Study on water extraction process of Herba epimedii with microwave technology / 中国中药杂志

<p><b>OBJECTIVE</b>To study, the high polar media-water extraction process of Herba epimedii with the microwave technology.</p><p><b>METHOD</b>The single parameters of extraction process was investigated with dry extract yield and extraction efficiency of icariin as content index.</p><p><b>RESULT</b>Through studying the single parameter, the optimal conditions are as follows: 70% ethanol as wetting solvent, volume of solvent to weight of material equal to 6:1 in wetting, 30 min wetting time, 2.5 min microwave irradiation time, volume of solvent to weight of material equal to 50:1 in extraction process, 10 min microwave-assisted extraction time.</p><p><b>CONCLUSION</b>Compared with conventional methods, microwave-assisted extraction (MAE) after Microwave Pretreament (MP) of raw material was higher extraction efficiency and time-saving.</p>

Changes in ultrastructure of fresh leaves of Ginkgo biloba after microwave-assisted extraction / 中草药

Object To study the ultrastructure destruction of plants in the process of microwave assisted solvent extracion and its mechanism.Methods Cell structures of fresh leaves of Ginkgo biloba L. were observed by transmission electron microscpoe.Results The cell structure changed when the leaves were under microwave radiation or soaked by solvents or heated, such as plasmoysis, destruction of cell organellaes, disappearance of starch grain and so on, while the cell wall was not broken both in microwave assisted solvent extraction and in traditional heating extraction.Conclusion Microwave radiation could lead to the relaxation of the cell structures, but not be enough to make the cell wall broken.

Comparison of three extraction methods to extract Zanthoxylum oil / 中成药

AIM: To extract Zanthoxylum oil from the seeds of Zanthoxylum bungeanum Maxin, and find out a better extraction method and its optimized operating conditions. METHODS: Zanthoxylum oil was extracted by distillation method, solvent extraction and supercritical fluid extraction, respectively. The products gained in each experiment was analyzed by GC after it had been methyl esterified. RESULTS: The yield of Zanthoxylum oil extracted by distillation, solvent extraction and supercritical fluid extraction was 0.88 %, 13.73 % and 13.52 %, respectively, and its content of unsaturated fatty acid 4.50 %, 65.97 %, 74.97 %, respectively. CONCLUSION: Supercritical fluid extraction was the better of the three mehtods, whose optimized operating conditions consisted of 30 MPa pressure, 50 ?C operating temperature and 5 h extraction time.