Terpenes are naturally occurring products that are found in all organisms, especially in aromatic plants like cannabis. In addition to chemotaxonomy, terpenes have a low toxicity and are commonly used in the production of various essential oils, perfumes, and vitamins and as food additives, due to their distinct aromas. As terpenes produce the distinctive smells of various cannabis strains, producers and processors may want to identify terpene profiles that appeal to consumers.
A blend of terpenes make up the volatile, essential oil of cannabis. Terpene profiles entirely govern the aroma of cannabis, because cannabinoids themselves are odorless. There have been approximately 200 terpenoids that have been identified in cannabis, none of which are unique to cannabis. However, it has been suggested that cannabinoid synthesis creates unique terpene profiles. Terpenes found in cannabis are synthesized inside the cannabis's glandular trichomes and may represent up to 10 percent of trichome content in harvested cannabis.
Terpenes that are present in cannabis plants, and their concentrations, vary greatly with growing, harvesting, and drying conditions. It should be also be noted that most putative medicinal effects of the terpenes found in cannabis have been extrapolated from their occurrences in other products.
Alpha-Bisabolol, alternatively known as levomenol, is a colorless, viscous oil with a light, flowery odor that is produced by many plants. A wide array of fats and oils, herbs, and teas are known to contain alpha-bisabolol. Alpha-Bisabolol is soluble in ethanol and slightly soluble in water. The perfume and cosmetics industries readily use alpha-bisabolol in the production of fragrances and cosmetics.
Alpha-Humulene, known simply as humulene, was first identified in hops and has since been found in many aromatic plants, principally in cannabis. Humulene generates the characteristic aroma of cannabis, as well as the hoppy aroma of beer. The smell of humulene is reminiscent of pine, oranges, and tobacco as pine trees, orange orchards, and tobacco plants emit humulene in large amounts. Humulene is also one of the principal components found in cloves, pepper, and Vietnamese coriander, an herb that is used in Southeast Asian cooking.
Alpha-Pinene is a fragrant terpene that is found frequently in nature, particularly in coniferous trees, such as pine trees, as well as in rosemary. Alpha-Pinene is also present in orange rinds and in eucalyptus oil. Alpha-Pinene has been identified as the predominant terpene in certain European and Chinese cannabis plants.
Temperature and light intensity are known to affect the amount of alpha-pinene emitted by alpha-pinene producing plants. An interesting property of alpha-pinene is that it is known to increase airflow to the lungs at low exposure levels. Alpha-Pinene is rapidly absorbed and metabolized when consumed. Alpha-Pinene has anti-inflammatory and memory-aiding properties and is suspected to be an antimicrobial, an agent that inhibits the growth of microorganisms. The concentration of alpha-pinene in cannabis tends to remain stable during drying and storage.
Alpha-Terpinene has a distinct, lemon-like odor. Alpha-Terpinene changes from a liquid to a resin during prolonged storage. Like other terpenes, Alpha-Terpinene is commonly used in essential oils and in the production of perfumes. Alpha-Terpinene is often used to synthesize other products and reagents.
Alpha-Terpineol is a terpene with a lilac-like odor that is found in many plants and serves as an important biological role as a plant metabolite. In addition to being found in cannabis, alpha-terpineol is also found in skullcap, cabbage, and lapsang souchong tea. Alpha-Terpineol is frequently used in perfumes, cosmetics, and flavors.
Beta-Caryophyllene is a compound that is commonly found in aromatic plants. Beta-Caryophyllene has an oily texture and a smell similar to that of cloves. In certain cannabis varieties, levels of beta-caryophyllene exceed levels of beta-myrcene, which is normally the dominant terpene in cannabis. Beta-Caryophyllene contributes to the distinct odor of cannabis and is also the compound that is sensed by drug detection dogs. The smell of beta-caryophyllene is very dry and spicy, with beta-caryophyllene being one of the dominant compounds found in black pepper, cloves, and hops. It should also be noted that the concentration of beta-caryophyllene in cannabis may increase during drying and storage as more volatile terpenes degrade.
Beta-Myrcene, or simply myrcene, is colorless terpene with a pleasant odor that typically dominates the terpene profile of a cannabis product. Myrcene is also found in hops, cinnamon, and oregano. Myrcene is a volatile terpene and may gradually degrade during drying and storage. Myrcene will also slowly evaporate at room temperature. For these reasons, it is recommended that cannabis products that are high in myrcene be stored in a cool place that is safe from light and air.
Beta-Pinene is commonly produced in trees, as well as in plants from numerous families, such as cannabis, and has a distinct pine odor. The presence of beta-pinene is widespread in plants, and is found in limes, ginger, nutmeg, mace, rosemary, and sage. Beta-Pinene has natural herbicide, insectifuge, and pesticide properties. The concentration of beta-pinene in cannabis tends to remain stable during drying and storage.
