Dive into the science behind terpenes and how these valuable compounds interact with the world through articles on research, products, and uses as they relate to terpenes both on the Terpenes and Testing blog and in our bi-monthly magazine editions.
Terpenes are a very large and diverse class of organic compounds, found in plants and even some insects. Terpenes can have strong aromas meant to deter the plants or insects from herbivores. They can also attract the predators of the herbivores that eat the plant.
Terpenoid is another word used for these types of molecules. While a terpene is a hydrocarbon, based off of the molecule isoprene, a terpenoid contains additional functional groups, like those containing oxygen. Terpenoids are also sometimes referred to as isoprenoids. Terpenes are not only end products, they can be essential building blocks in other organisms. They are also the major constituent in most essential oils. The term essential oil is a shortened version of quintessential oil. Aristotle believed that matter was made of four elements: air, earth, fire, and water. There was thought to be a fifth (quintus is Latin for five) element, called the life force or spirit of the matter, and it was also believed that this spirit could be extracted through means like distillation. Interestingly, this is where we get the term “spirits” for distilled alcohols.
Given the trademark organoleptic (fancy term for sensory) properties that terpenes are known for, it’s easy to see why they are so commonly used in perfumery, aromatherapy, and even in holistic medicine. These days, however, the word terpene is seemingly on everyone’s lips, as the cannabis industry storms across the globe.
Each cannabis variety has its own profile of terpenes that give the flower its flavor and aroma. These terpenes distinguish between different varieties. For example, cheesy, diesel, floral, herbal, earthy, woodsy, funky, or skunky aromas and flavors all stem from the terpenes native to that plant. The entourage effect, discussed by Raphael Mechoulam, and then popularized through Ethan Russo’s well-known and cited paper entitled “Taming THC: Potential Cannabis Synergy and Phytocannabinoid-Terpenoid Entourage Effects”, refers to the fact that the cannabinoids have been shown to work better when other phytomolecules from cannabis are present. Because of this, the involvement of the terpene in the medical properties of cannabis cannot be understated.
These are some of the most prominent terpenes in cannabis.
Primary Terpenes Found in Cannabis
α-pinene is one of the two isomers of pinene (β-pinene being the other). It emits an aroma of turpentine or pine trees, and is found in pine trees, rosemary, and parsley. It is one of the most commonly occurring terpenes in nature. Deep inhalations of forest air can be invigorating. α-Pinene is an expectorant and bronchodilator. It also offers anti-inflammatory, anti-cancer, and anti-microbial properties, and has shown promise as a memory aid. Thus, α-pinene has been evaluated for neuroprotective potential for enhanced management of memory disorders like dementia.
Cannabis varieties reported to contain higher pinene levels include the legendary Jack Herer, Blue Dream, the Kush Group, and AK-47.
Myrcene is present in many plants including hops, mangoes, tea tree, celery, and lemongrass. It emits a fruity, clove-like aroma, but has also been implicated as providing the trademark skunk of certain cannabis cultivars. Myrcene has been nominated as the most frequent terpene in cannabis, and is also highly prevalent in hoppy beers.
The concentration of the monoterpene myrcene in a cannabis plant or product could provide insight on whether that product will have a sedative effect. That said, higher concentrations of myrcene have been shown to cause anxiety in mice.
Myrcene also has anti-fungal, antibacterial, antiseptic, and anti-inflammatory properties. Additionally, myrcene can gobble up free radicals, making it a powerful antioxidant.
Myrcene is common to cannabis varieties like Jack Herer, Blue Dream, the Kush Group, Granddaddy Purple, Green Crack, White Widow, or Amnesia.
Ocimene refers to three different monoterpenes that have slight differences in their molecular structure (they are isomers). These monoterpenes are named α-ocimene, cis-β-ocimene, and trans-β-ocimene. These molecules are found in plants like lavender, marigold, tobacco, mint, parsley, basil, and mango, and impart herbal, sweet, and woodsy aromas.
While many terpenes are involved in plant health and defense, ocimene is quite the sentinel, being frequently cited as providing a strong natural defense to the plants that produce it. Spider mite infestation is a problem that many farmers combat, including those growing cannabis. Trans-β-ocimene was released by lima bean plants in response to onslaught by spider mites. When wild legume plants were intentionally infested with about 400 spider mites per plant, increased trans-β-ocimene were measured. The increased trans-β-ocimene attracted predatory mites that feed on spider mites.
