【作者】 聂金媛；

【导师】 李志良；

【作者基本信息】 重庆大学 ， 分析化学， 2004， 硕士

【摘要】 本论文将微波辅助提取新技术应用于茯苓水溶性多糖、柴胡多糖和桑叶多糖的提取,寻求最佳提取工艺。采用均匀设计和正交设计优化实验条件,借助苯酚-硫酸显色法和蒽酮-硫酸显色法测定样品多糖含量。另外,还将超声辅助提取技术、回流法、索氏提取法与微波辅助提取法进行比较。对实验结果进行了统计分析或直观分析,得到其最优条件下的提取率成倍高于常规的提取法,同时大大缩短了提取时间。本文的主要内容和研究结果如下:1. 茯苓多糖微波辅助提取新工艺及均匀实验实验优化。根据所得实验数据进行直观分析和多元非线性分析,得到四变量回归方程,找到最佳提取条件为:时间:18min;微波占空比42%;固液比:1:50,此时提取率为2.79%。与传统回流提取率最高的一组相比,时间大大缩短,提取率也远远超过传统法;与超声提取相比,只用不到一半的时间,提取率提高63.5%;另外,与文献中的酶法(时间:100min,温度:100℃,提取两次,加酶,提取率:2.4%)相比,提取时间明显缩短,提取率也相当,不论在节能还是在高效方面微波提取都优于酶法提取。2. 柴胡多糖的几种提取方法比较及实验优化。采用回流、超声和微波辅助提取柴胡多糖,并对几种提取方法都进行了均匀实验优化。在微波辅助提取法中,多糖提取率最高为28.46mg/g,其优化实验条件为:液固比8倍,乙醇浓度为 60%,微波输出时间百分比为44%,加热时间为10min。提取的时间相比起超声法要短13分钟,而比起传统的索氏提取法,所需时间更是大大缩短。3. 微波辅助提取桑叶多糖及实验优化。采用微波辅助提取法、超声提取法和回流法提取桑叶多糖,并对微波法进行了均匀实验设计、对超声法和回流法进行了正交实验设计。用超声提取法和微波辅助提取法提取桑叶多糖从提取时间、提取次数到所得多糖提取率都相当,但比起传统回流法,微波提取法优势明显。与茯苓和柴胡多糖的提取相比,用微波法提取桑叶多糖相对于其他提取方法(回流法和超声提取法)所表现的优势没有那么明显。4. 对水解前后的微波提取多糖衍生物用毛细管电泳检测。毛细管电泳对微波提取的多糖极其水解单糖的衍生物的分析说明,微波辅助提取所得的产物杂质较少,比较纯净。因而可以说,微波辅助提取法应用与中草药有效成分的提取(特别是微量组分或残留组分的提取)能够大大缩短提取时间,节约溶剂、得到理想的提取物,并且在省时、节能的同时得到较高的多糖提取率。更多还原

【Abstract】 Microwave-Assisted Extraction (MAE) as a novel technique is applied in this dissertation to extract the water-soluble pachyman from poria cocos, the Polysaccharide from Bupleurum chinense and mulberry leaf. MAE is a process of using microwave energy to heat solvents in contact with a sample in order to partition analytes from the sample matrix into the solvent. Uniform design and Orthogonal array design is used to optimize the MAE condition. Quantitative determination of Polysaccharide is undergone by phenol-sulfuric acid method and anthratone-acid method. Additionally, Ultrasonically Assisted Extraction (UAE) and Soxhlet extraction are studied as comparative extract techniques. Statistic analysis and intuitionistic analysis to the experimental data shows that the ability to rapidly heat the sample solvent mixture is inherent to MAE and the main advantage of this technique. The main contents and some conclusions are provided as follows:1. Extraction of the water-soluble pachyman from poria cocos using MAE. Uniform design is applied to find the optimal conditions. The extraction rate was 2.792% under the optimal condition(Extraction time:18min;power of macrowave:42%×800;ratio of solid to liquid:1:50), which is remarkably higher than that of traditional method(which is 1.353% only) and that of UAE(which is 1.706%). Compared with the method added enzyme in reference(extraction time: 100min,temperature:100℃,extraction rate:2.4%), the extraction rate of MAE process is comparable and the time it takes is also greatly shortened. 2. Extraction of Polysaccharide from Bupleurum chinense using MAE, UAE and Soxhlet extraction, in which Uniform design is applied to find the optimal conditions. The extraction rate was 28.46mg/g under the optimal condition in MAE process. The results indicated that the extraction rate of MAE under the optimal conditions was remarkably higher than traditional or ultrasonic-assisted extraction. The extraction time of MAE was greatly shortened as well.3. Extraction of Polysaccharide from mulberry leaf by MAE, UAE and traditional extraction method. Uniform design and orthogonal array design are used to find the optimal conditions. UAE technique is comparable with MAE process in extraction rate and extraction time. But the advantage of MAE is obviously when compared with traditional method. However, the advantages relative to other extraction techniques are <WP=6>not so obvious as the extraction of polysaccharide from poria cocos and Bupleurum chinense.Polysaccharide extracted from poria cocos, Bupleurum chinense and mulberry leaf is furthered separated and analyzed by Capillary electrophoresis after sample preparation and derivation. The results show that the MAE process is rational and confirmed to be efficient, which should be considered to be an excellent technique of sample preparation, extraction of micro-component from Chinese herb and extraction of pesticide residue from soil matrix.更多还原