Chemistry and Analysis of Cannabis Terpenes
This is a short review based on Rudolf Brenneisen’s book “Chemistry and Analysis of Phytocannabinoids and Other Cannabis Constituents” and other resources.
According to the author more than 483 compounds were identified in cannabis plant, of which more than 60 cannabinoids. So far at least 66 cannabinoids have been identified and divided into 10 subclasses. Some of them have already known pharmacological characteristics while majority are still under study.
Some of the known cannabinoid characteristics are as follow:
- Cannabigerolic acid (CBGA) – antibiotic
- Cannabigerol (CBG) – antibiotic, antifungal, anti-inflammatory, analgestic
- Cannabichromene (CBC) – anti-inflammatory, antibiotic, antifungal, analgestic
- Cannabidiolic acid (CBDA) – antibiotic
- Cannabidiol (CBD) – anxiolytic, antipsychotic, analgestic, anti-inflammatory, antioxydant, antispasmotic
- Delta-9-tetrahydrocannabinol (THC) – euphoriant, analgestic, anti-inflammatory, antioxidant, antiemetic
- Delta-9-tetrahydrocannabivarin (THCV) – analgestic, euphoriant
- Delta-8-tetrahydrocannabinol – similar to THC but less potent
- Cannabinol (CBN) – sedative, antibiotic, anticonvulsant, anti-inflamatory
Terpenes
According to the article the essential oil yield depends on cannabis type and pollination; sex, age, and part of the plant; cultivation (indoor, outdoor); harvest time and conditions; drying and storage. Depends on their structure terpenes can be classified as monoterpenes, diterpenes and sesquiterpenes.
For example, fresh buds from Afghani variety yielded 0.29% essential oil. Drying and storage reduces the content after 1 week to 0.20% and in 3 months – to 0.13%. Monoterpenes were reduced more than the rest of the components but none of the major components disappeared during the drying process.
The essential oils yield of nonpollinated cannabis plants was twice more than the pollinated plants.
Fresh bud oil from indoor-grown cannabis had 57 terpenes of which 92% monoterpenes, 7% sesquiterpenes and approximately 1% other components (ketones, esters, etc.). The dominant monoterpenes were myrcene (67%) and limonene (16%).
The concentration of monoterpenes in outdoor-grown cannabis varied between 47.9% and 92.1% of total terpenoid content. The sesquiterpenes ranged from 5.2 to 48.6%. The most common monoterpenes were β-myrcene, trans-caryophyllene, α-pinene, trans-ocimene and α-terpinolene.
“Drug-type” cannabis generally contained less caryophylene oxide than “fiber-type” cannabis.
Research of different varieties grown in Europe showed that the main terpenes were myrcene (21.1-35.0%), α-pinene (7.2-14.6%), α-terpinolene (7.0-16.6%), trans-caryophyllene (12.2-18.9%) and α-humulene (6.1-8.7%). The main differences were in the amount of α-terpinolene and α-pinene.
Other terpenoids present only in traces are sabinene, α-terpinene, 1,8-cineole (eucalyptol), pulegone, γ-terpinene, terpineol-4-ol, bornyl acetate, α-copaene, alloaromadendrene, viridiflorene, β-bisabolene, γ-cadinene, trans-β-farnesene, trans– nerolidol, and β–bisabolol.
Vitamin K is the only vitamin found in Cannabis. Carotene and xanthophylls are identified pigments in cannabis. Also eighteen elements were detected (e.g., Na, K, Ca, Mg, Fe, Cu, Mn, Zn, Hg).
Terpenes: Pharmacological Characteristics and Aroma
| Terpene | Pharmacological Characteristics | Aroma |
| β-Myrcene | analgestic, anti-inflammatory, antibiotic, antimutagenic | citrus, clove, earthy, fruity,green, vegetative |
| α-Pinene | bronchodilator potentially helpful for asthmatics and promotesalertness and memory retention | pine needles, rosemary |
| Limonene | dissolve gallstones, improve mood and relieve heartburn and gastrointestinal reflux and it was studied for anticancer activity | citrus (orange, tangerine, lemon, grapefruit) |
| Linalool | anti-anxiety, mediates stress, strong anticonvulsant, antidepressant, anti-inflammatory effect | floral (spring flowers), lilly, citrus and candied |
| β-caryophyllene | anti-inflammatory, cytoprotective (gastric mucosa) and antimalarial activity | spicy, sweet, woody, clove, camphor, pepper |
| Terpineol | anti-bacterial and anti-fungal properties | floral; lilac, citrus, apple/ orange blossoms, lime |
| Borneol | directed for fatigue, recovery from illness and stress | menthol, camphor, pine, woody |
| Delta 3-Carene | used to dry excess fluids, tears, running noses, excess menstrual flow and perspiration | sweet, pine, cedar, woodsy, rosemary |
| Pulegone | acetylcholinesterase inhibitor. It stops the action of the protein that destroys acetylcholine, which is used by the brain to store memories. | mint, camphor, rosemary, candy |
| Sabinene | antioxidant and anti-fungal properties | found in oak trees, tea tree oil, black pepper and is a major constituent of carrot seed oil |
| Eucalyptol | used to increase circulation, pain relief and easily crosses the blood-brain-barrier to trigger fast olfactory reaction | spicy, camphor, refreshing, minty |
| Nerolidol | antifungal, antimalarial properties and sedative effect | woody and fresh bark |
| Farnesol | anti-tumor effect | floral; muguet, lilly, tuberose, rose, musk |
| α-Caryophyllene | anti-tumor effect | vietnamese coriander, hops, woody, clove |