Trans-β-ocimene is a pheromone produced by honeybee larvae to chemically verbalize their nutritional needs to worker bees. The other dominant characteristics of ocimene that are pervasive in the scientific literature are its anti-bacterial, anti-fungal, and anti-septic properties, but ocimene has also demonstrated anti-cancer properties.
Ocimene has been explored in organic light-emitting diodes (OLEDs), which utilize films of organic molecules that give off light in response to electricity.
Cannabis varieties measured as containing ocimene include Golden Goat, Strawberry Haze, Strawberry Cough, the Kush Group, Sour Diesel, Trainwreck, Green Crack, and Headband.
β-Caryophyllene is what gives black pepper its spiciness. It’s also found in plants like hops, lavender, and rosemary. It’s considered to be the most common sesquiterpene in cannabis. To date, β-caryophyllene is the only terpene known to interact directly with the endocannabinoid system (CB2 receptors), which have involvement in anxiety and depression disorders.
β-Caryophyllene is a potent antioxidant and has been studied in cancer treatments. It’s also delayed the onset of epileptic seizures. Interestingly, β-caryophyllene has been studied in treatments for neurodegenerative disorders like Alzheimer’s disease. It’s also shown promise in treating addiction. And even more amazingly, it’s been shown to lengthen life, as least in the nematode commonly called roundworm.
This terpene is commonly found in cannabis varieties like Girl Scout Cookies, White Widow, the Kush Group, Sunset Sherbet, or Pineapple Express.
The monoterpenoid alcohol α-terpineol, which is one of four structural isomers (including terpinen-4-ol) can be found in plants like pine trees, skullcap, Lapsang Souchong tea, eucalyptus, sage, tea tree, and lilacs. Its essence imparts citrus, spice, lilacs, and apple blossoms.
Terpineol has displayed anti-cancer activity including studies involving colorectal, leukemia, small cell lung cancer, myeloma (cancer of plasma cells), and lymphoma. The small cell lung cancer was the most sensitive to the terpenoid. The colorectal and myeloma cancer cells were also sensitive to α-terpineol.
Terpineol also has anti-inflammatory properties, and has been effective as an anti-nociceptive agent. It also has antibacterial and antimalarial effects, and has exhibited gastroprotective properties against peptic ulcers.
The wonderful assortment of cannabis varieties measured as containing α-terpineol include Jack Herer, White Widow, Girl Scout Cookies, OG Group, Black Mamba, Skywalker, Blue Cheese.
α-Humulene is a sesquiterpene that is common to both hops and cannabis, and has been implicated as the terpene causing “hoppy” aromas in cannabis. It’s also found in tobacco, ginger, cilantro, basil, and evergreen trees. Like myrcene, and many, many other terpenes, α-humulene is a potent antioxidant. α-Humulene has proven to be toxic to several cancer cell lines, including breast, leukemia, cervical, colorectal, and lung.
Additionally, α-humulene provides anti-inflammatory properties, and is a potent insecticide.
Cannabis varieties measured to contain α-humulene include Durban Poison, Girl Scout Cookies, White Widow, Grand Daddy Purple, and the Kush group.
The monoterpenoid linalool provides lavender with its pleasing aroma. It’s also a constituent in bergamot, which provides the characteristic scent and flavor of Earl Grey tea, jasmine, basil, thyme, hops, coriander, oregano, grape vines, Assam tea, bay leaf, and citrus.
Linalool has demonstrated anti-cancer, anti-anxiety, anti-convulsant, and sedative properties. Like pinene, linalool has been evaluated for restoring cognitive function in degradative diseases like Alzheimer’s disease. Linalool’s also been postulated as being able to reduce lung inflammation from cigarette smoking.
Linalool has been nominated as the ingredient in lavender essential oils that’s responsible for providing relief from skin burns, without scarring. Linalool’s ability to provide pain-relief has been shown to possess a similar effectiveness to procaine and menthol.
Cannabis varieties like those in the OG group, AK47, Tangerine Dream, Lavender, Amnesia Haze, and Headband have been measured to contain linalool.
Any one familiar with natural, orange or citrus based cleaners is already familiar with limonene’s essence. This monoterpene, which is considered to be the second most widely distributed terpene in nature, is formed naturally from a pinene precursor, and is common to citrus fruits, in general, as well as juniper, herbs like dill, mint, and sage, celery, marigolds, and spices like cardamom and nutmeg.
