What's Chemistry Got to do With It?

I originally wrote the following article for www.herbmentor.com.

I've really enjoyed being a part of that community and helping out in the forums. Earlier this summer I got the idea of doing some more ebooks for the site and videoing Lexi and Chris at Ancestree Herbals about growing and harvesting tips for a variety of medicinal herbs. All of those projects along with another round of moving has kept me pretty busy. Currently I am busy being the Director of Student Affairs at the Institute of Structural Medicine, and once that is done I will be heading back to the woods for more herbal adventures. (I have several gallons each of elderberries and chokecherries which I will be attempting to turn into delicious wine - not to mention the frozen dandelion flowers hiding out in my freezer with the same fate.)




In this article we'll be delving into the chemistry involved with herbal medicine. Herbalists, and others who work daily with plants understand the complexity inherent in each green friend. Please keep in mind while reading this article that while knowing a plant's constituents can be very helpful, it gives us only a small piece of the puzzle to a plant's inner workings.

As a top-notch Herbmentor student you most likely go to the herb of the month entry in Herbalpedia as the first of the month rolls around. You read the botanical description, historical uses, and so far so good. Then comes the constituents section. Let's see, according to Herbalpedia dandelion's constituents are:

Root: taraxacin, triterpenes (taraxerol, taraxasterol), lactupicrine, inulin, sugars, glycosides, phenolic and citric acid, asparagine, vitamins A, C, B, potassium.

Leaves: contain carotenoids, vitamins A, B, C, D, minerals (potassium and iron).

If you know all of those strange words, the effects they have on our bodies, and how we can use different mediums to extract them (water, alcohol, vinegar, oil, etc) then you can skip this article.

If you maybe know a few of these but are interested in reaching for the next step as an herbalist then please read on.

Knowing the constituents of a plant helps us as herbalists to explain the action of what is going on. When first learning about plants we may learn that hawthorn is useful for the heart. Later we may refer to it as a cardiac tonic. The next step is learning that hawthorn is high in flavonoids, which protect our capillaries and slow down the rate of oxidation.

Knowing the basic constituents of a plant is useful in the herbalist's world. That burdock or dandelion root is high in inulin or that hawthorn berries are high in flavonoids gives us a deeper understanding of how that plant can be used to help us.

Also knowing which medium to extract these plants in is invaluable. If you are searching for the soothing (mucilaginous) effects of marshmallow root for example, you do not want to extract this plant in alcohol. Likewise, if you wanted to use the expectorant qualities of cottonwood buds, you wouldn't be very successful with a small glass of tea. Just as you would use water only for some herbs, or alcohol only for other herbs, a complex mixture of water, glycerin, vinegar and alcohol is optimal for others. Richo Cech's book, Making Plant Medicine, is a great reference for formulas.

The following is a very basic list of constituents and the mediums they are soluble in. To synthesize this information, I relied heavily on previously published materials. To delve into the chemistry behind plant constituents please refer to the reading list at the end of the article.

Common Chemical Compounds

Alkaloids:

Soluble: alcohol, water, vinegar

Alkaloids posess a huge variety of effects ranging from benign to extremely poisonous. They are extracted extremely well by alcohol and much less so by water (Cech, Nic en Fleishdier). Plants high in alkaloids are goldenseal, lobelia, and motherwort. Alkaloids can be sometimes dissipated with heat or tannins, or magnified with vinegar (Cech).

Glycosides:

Soluble in: water, alcohol

A glycoside is chemically described as a compound that contains a sugar as part of the molecule. There are several different types of glycosides with a variety of effects including beneficial and toxic effects on the heart (cardiac glycosides found in Digitalis and Hawthorn), laxatives (anthraquinone glycosides found in senna, rhubarb), and antiseptic qualities (arbutin found in Uva ursi). Stevia, rebaudiana bertoni, another glycoside, has 40-300 times the sweetness of sucrose.

Saponins
Soluble in: water, alcohol

Saponins are a special type of glycoside. We use saponins (hopefully) daily in our soaps. Saponins break up fat molecules (think of the Dawn commercials and the big piles of dirty dishes). They also have a variety of other effects including adaptogenic, diuretic, anti-spasmodic, and expectorant (Cech). Horse chestnut, licorice, and chickweed all have saponins.

Flavonoids:

Soluble in: water, alcohol

Flavonoids are another type of glycoside. Among the important effects of flavonoids is their antioxidant effect. An antioxidant is a molecule capable of slowing or preventing the oxidation of other molecules. They are also known to decrease capillary fragility.

Tannins:

Soluble: glycerin, water, alcohol

Oak, tea, witch hazel, and red clover all contain tannins. Herbs with high tannin content are generally used as an antiseptic, a styptic, and to shrink tissues. Tannins are rendered inactive with the presence of milk and may have the ability to render some alkaloids inactive (Kress, Cech).

Mucilage:

Soluble: Water (Cold preferred)

Soothing to the gut and urinary system, herbs high in mucilage also tend to be nutritive and nourishing to the immune system (Cech). Herbs with high mucilage content include marshmallow, mullein, comfrey, and slippery elm.

Polysaccharides:

Soluble: water

Generally immune stimulating and nutritive, herbs high in polysaccharides are burdock, astragalus, and boneset (Cech).

Minerals, trace elements:

Soluble: water, vinegar

Vitamins:

Soluble: water,

Vitamins A, D, E, and K are fat-soluble, with the rest being water soluble (Kress).

Resins:

Soluble: alcohol, oil

Resins are typically expectorant and bitter. Herbs containing high amounts of resins include cottonwood buds, calendula, and gumweed.

Solvents

Alcohol:
Almost everything is extracted by alcohol with the exception of minerals and trace elements. Mucilage is extracted by alcohol and then broken down by it, so it's best to use a cold water infusion and then add just enough alcohol if wanting to preserve it.

Glycerin:
Glycerin is a sweet substance made from plant or animal sources and is chemically related to alcohol. It's made by the breaking down of fat and oils with the use of high pressure steam (Cech). Herbalists use glycerin to extract medicinal properties from plants when wanting to avoid alcohol. Glycerin does poorly at extracting properties with dried plant material so fresh plants are highly recommended. According to Henriette Kress, some minerals and trace elements, some alkaloids, some acids, and some mucilage are extractable with glycerite. Richo Cech reports that tannins are extracted very well by glycerin.

Oil:
Oils have the ability to extract oils and resins.

Vinegar:
Vinegar has the ability to extract minerals, trace elements, and alkaloids. Most herbalists use apple cider vinegar, balsalmic vinegar, or other high quality vinegars. (Distilled white vinegar is not reccomended for internal use.) Besides extracting a variety of constituents, vinegar can also add other benefits to the end product as well.

Water:
Water extracts almost everything with the exception of resins. Different temperatures may effect the extraction (simmering for barks and roots, just boiled for leaves, cold for mucilaginous plants). Some herbalists prefer to use distilled water.

Further Reading

Making Plant Medicine, Richo Cech

Henriette Kress' website:http://www.henriettesherbal.com/

Medical Herbalism, David Hoffman

Village Herbalist Series on Herbmentor with Heather Nic an Fhleishdeir