Hashishene, the new terpene of cannabis

Hashish and terpenes

As we already know, terpenes are responsible for the taste and scent of many of the vegetables that produce them. They are a broad class of organic hydrocarbons derived from isoprene (CH2=C(CH3)CH=CH2) which compose the bulk of resins and essential oils of plants, thus providing unique flavours to each individual as a result of terpene combination. They are also called terpenoids when they have undergone an oxidating or molecular re-combination process. As we also know, most cannabis terpenes have properties of great medicinal value.

As the flowering stage progresses, more and more terpenes are secreted inside the trichome heads, so that the terpene profile of the plant changes as it ripens. The same thing happens when drying and curing buds, the process of oxidation and partial decarboxylation to which buds are exposed makes their terpene range to change over time. Some terpenes will degrade faster than others, so the terpene range of the weed – we must remember that we know of more than 100 terpenes in cannabis – will vary unless it is vacuum-sealed and properly stored. This fact explains why the smell and taste of one sample can evolve throughout the drying and curing process.

Hashish samples

Different hashish samples

Probably, any concentrate lover has realized that, many times, the extraction process changes the terpene profile of the weed, so the resulting extract lacks some of the organoleptic features of the buds from which it comes. In this way, cannabis extracts have a common taste and smell – with subtle variations – regardless of the strain used to make them. This happens especially when using dried/cured plant material, since as we have already seen in our posts about Fresh Frozen and Fresh Chilled, these type of concentrates have a smell and taste much closer to those of the fresh plant material. Somehow, isolating and concentrating the resing glands leads us to limit the terpene range, so we can’t properly appreciate the “personality” of each sample. But, why does it happen?

Study on the volatile compounds of cannabis sativa

A study conducted by Jean-Jaques Filippi, Marie Marchini, Céline Charvoz, Laurence Dujourdy and Nicolas Baldovini (“Multidimensional analysis of cannabis volatile constituents: Identification of 5,5-dimethyl-1-vinylbicyclo[2.1.1]hexane as a volatile marker of hashish, the resin of Cannabis sativa L.“) at the end of 2014 seems to have found the answer to this question. According to these researchers, the typical “hashish flavour” of many resin extracts made from dried and oxidized buds comes from the degradation of a single terpene, which creates an unusual and rare monoterpene (5,5-dimethyl-1-vinylbicyclo[2.1.1]hexane). The five researchers propose in their study a name for this particular monoterpene, Hashishene. While the rearrangement of myrcene and the formation of 5,5-dimethyl-1-vinylbicyclo[2.1.1]hexane was already investigated by Robert S. H. Liu and George S. Hammond in 1965 (US 3380903 A), this phenomenon had never been observed before in hashish samples.

Cannabis buds and hashish

Cannabis buds and hashish have different terpene profiles

The volatile constituents of the samples used to conduct the study (fresh buds, dried buds and hashish) were investigated using headspace solid phase microextraction (HS-SPME) and hyphenated gas chromatography techniques (GC-MS, GC×GC-MS), showing clear differences in terpene profile between weed and hashish samples, mainly resulting from photo-oxidation of the plant material during the drying and extraction processes. Thus, the hashish samples analyzed showed considerable amounts of a rare monoterpene among their volatile compounds, which came from a rearrangement of beta-myrcene during the manufacture of hashish. Moreover, the researchers claim that this monoterpene would be almost exclusive from cannabis plants, so they propose to call this new volatile marker “Hashishene”.

Let’s take a closer look now at what is beta-myrcene and how it degrades into Hashishene.

What is beta-myrcene?

Myrcene

Myrcene

Beta-myrcene – also known as myrcene – is a natural hydrocarbon (7-Methyl-3-methylene-1,6-octadiene), more precisely one of the most important monoterpenes found in cannabis plants (it is also found in other plants like hops, parsley or bay) and widely used in the production of fragances for its pleasant scent, although it is unstable in air and tends to polymerize. Its name comes from Myrcia sphaerocarpa, a medicinal plant found in Brazil with high amounts of myrcene.

