TERPS: What are terpenes?

By Nancy C Zepeda

IG: @missmmjgeek
Twitter: missmmjgeek



Terps. Terp city. Terp central. Terpenes. Terpenoids. What are terpenes?

Terpenes are organic hydrocarbons (compounds made up of Hydrogen and Carbon) characterized by repeating isoprene units— hence, they are also referred to as isoprenoids. Let’s add isoprenoids to my terp-town list above!  

Isoprene structure:

Hemiterpenes 1 C5
Monoterpenes 2 C10
Sesquiterpenes 3 C15
Diterpenes 4 C20
Sesterterpenes 5 C25
Triterpenes 6 C30
Tetraterpenes 8 C40
Polyterpenes n (C5)n

Because terpenes are made up of repeating isoprene skeletons—keep in mind that isoprene contains 5 carbon atoms, terpenes usually have 5n carbon atoms and are subdivided as such:

β-myrcene structure (a monoterpene consisting of 2 isoprene units found in cannabis):

Yes, terpenes can be found in cannabis plants. But, where exactly?

Let’s look into those scintillating glandular trichomes that embellish and drape our cannabis flowers and leaves.

Terpenes are major constituents of resin, making cannabis essential oil a complex symphony of monoterpenes and sesquiterpenes amongst cannabinoids and other participating compounds.

Being aware of specifications regarding chemical properties of such terpenes can aid in piloting the proper protocol that takes into account the preservation of volatile terpenes when attempting to isolate and harvest them.

There are many known terpenes identified in cannabis:

  • γ-terpinene
  • α-pinene
  • β-pinene
  • β-myrcene
  • Terpinolene
  • Limonene
  • α-guaiene (illustrated below)

More inclusively, compounds such as:

They can also be found in cannabis essential oil. While these may be referred to as terpenes, they should more specifically be termed terpenoids. Terpenoids contain functional groups in their molecular make-up in addition to their repeating hydrocarbon skeleton—hydrocarbons are only comprised of H and C remember. Particularly, in the list above the terpenoids contain a hydroxyl functional group (OH). Remember terpenes are hydrocarbons, H and C terpenoids can be made up of Oxygen in addition to H and C.

Terpenes are also the main components found in hop essential oil. And hops are absolutely necessary for brewing beer! Because nature is working with the same alphabet/building blocks she can only create so many combinations of compounds and because of this, we find that beer and cannabis share lots of terpenes in common.

β-myrcene, limonene, terpinolene, α-pinene, β-pinene, α-humulene, β-caryophyllene, and trans-β-farnesene can be found in both cannabis oil as well as hop oil. And although hop oil is mainly made up of terpene hydrocarbons, finished beer is predominated by terpenoids with hydroxyl (OH) functional groups; the two main terpenoids found in finished beer are linalool (also found in cannabis oil) and geraniol.

With the aid of yeast, these terpenoids are further biotransformed during fermentation giving rise to other derivatives such as α-terpineol, yet another terpenoid that can also found in cannabis oil.

So, the next time you’re enjoying a pungent beer and that song whose beat you could have sworn you’ve heard before, somewhere, begins to remind you of a doobie counterpart that once was, do not fight the feeling! Your body merely wants to tango with a familiar dance partner.  

Terpenes. Nature’s way of grasping your attention via your nose. Cannabis essential oil is a complex symphony of terpenes and terpenoids dancing amongst cannabinoids and other compounds. But, why do terpenes exist in nature? What purpose does it serve to cannabis plants and our experience with marijuana? Increasing trends in proper terpene preservation, isolation and extraction infer an important role played by terpenes during cannabis consumption. Taking note of specifications regarding chemical properties of such terpenes can further help during this journey to terp-city. The key lies in nailing temperatures—it’s always a numbers game!