Terpenes are interesting aromatic, volatile organic compounds (VOC’s), that are manufactured by the cannabis plant (and other plants) as a defence against predators like herbivores and insects, that want to feed on the plant. Terpenoids are terpenes that have been oxidized, with some oxygen functionality, and/or have had some rearrangement of some of the molecules. Terpenes are hydrocarbons, while terpenoids have functional groups added. Hence, terpenes are actually a precursor to the cannabis plant making its cannabinoids.
Cannabinoids are a type of terpenoid, and chemically speaking, are basically a terpene, combined with a phenol and a straight chained aliphatic “tail”, composed of either a 3 or 5 carbon alkane (propane or pentane). Different terpene combinations give the cannabis plant such unique properties and characteristics.
Terpenes have been used in the perfume industry for years, taking advantage of their aromatic properties of different pleasant fragrances. The major terpenes found in cannabis are myrcene and limonene.You will see different designations of some terpenes, like (alpha) or (beta) myrcene, which are structural isomers of the same compound. Isomers are molecules with the same chemical formula as another molecule, but with a different chemical structure. They contain the same atoms, just arranged differently. You may also see designations like (+) or (-), these refer to the different optical isomers of the terpene, ie, mirror images of the compound.
While it has been known for a while now that terpenes can actually enhance the effect of the cannabinoids, more recent studies have shown that individual terpenes like myrcene, can trigger some cannabinoid receptors themselves,. They are also able to penetrate the blood-brain barrier (like cannabinoids), and can provide many medically beneficial effects on their own.
We definitely need more, legitimate studies on cannabis, especially the terpenes, to find out what other beneficial properties are contained within these wondrous compounds.