Myrcene is also a precusor to other terpenes, helping to form them, and synergizes their antibiotic properties. It is also believed to play a crucial role in the effects of cannabis. A study conducted in Switzerland in 1997 showed that myrcene was the most common terpene in 16 different cannabis strains, being over 50% the total terpene content of some of them.

Myrcene can change the permeability of cell membranes to allow more cannabinoid absorption by the brain, thus regulating the effects of other cannabinoids (in a similar way than CBD does). It is also believed that myrcene makes THC, CBD and CBG more effective. Myrcene has many therapeutic effects, being used to relax muscles and combat pain. It also has anti-depressant and anti-inflammatory properties, plus antimicrobial, antioxidant, antiseptic, and anti-carcinogen effects. It slows bacterial growth, inhibits cell mutation (a very important factor when fighting cancer), suppresses muscle spasms and is even used to treat psychosis because of its relaxing and calming effect.

Its smell is very complex, earthy, balsamic and spicy, but also reminiscent of grapes, peaches, vanilla, grass, wood and pepper. Both the smell and taste dissipate with high temperatures.

Beta-myrcene:

  • Name: 7-Methyl-3-methylene-1,6-octadiene
  • Formula: C10H16
  • Molecular Weight: 136.23404 g/mol
  • Decarboxylation Point: 115-145°C (239°F to 293°F)
  • Boiling Point: 168°C (334°F, 442ºK)
  • Critical Pressure: 2421.88 kPa
  • LD50 (Lethal Dose): >5g/kg

Therapeutic uses of myrcene:

  • Analgesic – Pain relief
  • Antibacterial – Slows bacterial growth
  • Anti-Diabetic – Helps mitigate the effects of diabetes
  • Anti-inflammatory – Systemic reduction of inflammations
  • Anti-Insomnia – Aids with sleep disorders
  • Anti-Proliferative/Anti-Mutagenic – Inhibits cell mutation, including cancer cells
  • Antipsychotic – Tranquilizing effects, relieves symptoms of psychosis
  • Antispasmodic –  Suppresses muscle spasms
Beta-myrcene molecule ball

Beta-myrcene molecule ball

Hashishene as rearrangement of beta-myrcene

We know that cannabis contains high amounts of monoterpenes and sesquiterpenes. Alpha and beta-pinene, beta-myrcene and limonene are the most commonly found monoterpenes, while the predominant sesquiterpenes are beta-caryophyllene and alpha-humulene. Seven out of ten cannabis samples used in this study contained large amounts of beta-myrcene (19,5-28,7%), but what about the hashish samples?

After a first series of analyses, researchers found out that every hashish sample contained remarkable amounts of an unusual monoterpene – 5,5-dimethyl-1-vinylbicyclo[2.1.1]hexane – eluting before alpha-pinene. This finding was quite surprising since this compound had only been isolated once before this study – although it was first identified in Boswellia species – and it was as a constituent of the essential oil of Mentha cardiaca L. Moreover, and on a second series of analyses, “hashishene” was found in almost all hashish samples among the most abundant apolar constituents (1,1-14-9%), while it was detected in samples of dried and fresh herb in very low amounts. A total of 186 constituents were identified in these analyses.

Hashish has high amounts of Hashishene

Hashish has high amounts of Hashishene

Before this study, beta-myrcene was already considered as one of the most abundant volatile constituents of cannabis, and has been proposed as specific marker of marijuana. According to the results of this study, the presence of “hashishene” would be directly linked with the high amounts of beta-myrcene detected in fresh cannabis buds. Researchers state that exposure to sunlight would be one of the factors related with the formation of hashishene from beta-myrcene, supporting the photolytic origin of “hashishene”.

