Lactones are called cyclic esters and are formed when an ester links a hydroxyl group and a carbonyl group within a lactic acid molecule to form a ring structure that is usually pentagonal or hexagonal. They can be sesquiterpenoid (with 15 carbons) or monoterpenoid (with 10 carbons) and play a small part in essential oils and a larger part in herbs.
In essential oils, lactones can be found in very small quantities in both German and Roman Chamomile, Inula, Laurel, and Yarrow, and in larger quantities in Catnip. The small quantity is due to the fact that they are large molecules, so few make it through the distillation process. We find larger quantities of lactones in herbs. Obviously, they are in the herbs that correspond to the oils listed above, as well as many others including: Arnica, Dandelion, Elecampane, and Lavender (the latter in the form of coumarins). Lactones are known for being digestive bitters, decongestant, expectorant, and mucolytic. Energetically, they are uplifting, stimulating, and can motivate and inspire. They also have antifungal and antiviral activity. Gamma-lactone causes the milky white color of Dandelion sap. Delta-lactone is very bitter. There are more than 5000 different lactones, and they are responsible for a variety of flavors and fragrances. Note: Coumarins, which will be discussed next week, are lactones that have undergone further intramolecular reactions. To learn more abut lactones, check out the chemistry datasheets found in the membership section. When secondary alcohols oxidize (pick up an oxygen atom) they can become ketones. Ketones are similar to aldehydes in form and tend to be stable, meaning they're not likely to oxidize any further. One ketone you may be familiar with is Camphor, and if you've ever experienced camphor, you'll have an idea of the strength of ketones.
Ketones are powerful and their therapeutic properties differ from one to the other as do their precautions. The primary ketones found in essential oils are camphor, fenchone, isopinocamphone, jasmone, menthone, pinocamphone, pulegone, thujone, tumerone, valeranone, verbenone, and vetivone. (You'll notice that most of the ketones take the -one suffix.) Because of their differences, we'll explore camphor since it's so widely known and used. Camphor's therapeutic properties include relieving pain, being antibacterial and antifungal, reducing mucus and coughing, stimulating the central nervous system, and possibly helping maintain bone density. As with many strong constituents, camphor needs to be used with care. It should not be used near the faces of infants or young children as it can slow their breathing or even cause respiratory collapse. Babies and young children should not ingest camphor. Even for older children and adults, too much camphor can depress the CNS and be toxic, so it needs to be limited to 4.8 % at the most in topical blends. There are cautions for ingestion as well, which is why cough drops containing camphor limit use to a few hours apart. While there are some ketones that are considered safe, others, like isopinocamphone, pinocamphone, pulegone, and thujone are either toxic to the liver, toxic to the brain, or both. These should be used in small amounts for short-term and should not be used if you are pregnant, breastfeeding, have liver disease, or have a seizure disorder. When primary alcohols oxidize, they make aldehydes. Aldehydes have a carbonyl group (Carbon+Hydrogen+Oxygen) on one end. Common aldehydes in aromatherapy include cinnamaldehyde, citral, citronellal, neral, geranial, myrtenal, and octenal.
Aldehydes tend to be cooling, calming, and uplifting. Their sedative and antispasmodic properties can help you relax and improve your mood. They are great in diffusers because, with their antibacterial and antiviral properties, they can get rid of cold and flu germs that are floating around. Yet, rather than smelling medicinal, they have fresh, herbaceous, floral, or fruity aromas. Those wonderful aromas are the reason you'll even find aldehydes in perfume. There are some cautions that go with oils high in aldehydes. They may irritate the skin and mucous membranes, so they need to be limited to 1% or less of a blend. When used topically, they should be used short term only (meaning a few days at most). |
DisclaimerThe information contained in this blog is for educational purposes only and has not been evaluated by the Food and Drug Administration. Archives
February 2021
Categories |