Tetrahydrocannabinol (THC) is a terpenoid found in cannabis. It is the principal psychoactive constituent of cannabis and one of at least 113 total cannabinoids identified on the plant. Its chemical formula C21H30O2 includes compounds, the term THC usually refers to the delta-9-THC isomer with chemical name (−)-trans-Δ9-tetrahydrocannabinol. It is a colorless oil.
Cannabinoids are several structural classes of compounds found in the cannabis plant primarily and most animal organisms or as synthetic compounds. The most notable cannabinoid is the phytocannabinoid tetrahydrocannabinol (THC) (delta-9-THC), the primary psychoactive compound in cannabis. Cannabidiol (CBD) is also a major constituent of temperate cannabis plants and a minor constituent in tropical varieties. At least 113 distinct phytocannabinoids have been isolated from cannabis, although only four have been demonstrated to have a biogenetic origin. It was reported in 2020 that phytocannabinoids can be found in other plants such as rhododendron, licorice and liverwort, and earlier in Echinacea.
Cannabinol (CBN) is a mildly psychoactive cannabinoid that acts as a low affinity partial agonist at both CB1 and CB2 receptors. This activity at CB1 and CB2 receptors constitutes interaction of CBN with the endocannabinoid system (ECS).
Cannabidiol (CBD) is a phytocannabinoid discovered in 1940. It is one of 113 identified cannabinoids in cannabis plants, along with tetrahydrocannabinol (THC), and accounts for up to 40% of the plant's extract. As of 2022, clinical research on CBD included studies related to the treatment of anxiety, addiction, psychosis, movement disorders, and pain, but there is insufficient high-quality evidence that cannabidiol is effective for these conditions. CBD is also sold as a herbal dietary supplement promoted with unproven claims of particular therapeutic effects.
Cannabigerol (CBG) is one of more than 120 identified cannabinoid compounds found in the plant genus Cannabis. Cannabigerol is the decarboxylated form of cannabigerolic acid, the parent molecule from which other cannabinoids are synthesized.
G protein-coupled receptor 55 also known as GPR55 is a G protein-coupled receptor that in humans is encoded by the GPR55 gene.
A cannabinoid receptor antagonist, also known simply as a cannabinoid antagonist or as an anticannabinoid, is a type of cannabinoidergic drug that binds to cannabinoid receptors (CBR) and prevents their activation by endocannabinoids. They include antagonists, inverse agonists, and antibodies of CBRs. The discovery of the endocannabinoid system led to the development of CB1 receptor antagonists. The first CBR inverse agonist, rimonabant, was described in 1994. Rimonabant blocks the CB1 receptor selectively and has been shown to decrease food intake and regulate body-weight gain. The prevalence of obesity worldwide is increasing dramatically and has a great impact on public health. The lack of efficient and well-tolerated drugs to cure obesity has led to an increased interest in research and development of CBR antagonists. Cannabidiol (CBD), a naturally occurring cannabinoid and a non-competitive CB1/CB2 receptor antagonist, as well as Δ9-tetrahydrocannabivarin (THCV), a naturally occurring cannabinoid, modulate the effects of THC via direct blockade of cannabinoid CB1 receptors, thus behaving like first-generation CB1 receptor inverse agonists, such as rimonabant. CBD is a very low-affinity CB1 ligand, that can nevertheless affect CB1 receptor activity in vivo in an indirect manner, while THCV is a high-affinity CB1 receptor ligand and potent antagonist in vitro and yet only occasionally produces effects in vivo resulting from CB1 receptor antagonism. THCV has also high affinity for CB2 receptors and signals as a partial agonist, differing from both CBD and rimonabant.
Abnormal cannabidiol (Abn-CBD) is a synthetic regioisomer of cannabidiol, which unlike most other cannabinoids produces vasodilator effects, lowers blood pressure, and induces cell migration, cell proliferation and mitogen-activated protein kinase activation in microglia, but without producing any psychoactive effects.
HU-320 (7-nor-7-carboxy-CBD-1,1-DMH) is a drug related to cannabidiol, which has strong antiinflammatory and immunosuppressive properties while demonstrating no psychoactive effects.
