Chemistry matters – Knowing the terpenes

Dr Sona A Pungavkar
When referring to medicinal Cannabis, the conversation revolves around the mainstream cannabinoids, THC and CBD. However, terpenes are now the new buzzword in the industry, as their effects are known more and more. Terpenesare organic hydrocarbons(containing hydrogen and carbon) found in many plants, from which essential oils are derived. The aroma of lemons, oranges and pine needles and relaxing effect of lavender are due to terpenes.Theterpenes are thought to repel animals and insects that might devour them, provide a natural barrier to bacteria, fungi and help attract pollinators.  Terpenoids are derivatives of terpenes after oxidation or chemical modification. The terms terpenes and terpenoids are used, interchangeably.
Why are terpenes important in medicinal Cannabis? : Cannabis plant contains high concentrations of terpenes, which are found within trichomesin unfertilised female flowers. 
Different Cannabis strains can have different effects on individuals and is partly due to differenttypes and concentrations of terpenes. Hence, it may be possible that terpenes are the differentiators. If one is attracted to a particular strain, it could be the one, which is most suited for that person and the attraction is usually towards the smell, resulting from the terpenes. It may be Nature’s way of letting us know which strain may be most useful for us.
1. Mood alteration
Popularly, the psychoactive effect of Cannabis plantis thought to be due to THC. However, it is now known that terpenes can elevate mood and promote relaxation and stress-relief.
2. Medical benefits
Terpenes can also produce several medical benefits and are responsible for the entourage effect, described during the use of whole plant extract.They canalter the effects of one another in the endocannabinoid system of the human body.
3. Taste and Flavors
Terpeneshave different tastes and smells and are thought to be like spices in the world of natural medicines.These provide distinct aromas and flavors emanated by the plant and hence, give the strains of Cannabis,their natural signatures. Hence, there are different varieties with distinctive flavors like citrus, berry, mint, and pine. Knowing this, one can appreciate the peculiar smells of different Cannabis strains.
Few of the several terpenes found in the cannabis plant have been studied.
Myrcene: Most common terpenein  cannabis, it is also found in hops, mango and lemongrass. It has a highly sedative effect, relaxing and anti-inflammatory properties and can prevent ulcer disease.It lowers the resistance to the blood-brain barrier,  increasing passage of cannabis compounds. Indica plants have more than 0.5 percent myrcene and can produce the “couch-lock” effect (strong sedation).
Limonene: Limonene is commonly found in citrus, rosemary, juniper and peppermints and issecond most abundant terpene in cannabis, though, it may not be found in all strains.It is easily absorbed by inhalation and promptly found in blood. It is effective in increasingenergyand acts an antidepressant, acting as a stress-buster and mood enhancer. It has antifungal and antibacterial properties and great smell, and hence can be used in cleaning and cosmetic products.
Pinene : As indicated by the name, pinene is found in pine tree,rosemary, dill, basil or parsley and is responsible for the smell of pine needles. It is found in two varieties, alpha pinene, whichhas anticancer properties, and betapinene is a strong bronchodilator,expectorant, anti-inflammatory andantiseptic.
Linalool : Linalool is known for stress-relieving, anti-anxiety, and anti-depressant effects and is a major constituent in lavender oil, known for the relaxing effects. It is suggested that linalool can boost immune system, reduce lung and brain inflammation, and can restore cognitive and emotional functions, which are disturbed in diseases such as Alzheimer’s. It is a critical precursor of Vitamin E.
T Beta-Caryophyllene: It hasa spicy, woody, peppery taste and is also found in black pepper, clove and cinnamon. It is known to have anti-anxiety effect andcan aid in peptic ulcer disease, depression and inflammation.
Humulene: Humuleneis foundin hops, cloves, and basil and is what gives beer its distinct ‘hoppy’ aroma. It may help to decrease appetite, helping in weight loss and also has anti-tumor,anti- inflammatory and antibacterial properties.
Terpinolene: It is found in nutmeg, tea tree, lilacs, cumin, sage, rosemary and Monterey cypress. It has asmokey or woody aroma, that is slightly sedative causing drowsiness and inducing sleep as well as alleviate psychological excitement and anxiety.Terpinolene has antioxidant, anti-cancer and antibacterial properties.
Camphene: It has a pungent odor of damp woodlands and fir needles. Camphene reduces plasma cholesterol and triglycerides in rats and could be an alternative to pharmaceutical lipid lowering agents whichhave side effects such as intestinal problems, liver damage and muscle inflammation.
Phellandrene: Phellandrene is described as pepperminty, with a slight scent of citrus. Phellandrene is believed to have special medicinal values and has been used in traditional medicine to treat digestive disorders. It is the main compound in turmeric leaf, which is used to prevent and treat systemic fungal infections.
It is also present in eucalyptus, cinnamon, garlic, dill, ginger, lavender and grand fir. Phellandrene can be absorbed through skinand hence gets included in perfumes and is also used as flavoring agent for food products. Companies are likely to be listing analysis of their products on websites and product packaging.
Most companies are also providing a “terpene wheel” to allow selection of seeds and medicinal cannabis products. It is quite likely in future, cannabis cultivation may involve preferential inclusion of  certain terpenes and cannabinoids to create strains tailored to produce specific effects.
For example, if one is looking for sedative effect for treating pain and anxiety, a product containing myrcene in a concentration greater than 1% is desirable, while for people who would like to continue normal activity, myrcene may not be ideal. Extracting full content of Cannabis plant is one of the ways to preserve the original recipe provided by Nature. It starts with using high quality, terpene rich plant.
The author is a Cannabis researcher, a senior radiologist and Vice President, Cannabis Health and Sciences.