Borneol is a terpene derivative with a strong, unique smell that easily oxidizes into camphor, a waxy, white or transparent compound with a very strong aroma. In addition to cannabis, borneol is also found in nutmeg, pepper, ginger, and saffron. A peculiar place where borneol can also be found is in castoreum, a substance that is secreted by beavers to mark their territory with their scent. The secretion is used in tinctures, perfumes, and as a food additive.
Camphene has a pungent smell that is described as camphor-like. Camphene is insoluble in water, but very soluble in most organic solvents. Camphene typically changes directly into vapor when heated and easily evaporates at room temperature. Interestingly, however, camphene is stable when exposed to either air or light. Camphene can be found in many essential oils and is also used to improve the odor of certain industrial products.
Citral is a distinctive terpene that is found in limes, lemons, and oranges. Citral is known for its citrus aroma, and occurs in many tropical herbs, such as in lemongrass, lemon tea-trees, and lemon balm. Citral is also used to supplement perfumes with its citrus aroma and produce products that mask the smell of smoke. Citral has a bitter taste of lemons and is notable for having antimicrobial and insect repelling properties. It should also be noted that studies suggests that citral can heighten allergy susceptibility and approximately 1 to 1.7 percent of people are allergic to citral.
(+)-Citronellol is predominantly found in black cumin, and various other plant oils, herbs, and spices, while (−)-Citronellol is mainly found in roses and geraniums.
Citronellol is commonly used in perfumes and insect repellents, being particularly good at repelling mosquitos at short distances. Currently, the scientific community is in dispute as to if citronellol can cause an allergic reaction. Citronellol is recognized by the U.S. FDA as a safe food additive, however, citronellol is subject to restrictions on its use in perfume because some people report sensitivity to the compound.
Delta-3-Carene, or simply carene, has a penetratingly sweet odor. Carene is a major constituent of turpentine, and has been described as having a turpentine-like odor. Carene is not soluble in water, but readily mixes with fats and oils. Cannabis products that contain high levels or delta-3-carene should be kept in airtight containers to maintain stability, because carene will undergo autoxidation and resiniﬁcation if exposed to air.
Dihydrocarveol is a terpene with a minty, cool, sweet, fresh odor and a sweet, weedy, spicy taste. Dihydrocarveol is an extremely weak acidic compound that is only slightly soluble in water. Aside from cannabis, dihydrocarveol is found in dill, pepper, and wild celery.
D-Limonene, or simply limonene, is found commonly in nature and is a precursor to many other terpenoids that derives its name from its occurrence in lemon peels. Limonene, is a clear, colorless hydrocarbon that is the main component in the oil of citrus fruit peels. Limonene is highly bioavailable, so when consumed, a large proportion enters into circulation of the body. Skin contact with Limonene may cause irritation, but there are no other known adverse effects in humans. However, limonine is toxic to aquatic life. Limonene produces a fragrance of oranges and is therefore used in a wide array of products; from lotions, bath products, and personal care products to cleaning products and botanical insecticides. An interesting note is that Limonene can be used as a solvent for cleaning purposes, as the compound has the ability to dissolve oil. Limonene is also commonly used as a flavoring agent in food manufacturing. Limonene can be the predominate terpene found in certain cannabis varieties. Limonene is relatively stable during drying and storage, but oxidizes easily in moist air.
Fenchone, a clear, oily compound, is found in various foods, perfume, and notably in absinthe. Fenchone has an odor similar to camphor. Fenchone's presence is widespread in plants and it is commonly used as a flavoring ingredient. Fenchone has been detected in fennel, rosemary, and star anise. Fenchone is also found in cinnamon, sweet basil, saffron, and dill.
Gamma-Terpinene is colorless, oily terpene with an odor that resembles turpentine. Gamma-Terpinene exudes a tropical, lemon-lime, woody scent and has a bitter taste. Gamma-Terpinene is a insectifuge, a compound that repels insects non-lethally, and can also be an irritant. Gamma-Terpinene is also an antifeedant, a naturally occurring substance that adversely affects creatures that feed upon plants that produce it. Gamma-Terpinene is found in a variety of foods, including allspice, carrots, cinnamon, oregano, sage, and thyme. Commercially, gamma-terpinene is used as a flavor and a production input in perfumery.
Geraniol is an alcohol that is found in geraniums, lemons, and various essential oils. Most notably, Geraniol is the primary component of rose oil. Geraniol has an odor of roses, which makes it a desirable input for perfume. Geranial is also produced by honeybees to mark nectar-bearing flowers and their hive entrances and is suspected to be a mosquito repellent. Interestingly, geraniol is used as flavoring for a wide array of flavors, including peach, plum, raspberry, watermelon, pineapple, grapefruit, lemon, lime, orange, apple, and blueberry flavor.
Guaiol is a crystalline solid alcohol that melts at almost 200° F. Guaiol is found in the oil of guaiacum and cypress pine. Interestingly, Guaiol will yield a deep purple color when treated with certain reagents. Guaiol is an alcoholic terpene that is found in several plants, especially in the essential oil of guaiacum and cypress pine.
