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.
Cannabinoid receptors, located throughout the body, are part of the endocannabinoid system of vertebrates– a class of cell membrane receptors in the G protein-coupled receptor superfamily. As is typical of G protein-coupled receptors, the cannabinoid receptors contain seven transmembrane spanning domains. Cannabinoid receptors are activated by three major groups of ligands:
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.
G protein-coupled receptor 55 also known as GPR55 is a G protein-coupled receptor that in humans is encoded by the GPR55 gene.
Cannabinoid receptor 1 (CB1), is a G protein-coupled cannabinoid receptor that in humans is encoded by the CNR1 gene. The human CB1 receptor is expressed in the peripheral nervous system and central nervous system. It is activated by endogenous cannabinoids called endocannabinoids, a group of retrograde neurotransmitters that include lipids, such as anandamide and 2-arachidonoylglycerol (2-AG); plant phytocannabinoids, such as docosatetraenoylethanolamide found in wild daga, the compound THC which is an active constituent of the psychoactive drug cannabis; and synthetic analogs of THC. CB1 is antagonized by the phytocannabinoid tetrahydrocannabivarin (THCV).
The cannabinoid receptor 2(CB2), is a G protein-coupled receptor from the cannabinoid receptor family that in humans is encoded by the CNR2 gene. It is closely related to the cannabinoid receptor 1 (CB1), which is largely responsible for the efficacy of endocannabinoid-mediated presynaptic-inhibition, the psychoactive properties of tetrahydrocannabinol (THC), the active agent in cannabis, and other phytocannabinoids. The principal endogenous ligand for the CB2 receptor is 2-Arachidonoylglycerol (2-AG).
O-1057 is an analgesic cannabinoid derivative created by Organix Inc., Newburyport, Massachusetts, for use in scientific research. Unlike most cannabinoids discovered to date, it is water-soluble, which gives it considerable advantages over many related cannabinoids. It has moderate affinity for both CB1 and CB2 receptors, with Ki values of 8.36 nM at CB1 and 7.95 nM at CB2
O-1125 (3-(1,1-dimethylhexyl-6-dimethylcarboxamide)-Δ8-tetrahydrocannabinol) is a research chemical which is a cannabinoid derivative. It has analgesic effects and is used in scientific research. It is a potent CB1 full agonist with a Ki of 1.16 nM.
CP 55,244 is a chemical compound which is a cannabinoid receptor agonist. It has analgesic effects and is used in scientific research. It is an extremely potent CB1 full agonist with a Ki of 0.21 nM, making it more potent than the commonly used full agonist HU-210.
JWH-030 is a research chemical which is a cannabinoid receptor agonist. It has analgesic effects and is used in scientific research. It is a partial agonist at CB1 receptors, with a Ki of 87 nM, making it roughly half the potency of THC. It was discovered and named after John W. Huffman.
L-759,633 is an analgesic drug that is a cannabinoid agonist. It is a fairly selective agonist for the CB2 receptor, with selectivity of 163x for CB2 over CB1.
L-759,656 is an analgesic drug that is a cannabinoid agonist. It is a highly selective agonist for the CB2 receptor, with selectivity of 414x for CB2 over CB1, although it is still not as selective as newer agents such as HU-308.
O-806 is a drug which is a cannabinoid derivative that is used in scientific research. It is described as a mixed agonist/antagonist at the cannabinoid receptor CB1, meaning that it acts as an antagonist when co-administered alongside a more potent CB1 agonist, but exhibits weak partial agonist effects when administered by itself.
O-1238 is a drug which is a cannabinoid derivative that is used in scientific research. It is a partial agonist at the cannabinoid receptor CB1, producing a maximal stimulation of 58.3% with a Ki of 8.45 nM.
AM-1241 (1-(methylpiperidin-2-ylmethyl)-3-(2-iodo-5-nitrobenzoyl)indole) is a chemical from the aminoalkylindole family that acts as a potent and selective agonist for the cannabinoid receptor CB2, with a Ki of 3.4 nM at CB2 and 80 times selectivity over the related CB1 receptor. It has analgesic effects in animal studies, particularly against "atypical" pain such as hyperalgesia and allodynia. This is thought to be mediated through CB2-mediated peripheral release of endogenous opioid peptides, as well as direct activation of the TRPA1 channel. It has also shown efficacy in the treatment of amyotrophic lateral sclerosis in animal models.
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 or sedative effects. Abn-CBD can be found as an impurity in synthetic cannabidiol.
A-834,735 is a drug developed by Abbott Laboratories that acts as a potent cannabinoid receptor full agonist at both the CB1 and CB2 receptors, with a Ki of 12 nM at CB1 and 0.21 nM at CB2. Replacing the aromatic 3-benzoyl or 3-naphthoyl group found in most indole derived cannabinoids with the 3-tetramethylcyclopropylmethanone group of A-834,735 and related compounds imparts significant selectivity for CB2, with most compounds from this group found to be highly selective CB2 agonists with little affinity for CB1. However, low nanomolar CB1 binding affinity is retained with certain heterocyclic 1-position substituents such as (N-methylpiperidin-2-yl)methyl (cf. AM-1220, AM-1248), or the (tetrahydropyran-4-yl)methyl substituent of A-834,735, resulting in compounds that still show significant affinity and efficacy at both receptors despite being CB2 selective overall.
AM-630 (6-Iodopravadoline) is a drug that acts as a potent and selective inverse agonist for the cannabinoid receptor CB2, with a Ki of 32.1 nM at CB2 and 165x selectivity over CB1, at which it acted as a weak partial agonist. It is used in the study of CB2 mediated responses and has been used to investigate the possible role of CB2 receptors in the brain. AM-630 is significant as one of the first indole derived cannabinoid ligands substituted on the 6-position of the indole ring, a position that has subsequently been found to be important in determining affinity and efficacy at both the CB1 and CB2 receptors, and has led to the development of many related derivatives.
