葛根化学及生物活性物质的分离、纯化

【作者】 徐燕；

【导师】 黄继轸； 宛晓春；

【作者基本信息】 安徽农业大学 ， 茶学， 2003， 硕士

【摘要】 葛是豆科植物，我国大部分地区都有分布，喜温暖、潮湿的环境。其品种主要分为粉葛、野葛二种。粉葛富含淀粉，是重要的食材及食品添加剂；野葛中富含异黄酮类物质，具有重要的药理功能和药用价值。异黄酮是医药和化工工业的稀缺原料，葛根富含异黄酮，且葛是速生植物，适于大面积的种植。鉴于国内葛根资源丰富，国内国际市场的需求旺盛，而现有加工提取技术尚存在许多不完善之处，本文对葛根异黄酮制备及纯化过程中的技术环节进行了较为系统的研究，研究结果表明： 1．在葛根黄酮提取过程中，pH值、温度、溶剂种类、溶剂浓度对葛根黄酮总浸出率影响较大。pH小于4或pH大于8均不利于葛根黄酮提取；随着温度升高，葛根黄酮浸出率逐渐增大，但考虑到温度过高，可能会破坏葛根异黄酮的结构，所以温度控制在85℃左右，既有利于黄酮的浸出，又不致破坏黄酮的结构，使其变性；溶剂种类和溶剂浓度对浸提效果影响较大，综合比较认为乙醇提取优于水提（浸出率低），乙醇浓度若在50％以下，浸提后溶液不利于过滤，乙醇浓度过大（95％以上），黄酮浸出率很低，乙醇浓度以70-80％为宜。 2．正交实验结果表明浸提的优化工艺条件是：葛根粉碎过3号筛、用70％的乙醇溶液萃取、85℃、pH6、固液比1∶10、浸提2次、提取1小时。实验结果：固形物浸出率为19.85％，葛根粗粉的总黄酮百分含量为42％。葛根黄酮浸出率为92.0％。 3．葛根粗提物在萃取前经酶解或双相酸水解处理后，可提高下一步的萃取率。一般葛根粗提物经有机溶剂萃取4次后，基本萃取完全，固形物浸出率可达到50.86％，黄酮萃取率可达到80.85％。 4．葛根素结晶优化条件为：温度为10℃、固液比为1∶1.5、溶剂浓度为95％。在此条件下，葛根素的结晶率为36.5％、纯度为79.2％。 5．柱层析研究结果表明：聚酰胺柱、硅胶柱分离纯化葛根素的效果较好，氧化铝柱分离纯化效果不理想。分部收集液采用TLC或HPLC检测，葛根素产品的纯度达95％。 6．研究设计了葛根素制备工艺。 7．对制备的葛根素样品做了光谱分析(质谱图、IR光谱图、¹HNM谱图、¹³CNMR谱图)，检测结果与葛根素标准图谱及波谱数据一致。更多还原

【Abstract】 Pueraria Lobata is a kind of leguminous plant. It distributes in most districts of China and grows in warm and moist surroundings. It can be divided into Pueraria lobata (wild) Ohwi and Pueraria thomsonii Benth. Pueraria Thomoni Benth is rich of starch, which is a kind of important source of food material and additive. Pueraria isoflavones are blieved to have significant pharmaceutical functions to human health.Isoflavones are a kind of scarce raw materials of medicine and chemical industries. Radix Pueraria contains rich isoflavones. Pueraria Lobata is a kind of rapidly growing plant, which is suitable for extensive implantation. Since the rich resources of Pueraria in our country, Pueraria flavonoids are eagerly needed in either domestic or the international markets, while the extraction and prification techniques are needed to be improved at present. We report here the studies on the extraction and purification of the isoflavones from Radix Pueraria and preparation of pury Puerarin.As the results:1. In the course of Pueraria isoflavones extraction, pH value, temperature, solvent and consistency of solvent affected the macerating efficiency. The bad efficiency was monitored when pH value of solution was lower than 4 or higher than 8. As for the temperature, it indicated that the higher temperature was, the higher macerating efficiency was. However, the high temperature over 85Cmay destroy the structure of isoflavones. By comprehensive corporations, it showed that extract with alcohol was better than that with water. The extract was difficult to be filtered when the content of alcohol was lower than 50%, and lower macerating efficiency when the content of alcohol was higher than 95%. The suitable consistency of alcohol was about 70-80%.2. By the orthogonal experiments, the optimum macerating conditions we acquired were pulverized and powdered the samples before extraction, 70% alcohol, 85 C, pH6-8, Ihr, 2 times, solid/liquid 1: 10. In such conditions, the yield, the content of products and the macerating efficiency were 19.85%, 42.00%, and 92.0% respectively.3. By hydrolyzed of alcohol extract with enzymes or 5% HC1 in two-liquid-system, the extract efficiency was monitored increased a little. After extracted for four times, the Pueraria isoflavones was almost completely extracted. The yields and the purity were up to 50.86% and 60.85% respectively.4. The crystallization conditions for Pueraria isoflavones were optimized to be 10C , 95% consistency of solvent, solid/liquid 1: 1.5. The yield and the purity were 36.5% and 79.2% respectively.5. The poliamid column chromatography was shown to be better than Silica gel and Al2O3 for the isolation of Puerarin, and both the HPLC and TLC could be settled to monitor the elutes from column chromatography. By the poliamidcolumn chromatography, the content of Puerarin in the elute was up to 95%.6. We designed a preparation process for Puerarin.7. We carried out the spectral analyses (MS, IR, 1HNMR, 13CNMR) of our product. Our product was conformed to be Puerarin by comparing the charts and data with that of the standard atlas and the document data.更多还原