17945 - Extraction of Drugs

Learning outcomes

The course consists of theorical lessons and experiments in laboratory. Major objectives of the practical experiences are improvement of skill in the technical aspects of laboratory work and introduction to techniques and procedures important for the extraction of the active principle from vegetable sources.

Course contents

The course provides an introduction to various techniques of extraction and purification of compounds of pharmaceutical interest, supplying the basic theorical-practical knowledge for the extraction of natural products, and for the isolation of active principles from several sources.
Theoretical lessons: Safety chemical laboratory. Techniques and equipments: glassware and equipment with interchanging joints of general use in preparative organic chemistry. Methods for cooling and heating of mixture. Technical methods for isolation, agitation and purification. Organic laboratory techniques: extraction, crystallization and precipitation. Filtering techniques: vacuum filtration, suction filtration; filters of depth and filters of surface. Extraction theory and equipment: solvent extractions of organic compounds from aqueous solutions, counter current distribution, liquid-liquid extraction; solid-phase extraction, microwave extraction. Basic principles for evaporation, distillation and drying, methods for drying solid compounds, devices for drying laboratory glassware and apparatus. Drying organic liquids or solutions, drying agents. Anhydrous reactions. Distillation principles: fractional distillation, vacuum distillation, steam distillation. Distillation equipments, rotary evaporator. Drying solvents by distillation. Separation techniques: Chromatography. Chromatographic separation techniques: column chromatography on silica gel, flash chromatography. Laboratory experiences: Isolation of the b-carotene from the Lycospericon Esculentum and Capsicum Annum - Isolation and separation of the constituents of Hibiscus Sabdariffa calyces (hibiscus acid, the hibiscin and caffeic acid) by counter-current chromatography. Isolation of trimyiristine from the Myristica Fragrans. Steam distillation for the isolation of eugenol from Syzygium Aromaticum. Isolation and separation of cichoric acid, chlorogenic acid, echinaceine, echinacoside and caffeoyl conjugates from Echinacea Pallida and from Echiancea Angustifolia dryed roots. Extraction, isolation and separation of components of Matricaria Camomillae: flavonoids and essential oils. Extraction and quantitative determination of nicotine from Nicotiniana Tabaccum leaves. Solid-phase extraction and quantitative determination of xanhtine from Thea Synensis leaves. Isolation of salicilic acid and vitexin from Viola Tricolor.

Readings/Bibliography

1) VOGEL. CHIMICA ORGANICA PRATICA. CASA EDITRICE AMBROSIANA, SECONDA EDIZIONE, MILANO 1988 2) R. M. ROBERTS, J.C. GILBERT, S. F. MARTIN. CHIMICA ORGANICA SPERIMENTALE. ZANICHELLI, BOLOGNA 2003 3) A.J. HANDELY. EXTRACTION METHODS IN ORGANIC ANALYSIS. SHEFFIELD ACADEMIC PRESS, CANADA 1999 4) D.L. PAVIA, G. M. LAMPMAN, G.S. KRIZ. IL LABORATORIO DI CHIMICA ORGANICA, EDIZIONI SORBONA , MILANO 1994 5) P.M. DEWICK. CHIMICA, BIOSINTESI E BIOATTIVITA' DELLE SOSTANZE NATURALI. PICCIN, PADOVA 2000 6) MARCO D'ISCHIA LA CHIMICA ORGANICA IN LABORATORIO PICCIN PADOVA 2002 LUCIDI, CD, APPUNTI DI LEZIONI, COPIE DI ARTICOLI INERENTI GLI ARGOMENTI DI LEZIONE 7) PAUL H. LIST, PETER C. SCMIDT I FARMACI DI ORIGINE VEGETALE TECNOLOGIE DI ESTRAZIONE DELLE PIANTE MEDICINALI, HOEPLI 1993

Teaching methods

Transparencies, notes and CD provided during the lessons. Articles from scientific journals.

Assessment methods

Final examination consists in an oral test aimed to assess the comprehension of the different subject elucidated of the course.

Teaching tools

overhead projector, PC, laboratory for the practical experiments.