All hashish samples showed a wider diversity in oxygenated terpenes than cannabis buds, and many alcohols, aldehydes and ketones could be related to the hydrocarbons found in cannabis. They observed that many oxygenated derivatives actually came from the initial terpenes, more specifically from a photo-oxydation process. In this way, terpene photo-oxidation leads to the formation of allylic hydroperoxides, which will soon generate alcohols when losing an oxygen atom.

Hashishene synthesis

Synthesis of hashishene from myrcene using UV-light

Other volatile constituents widely detected in most hashish samples were caryophyllene/humulane derivatives – as well as linear alkanes, esters, fatty acids or alcohols – all as a result of processes of  isomerization, dehydration, cyclisation and photo-oxidation from the manufacture of hashish. Researchers propose to rename monoterpene 5,5-dimethyl-1-vinylbicyclo[2.1.1]hexane – a photolytic rearrangement of beta-myrcene – as “hashishene” due to its rare occurrence in other essential oils and to its high abundance in hashish.

Hashishene:

  • Name: 5,5-dimethyl-1-vinylbicyclo[2.1.1]hexane
  • Formula: C10H16
  • Molecular Weight: 136.234 g/mol
  • Boiling Point: 161°C (321°F, 434ºK)
  • Critical Pressure: 3022.28 kPa
Fresh frozen extraction

Fresh frozen extractions yield much less hashishene

You can take a look at this study in this link.

January 29, 2016 | Cannabinoids and terpenes
18 Comments


18 comments on “Hashishene, the new terpene of cannabis

  1. Kathy Skidmore

    Excellent article. I have always loved hashish. Always will.

    1. Dani Alchimia Post author

      Hi Kathy,

      Thanks for your kind comment!

      😉

  2. James Owens

    I loved what i, as a lay person, could understand of this article (beautifully brilliant); who would have thought that substances i once smoked, could/would help me get my health at an optimum level. Thank you for the data.

    1. Dani Alchimia Post author

      Hi James,

      The number of new medical applications of cannabis is really surprising, we hope people will be able to grow their own medicine at home some day…

      All the best!

  3. Lori Harju

    Please keep me informed on the strain for illness, pain , energy, depression… Thank you ! You know your stuff ! 🙂

    1. Dani Alchimia Post author

      Hi Lori,

      We have several categories on our website, like medicinal strains, or varieties with relaxing or stimulant effect.

      Hope you’ll find what you’re looking for!

      😉

  4. Peter Stopp

    Great article ! keep up the good work and hopefully in the near future everyone will know the real value of this plant

    1. Dani Alchimia Post author

      Hi Peter,

      We’re glad you liked the article!

      All the best! 😉

  5. Steve Short

    Great article! Just a brief note that it is also useful to record and list the freezing points of the individual terpenes and cannabinoids. The reason? It is actually possibly to freeze these out of some solvents either en masse over a wide range or individually/selectively over narrower ranges.
    I’ll say no more because it is a work in progress….

    1. Dani Alchimia Post author

      Hi Steve,

      Very interesting contribution, I’ll be investigating on this for sure… 😉

      Thanks for your comment!

  6. BrandynBlaze

    I’ve tried many times to verify the claim that “Myrcene can change the permeability of cell membranes to allow more cannabinoid absorption by the brain, thus regulating the effects of other cannabinoids (in a similar way than CBD does).”

    Do you happen to have a source for that? I’d love to find the original research.

  7. Dani Alchimia Post author

    Hi BrandynBlaze,

    You have a link to the complete document at the bottom of the post.

    Hope it helped!

  8. Viktoria

    sehr gute seite!

  9. Viktoria

    es war sehr amjusandt!

    1. Dani Alchimia Post author

      Vielen Dank Viktoria!

      😉

  10. Joachim

    great info here. thanks for providing the newest insights on cannabis.

    1. Dani Alchimia Post author

      Hi Joachim,

      Thanks for your kind comment!

      😉

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