Terpenes: molecules of mystery and wonder

Don Shelly

If you have been afforded the luxury of witnessing a sunrise or sunset in the Appalachian Mountains in the eastern United States, especially the Blue Ridge mountain range, you would have noticed that the mountains appear to be covered with a blue haze. The high density of coniferous trees native to the region release terpenes (Pinene), especially in warm weather, which reacts with natural ozone to produce this hazy blue appearance (with the help of atmospheric filtering). We hope your romantic mountain-gazing experiences are not interrupted by this brief chemistry lesson!

Besides sightseeing, terpenes affect our lives in other ways. The ancient spice routes and related economies owe much of their existence to the terpenes found in highly-prized herbs and spices, due to the strong smells associated with many of these organic compounds. Below are some of the more popular terpenes, their origins and common uses:

1. Myrcene – found in hops, citrus, bay leaves, eucalyptus, thyme and lemongrass

2. Pinene – found in coniferous trees and some citrus; primary ingredient in turpentine

3. Limonene – found in citrus, rosemary, juniper, peppermint and pine; used in perfumes and citrus cleaners

4. Caryophyllene – found in basil, cloves, cinnamon leaf, black pepper and lavender; sometimes used in chewing gum

5. Linalool – found in many plants including mint, cinnamon, rosewood, birch trees and citrus; used as pesticide, food flavouring, perfumes, cosmetics, soaps and oils

6. Terpinolene – found in sage and rosemary; used in soaps, perfumes and insect repellents

7. Camphene – found in coniferous trees, nutmeg, ginger and rosemary; used in turpentine, camphor oil, citronella oil and ginger oil, flavouring and perfumes

8. Phellandrene – found in cinnamon, garlic, dill, eucalyptus, ginger, parsley and lavender; used in flavourings and perfumes

9. Carene – found in cypress, juniper berry, pine, bell pepper, basil, citrus and fir; used in flavourings and turpentine

10. Humulene – found in hops and coriander

11. Pulegone – found in rosemary; sometimes used as an insecticide

12. Sabinene – found in Norway spruce, black pepper and nutmeg

13. Geraniol – found in rose oil, citronella and lavender; used in flavouring, perfumes and cosmetics

14. Eucalyptol – found in eucalyptus, wormwood and rosemary oil; used in cosmetics

Now that we have a “taste” of what terpenes are and what they can offer, we will dig further into the uses for terpenes in our next post, when we discuss the purported medicinal properties of these amazing molecules.

Learn more about our portfolio of terpene certified reference materials, which can support your analytical testing for these remarkable molecules, on our webshop.