Structurally, CDB and THC are very similar. However, they differ significantly in their mode of action and properties. CBD is non-psychoactive cannabinoid, owing to its very weak ability to activate the CB1 receptor. Indeed, CBD has been classified as an allosteric modulator of CB1, meaning that it modifies the receptor in such a way that binding of cannabinoids, such as anandamide or THC, are dramatically reduced. As such, CBD is free of psycho-active properties and is devoid of intoxicating effects.
In The Presence of Acid CBD Converts to THC:
At the same time, CBD in solution is very unstable. It needs to be stored at temperatures below 80C and be protected from light. Under acidic conditions, CBD can be converted to THC and other cannabinoids, by a process of isomerization.
This has at least two implications: 1) that CBD in ingested cannabis-containing products may be converted to THC in the acidic environment of the stomach due to the presence of stomach acid and 2) that CBD can be converted to THC chemically, by a series of acid extraction and purification techniques.
Can CBD Convert to THC in Your Stomach?
The possibility of CBD converting to THC in the stomach was recently explored. Importantly, this conversion would never occur using other methods of consumption, such as inhalation or topicals.
In one study, gastric fluid was made artificially and adjusted to pH 1 (which is that of the actual gastric fluid) and CBD was dissolved in methanol. About 85% of the present CBD isomerized to a mixture of D9- and D8-THC.
In another study the composition of gastric juice was different that stomach acid pH and the conversion rate to THC was only 2.9%.
It is apparent that different composition of the in vitro gastric fluid produces very different results, advising that the interpretation of these data should be done with caution. Additionally, the gastric fluid in your body contains a plethora of gastric enzymes, such as pepsin, gastrin, amylase, and various inorganic ions, such as potassium, sodium and calcium. Since CBD is capable of significant protein binding, it is possible that in the stomach it is protected from the acidic environment via this mechanism. Therefore, it remains true that in biological systems, such as the human GI tract, there have been no conclusive reports of CBD conversion to THC.
Patent to Convert CBD to THC in the Works:
Still, theoretically, because of similar chemical structure between CBD and THC, the possibility of CBD conversion to THC, using a series of acid treatments and extraction by chromatography techniques, remains valid. Indeed, a patent application has been filed describing the series of steps to accomplish this.
The utility of this conversion can be appreciated when considering how certain cannabinoids, such as D8-THC, are very minor constituents of most varieties of the cannabis plant. D8-THC is considered to be about 50% less potent than D9-THC in psychoactive effects, but it was also shown to be 200% more effective as an anti-nauseant than D9-THC.
In this patent, CBD is dissolved in an organic solvent (i.e. toluene). Then the organic and aqueous phases were separated by evaporating the aqueous phase and passed through a high performance liquid chromatography purification. This is done using a column made of silica gel, which yielded 86% D8-THC.
The entire reaction is performed under nitrogen atmosphere, rather than room air. This is to prevent oxidation of the reaction intermediates, which is expected to increase the yield of the pure compound. Changing the starting organic solvent to methylene chloride and with a few modification steps, the same extraction and purification protocol yields D9-THC at about 57% efficiency, which as 98.7% pure.
Not a DIY Project:
Therefore, chemical isomerization of CBD to D8- and D9-THC is possible in a well-equipped chemistry laboratory set-up. The instruments needed for extraction and purification, such as HPLC and gas chromatography mass spectrometer are rather pricey luxury items. And knowing how to operate them requires years of work and deep understanding of the principles of organic chemistry. In other words, successful completion of these procedures definitely necessitates the professional set-up rather than one’s kitchen or a garage.