【作者】 李红茹；

【导师】 李淑芬；

【作者基本信息】 天津大学 ， 化学工艺， 2008， 博士

【摘要】 超临界流体萃取技术是环境友好且高效节能的新的化工分离技术,是中药现代化的关键技术之一;中药雷公藤具有免疫抑制的作用,通过传统提取工艺得到的提取物毒副作用较大,主要有效成分含量低;本论文研究利用超临界流体萃取技术提取并分析雷公藤有效成分的可行性,同时对雷公藤药物的新剂型进行了研究,这对提高药物的药效和促进中药产业的现代化和国际化,具有重要的意义;本课题还对溶质在超临界流体中的溶解度进行了理论研究,该理论研究对超临界流体萃取的工艺设计具有指导作用。首先,采用超临界CO₂结合静态夹带剂萃取的方法对雷公藤有效成分的萃取进行了研究。实验以有效成分雷公藤甲素、雷公藤总生物碱以及毒性成分雷公藤红素的收率以及在浸膏中的质量分数为指标,分别对夹带剂种类与组成、萃取温度、萃取压力、静态浸泡时间等因素进行了考察。实验结果表明,当75%乙醇水溶液为夹带剂、萃取温度为43℃、萃取压力为25 MPa、静态萃取时间为3 h时,超临界流体萃取雷公藤甲素收率是传统工艺95%乙醇回流提取?氯仿萃取方法的3.49倍。色谱指纹图谱的分析表明,超临界流体萃取工艺稳定,批次之间的相似度在0.95¹.0之间;雷公藤超临界提取物的体外以及体内的药理和毒理实验结果表明:雷公藤超临界流体萃取物的药效为市售药物的3⁴倍,毒性只是其1/2。在上述超临界CO₂结合静态夹带剂萃取的基础上,采用超临界CO₂结合高压溶剂萃取的方法对雷公藤甲素的萃取工艺进行进一步研究,考察溶剂的种类、加入方式以及用量,萃取温度,萃取压力对萃取的影响,结果表明:以85%乙醇溶液为高压溶剂,采用预浸?连续加入溶剂的方式,当萃取温度为50℃,萃取压力为25 MPa时,雷公藤甲素的提取率是超临界CO₂结合静态夹带剂萃取的1.25倍,但是该方法所用的有机溶剂量为超临界CO₂结合静态夹带剂萃取的31倍,对设备的要求也更高,其工业可行性需要进一步探讨。为了进一步降低超临界CO₂结合静态夹带剂萃取得到的提取物的毒性,本文还将雷公藤复杂提取物制备成脂质体并测定提取物中的主要成分的包封率。研究中采用薄膜?超声法制备脂质体,考察工艺参数以及处方组成对提取物中雷公藤红素以及雷公藤总生物碱包封率的影响。实验结果表明,在优化的工艺条件下,雷公藤红素和雷公藤总生物碱的包封率都较高,可分别达到98.18%和88.63%。另外,本文还以超临界CO₂结合静态夹带剂萃取作为样品前处理手段,建立雷公藤药材中雷公藤红素的快速分析方法。通过考察夹带剂种类、萃取温度、萃取压力、萃取次数以及夹带剂用量对雷公藤红素萃取的影响,优化了前处理条件。该方法大大减少了有机溶剂的用量和萃取所用的时间,回收率范围达到90.5%¹03.2%,检测限和定量限分别为2.2μg/mL和7.36μg/mL,符合分析的要求。最后,对脂肪酸、脂肪醇、脂肪酸酯以及甘油三酯类物质在超临界CO₂中的溶解度进行了研究,采用Chrastil方程对溶质在超临界CO₂中的溶解度进行关联,首次建立了溶质的分子连接指数（MCIs）与Chrastil方程中的参数的线性关系,对溶质在超临界CO₂中的溶解度进行预测,该预测过程不需要溶质的具体物化性质,只通过简单的计算,即可对物质在超临界CO₂中的溶解度在数量级范围内进行估算。更多还原

