Tetrahydrocannabivarin (THCV) is one of the better-studied and most medically important of the known cannabinoids. It is thought to act as an antagonist of the cannabinoid receptors at low doses, but surprisingly, it may act as an agonist at high doses, giving effects similar to THC.
Since its discovery in 1973, THCV has gradually grown in importance within medical circles, and over the last ten years or so, research into its pharmacological properties has started to intensify. Like CBD, it is thought to have important roles to play in the regulation of the immune system, particularly with regards to inflammation and inflammatory pain.
Chemical Structure & Properties of THCV
THCV is a molecule with the chemical formula C??H??O?, containing nineteen atoms of carbon, twenty-six of hydrogen and two of oxygen. As with all other known phytocannabinoids, THCV is an oily compound that is insoluble in water but highly soluble in lipid-based solvents.
THCV is structurally very similar to THC. Its atoms are arranged almost identically, creating a similar 3D structure to the molecule. However, THC has a side-chain composed of a pentyl group (-C?H??), whereas THCV has a side-chain composed of a propyl group (-CH?CH?CH?). Just like THC, THCV has various isomers; the more common isomer is Δ?-THCV, while Δ?-THCV is somewhat rarer.
THCV is not the only cannabinoid that has a propyl group instead of a pentyl group. Other propyl cannabinoids corresponding to major pentyl cannabinoids are known to exist, such as cannabidivarin (CBDV; homologous to CBD) and cannabivarin (CBV; homologous to CBN); all these propyl cannabinoids have the suffix “varin”.
How is THCV Produced By the Cannabis Plant?
Many cannabinoids, including THC and CBD, are produced via the precursor cannabigerolic acid (CBGA), which is formed as a result of the reaction between the two compounds, olivetolic acid and geranyl pyrophosphate.
However, THCV and is formed via a slightly different mechanism. Instead of reacting with olivetolic acid, geranyl pyrophosphate reacts with divarinolic acid, a molecule that is very similar but has two carbon atoms fewer.
This reaction leads to the formation of cannabigerovarinic acid (CBGVA), which then reacts with an enzyme known as THCV synthase (similar to the THC synthase that aids in the production of THC) to form tetrahydrocannabivarin carboxylic acid (THCVA). THCVA is then broken down via an identical process of decarboxylation to produce THCV.
A study published in the American Journal of Botany in 2004 tested landrace populations from across the world to determine their cannabinoid content and ratios. THCV was found to be present in all varieties, with higher concentrations in feral C. indica populations originating in central/southeast Asia and southern Africa.
In another study conducted in 1973 by the pharmaceutical company Syntex, one South African strain was found to have THCV levels of a staggering 53.7 percent, while an Afghani variant was found to contain 48.2 percent.
Commercial indoor varieties rarely have THCV levels this high. However, a handful of strains have now been developed with the aim of maximising THCV levels, such as Doug’s Varin, a mysterious strain (of which the seeds are apparently not yet available) tested by Steep Hill Labs and found to contain 21.1% THC and 24.3% THCV in the decarboxylated sample.
The Importance of THCV in Medicine
THCV, along with several other cannabinoids, binds to special “receptor” sites in the body that are located in the brain, within the major organs, and throughout the cells of the immune system. These “receptors” are specialised proteins situated at the presynaptic junctions between neurons (nerve cells). So far two major receptors associated with cannabinoids have been identified – cannabinoid receptors type I & II, or CB? and CB?.
THCV is capable of binding to both the CB? and CB?-receptors. Interestingly, it also seems that THCV exerts either an agonising or antagonising effect on the CB?-receptor, depending on dose. In small doses, THCV appears to antagonise (block) the CB?-receptor, while in higher doses it actually appears to have an agonising effect similar to THC!
Thus, there is a strong argument for considering THCV to be another psychoactive compound – and there is evidence to suggest that its effect can in some respects be complementary to that of THC itself. According to Steep Hill Labs, THCV has a more energetic and active effect than THC, and also appears to counteract the “couch-lock” effect of the monoterpene myrcene.
Studies on THCV have demonstrated that it has strong potential as a means of treating obesity-related glucose intolerance in diabetics, as well as having marked anti-inflammatory effects. It has also been shown that THCV has the ability to significantly reduce seizure activity in rats, similarly to CBD, which indicates its value as a target of research for disorders such as epilepsy.