Cannabigerol CBG: The main precursor to all cannabinoids
What is CBG?
- Name: Cannabigerol
- Formula: C21H32O2
- IUPAC name: 2-[(2E)-3,7-dimethylocta-2,6-dienyl]-5-pentylbenzene-1,3-diol
- Molecular mass: 316,48 g/mol
- Boiling point: Not available
- Apearance: White powder/crystals
Discovered by Gaoni and Mechoulam in 1964, CBG or cannabigerol is one of the cannabinoids exclusively produced by the cannabis plant, which is stored in the trichome heads with the rest of cannabinoids and terpenes. While the CBG content in most plants is often low or very low - in most cases lower than 1% - this particular compound is crucial for cannabinoid synthesis, as we have known for the past 4 decades ( (Shoyama, Yagi and Nishioka, Phytochemistry Journal, October 1975). As a general rule, hemp contains higher amounts of CBG than commercial, narcotic cannabis strains.
CBG is a non-psychoactive phytocannabinoid, which means it is produced by plants and does not "get you high". It is believed that it has multiple medicinal properties which can be used to treat different conditions, and is also precursor - its acid form, to be exact - to the main cannabinoids (THCA, CBDA, CBCA) secreted in the trichome heads, which in turn explains the low percentage of CBG found in mature plants when compared to their THC or CBD content.
CBG and the synthesis of cannabinoids
Cannabinoid synthesis in marijuana plants starts with the production of cannabigerolic acid or CBGA - the acid form of CBG, whose formula is C22H32O4 - in the trichome heads from the combination between olivetolic acid (and/or divarinic acid) and geranyl pyroshosphate (the combination with divarinic acid produces cannabigevarolic acid or CBGVA). After a series of reactions caused by the production of specific synthases (enzymes)- which are named depending on the cannabinoid they produce - CBGA is transformed into the acid form of the three main cannabinoids:
- THCA or tetrahydrocannabinolic acid, which is produced from enzyme THCA-synthase
- CBDA or cannabidiolic acid, produced by the action of enzyme CBDA-synthase
- CBCA or cannabichromenic acid, which is produced by enzyme CBCA-synthase
As we mentioned, this rapid transformation explains the low CBG content found in cannabis strains, while the THC and CBD content is normally much higher. If cannabinoids produced from CBGA (THCA, CBDA, CBCA) are heated or aged (UV light), they'll lose a CO2 molecule and will turn into their active - decarbed - form, THC, CBD and CBC, a process called decarboxylation.
Normally, hemp strains contain more CBG than narcotic cannabis varieties. According to studies, this could be caused by a recessive gene which inhibits the production of some of the aforementioned synthases, so that most CBG produced will not be transformed into other cannabinoids by these enzymes.
In this way, and by using this recessive gene, some cannabis breeders are developing CBG-rich strains just in the same way they first produced THC hybrids and then CBD strains. Thus, breeders like TGA Subcool are already developing new genetics with high CBG content, as is the case with Galactic Jack or Nurse Jackie. Moreover, and if you're interested in getting higher CBG ratios, recent studies show that CBG content is higher a few weeks prior to what we understand as optimal harvest point, around week 6 in strains that we'd normally harvest by week 8.
Properties and effects of cannabigerol (CBG)
Until today, the therapeutic properties of CBG have not been studied as thoroughly as those of other compounds produced by the cannabis plant, like THC or CBD. Despite that fact, and as happens with cannabinol (CBN), there is a growing interest in these secondary molecules, with an increasing number of scientific studies about them. Next we highlight the most important and well documented medicinal effects of CBG:
- Reduction of intraocular pressure (Glaucoma)
- Antibiotic and antibacterial effect (probably, the most efficient cannabinoid in this regard)
- Prevention of colon carcinogenesis
- Inhibits growth of cancer cells
- Inflammations of the digestive system (Crohn's disease, ulcerative colitis, bowel inflammation)
- Relief of pain and anxiety
- Neuroprotective properties (multiple sclerosis, Huntington's disease and other neurodegenerative conditions)
- Antiseptic properties (treatment of MRSA, Methicillin-resistant Staphylococcus aureus)
- Inhibits the uptake of GABA (anxiety, muscle tension)
- Stimulates appetite (cachexia)
- Stimulates bone formation and healing
- Antispasmodic effect (Dravet syndrome, epilepsy)
As often happens, the effects of CBG are enhanced when used along with other cannabinoids and terpenes, in what is called entourage effect. CBG is classified as antagonist of the CB-1 receptor, which affects the central nervous system. That's why it is believed that it could counter the effects of THC. Furthermore, it has been proved that CBG also affects the CB-2 receptor, although more studies are needed in order to determine whether it promotes or inhibits the activity of this receptor.