4'-Fluorocannabidiol is a fluorinated cannabidiol derivative that has more potent anxiolytic, antidepressant, antipsychotic and anti-compulsive activity in mice compared to its parent compound. It was first synthesized in 2016, alongside 10-fluorocannabidiol diacetate and 8,9-dihydro-7-fluorocannabidiol, which showed much weaker activity.
Cannabidiol-dimethylheptyl (CBD-DMH or DMH-CBD) is a synthetic homologue of cannabidiol where the pentyl chain has been replaced by a dimethylheptyl chain. Several isomers of this compound are known. The most commonly used isomer in research is (−)-CBD-DMH, which has the same stereochemistry as natural cannabidiol, and a 1,1-dimethylheptyl side chain. This compound is not psychoactive and acts primarily as an anandamide reuptake inhibitor, but is more potent than cannabidiol as an anticonvulsant and has around the same potency as an antiinflammatory. Unexpectedly the “unnatural” enantiomer (+)-CBD-DMH, which has reversed stereochemistry from cannabidiol, was found to be a directly acting cannabinoid receptor agonist with a Ki of 17.4nM at CB1 and 211nM at CB2, and produces typical cannabinoid effects in animal studies, as does its 7-OH derivative.
8,9-Dihydrocannabidiol is a synthetic cannabinoid that is closely related to cannabidiol (CBD) itself. that was first synthesized by Alexander R. Todd in 1940 derived from the catalytic hydrogenation of cannabidiol.
Δ-8-tetrahydrocannabinol is a psychoactive cannabinoid found in the Cannabis plant. It is an isomer of delta-9-tetrahydrocannabinol, the compound commonly known as THC, with which it co-occurs in hemp; natural quantities of ∆8-THC found in hemp are low.
7-Hydroxycannabidiol (7-OH-CBD) is an active metabolite of cannabidiol, generated in the body from cannabidiol by the action of the enzyme CYP2C19. While methods have been developed for its synthetic production, and measurement of levels in the body following consumption of cannabidiol, its pharmacology has been relatively little studied, though it has been found to possess similar anticonvulsant effects to cannabidiol itself, as well as lowering blood triglyceride levels. Like its precursor CBD, it is not known to exhibit any psychoactive effects on the body and is known to counter the psychoactive effects of THC if it is present at the same time. This mode of action in 2015 was discovered to be at least contributing in part by being a non competitive negative allosteric modulator of the Cannabinoid receptor type 1.
Hexahydrocannabinol (HHC) is a hydrogenated derivative of tetrahydrocannabinol (THC). It is a naturally occurring phytocannabinoid that has rarely been identified as a trace component in Cannabis sativa, but can also be produced synthetically by hydrogenation of cannabis extracts. The synthesis and bioactivity of HHC was first reported in 1940 by Roger Adams using tetrahydrocannabinol prepared from cannabidiol.
Δ-6-cannabidiol is a positional isomer of cannabidiol, found in only trace amounts in natural cannabis plants but readily synthesised from cannabidiol by base-catalysed migration of the double bond.
11-Hydroxyhexahydrocannabinol is an active metabolite of tetrahydrocannabinol (THC) and a metabolite of the trace cannabinoid hexahydrocannabinol (HHC).
H4CBD is a cannabinoid that was first synthesized by Alexander R. Todd in 1940 derived from the catalytic hydrogenation of cannabidiol.
O-1656 is a cannabinoid agonist which was invented by Billy R Martin and Raj K Razdan at Organix Inc in 2002. It is moderately selective for the CB2 receptor with a CB1 receptor affinity of 18 nM and a CB2 receptor affinity of 2 nM. Since it has a cycloheptyl ring attached to the phenol core, it falls outside the definition of a "cyclohexylphenol derivative", but may still be controlled by generic legislation in some jurisdictions.
Cannabidiol diacetate is a semi-synthetic derivative of cannabidiol derived by acetylation of the OH groups, which presumably acts as a prodrug for CBD. It has been found as a component of grey-market cannabis products such as e-cigarette liquids and edible gummy lollies.
