THCV – Tetrahydrocannabivarin
„Cannabis sativa: The Plant of the Thousand and One Molecules“ is the title of a paper by Andre et al. which eloquently shows the complexity and immense therapeutic potential of this plant. Cannabis sativa L. is most known for its cannabinoids and is the only plant that produces them in such high quantities. 
Besides phytocannabinoids (plant-cannabinoids) there are a vast number of other compounds such as terpenes, flavonoids, strereoids and fatty acids that all together have a synergistic effect on the efficacy of cannabis therapy. 
In the past, most of the research has been concentrated on the psychotropic compound delt-9-tetrahydrocanabinol (THC), while other „lesser “cannabinoids have been mainly overlooked. One of the overlooked minor cannabinoids is THC’s little brother, (THCV).
The two cannabinoid families
There are two major cannabinoid “families” that dominate the cannabis plant and the difference is only in 2 carbon atoms. The pentyls have a phenolic sidechain of five carbon atoms, while the propyls have only three. This difference is due to two different acids being used in the synthesis of phytocannabinoid precursors. If olivetolic acid is combined with geranyl pyrophosphate, we get cannabigerolic acid (CBGa). CBGa can then be converted to other cannabinoid acids depending on the acid sythethase that is present. THCa sythethase transforms it into THCa, CBDa synthethase into CBDa and CBCa synthethase into CBCa.
If instead of olivetolic acid, divarinolic acid is combined with geranyl pyrophosphate, we get cannabigerovarinic acid (CBGVa). The same acid synthetases that convert the pentlys also convert the propyls; THCa sythethase transforms it into THCVa, CBDa synthethase into CBDVa and CBCa synthethase into CBCVa
The discovrery of THCV
THCV was fist isolated in 1970 by Gill et al. by extracting it from a licensed cannabis tincture, that was available in UK at the time. The tincture was legally imported and made from Pakistani grown cannabis. The tinctures main constituents were THC (2,4%) and THCV (2%), an interesting 5:4 ratio, that can also be found in newer chemotypes (Doug’s Varin). 
As a side note, the propyl analog of CBD, cannabidivarin (CBDV) was isolated, as so many other cannabinoids, form hashish, by Vollner et al., in 1969. 
High THCV chemovars
THCV is inherently rare in the usual cannabis “strains” and it has been difficult to find chemovars with high percentages of this cannabinoid. Higher levels of this cannabinoid have been usually found in certain Asian and African landraces.
GW Pharma has developed their high THCV strain from selective inter-breeding of high 1:1 THC: THCV landraces (China, South Africa) and named (California orange, Malawi Gold) chemovars. By a selective process of self-pollination and cross breeding of the phenotypes with the highest levels of the propyl cannabinoids, they obtained a genotype with 96% of total propyl cannabinoids. 
One of the most well-known chemovars, with a high THCV, is the appropriately named Doug’s Varin. In tests done by Steep Hill Labs, they detected 19 % THC-A and a whopping 15% THCV-A. The main terpenes were beta-myrcene 1,5%, pinene 0,53 and limonene 0,48. They also performed an analysis on decarboxylated kief of this chemovar, and they measured 24,25% THCV and 21,13% of THC. The only measured terpene in the decarboxylated kief was beta-myrcene (0,38%), which shows us, how the monoterpenes are lost during this process. 
Recently, some chemovars have tested higher THCV values such as Jack el frutero (6%), Jack the Ripper (6%), Pink Boost Goddess (5%), and Black beauty (3-4%).
There might be other chemovars containing higher percentages of THCV, but sadly, a lot of analytical laboratories, still do not test for the presence of this cannabinoid.
THCV part 2
In the second part of this 2 part THCV article, I will be tackling the important question of THCV’s psychotropic effects (or lack thereof), its potential therapeutic applications in various diseases and if it really is the “skinny” cannabinoid.
- Andre et al. Cannabis sativa: The Plant of the Thousand and One Molecules . 2016, Frontiers in plant science
- Roger Pertwee. The Handbook of Cannabis. 2014, Pages 14-19
- Gill et al. Preliminary experiments on the chemistry and pharmacology of cannabis. 1970, Nature 228:134–136
- Vollner, L., Bieniek, D., and Korte, F. (1969). Haschisch XX. Cannabidivarin, ein neuer Haschischinhaltsstoff. Tetrahedron Letters, 3, 145–147.
- P. M. de Meijer, E & M. Hammond, K. The inheritance of chemical phenotype in Cannabis sativa L. (V): regulation of the propyl-/pentyl cannabinoid ratio, completion of a genetic model. 2016, Euphytica. 210.
- THCV Update: Doug’s Varin Strain. 2014 http://steephilllab.com/thcv-update-dougs-varin-strain/