I am hoping someone can point me in the right direction in regards to extracting medicinal constituents from herbs. I realize some properties are water soluble and others are fat soluble, but I am having difficulty understanding which are which and why. Is there a book on the subject that I could get that is essentially chemistry for dummies that can help me understand which herbs are best for infusions and which are best for decoctions?
Infusion or decoction? Purely depends on which type of chemical constituents one want from extracts. If extract have thermolabile constituents one should move for infusion and if extract have thermostable constituents than one should move for decoction.
If one want alkaloid which are soluble generally in non aqueous solvent e.g. chloroform etc. but their salts are soluble in polar solvents.
If one want glycoside, tannin etc. which are water soluble
volatile oil than it will be soluble in non polar solvents like ether, hexane etc.
I have found review on phytochemical extraction answering your question which and why? Hope it will be helpful for you.
You can try sequential extraction (from nonpolar solvent to polar solvent ex. Pet ether, chloroform, Ethyl acetate, Methanol, Aqueous) using soxlet's apparatus (expect Aqueous extract).
Go with the text book Phytochemical Methods, by A J Harborne. As its predecessors, a key tool for undergraduates, research workers in plant biochemistry, plant taxonomists and any researchers in related areas where the analysis of organic plant components is key to their investigations
Hi Dr. Betsy
Some of the books which can help you in the matter related to extraction and isolation of natural products and secondary metabolites are listed below:
Wagner H, Baldt S. (1996). Plants Drug Analysis, Springer Verlag, Berlin Heidelberg
Harborne JB (1973). Phytochemical Screening Methods In: A Guide to Modern Techniques of Plant Analysis. 1st Edition, Chapmann and Hall, London.1973
Pharmacognosy by Trease and Evans
Phytochemistry by JB Harborne 1969
Natural Products: The Secondary Metabolites by James Ralph Hanson. Royal Society of Chemistry, 2003
Plant Secondary Metabolism by David S. Seigler. Springer, 1998
Regarding your query related to solubility, most of the fatty acids, fixed oils, lipids, waxes, steroids, triterpenoids, steroidal alkaloids and non-polar components are fat soluble and they can be obtained using hexane/petroleum ether as a solvent. Most of the other components are soluble in ethanol and methanol like saponins, alkaloids, glycosides, carotenoids, flavonoids, phenolics etc. For semipolar constituents, ethyl acetate can be used eg. saponins. Water soluble components include tannins, mucilages, carbohydrates, phenolics etc. So according to the presence of constituents and their polarity, you can choose the solvents for extraction.
Do you specifically want to make infusions or decoctions for the drugs you have or you need a general method of extraction. I think maceration or soxhlet extraction is the best method for extracting the phytoconstituents.
Gud Luck and regards
This is an important question for me and i,m interesting in this item
Hello everyone,
Thank you so much for all the great suggestions and answers. Forgive me for not replying to everyone earlier as I was on a sabbatical of sorts from my research.
Also, thank you for taking your personal time to reply and share your knowledge. It is greatly appreciated. I feel that I have a lot of useful information to work from. Again, thank you!
Betsy
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