Updated: Apr 29, 2022
Terpenes : Everything you need to know
There are more than 20000 Terpenes throughout nature. They are the most popular chemical medium on our planet for communication to happen. It has been seen that even some insects produce terpenes. If we consider terpenes or terpenoids in a cannabis plant, we can safely say that terpenes are hydrocarbons and terpenoids are oxygen-containing terpenes. They can be visualized as the result of linking isoprene units “head to tail” to form chains, which can be arranged to form rings. ¹
Isoprene is the precursor to most terpenoids. There are different classifications which can be done as per the chosen factor of division but terpenoids are mostly classified into Steroids, Carotenoids and Terpenes. Terpenes are very small, smaller than most other molecules and are highly aromatic compounds that determine the smell of many plants and herbs, such as rosemary and lavender, as well as some animals. Terpenes play a vital role in plants. In some plants, terpenes attract pollinators, while in other plants, they cause a strong reaction to repel predators, such as insects or foraging animals. Some terpenes play a protective role in the plant, helping the plant to recover from damage; others act as a part of the plant’s immune system to keep away infectious germs.
Based on the number of isoprene units they have, they are classified as mono, di, tri, tetra, and sesquiterpenes. They are mostly found in plants and form the major constituent of essential oils from plants. Among the natural products that provide medical benefits for an organism, terpenes play a major and variety of roles. The common plant sources of terpenes are tea, thyme, cannabis, Spanish sage, and citrus fruits (e.g., lemon, orange, mandarin)
Terpenes are naturally-occurring compounds found in the trichomes of female cannabis plants. Trichomes are sticky, translucent glands that cover the surface of buds, and in much smaller amounts, on leaves and stems. Critically, trichomes contain resin glands that produce terpenes. Cannabis contains more than 150 types of terpenes.
Why are Terpenes important?
Terpenes have a wide range of medicinal uses among which antiplasmodial activity is notable as its mechanism of action is similar to the popular antimalarial drug in use—chloroquine.²
Terpenes have many functions in plants such as a thermoprotectant, signalling functions, and not limited to, pigments, flavouring, and solvents but also have various medicinal uses.³
Terpene is a natural compound with various medical properties and found in both plants and animals. Among natural products that mediate antagonistic and beneficial interactions within the organism, terpene play a variety of roles. Terpene protects many living organisms like microorganisms, animals and plants from abiotic and biotic stresses. Terpene can ward off pathogens, predators, and competitors. Living organisms use terpene for multiple reasons like medicinal purposes and communications about food, mates, or enemies. It is impressive how different organisms use terpene for common purposes even though terpene contain many forms and varieties.⁴
Different types of terpenes and their properties
Species produced from
Treat malaria, treat bacterial infections, and migraines
Euphorbia, salvia miltiorrhiza
Anti-inflammatory, cardiovascular diseases
Wound healing, increases circulation
Terpenes are pretty diverse. There are eight different types in total, each one characterized by how many hydrocarbon units it's made of.
Monoterpenes (and monoterpenoids) are the most common type in nature; they're also the most common type in hemp and cannabis. Mixtures of different monoterpene-based oils are used as fragrances for making perfumes and in other cosmetics. Most of the monoterpenes are active biologically with strong antibacterial activities to them as well. So far only a small percentage of terpene is investigated. Cannabis is one of the most common sources for the medicinal terpene. Cannabis contains many medicinal properties like anticancer, antimicrobial, antifungal, antiviral, antihyperglycemic, analgesic, anti-inflammatory, and antiparasitic. Terpene is also used to enhance skin penetration, prevent inflammatory diseases. Nowadays modern medication use large scales of terpene for various treatment drugs.⁵
Contains the active ingredient to treat cutaneous infections
Possesses powerful antibacterial and antifungal properties
Possesses psychoactive properties and used against many infectious diseases
Enhances memory and is used in anti-dementia drugs
Drugs against pediculosis
Antibacterial and antifungal effects
Terpenes/terpenoids are largely responsible for the characteristic aroma of cannabis. An essential oil (mostly terpenes or terpenoids), especially when distilled, is not necessarily identical in its chemical composition with the oil that is present in the living plant. Quite often very high-boiling or low-boiling chemicals are simply “lost” due to the nature of the distillation process and due to economic and time constrains. Although most constituents remain intact during distillation, a few undergo chemical changes. Oil also contains substances that are formed from reactive precursors on distillation. The variation in essential oil composition may be due to factors that affect the plant’s environment, such as geographical location, weather conditions, soil type, fertilizer used, the age of the plant, and the time and weather of day or year when it is harvested. Degradation tends to occur on prolonged storage, under poor storage conditions, or when the essential oil is otherwise exposed to air. Atmospheric oxygen can change the chemical composition of an essential oil by reacting with some of its constituents.⁶
Effect of Terpenes
To understand the full effects of terpenes/terpenoids, it is necessary to explain some terms.
The term synergy comes from the Attic Greek word συνεργία (synergía, “collaboration”), which is based on the word συνεργός (synergos, “working together”). Explanation is easy. When we have 2 active compounds, they work together better than each one separately, which can be expressed by strict inequality: 1 + 1 > 2.
The term entourage effect was introduced in 1988 by Mechoulam and colleagues⁷ and was explained as increased activity of an active compound with an inactive one, which can be expressed by strict inequality: 1 + 0 > 1.
It is believed that all components of the cannabis plant likely exert some therapeutic effect, more than any single compound alone. There is increasing evidence that these compounds work better together than in isolation and that is exactly what is called today “entourage effect.”
When we smoke or vaporize cannabis, our bodies take in hundreds of botanical compounds. Each one arrives with unique effects and benefits, and their behavior may change in the presence of other compounds. This is the entourage effect.⁸
In a 2010 study ⁹, patients with cancer pain were given either a pure THC extract or an extract containing near-equal levels of both THC and CBD—patients given the THC/CBD combo reported having less pain.But cannabis is far more than just THC and CBD. It also produces other cannabinoids like CBN, CBC, CBG, and dozens more—as well as terpenes, which are aromatic compounds also readily found in the essential oils of lavender, orange, black pepper, eucalyptus, and much more. With such a diversity of useful compounds in cannabis, the possible synergies could make your head spin with excitement. Unfortunately, there are very few studies that explore these synergies in humans—it’s still only a theory supported by a small body of research, and, of course, loads of anecdotal evidence from curious cannabis enthusiasts around the world experimenting with new varieties of the plant.
The entourage effect gained some ground in 2011 when Russo published a paper in the British Journal of Pharmacology reviewing the potential interactions between THC and various cannabinoids and terpenes. For example, he cites work suggesting alpha pinene—a terpene that gives some marijuana a fresh pine scent—might help preserve a molecule called acetylcholine, which has been implicated in memory formation. “So one main side effect of THC is short-term memory impairment,” he says. “People go, ‘Uh…what were you saying?’ That can be prevented if there’s pinene in the cannabis.”¹⁰