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| Extraction of Medicinal Compounds |
Answered by: Conrad Richter
Question from: James Poepperling
Posted on: November 28, 1998
I am seeking information concerning medicinal plants. I have a BS in Biology and at the present time I am attending Pacific College of Oriental Med. where I am studying acupuncture and herbal med. I am looking for detailed books concerning procedures and protocols for extracting compounds from herbs. I want to know how to isolate these compounds found in the herbs. I want to learn more about and understand the substances that have medicinal value within the herb itself. I have searched Amazon.com and have found nothing. I am seeking books from beginning level to professional.
No book that gives detailed extraction protocols of medicinal constituents comes to mind. You will need to search the pharmacological and phtyochemical literature for this information and it might be found scattered in many scientific papers and books.
An important first step is to know what solvents work for the various medicinal compounds in plants. The different classes of compounds are dissolved using different solvents depending on the chemical properties of the compounds themselves and chemical and physical characteristics of the raw herb.
Although the focus is on authentication of medicinal plants, an excellent source of information is Norman Grainger Bisset’s "Herbal Drugs and Phytopharmaceuticals" (which will be available from Richters starting with the 1999 catalogue) has detailed information on solvent systems used in thin layer chromatographic (TLC) and other analytical test methodologies. Any attempt to isolate active constituents will require analysis to prove that you have the intended final product, and this book is a good reference for that type of information. It also gives key references to the scientific literature where you can find extraction protocols.
Alma Hutchens’ book "Indian Herbalogy of North America" (available from Richters) lists solvents used for crude extracts of herbs. Although this information is not directly applicable to your needs, it can help to point you in the right direction. For example, lady’s slipper (Cypripedium pubescens) requires boiling water or dliuted alcohol, while shepherd’s purse (Capsella bursa-pastoris) requires water.