While the cannabinoids delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD) are the most well-known compounds found in the cannabis sativa plant, one of the cannabinoids that regularly flies under the radar is cannabigerol or CBG.
Although we’ve written about CBG’s health benefits and mechanisms of action in a previous article, one area we did not touch on was its role as a “stem cell” cannabinoid – or a cannabinoid that is capable of giving rise to other kinds of cannabinoids.
To briefly recap, CBG was first discovered in the 1960s by cannabis research pioneers Yechiel Gaoni and Raphael Mechoulam. It is found in higher concentrations in hemp strains of cannabis (likely due to a recessive trait, which may imply higher amounts of CBGA) and unlike THC, it is a non-psychoactive cannabinoid.
However, what’s interesting about CBG is that its precursor, cannabigerolic acid (CBGA), is the first biogenic cannabinoid formed in the plant and that it is in fact known as the “mother cannabinoid” in the maturing cannabis flower – a parent molecule from which other cannabinoids are made.
This unique trait makes CBG one of the most important components of cannabis since without CBG, the powerful cannabinoids we’ve discovered over the last several decades would simply not exist.
CBG makes the medicinal effects of cannabis possible
Part of the cannabinoid biosynthetic pathway of the cannabis plant is the formation of cannabigerolic acid (CBGA). The “A” in CBGA refers to the presence of a certain chemical structure called carboxylic acid. Through biosynthesis, CBGA is produced by the alkylation of olivetolic acid with geranyl pyrophosphate by an enzyme called geranylpyrophosphate:olivatolate geranyltransferase.
From this point, CBGA can undergo a number of changes before ultimately producing the most common cannabinoids delta-9-tetrahydrocannabinol (THC), cannabidiol (CBD), cannabichromene (CBC), and CBG.
The process that produces the cannabinoids involves the exposure of CBGA to genetically encoded “switches” or enzymes which will direct CBGA towards a specific outcome. The three different enzymes are the THCA synthase, the CBDA synthase, or the CBCA synthase, with the amount of each enzyme determined by the genetics of the plant.
These “switches” then fold CBGA molecules into either the acidic form of THC, the acidic form of CBD, or the acidic form of CBC.
Finally, in a process called decarboxylation (the elimination of a carboxylic acid group from the chemical structure), light or heat converts THCA, CBDA, and CBCA into their neutral forms of THC, CBD, and CBC, respectively. CBGA itself converts to its non-acidic form, CBG, when heated as well.
The “mother cannabinoid”
As you can see, while CBGA itself provides a defense mechanism for the plant, its role as a parent molecule is much more important since the presence of CBGA is crucial for the biosynthetic pathway that produces the major cannabinoids THC, CBD, CBC, and CBG.
Simply put, these major cannabinoids are responsible for the many of the cannabis plant’s most powerful medicinal effects. Without their foundational precursor, the cannabinoids – and their powerful health benefits – would cease to exist.
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