Limonene has significant medical properties. This terpene has anxiolytic properties, meaning it’s good for anxiety. It’s also been studied for facilitating weight-loss, and has demonstrated anti-depressant, anti-inflammatory, and antioxidant properties. Limonene can facilitate the absorption of other drugs through the skin and tissue, making it an interesting molecule to evaluate in topical and transdermal products. For example, it (along with the terpenes menthone and eugenol) was found to enhance the ability of the breast cancer drug tamoxifen to pass through the outer layer of skin, called the stratum corneum. It’s also been used in treating gastroesophogeal reflux disease (GERD).
Cannabis varieties measured as containing higher limonene levels include Sour Diesel, Lemon Skunk, Do-Si-Dos, Trainwreck, and the OG Group.
Terpinolene can be found in pine or conifer trees, as well as parsnips, herbs like sage or mint, spices like nutmeg, or flowers like lilacs. Terpinolene invokes scents of the woods and smoke, and has also been said to have an herbal fragrance. Terpinolene exhibits antioxidant, anti-cancer, anti-nociceptive and sedative properties.
Cannabis varieties reported to have higher terpinolene concentrations include Jack Herer, Afghani, Pineapple Kush, the OG Group, Chocolope, Acapulco Gold, Super Lemon Haze, Chernobyl, Dutch Treat, and Durban Poison.
Geraniol has also been found in catnip, beebalm, Assam tea, lemongrass, grapes, citronella, and Citra hops. Interestingly, it’s also found in tobacco plants. Geraniol is also one of the main components of the Nasonov pheromone that is released by worker honeybees to help re-orient the bees that were out foraging when they return to the hive. Bees also create it to mark nectar-bearing flowers. This terpene has been shown to be an effective plant-based mosquito repellent.
Geraniol is a neuroprotectant, making it an attractive molecule for further study in treating or preventing neurodegenerative disorders like Parkinson’s disease. It is an antioxidant, and has shown anti-cancer properties for skin, oral, breast, lung, colon, prostate, pancreatic, kidney, and liver cancers. Additionally, geraniol has augmented the efficacy of chemotherapy drugs.
Cannabis cultivars measured to contain geraniol include Lavender, Amnesia Haze, Headband, Great White Shark, Black Mamba, Skywalker, and Death Star OG.
Obtained rather inexpensively from Valencia oranges, Valencene is a sesquiterpene. It is often used as a flavoring ingredient and aromatic additive. Some studies show that this terpene could have anti-inflammatory properties.
Secondary Terpenes Found in Cannabis:
The name phellandrene actually refers to two monoterpenes, alpha-phellandrene and beta-phellandrene (α-phellandrene and β-phellandrene), that differ only in the positioning of one of their chemical bonds. This terpene can be found in eucalyptus, frankincense, cardamom, ginger, star anise, American pepper (aka Peruvian peppertree), Dutch myrtle (aka sweetgale), velvet nightshade, tomato leaves, and dill. Its essence suggests eucalyptus, mint, citrus, and pepper.
Phellandrene has exhibited anti-cancer properties, and has demonstrated anti-inflammatory, antibacterial, and antioxidant attributes.
Cannabis varieties measured as containing phellandrene include Jack Herer, Trainwreck, Kashmir Red, Arjan’s Haze #3, Arjan’s Strawberry Haze, and XJ-13.
Terpinene is used as a fragrant additive in both the cosmetic and food industries. It is also considered to be a well-tolerated additive in the pharmaceutical industry. It has very strong antioxidant properties.
Borneol & Isoborneol
The monoterpenoid borneol can be found in a diverse group of plants, including mugwort, wormwood, sagebrush, valerian, garry oak, different tropical trees, and ginger. It possesses an herbal and woodsy scent.
Borneol is a known drug potentiator, and can help drugs targeting the central nervous system by aiding their transport across the blood-brain barrier (BBB). It’s ability to unlock the BBB is dose-dependent, and there is essentially a “Goldilocks” zone of efficacy.
Borneol has therapeutic applications for pain-relief and anti-nociception. It also demonstrates anti-inflammatory, antioxidant, anticancer, anti-microbial, anti-convulsant, and anti-coagulant properties.
Isoborneol is an isomer of borneol, and has revealed anti-viral attributes.
Cannabis varieties measured to contain borneol include Amnesia Haze, Golden Haze, the Kush Group, Blue Cheese, and the OG Group.
