A phytocannabinoid is a cannabinoid of plant origin. In cannabis they are terpenophenolics: a phenolic ring from olivetolic acid joined to a terpene chain from geranyl pyrophosphate, forming CBGA, which enzymes then convert into THCA, CBDA or CBCA. The plant makes them almost entirely as carboxylic acids in the secretory cells of capitate glandular trichomes and stores them in the resin head.
In practice
When a COA lists THCA, CBDA, CBGA, THCVA and CBCA, every one of those is a phytocannabinoid. Hanuš and colleagues catalogued well over 100 from cannabis, but most growers will only ever see five to eight on a standard panel. A few plants outside the genus (some liverworts, some Helichrysum species) also make cannabinoid-like compounds, which is why the term is broader than "cannabis compound".
Don't confuse with
- Endocannabinoid: made by animals, including humans, not by plants.
- Semi-synthetic cannabinoid: such as delta-8 THC or HHC as sold, produced by chemically converting plant CBD or THC rather than by the plant itself.
- Terpene: a different compound class, though it supplies part of the cannabinoid skeleton.
A cannabinoid is any compound that binds the body's cannabinoid receptors or shares the typical cannabis terpenophenolic structure; the plant-made ones are phytocannabinoids such as THCA and CBDA.Terpenes are volatile hydrocarbon compounds built from five-carbon isoprene units; in cannabis they are made in the trichome heads and are a major part of aroma and flavour.Geranyl pyrophosphate (GPP) is a ten-carbon terpene precursor that cannabis uses both to build monoterpenes and, joined to olivetolic acid, to make the cannabinoid precursor CBGA.CBGA (cannabigerolic acid) is the precursor cannabinoid that the plant converts into THCA, CBDA or CBCA, formed by joining olivetolic acid to geranyl pyrophosphate.THCA (tetrahydrocannabinolic acid) is the acid cannabinoid that drug-type cannabis makes in its trichomes; heat or time decarboxylates it into THC, losing about 12% of its mass.CBDA (cannabidiolic acid) is the acid cannabinoid made by CBDA synthase from CBGA; it dominates hemp-type and CBD-type cannabis and decarboxylates to CBD.THC (Δ9-tetrahydrocannabinol) is the neutral, decarboxylated cannabinoid mainly responsible for cannabis's reported intoxicating effects; the living plant makes it almost entirely as THCA.CBD (cannabidiol) is a non-intoxicating neutral cannabinoid formed when CBDA decarboxylates; hemp-type and CBD-dominant cannabis make it mainly as CBDA in their trichomes.Trichome heads are the bulbous resin-filled tops of capitate glandular trichomes, where cannabis makes and stores nearly all its cannabinoids and terpenes; they are the raw material of hash.Olivetolic acid is the phenolic building block of cannabinoids; joined to geranyl pyrophosphate it forms CBGA, and its five-carbon chain becomes the pentyl tail of THC and CBD.