【Abstract】 Supercritical fluid extraction （SFE） is one of the key technologies used in modernization of traditional Chinese medicine. It is environment friendly and efficient energy saving. Tripterygium Wilfordii Hook.f. （T.Wilfordii） is a kind of traditional Chinese medicine, which has immunosuppressive effect. The extracts derived from traditional methods have severe toxic and side effects and the content of the main active component in the extracts is very low. So in this article, the SFE was applied in the extraction and analysis of the active components in T.Wilfordii. Meanwhile, the new dosage form of the extract of T.Wilfordii was also investigated. These researches can improve the efficacy of the medicine and promote the modernization and internationalization of traditional Chinese medicine industry. The theoretical research on the solubility in supercritical fluid was also done. This theoretical research has the guiding role for the process design of SFE.The supercritical carbon dioxide （SC-CO₂） modified with static co-solvent extraction was used to extract the active components from T.Wilfordii. Taking the yield and content of triptolide, total alkaloids and tripterine as quality indexes, Some influence factors such as co-solvent variety and its composition, the extraction temperature, pressure and the static soak time were studied. The experimental results show that when 75% ethanol as co-solvent is used for 3 h of static soak time under the extraction temperature of 43℃and pressure of 25 MPa, the yield of the main active component triptolide is 3.49 times as much as that of the traditional method of 95% ethanol reflux extraction-chloroform extraction. The results of chromatographic fingerprint of the SFE extract show that the extraction by the SC-CO₂ modified with static co-solvent is stable and the similarity of ten batches of SFE extracts is between 0.95 and 1.00. The results of pharmacological experiments in vivo and in vitro show that the efficacy of SFE extract is 3⁴ times as much as that of the drugs while the toxicity of SFE extract is only one half of that of the drugs on sale.Based on the above extraction results, triptolide in the plant was further extracted with SC-CO₂ combined with high-pressure solvent. The effect of variety of co-solvents, adding modes and usage, extraction temperature and pressure were investigated. The results show that, the yield of triptolide is 1.25 times higher than that of SC-CO₂ modified with static co-solvent extraction when the operation parameters are as follow: the ratio of 85% ethanol solution added to the raw material is 1 mL/g in the presoak stage, the flow rate of SC-CO₂ is 1.5 L/min, the flow rate of co-solvent of 85% ethanol, 1 mL/min, the extraction temperature, 50℃, extraction pressure,25 MPa, 15 min of presoak, and 30 min of extraction time. As this process needs a large amount of solvent, its feasibility should be investigated further.In order to reduce the toxicity of the SFE extract of T.Wilfordii, the complicated extracts were entrapped into liposomes by thin film-dispersion method. The effects of process parameters and composition of prescription on the entrapment efficiency of tripterine and total alkaloids were studied. The results showed that the entrapment efficiency of tripterine and the total alkaloids are respectively 98.10% and 88.63% under the optimum conditions.The SC-CO₂ modified with static co-solvent extraction was also used as pretreatment method in the determination of tripterine in T.Wilfordii. The pretreatment process was optimized by investigating the effects of co-solvent variety, extraction temperature, extraction pressure, extraction times and usage of co-solvent on the yield of tripterine. This method reduced the consumption of the organic solvent and time. Recovery of tripterine for SFE varies from 90.5% to 103.2% for samples with different content levels. The limit of detection and quantification are 2.2μg/mL and 7.36μg/mL. All the other indexes also satisfy the analytical requirements.Finally, the solubility of fatty acids, fatty alcohols, fatty esters and triglycerides in SC-CO₂ was studied. In this research, the linear relationship between the parameters in Chrastil’s equation and the solutes’molecular connectivity indices （MCIs） was built. So the solutes’solubility can be estimated only by their MCIs. This method is proved to be simple and can estimate the solubility in the order of magnitude.更多还原