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What is selinene?

selinene terpene

The cannabis terpene you've never heard of

“Selinenes are a group of closely related isomeric chemical compounds classified as sesquiterpenes. Selinenes all have the molecular formula C15H24 and have been isolated from various plant sources. α-selinene and β-selinene are the most common and are two of the main components of celery seed oil. γ-selinene and δ-selinene are less common.”

Several preliminary studies have demonstrated antimicrobial, anti-inflammatory and neuroprotective properties, and the (+) δ-selinene showed antitumor activity. But, unlike other terpenes, selinene has never been tested for its pharmacological or even botanical properties.

Pinene smells like pine, linalool like lavender, but what about selinene? Selinene is so little known that there is very little information online about the smell of this family of terpenes. At best, I could only find a vague reference to a weed smell.

Despite the lack of aromatic information, selinene is present in many herbs and spices, including allspice, basil, celery seed, galangal root and others. It is very present in aromatic wood oils, notably cedar and amyris. And although you'll never see it in a lab test, selinene also appears frequently in the most common cannabis cultivars.
Selinene Terpenes in Cannabis

During a recent interview with Cannabis Tech, Hubert Marceau, development director at the PhytoChemia Laboratory in Quebec, Canada, mentioned selinene. Although our interview focused on his work on terpene clusters, our conversation quickly turned to this mysterious compound.

According to Marceau, selinene is far from being one of the rarest terpenes in cannabis. He found that it can account for up to one percent of the most volatile fraction. Yet this family of sesquiterpenes is almost entirely ignored by the cannabis industry. How is it possible ?

To date, few studies mention selinene and cannabis in the same document. Current research has focused more on listing and classifying terpenes derived from cannabis than to delve into the mysteries of the compounds individual. This means that selinene, in relation to cannabis, has largely ended up on a list and nothing more.

En 2020, the study “Terpenes/Terpenoids in Cannabis: Are They Important?” tested the abundance of major terpenes/terpenoids in 54 samples, finding that γ-selinene ranked among the top 13 terpenes/terpenoids discovered, including one variety that was primarily composed of selinene.

En 2021, “Metabolomic Analysis of Cannabinoid and Essential Oil Profiles in Different Hemp (Cannabis sativa L.) Phenotypes” revealed a positive correlation between the prevalence of γ-selinene and β-selinene (among several other terpenoids), and THC-A , with a negative correlation with CBD-A.

A 2022 publication showed that selinene was more pronounced in male CBD flowers than in female flowers. But in male flowers, it represented 3,4% of the essential oil tested.

Despite the often high concentration and frequency of appearance of selinene in cannabis, few people have been interested in this little-known terpenoid.
Selinene missing from the conversation about cannabis terpenes

Part of the problem, as Marceau pointed out, is that selinene is not commercially available. It can only be purchased through a chemical supplier, such as EvitaChem or sMolecule.

Mr. Marceau explains: “As they are not commercially available, if you carry out a targeted analysis, that is to say you have to buy a standard and compare it to the sample, you will not obtain the more often than them, or you won't see them”.

Scott Holden, founder and CEO of Lab Effects & CBD Global, explained that it is typically extracted from celery seeds and “it is difficult to extract and isolate naturally in high concentrations, which is why perhaps why it is not commonly available”.

According to Holden, “Natural forms typically have a purity of 40-60%, which is very low. Chemical purity is not sufficient for most applications. Certainly not for analytical chemistry, but even much too weak for use in formulation as we do at Lab Effects. Our isolated terpenes are all over 98% purity, and purity below 60% is too low for our standards.

While Lab Effects is one of the only terpene brands committed to using 100% natural terpenes, they are not the only one that is selinene-free. None of the big terpene companies sell selinene, even synthetic, or include it in their blends.

It's an interesting paradox. Yes, selinene is one of the most common cannabis terpenes, among a list that now numbers over 150. However, it is difficult to obtain high purity from a natural source, while synthetic versions remain prohibitive in terms of price and/or impossible to obtain. Additionally, labs don't set standards for selinene, meaning that in the absence of testing, the cannabis industry isn't talking about it.
The role and safety profile of selinene remains a mystery

In the absence of data other than those contained in scientific publications and in the databases of laboratories like Marceau's, the properties of selinene remain largely a mystery. Even Marceau can only speculate on its potential properties. According to the tests he carried out, selinene behaves like a switch, which leads him to hypothesize that it could serve as an indicator for other systems, genetic or metabolic.

Is selinene even safe for human consumption? Holden is wary of including rare terpenes just for the sake of novelty. When he reads a label listing rare terpenes, he knows that most, if not all, of them are impossible to find on the open market. In his experience, “most of the rare terpenes we've seen come from very woody essential oils that are known to be dangerous for human consumption or inhalation.”

Unlike almost all other terpenes commons attributed to cannabis, selinene is one of the least studied. It has never been used in perfumery, as an aromatic additive or in the pharmaceutical sector. No one tests for selinene and, as a result, no one finds it – even though it is commonly present in many popular cultivars. Its botanical characteristics and safety profile remain mysterious.

Tags : Research and Scientific Advancement
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Weed media broadcaster and communications manager specializing in legal cannabis. Do you know what they say? knowledge is power. Understand the science behind cannabis medicine, while staying up to date with the latest health related research, treatments and products. Stay up to date with the latest news and ideas on legalization, laws, political movements. Discover tips, tricks and how-to guides from the most seasoned growers on the planet as well as the latest research and findings from the scientific community on the medical qualities of cannabis.