The future of CBG
As we mentioned before, cannabis breeders are already developing strains rich in CBG. While it is hard to believe that they'll reach the THC or CBD content of existing varieties, the appearance of these genetics will surely facilitate the production of CBG extracts, also the creation of strains with wider cannabinoid content. It is believed that CBG produces a more balanced effect in narcotic cannabis strains, reducing both anxiety and the feeling of "being high". Varieties like Nurse Jackie, Querkle or Galactic Jack (all from TGA Subcool) have avobe-average CBG content, as well as Sick Meds Williams Wonder, Wonder Kush or Psycho Crack, or the wonderful Lemon OG Candy from Philosopher Seeds.
Scientific research also glimpse a very interesting future for CBG as inseticide and fungicide. Indeed, it efficiently repels insects when combined with limonene, and is a great fungicide when combined with caryophyllene, a sesquiterpene commonly found in different plants.
Without a doubt, we're facing a very special moment in regard with cannabinoid research. More and more data is being collected from the scientific community, which demonstrates the high therapeutic potential of these molecules and grants them a very promising future in preventing and treating a large number of medical conditions and symptoms.
CBG products, extracts and concentrates
Today, and as happens with CBD products, you can find several CBG extracts and concentrates, something unimaginable just a few years ago. As an example, we offer Ekati CBG extract and Pharmahemp's 97% CBG Crystals.
We hope this knowledge flow about these interesting compounds will not cease!
Studies and publications on CBG consulted for the writing of this article:
- Colon carcinogenesis is inhibited by the TRPM8 antagonist cannabigerol, a Cannabis-derived non-psychotropic cannabinoid.
Borrelli F, Pagano E, Romano B, Panzera S, Maiello F, Coppola D, De Petrocellis L, Buono L, Orlando P, Izzo AA
- A Comparison of the Ocular and Central Effects of ?9-Tetrahydrocannabinol and Cannabigerol. Brenda K. Colasanti
- Interaction between non-psychotropic cannabinoids in marihuana: effect of cannabigerol (CBG) on the anti-nausea or anti-emetic effects of cannabidiol (CBD) in rats and shrews. Erin M. Rock, Jennifer M. Goodwin, Cheryl L. Limebeer, Aviva Breuer, Roger G. Pertwee, Raphael Mechoulam, Linda A. Parker
- Beneficial effect of the non-psychotropic plant cannabinoid cannabigerol on experimental inflammatory bowel disease. Borrelli F, Fasolino I, Romano B, Caspasso R, Maiello F, Coppola D, Orlando P, Battista G, Pagano E
- Evidence that the plant cannabinoid cannabigerol is a highly potent alpha(2)-adrenoceptor agonist and moderately potent 5HT receptor antagonist. Cascio MG, Gauson LA, Stevenson LA, Ross RA, Pertwee R
- Taming THC: potential cannabis synergy and phytocannabinoid-terpenoid entourage effects. Ethan B. Russo
- Biosynthesis of cannabinoid acids. Yukihiro Shoyama, Masahiro Yagi, Itsuo Nishioka
- Antibacterial cannabinoids from Cannabis sativa: a structure-activity study. Appendino G, Gibbons S, Giana A, Pagani A, Grassi G, Stavri M, Smith E, Rahman MM
- Neuroprotective properties of cannabigerol in Huntington?s disease: studies in R6/2 mice and 3-nitropropionate-lesioned mice. Valdeolivas S, Navarrete C, Cantarero I, Bellido ML, Muñoz E, Sagredo O.