天然产物化学提取.pptx

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1、Initial and Bulk ExtractionBy Veronique Seidel 汇报人：曾谛Content1.Introduction2.Method Extraction of Plant Natural Products3 Conclusion1 IntroductionInterest：Mol2000 Secondary metabolitesFrom：Plants,Microbes,marine organisms,insects,and amphibia.Since different physicochemical properties,different metho

2、ds be used in this chapter2.1.Extraction of Plant Natural ProductsVarying polarities and different functional groupsE.g.waxes and fatty acids,polyacetylenes,terpenoids sesquiterpenoids,diterpenoids,triterpenoids),steroids,essential oils,phenolics,alkaloids,and glycosidic derivativesMethod:maceration

3、,percolation,Soxhlet extraction,pressurized solvent extraction,ultrasoundassisted solvent extraction,extraction under reflux,and steam distillation.2.1.1.Preparation of Plant MaterialSELECTION:1.plants are used to treat diseases.2.related to the plant 3.particular group of natural products2.1.1.Prep

4、aration of Plant MaterialCOLLECTION AND IDENTIFICATION:The whole plant or a particular plant part Healthy specimensthe age of the plant and environmental conditions2.1.1.Preparation of Plant MaterialDRYING AND GRINDING:Contains volatile or thermolabile compounds:snapfreeze,wash,Grind in a mortar wit

5、h liquid nitrogenUsual:dry on trays at ambient temperature and in a room with adequate ventilation.dried in an oven;Storage for short periods.2.1.1.Preparation of Plant MaterialDRYING AND GRINDING:Aim of grinding:increasing the surface areafacilitating the penetration of solvent into the cells2.1.2.

6、Range of Extraction MethodsMACERATION:room temperatureusing mechanical shakers or mixers to guarantee homogenous mixingDisadvantage:time-consuming consume large volumes of solvent 2.1.2.Range of Extraction MethodsULTRASOUND-ASSISTED SOLVENT EXTRACTION:through the production of cavitations instrument

7、 frequency,and length and temperature of sonicationrarely applied to large-scale extraction2.1.2.Range of Extraction Methods PERCOLATION:clog the percolatormaterial is not distributed homogenously Temperature2.1.2.Range of Extraction MethodsSOXHLET EXTRACTION:Less-time and solvent-consumingheated2.1

8、.2.Range of Extraction Methods(ASE)PRESSURIZED SOLVENT EXTRACTION:the rapid and reproducible initial extractionHigh temperatures High pressures 2.1.2.Range of Extraction MethodsEXTRACTION UNDER REFLUX AND STEAM DISTILLATIONplant essential oils thermolabile components being degraded.2.1.3.Selection o

9、f an Extraction Method and Solventa low potential for artifact formation,a low toxicity,a low flammability,a low risk of explosion.Economicalwater-miscible or water-immiscible2.1.3.Selection of an Extraction Method and Solvent nonpolar solvents:alkanes,fatty acids,pigments,waxes,sterols,some terpeno

10、ids,alkaloids,and coumarinspolarity some alkaloids,flavonoidspolar compounds flavonoid glycosides,tannins,some alkaloidssolvents of increasing polarity2.1.3.Selection of an Extraction Method and SolventpHE.g.alkaloids produce some artifacts lead to the degradation of compounds a solvent mixtureSoxhlet extraction3.Conclusion“Classic solvent-based procedures lack reproducibility and are both time-and solvent-consuming.Find new resource