【作者】 王洋；

【导师】 赵博；

【作者基本信息】 辽宁师范大学 ， 植物学， 2008， 硕士

【摘要】 天然植物中含有丰富的活性物质,被广泛用于药品、保健品和化妆品中。我国拥有丰富的中药资源,但中药提取物的国际市场占有率还不足5%。目前,我国中药提取物生产多采用乙醇、甲醇、丙酮等传统有机溶剂加热、回流提取,效率低,成本高,工艺复杂,难以提高商业价值。而且,多数有机溶剂具有毒性,污染环境,且易燃易爆,存在生产安全隐患。因此,如何实现药材的高效利用,开发绿色环保、低成本、技术成熟度高的提取技术无疑是一个亟待解决的问题。本研究采用机械化学法,以水作溶剂提取穿心莲内酯和银杏叶总黄酮。首先,筛选和确定了机械化学辅助提取的最佳助剂;其次,初步考察目标提取物与助剂间的作用情况并比较不同预处理方法对目标提取物的形态及提取率的影响;最后,在单因素试验基础上,通过正交试验优化提取工艺并与热回流提取比较。结果表明,经固态研磨后,穿心莲内酯及芦丁可能分别与最佳助剂Na2CO3、Na2CO3 & Na2B4O7反应成盐;芦丁可能与羟丙基-β-环糊精(HP-β-CD)形成复合物;以水作溶剂,机械化学法的提取率显著高于物理混合及超微粉碎辅助提取;物料的粒度及扫描电镜分析表明经机械化学处理后穿心莲及银杏叶的大部分细胞可能被充分破碎。机械化学辅助提取穿心莲内酯的最佳工艺为:Na2CO3用量3% (w/w),研磨时间为45min,水(乙醇浓度0%, v/v)作溶剂,料液比为1:60 g:ml。此时穿心莲内酯提取率为1.59%,比粗粉蒸馏提取率提高25.2%。机械化学辅助提取银杏叶中总黄酮的最佳工艺为:(1)碱作助剂。Na2CO3 & Na2B4O7用量9% (w/w),研磨时间35min(物料粒度D95≤37μm),乙醇浓度为20% (v/v),料液比为1:50 g:ml。以水替换乙醇,其提取率与乙醇提取相当。(2) HP-β-CD作助剂。用水提取,HP-β-CD用量18% (w/w),循环水温度60℃,研磨时间25min。最佳工艺条件下与热回流提取比较,以Na2CO3 & Na2B4O7及HP-β-CD作助剂的机械化学辅助提取,总黄酮提取率分别提高15.49%和18.90%,以水作溶剂,室温下提取,大大缩短了提取时间。更多还原

【Abstract】 Natural plant contains a diverse group of bioactive substances with a broad range of applications in medicine, healthcare product and cosmetic. China is rich in medical herb resources, but has a weak market share (less than 5%) for plant extract in the world market. At present, heat or heat reflux extraction with conventional organic solvents such as ethanol, methanol and acetone is widely used in the industrial-scale production of herb extracts in China. This method with limitations such as high cost and complex procedures required has greatly decreased the production efficiency and profits. Moreover, the requirements for hazardous organic solvents which is inflammable-explosive could also increase the probability of safety risks in production and environmental contamination. Therefore, environmental friendly and industry-ready technique with low cost and enhanced efficiency is required in order to accelerate the development of herb extract industry in China.The present study was focused on the mechanochemical assisted extraction (MCAE) of andrographolide and total flavone from Ginkgo bilobal with water as solvent. First, the chemical reagent was selected according to the yield of target compounds by MCAE; Second, a preliminary investigation was conducted on the interaction of the target compound-chemical reagent. Different pretreatment was compared with respect to their effects on the plant material morphology as well as the target compound yield. Finally, the MCAE process was optimized based on both orthogonal and one-factor experiment, and was compared with conventional heat reflux extraction.Preliminary investigation showed that andrographolide and lutin could possibly be neutralized by Na2CO3, Na2CO3 & Na2B4O7 respectively, and certain complexes may have been formed between lutin and hydroxypropyl-β-cyclodextrin (HP-β-CD) after the solid grinding process. The yield of MCAE treated samples (extracting with water) was significantly improved (P <0.05) comparing with physical mixing and superfine grinding samples. Both particle analysis and scanning electron micrographs suggested that the plant cell wall could be broken up after the mechanochemcal treatment.The optimum parameters for MCAE of andrographolide were as follows: Na2CO3 content, 3% (w/w); milling period, 45min; extraction solvent, water (0% v/v, aqueous ethanol); liquid/solid ratio, 1:60g:ml. The water extraction yield by MT is higher than that of heat reflux extraction from crude powder by 25.2%.The optimum parameters for MCAE of total flavone from Ginkgo bilobal were as follows: (1) alkali reagent. Na2CO3 & Na2B4O7 content, 9% (w/w); milling period ,45min(particle size, D95≤37μm); extraction solvent, 20% v/v aqueous ethanol; liquid/solid ratio, 1:50 g:ml. Aqueous ethanol was replaced by water, and no significant difference in yield was observed with other optimized parameters settings. (2) HP-β-CD reagent. HP-β-CD content, 18% (w/w); circulating water temperature, 60℃; milling period, 25 min. The water extraction yield by MT is higher than that of heat reflux extraction from crude powder by 15.49% and 18.90%.Under the optimized parameters determined herein, significant enhancement such as improved yield, shorter time and more simplified procedures over heat-reflux extraction was observed, which makes MCAE (a combination of physical and chemical method) a potential convenient tool for andrographolide and total flavone extraction from Ginkgo bilobal. Moreover, the favorable solvent is water, making MCAE a less expensive and eco-friendly technique.更多还原