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: endocannabinoids; phytocannabinoids ; and synthetic cannabinoids. All endocannabinoids and phytocannabinoids are lipophilic.
Siderophores (Greek: "iron carrier") are small, high-affinity iron-chelating compounds that are secreted by microorganisms such as bacteria and fungi. They help the organism accumulate iron. Although a widening range of siderophore functions is now being appreciated, siderophores are among the strongest (highest affinity) Fe3+ binding agents known. Phytosiderophores are siderophores produced by plants.
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).
AM-251 is an inverse agonist at the CB1 cannabinoid receptor. AM-251 is structurally very close to rimonabant; both are biarylpyrazole cannabinoid receptor antagonists. In AM-251, the p-chloro group attached to the phenyl substituent at C-5 of the pyrazole ring is replaced with a p-iodo group. The resulting compound exhibits slightly better binding affinity for the CB1 receptor (with a Ki value of 7.5 nM) than rimonabant, which has a Ki value of 11.5 nM, AM-251 is, however, about two-fold more selective for the CB1 receptor when compared to rimonabant. Like rimonabant, it is additionally a μ-opioid receptor antagonist that attenuates analgesic effects.
WIN 55,212-2 is a chemical described as an aminoalkylindole derivative, which produces effects similar to those of cannabinoids such as tetrahydrocannabinol (THC) but has an entirely different chemical structure.
2-Arachidonoylglycerol (2-AG) is an endocannabinoid, an endogenous agonist of the CB1 receptor and the primary endogenous ligand for the CB2 receptor. It is an ester formed from the omega-6 fatty acid arachidonic acid and glycerol. It is present at relatively high levels in the central nervous system, with cannabinoid neuromodulatory effects. It has been found in maternal bovine and human milk. The chemical was first described in 1994–1995, although it had been discovered some time before that. The activities of phospholipase C (PLC) and diacylglycerol lipase (DAGL) mediate its formation. 2-AG is synthesized from arachidonic acid-containing diacylglycerol (DAG).
JWH-073, a synthetic cannabinoid, is an analgesic chemical from the naphthoylindole family that acts as a full agonist at both the CB1 and CB2 cannabinoid receptors. It is somewhat selective for the CB1 subtype, with affinity at this subtype approximately 5× the affinity at CB2. The abbreviation JWH stands for John W. Huffman, one of the inventors of the compound.
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.
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.
AM-694 (1-(5-fluoropentyl)-3-(2-iodobenzoyl)indole) is a designer drug that acts as a potent and selective agonist for the cannabinoid receptor CB1. It is used in scientific research for mapping the distribution of CB1 receptors.
JWH-203 (1-pentyl-3-(2-chlorophenylacetyl)indole) is an analgesic chemical from the phenylacetylindole family that acts as a cannabinoid agonist with approximately equal affinity at both the CB1 and CB2 receptors, having a Ki of 8.0 nM at CB1 and 7.0 nM at CB2. It was originally discovered by, and named after, John W. Huffman, but has subsequently been sold without his permission as an ingredient of synthetic cannabis smoking blends. Similar to the related 2'-methoxy compound JWH-250, the 2'-bromo compound JWH-249, and the 2'-methyl compound JWH-251, JWH-203 has a phenylacetyl group in place of the naphthoyl ring used in most aminoalkylindole cannabinoid compounds, and has the strongest in vitro binding affinity for the cannabinoid receptors of any compound in the phenylacetyl group.
AM-679 (part of the AM cannabinoid series) is a drug that acts as a moderately potent agonist for the cannabinoid receptors, with a Ki of 13.5 nM at CB1 and 49.5 nM at CB2. AM-679 was one of the first 3-(2-iodobenzoyl)indole derivatives that was found to have significant cannabinoid receptor affinity, and while AM-679 itself has only modest affinity for these receptors, it was subsequently used as a base to develop several more specialised cannabinoid ligands that are now widely used in research, including the potent CB1 agonists AM-694 and AM-2233, and the selective CB2 agonist AM-1241. AM-679 was first identified as having been sold as a cannabinoid designer drug in Hungary in 2011, along with another novel compound 1-pentyl-3-(1-adamantoyl)indole.
Neocosmospora is a genus of fungi in the family Nectriaceae.
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.
JWH-185 is a synthetic cannabinoid receptor ligand from the naphthoylindole family. It is the carbonyl-reduced derivative of related compound JWH-081. The binding affinity of JWH-185 for the CB1 receptor is reported as Ki = 17 ± 3 nM.
JWH-196 is a synthetic cannabinoid receptor ligand from the naphthylmethylindole family. It is the indole 2-methyl derivative of related compound JWH-175, and the carbonyl reduced analog of JWH-007. The binding affinity of JWH-196 for the CB1 receptor is reported as Ki = 151 ± 18 nM.
Endomorphin-1 (EM-1) (amino acid sequence Tyr-Pro-Trp-Phe-NH2) is an endogenous opioid peptide and one of the two endomorphins. It is a high affinity, highly selective agonist of the μ-opioid receptor, and along with endomorphin-2 (EM-2), has been proposed to be the actual endogenous ligand of the μ-receptor. EM-1 produces analgesia in animals and is equipotent with morphine in this regard. The gene encoding for EM-1 has not yet been identified, and it has been suggested that endomorphins could be synthesized by an enzymatic, non-ribosomal mechanism.
Tetrahydrocannabiphorol (THCP) is a potent phytocannabinoid, a CB1 and CB2 agonist which was known as a synthetic homologue of THC, but for the first time in 2019 was isolated as a natural product in trace amounts from Cannabis sativa. It is structurally similar to Δ9-THC, the main active component of cannabis, but with the pentyl side chain extended to heptyl. Since it has a longer side chain, its cannabinoid effects are "far higher than Δ9-THC itself." Tetrahydrocannabiphorol has a reported binding affinity of 1.2 nM at CB1, approximately 33 times that of Δ9-THC (40 nM at CB1).
ADB-BINACA is a cannabinoid designer drug that has been found as an ingredient in some synthetic cannabis products. It was originally developed by Pfizer as a potential analgesic, and is a potent agonist of the CB1 receptor with a binding affinity (Ki) of 0.33 nM and an EC50 of 14.7 nM.
