具有三螺旋结构而地下茎多糖和茎多糖存在三螺旋结构。叶多糖的体外抗氧化活性与α-葡萄糖苷酶抑制活性最强。试验发现不同部位鱼腥草多糖的结构和生物活性存在差异,研究结果为鱼腥草多糖的构效关系研究提供了理论依据,并为鱼腥草多糖的开发和利用提供理论参考。

Houttuynia cordata Thunb(H.cordata)is a medicinal and edible homologous plant.The abundant water-soluble polysaccharides of H.cordatahave been proved to have a variety of biological activities.However,the current research on polysaccharides from H.cordata mainly focuses on the whole plant or aboveground parts.The differences in the structure and activity of polysaccharides from different parts of H.cordataare rarely reported.In this study,the polysaccharides from the rhizome(RHCP),stem(SHCP)and leaf(LHCP)of H.cordata were extracted and separated,and their structural characterization,antioxidant activity in vitro andα-glucosidase inhibitory activity were determined.The aim was to explore the relationship between the structure and biological activity of H.cordata polysaccharides(HCPs).Results showed that polysaccharides in different parts of H.cordata were acidic polysaccharides,which were composed of glucose,galactose,arabinose,rhamnose,galactose uronic acid,and a small amount of fucose,mannose,xylose,and glucuronic acid,but the proportions are different;The molecular weight was 4.11×10^(4)u to 1.20×10^(6)u;The infrared structure was basically the same;LHCP had higher content of methyl and acetyl groups,and their contents were 0.95%and 1.05%respectively;The surface morphology of the three polysaccharides was smooth and flat;LHCP was not triple helix polysaccharide,while RHCP and SHCP existed triple helical structure.The in vitro antioxidant andα-glucosidase inhibition ability of LHCP were the strongest.It was found that the structure and activity of polysaccharides from different parts of H.cordata were different,providing a theoretical basis for the study of the structure-activity relationship of HCPs and providing a theoretical basis for the development and utilization of HCPs.