The diterpene alcohol phytol is common to plants like beach morning glory, spider plants, verbena, parsley, meadow fescue, mugwort, jasmine and green tea. It imparts a light floral aroma. Phytol is ubiquitous in plants, in general, as a degradation product of chlorophyll.
Our guts can convert free phytol to phytanic acid, the latter of which becomes toxic when it is not properly broken down and it over-accumulates, causing Refsum disease, which includes peripheral nerve damage, hearing loss, cerebellar ataxia (where inflammation in the cerebellum causes a loss of coordination), retina damage, and a loss of the sense of smell. Interestingly, great apes are capable of storing larger quantities of phytanic acid, whereas humans have evolved to effectively metabolize it, such that it doesn’t over-accumulate.
Phytol interacts with gamma-aminobutyric acid (GABA)-related systems, and substances that increase the levels of GABA have relaxing, anxiolytic properties. It also can inhibit Vitamin A teratogenesis, or birth defects in a developing embryo. And like most other terpenes, phytol offers antibacterial, anti-oxidant and anticancer properties.
Cannabis varieties containing phytol have been reported to include Sour Diesel, Cheese, Blue Cheese, Blue Dream, and the OG Group.
Menthol showcases its trademark minty flavor and aroma and is a dominant constituent in the aromatic profile of plants in the mint family. It’s rather unfortunate that most people know of this refreshing molecule from its popularity in cigarettes. The addition of menthol to cigarettes helps reduce the perceived harshness of the inhaled smoke. One study found that smokers of menthol cigarettes revealed an increased dependency on nicotine, compared to users of non-mentholated cigarettes.
Menthol is a common ingredient in many different types of health products, especially those for combating respiratory ailments like colds. Menthol evokes cooling sensations through its action on temperature-activated receptors involved in thermal and pain sensations. One such receptor, called TRPM8 (transient receptor potential cation channel subfamily M member 8), is the main detector of environmental cold, and can be activated via cold temperatures (< 26°C, 79°F), and chemicals like menthol.
Menthol has been used as a model for studying the cold pain reported by sufferers of neuropathy. The terpenoid can also help ferry other molecules through the skin, making it of interest in transdermal products. And like many other terpenes, menthol has shown anticancer properties.
The monoterpene sabinene can be found in an interesting assortment of plants like oak or Norway spruce trees, the leaves of redwood trees, tansies, juniper berries, carrots, citrus, marjoram, black pepper, tea tree, black sage, thyme, and nutmeg. It imparts a combination of aromas, with touches of pine, orange, and spiciness filling out its bouquet.
Sabinene aids liver function, and has anti-fibrosis properties. Sabinene, a dominant component of the essential oil extracted from juniper berries, exhibited anticancer properties. Of course, like most other terpenes discussed, sabinene offers antibacterial, antifungal, and antioxidant properties.
It’s also be studied for use as a precursor molecule for an alternative to fossil-fuel based jet fuel.
Cannabis varieties with sabinene include Super Silver Haze and Arjan’s Ultra Haze #1.
The fragrant sesquiterpenoid nerolidol can be experienced in plants like corn, tomatoes, citrus fruits and orange blossoms, jasmine, lavender, Japanese cypress, and in tea tree’s essential oil. It’s also found in different types of peppers, teas, yarrow, and magnolias. This terpene ties together the pleasing and diverse medley of roses, citrus, and the woods.
Nerolidol can be ejected by plants into the atmosphere to sound the alarm of herbivore attack, such as from spider mites. Carnivorous mites, in turn, waft the delicious fragrance, and come to the plant’s defense. Another example of fragrant weaponry.
Nerolidol also offers anti-fungal properties and anti-parasitic properties. Nerolidol proved to be beneficial as a natural treatment for schistosomiasis, a parasitic disease caused by worms that live inside certain types of snails, and second only to malaria, as the most devastating parasitic disease.
Nerolidol helps breakdown antibacterial resistance in harmful bacteria like Staphylococcus aureus and Escherichia coli. This wonderful terpene also has conveyed anticancer properties, is sedative, has anti-inflammatory properties, and has use in treating gastric ulcers.
Cannabis varieties containing nerolidol include Jack Herer, the OG Group, Gorilla Glue #4, and San Fernando Valley (SFV). In a study of 442 cannabis users, trans-nerolidol was found to provide the strongest anti-anxiety effect.
