报告题目：Subcritical Water Extraction of Active Pharmaceutical Ingredients from Medicinal Herbs

报告时间：2017年5月25日（周四）9:00-10:30

报告地点：南校区第四教学楼204室

报 告 人： Professor Yu Yang

           Director of Chemistry Graduate Studies, East Carolina

           University, USA

主 持 人：侯晓虹

主办单位：制药工程学院 化学工程与技术分学位委员会

研究生处（学科建设办公室）

           辽宁省研究生现代药物领域创新与交流中心

           国际交流处

报告人简介:

Dr. Yu “Frank” Yang is a Professor and Director of Chemistry Graduate Studies at East Carolina University, located in Greenville, North Carolina, USA. East Carolina University is the third largest university in North Carolina and one of the campuses of the University of North Carolina (UNC). Dr. Yang received his Ph.D. in Chemistry from University of Mainz, Germany in 1993. He joined the Department of Chemistry at East Carolina University as an assistant professor in 1997, tenured in 2003, and promoted to full professor in 2007.

Dr. Yang's group is the international leader in the field of comprehensive subcritical water research. His principal areas of interest and expertise include pharmaceutical analysis, green chemical processes, environmental chemistry, subcritical water chromatography and extraction, solubility and stability of organics in subcritical water. The main goal of Dr. Yang’s research programs is to eliminate or minimize the use of toxic organic solvents in extraction, chromatography, environmental remediation, and other chemical processes. Honors include the University Five-Year Achievement for Excellence in Research Award, the Sigma Xi Helms Research Award, the University of North Carolina Board of Governors Distinguished Professor for Teaching Award, the Scholar-Teacher Award, Cottrell College Science Awards from Research Corporation, and the Starter Grant Award from the Society for Analytical Chemists of Pittsburgh. 

报告内容简介:

Subcritical Water Extraction of Active Pharmaceutical Ingredients from Medicinal Herbs

Due to its green nature and low side effects, herbal medicine has gained much greater attention in the western world. Both raw and pre-prepared herbal medicines and dietary supplements are sold in many developed countries, especially in the United States. It is estimated that around 60% of American adults are currently taking at least one herbal medication or herbal supplement.

The traditional way for patients to take the herbal medicine prescribed by doctors has been to cook the herbs in boiling water for 60 to 90 min and then drink the “medicinal soup.” This herbal medicine preparation method is called traditional herbal decoction (THD). Although this herbal decoction method has been used since ancient times, there are several major problems associated with the THD method. Therefore, a scientifically rigorous path for modernization of herbal preparation techniques is of great interest. It is important not only to simply mimic THD, but also to improve the efficacy of the herbal medicine than that prepared by THD.

Subcritical water refers to high-temperature and high-pressure water under conditions lower than water’s critical point, 374 °C and 218 atm. Water at elevated temperatures acts like an organic solvent due to its weakened hydrogen bonds and decreased polarity. The solubility of organic compounds such as active pharmaceutical ingredients in medicinal herbs is dramatically enhanced by simply increasing the water temperature. This unique characteristic of water makes high-temperature water an excellent extraction fluid for efficient removal of organics from various sample matrices, including medicinal herbs. Because different temperatures can be employed to carry out subcritical water extractions, there will be an optimized temperature that yields the highest concentration of active pharmaceutical gradients and in turn produces the most potent herbal medicine.

In this work, an important Chinese medicinal herb, Dan Shen, was extracted using subcritical water. The extractions were carried out at 75, 100, 125, and 150 °C. The temperature and kinetic effects on the extraction efficiency of the active pharmaceutical gradients from Dan Shen will be presented and discussed. The toxicity of the herbal extracts at different temperatures will also be evaluated and presented.