Formula: C10H16, the same as myrcene .

Molecular Mass: 136.234 g/mol

Boiling Point: Unknown

Vapor Pressure: Unknown

LD50 (Lethal Dose): Unknown

The November 2014 Journal of Chromatography featured a study entitled “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.” While unfortunately this study has nothing to do with traveling to other dimensions, it has some very interesting findings for anyone making dry sieve hash, potentially other forms of hash, and perhaps other plant concentrates as well. The researchers analyzed numerous samples of hashish, a total of “15g of hashish (probably originating from Morocco).” Analysis was made using various techniques including “headspace solid phase microextraction (HS-SPME) and gas chromatography techniques (GC-MS, GC×GC-MS).”

Before we go any further, lets talk about how the researchers define hashish. For this study, hashish is a concentrated form of cannabis “produced via a relatively long cottage industry process that consists in successively drying, sieving, and finally pressing the resin-rich buds of cannabis plants that have been harvested at full blooming stage. It results in a medium hard greenish-brownish paste that softens upon heating.” That means these researchers were looking at hashes that were not decarboxylated by anything more than body heat, unlike rosin. They also were not looking at chemical-extracted hashes, like CO2 oils, BHO, or iso hash.

Looking at their samples, the researchers found they could tell which samples were dried herb from those that were hashish, because hash contained “remarkable amounts of a rare and unusual monoterpene 5,5-dimethyl-1-vinylbicyclo[2.1.1]hexane [1.1 to 14.9% (median value: 10.2 %)].” The researchers were “rather surprising to find [it] in such high abundance among the volatile constituents of hashish samples since the natural occurrence of this compound was reported only once in the past as a minor constituent (<0.1%) of the essential oil of Mentha cardiaca L [Scotch Spearmint Oil].” Due to its high abundance in hash and relative scarcity elsewhere, the researchers have proposed renaming it hashishene.

You may now be wondering, how exactly is this new terpene formed? Hashishene was found to be created by the “light induced rearrangement of β-myrcene during the manufacture of hashish.” In other words, hashishene is a somewhat-degraded form of myrcene ; which is why it has the same molecular weight and formula as myrcene, though a radically different chemical structure. The researchers suspect that because “hashish is manufactured according to a lengthy process involving repetitive steps of sieving and drying of the resin-rich female heads of cannabis plants” there is plenty of opportunity for “exposure to sunlight during those drying steps [which] could therefore be reasonably considered responsible for the photolytic formation of [hashishene] from [myrcene].”

The use of hashishene as a way to detect hash samples has clear value to law enforcement and other government and research groups, as a result the researchers have already submitted “the use of 5,5-dimethyl-1-vinylbicyclo[2.1.1]hexane as volatile marker of hashish” to the European Union for patent protection. But, since hashishene has already been found in at least one other plant, Scotch Spearmint, perhaps use of this method will result in false positives. Since hashishene is a mutated form of myrcene, and myrcene exists widely in nature, in fruit like mangoes and herbs like hops, then theoretically hashishene should exist in other concentrated forms of plants, such as heavily hopped beer or potentially in essential oils used in aromatherapy. Investigating other concentrates, like heavily-hopped beers, could make for interesting follow-up research. Little is known about hashishene, including its medical properties, that will also take further study to know more.

Explore all issues of The Leaf Online’s Terpene Profile series.