Isopulegol is a chemical precursor to menthol, and has a variety of promising routes for therapeutic research. Studies have shown that isopulegol possess gastroprotective and anti-inflammatory effects, and reduces the severity of seizures in animal models.
Carene has a sweet, pungent odor and is a main constituent of pine and cedar resin. It is used to dry out excess body fluids, such as tears, mucus, and sweat.
Fenchol is found in basil and is used extensively in perfumery. It is known to exhibit antibacterial properties.
Bisabolol is the primary constituent of German chamomile essential oil and has recently been shown to induce apoptosis in models of leukemia.
Camphene is found in essential oils extracted from certain trees. It has recently shown promise for pain relief and antioxidant effects.
Camphor, a monoterpenoid, is found in different trees, such as the camphor laurel, an evergreen tree native to certain regions of Asia, such as Sumatra and Indonesia, as well as citronella, rosemary, sage, and ginger. The medical properties of this terpene include anti-bacterial, anti-fungal, antioxidant, cough-suppressing, pain-relieving, anti-cancer attributes. Camphor was used as a fumigant during the 14th century plague called the Black Death.
When applied topically, it produces a cooling sensation similar to that of menthol. Camphor also acts as a slight local anesthetic and has been studied as an herbicide. Despite its branding as a rather potent killer of bugs and microorganisms, camphor is also a known aphrodisiac, and can help get our blood pumping, enabling better circulation.
Cannabis varieties said to contain camphor include Black Mamba and Skywalker.
Cedrene is present in the essential oil of cedar.
Guaiol is an alcohol found in the oil of guaiacum and cypress pine. It possesses antimicrobial properties.
Geranyl Acetate is found in a variety of natural oils, derived from citronella, lemongrass, sassafras, roses, and many others. It has a strong floral aroma with a fruity twist, and exhibits strong antimicrobial effects.
Commonly found in the essential oils of cumin and thyme, cymene has documented anti-inflammatory effects. Research also shows potential protective effects against acute lung injury.
This terpene is obviously common to eucalyptus, however, additional plants containing eucalyptol include bay leaves, tea tree, wormwood, and basil. Eucalyptol is also known as 1,8-cineole.
Eucalyptol is an effective bio-insecticide used by beekeepers to rid the hive of honeybee mites, and has demonstrated the ability to hasten the death of house and blowflies. It can also be used as a mosquito repellent, as it deters feeding and the laying of eggs. Eucalyptol also has anti-fungal and antimicrobial which make it an attractive molecule for study in topical or transdermal applications. Eucalyptol from turmeric showed antibacterial properties against skin fungi including Micrococcus luteus, Staphylococcus epidermidis, Bacillus substilis, Escherichia coli, Staphylococcus aureus and Pseudomonas aerogenosa.
Products containing eucalyptol have traditionally been used for remediating conditions that affect breathing, like bronchitis, sinusitis, or the common cold. Eucalyptol is a potent antioxidant, and treatment with eucalyptol alleviated the effects of acute pancreatitis in mice through the terpenoid’s anti-inflammatory and anti-oxidant properties.
Cannabis varieties said to contain eucalyptol include the legends Super Silver Haze, Headband, and ACDC.
Pulegone has a pleasant peppermint aroma and is a strong insecticide.
The sesquiterpenoid alcohol guaiol is found in bee-brush, guaiacum plants and cypress trees, as well as palo santo, a holy wood that is thought to impart medical and therapeutic benefits when burned. Palo santo has been used in aromatherapy to treat arthritis, rheumatoid arthritis, and gout.
Guaiol has exhibited anti-cancer properties when treating non-small cell lung cancer (NSCLC). Guaiol, extracted from the bark of the tropical plant called Nectandra lanceolate, exhibited activity against leukemia, brain, kidney, and colorectal cancer cell lines.
Perhaps the most well-cited medicinal attribute of guaiol is that of anti-microbial agent. It’s also demonstrated anti-inflammatory effects, and has been implicated as being an anxiogenic (anxiety-causing) terpene found in cannabis. In a study of which cannabis cultivars cause or alleviate anxiety, guaiol represented the only major terpene to produce a “perfect” correlation of -1.000, meaning it was most correlated with invoking anxiety.
Cannabis varieties measured as containing guaiol include Afghan, Chocolope, White Widow, Harlequin, the Kush Group, Medical Mass, and Dream Queen.
These statements have not been evaluated by the FDA and are not intended to diagnose, treat or cure any disease. Always check with your physician before starting a new dietary supplement program.