Tetrahydrocannabinol (THC) is a cannabinoid found in cannabis. It is the principal psychoactive constituent of cannabis and one of at least 113 total cannabinoids identified on the plant. Although the chemical formula for THC (C21H30O2) describes multiple isomers, 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 phytocannabinoid 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).
Tetrahydrocannabivarin is a homologue of tetrahydrocannabinol (THC) having a propyl (3-carbon) side chain instead of pentyl (5-carbon), making it non-psychoactive in lower doses. It has been shown to exhibit neuroprotective activity, appetite suppression, glycemic control and reduced side effects compared to THC, making it a potential treatment for management of obesity and diabetes. THCV was studied by Roger Adams as early as 1942.
Parahexyl is a synthetic homologue of THC which was invented in 1941 during attempts to elucidate the structure of Δ9-THC, one of the active components of cannabis.
11-Hydroxy-Δ9-tetrahydrocannabinol, usually referred to as 11-hydroxy-THC is the main active metabolite of tetrahydrocannabinol (THC), which is formed in the body after Δ9-THC is consumed.
Cannabigerol (CBG) is a non-psychoactive cannabinoid and minor constituent of cannabis. It is one of more than 120 identified cannabinoids found in the plant genus Cannabis. The compound is the decarboxylated form of cannabigerolic acid (CBGA), the parent molecule from which other cannabinoids are biosynthesized.
Machaerium is a genus of flowering plants in the family Fabaceae, and was recently assigned to the informal monophyletic Dalbergia clade of the Dalbergieae. It contains the following species:
Δ9-Tetrahydrocannabutol is a phytocannabinoid found in cannabis that is a homologue of tetrahydrocannabinol (THC), the main active component of Cannabis. Structurally, they are only different by the pentyl side chain being replaced by a butyl side chain. THCB was studied by Roger Adams as early as 1942
JWH-200 (WIN 55,225) is an analgesic chemical from the aminoalkylindole family that acts as a cannabinoid receptor agonist. Its binding affinity, Ki at the CB1 receptor is 42 nM, around the same as that of THC, but its analgesic potency in vivo was higher than that of other analogues with stronger CB1 binding affinity in vitro, around 3 times that of THC but with less sedative effect, most likely reflecting favourable pharmacokinetic characteristics. It was discovered in 1991 by Sterling Drug as a potential analgesic following the earlier identification of related compounds such as pravadoline and WIN 55,212-2.
Perrottetinene is a naturally occurring cannabinoid compound found in liverworts from the genus Radula native to Japan, New Zealand and Costa Rica, namely Radula perrottetii, Radula marginata and Radula laxiramea, along with a number of similar compounds. Its chemical structure closely resembles that of THC, the main active component of marijuana but with a cis rather than trans conformation and a bibenzyl tailchain instead of pentyl. The absolute configuration of perrottetinene was established in 2008 by an enantioselective total synthesis.
KM-233 is a synthetic cannabinoid drug which is a structural analog of Δ8-tetrahydrocannabinol (THC), the less active but more stable isomer of the active component of Cannabis. KM-233 differs from Δ8-THC by the pentyl side chain being replaced by a 1,1-dimethylbenzyl group. It has high binding affinity in vitro for both the CB1 and CB2 receptors, with a CB2 affinity of 0.91 nM and 13-fold selectivity over the CB1 receptor. In animal studies, it has been found to be a potential treatment for glioma, a form of brain tumor. Many related analogues are known where the 1,1-dimethylbenzyl group is substituted or replaced by other groups, with a fairly well established structure-activity relationship.
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. Psychoactive effects are similar to that of Δ9-THC, with central effects occurring by binding to cannabinoid receptors found in various regions of the brain.
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 firstly acid cyclization of cannabidiol and then hydrogenation of tetrahydrocannabinol. The synthesis and bioactivity of HHC was first reported in 1940 by Roger Adams.
11-Hydroxyhexahydrocannabinol is an active metabolite of tetrahydrocannabinol (THC) and a metabolite of the trace cannabinoid hexahydrocannabinol (HHC).
Tetrahydrocannabihexol is a phytocannabinoid, the hexyl homologue of tetrahydrocannabinol (THC) which was first isolated from Cannabis plant material in 2020 along with the corresponding hexyl homologue of cannabidiol, though it had been known for several decades prior to this as an isomer of the synthetic cannabinoid parahexyl. Another isomer Δ8-THCH is also known as a synthetic cannabinoid under the code number JWH-124, though it is unclear whether this occurs naturally in Cannabis, but likely is due to Δ8-THC itself being a degraded form of Δ9-THC. THC-Hexyl can be synthesized from 4-hexylresorcinol and was studied by Roger Adams as early as 1942.
Δ-11-Tetrahydrocannabinol is a rare isomer of tetrahydrocannabinol, developed in the 1970s. It can be synthesised from Δ8-THC by several different routes, though only the enantiomer is known. In recent studies in 2022 it was found to "significantly reduce" the effects of Δ9-THC and has been suggested as antagonist of the CB1 receptor in humans, with the cited study showing "one partial success in the quest for an antagonist is the fact that D9,11-THC was found to significantly reduce the effect of D9-THC." and did not substitute for THC in rhesus monkeys. It has been identified as a component of grey market vaping liquids sold for use in humans.
