九华黄精炮制前后多糖类成分结构变化研究

目的 研究九华黄精酒制和九蒸九晒炮制前后多糖类成分的结构差异.方法 采用水提醇沉、透析纯化得到九华黄精生药材及其炮制品多糖,苯酚硫酸法测定总多糖含量,高效凝胶渗透色谱法、气相色谱法和红外光谱法解析炮制前后多糖分子量、单糖组成及结构差异.结果 与生黄精相比,酒制和九蒸九晒黄精多糖含量分别降低20.94％、26.51％.生黄精多糖的分子量为5.34 kDa,酒制和九蒸九晒后多糖分子量增大;九华黄精炮制前后多糖均由半乳糖、半乳糖醛酸、葡萄糖、甘露糖、鼠李糖组成,酒制黄精半乳糖醛酸含量比生黄精降低11.1％,而鼠李糖含量增加了5.31％.3种多糖均是含有β-糖苷键的吡喃环杂多糖,与生黄精相比,酒制和九蒸九晒后分别有19.64％和15.72％羧基发生了酯化.结论 与生黄精相比,酒制和九蒸九晒黄精在多糖含量、分子量、单糖组成、酯化程度等方面均发生不同程度的变化,该结果 为黄精的炮制过程及活性研究提供参考.

Structural Change of Polysaccharide Constituents from Polygonatum cyrtonema in Jiuhua Mountain after Processing

Objective To investigate the structural change of polysaccharides from Polygonatum cyrtonema in Jiuhua Mountain after processing with wine or nine times of steamed and sun-bathed processing.Methods Water extraction,ethanol precipitation,dialysis,and purification were performed to obtain polysaccharides from the crude drug and processed product of P.cyrtonema;the phenol-sulfuric acid method was used to measure the content of total polysaccharides;high-performance gel-permeation chromatography,gas chromatography,and infrared spectroscopy were used to investigate the changes in the molecular weight,monosaccharide composition,and structure of polysaccharides after processing.Results Compared with crude P.cyrtonema,the content of polysaccharides was reduced by 20.94%after processing with wine and 26.51%after nine times of steamed and sun-bathed processing.The molecular weight of polysaccharides from crude P.cyrtonema was calculated to be 5.34 kDa,and there was an increase in molecular weight after processing with wine or nine times of steamed and sun-bathed processing.The polysaccharides of P.cyrtonema were mainly composed of galactose,galacturonic acid,glucose,mannose,and rhamnose before and after processing;after processing with wine, the content of galacturonic acid was reduced by 11.1%, while the content of rhamnose was increased by 5.31%. The three polysaccharides were heteropolysaccharides with a pyran ring containing the β-glycosidic bond, and after processing with wine or nine times of steamed and sun-bathed processing, esterification was observed in 19.64% and 15.72%, respectively, of the carboxyl. Conclusion Polygonatum cyrtonema show varying degrees of changes in the content, molecular weight, monosaccharide composition, and esterification degree of polysaccharides after processing with wine or nine times of steamed and sun-bathed processing, which provides a reference for the research on the processing and activity of P. cyrtonema .