Isopulegol is found in a variety of essential oils, in particular, it is found in the lemon-scented tea tree. Isopulegol is also found in a number of fats and oils, cornmint (wild mint), and Ceratocystis coerulescens, the species of fungus that causes sapstreak disease in sugar maples. Commercially, isopulegol is used in fragrances and as a flavoring agent.
Linalool is known for its occurrence in lavender and is used in between 60% to 80% of all scented hygiene and cleaning products, including soap, detergent, shampoo, and lotion. Linalool is also used as an intermediary input in the production of vitamin E. Linalool naturally occurs in many flowers and spices, found in more than 200 species of plants. The main plants that produce linalool are mint, laurel, cinnamon, rosewood, and birch. Linalool is also found in citrus fruits and basil. Linalool is a major component in cilantro, as well as a large number of fruits and essential oils Linalool has numerous commercial applications due to its floral, spicy, and pleasant smell.
Linalool can be absorbed through inhalation and through the skin. Some people may have slight irritation, pain, or allergic reactions when exposed to linalool. When inhaled, linalool may cause drowsiness or dizziness. Interestingly, there are two forms of linalool, each having a distinct scent. One form of linalool has a sweet, floral, orange-like smell, while the other form smells like lavender and has a woody odor. Linalool is also frequently used as an insecticide, used by flea, fruit fly, and cockroach exterminators and in some mosquito-repellent products. Interestingly, linalool concentration in cannabis has been shown to increase during drying and storage.
There are two isomers of nerolidol, cis-nerolidol and trans-nerolidol, each with a slightly different molecular geometry. Nerolidol is found in jasmine, lavender, lemon grass, citrus trees, and tea trees. Nerolidol smells of fir, linoleum, and pine. Nerolidol can also be described as having a scent that is reminiscent of fresh bark.
Nerolidol is used in flavoring agents and perfumes, as well as in detergents and cleansers. cis-Nerolidol is also a pheromone, a chemical that can affect human physiology and behavior. Interestingly, nerolidol is one of several chemicals produced by certain plants in response to insect attacks.
Ocimene is found in many essential oils, plants, and fruits. Each ocimene compound is a colorless oil with a pleasant odor. Ocimene is often used in perfumery.
Cannabis products that are high in ocimene should be kept in airtight containers, because ocimene is very sensitive to oxidation, however, the ocimene in products that are not exposed to air will be stable for long periods of time.
β-Ocimene is found in a number of foods, including oregano, spearmint, lemons, and black elderberries. It should be noted that ocimene will react at high temperatures.
You can find p-cymene used as a fragrance in soaps and musk perfumes. P-cymene is also used in the production of certain dyes and varnishes. Cannabis products that contain p-cymene should be kept in airtight containers that are not exposed to light, as light and air will cause p-cymene to degrade.
Pulegone is a minor terpenoid in cannabis that also naturally occurs in cornmint (wild mint), orange mint, peppermint, and spearmint. Pulegone is also notable in rosemary. Pulegone has a cool, mint taste. Pulegone's remarkable mint flavor makes it a desirable use in food products. Pulegone is also used in fragrances because of its pleasant odor. Pulegone's primary therapeutic use is in peppermint and mint essential oils that are used to self-medicate common cold and gastrointestinal disturbances, however, it is suspected that any side effects from consuming pulegone in this manner are underreported. Pulegone is the most powerful natural insecticide found in mint plant species. Additionally, pulegone is one of the major constituents of pennyroyal oil, usually comprising between 62 and 97 percent of the oil. Pennyroyal oil is a powerful insect repellant that is also extremely toxic to humans, even in small quantities. Ingestion of pennyroyal oil has caused severe toxicity and occasionally death, wherein pulegone was identified as the root cause for the toxicity. Despite its potential toxicity, pulegone is a permitted food additive as long as only a minimal quantity is used to produce the desired effect. Interestingly, in thyme basil, a plant that produces pulegone, pulegone is produced in greater quantities when the plant is grazed upon by herbivores, demonstrating how pulegone uses chemical warfare to protect the plants that produce it.
More than 50,000 pounds of terpinolene are used every year in the U.S. in the production of fragrances. Terpinolene has been described as having an odor of turpentine, a pungent oil distilled from pine sap or pine wood. Terpinolene is commonly used to improve the odor of various industrial and household products, like mixing paints and varnishes. Terpinolene is found in citrus, allspice, mentha, juniper, and parsnip essential oils. Terpinolene is used as an input in soap, detergent, creams, lotions, perfume, fragrances, flavoring ingredients, and laundry and dishwashing products. In certain cannabis varieties, terpinolene can be the predominate terpene.
2-Piperidinone is a colorless, fuming liquid that is a derivative of piperidine, a compound that is also found in black pepper. Piperidine is responsible for black pepper's sharp aroma and hot taste. Additionally, 2-Piperidinone's name is derived from its genus name Piper, the Latin word for pepper. 2-piperidinone is also known as σ-valerolactam, and is primarily used as an intermediate input in the production of other chemicals. In particular, 2-piperidinone is used in the pharmaceutical industry as a building block and chemical reagent in the production of various organic compounds.