AM-411 is an analgesic drug that is a cannabinoid agonist. It is a derivative of Δ8-THC substituted with an adamantyl group at the 3-position, demonstrating that the binding pocket for the alkyl chain at this position can accommodate significant bulk.
AMG-3 (part of the AM cannabinoid series) is an analgesic drug which is a cannabinoid agonist. It is a derivative of Δ8-THC substituted with a dithiolane group on the 3-position side chain. AMG-3 is a potent agonist at both CB1 and CB2 receptors with a Ki of 0.32 nM at CB1 and 0.52 nM at CB2, and its particularly high binding affinity has led to it being used as a template for further structural development of novel cannabinoid drugs. It has sedative and analgesic effects, with analgesia lasting for up to 36 hours after administration.
AMG-36 (part of the AM cannabinoid series) is an analgesic drug which is a cannabinoid agonist. It is a derivative of Δ8-THC substituted with a cyclopentane group on the 3-position side chain. AMG-36 is a potent agonist at both CB1 and CB2 with moderate selectivity for CB1, with a Ki of 0.45 nM at CB1 vs 1.92 nM at CB2.
AMG-41 (part of the AM cannabinoid series) is an analgesic drug which is a cannabinoid agonist. It is a derivative of Δ8-THC substituted with a cyclopropyl group on the C1'-position of the C3-alkyl side chain. AMG-41 is a potent agonist at both CB1 and CB2, with a Ki of 0.44 nM at CB1 vs 0.86 nM at CB2.
AM-905 (part of the AM cannabinoid series) is an analgesic drug which is a cannabinoid agonist. It is conformationally restricted by virtue of the double bond on its side chain, leading an increased affinity for and selectivity between CB1 and CB2 receptors. It is a potent and reasonably selective agonist for the CB1 cannabinoid receptor, with a Ki of 1.2 nM at CB1 and 5.3 nM at CB2.
AM-855 (part of the AM cannabinoid series) is an analgesic drug which is a cannabinoid agonist. It is a derivative of Δ8Tetrahydrocannabinol with a conformationally restricted side chain which has been bound into a fourth ring fused to the aromatic A-ring of the cannabinoid skeleton. AM-855 is an agonist at both CB1 and CB2 with moderate selectivity for CB1, with a Ki of 22.3 nM at CB1 and 58.6 nM at CB2.
AMG-1 (part of the AM cannabinoid series) is an analgesic drug which is a cannabinoid agonist. It is a derivative of Δ8-THC with a rigidified and extended 3-position side chain. AMG-1 is a potent agonist at both CB1 and CB2 with moderate selectivity for CB1, with a Ki of 0.6 nM at CB1 vs 3.1 nM at CB2.
AM-919 is an analgesic drug which is a cannabinoid receptor agonist. It is a derivative of HU-210 which has been substituted with a 6β-(3-hydroxypropyl) group. This adds a "southern" aliphatic hydroxyl group to the molecule as seen in the CP-series of nonclassical cannabinoid drugs, and so AM-919 represents a hybrid structure between the classical dibenzopyran and nonclassical cannabinoid families.
AM-938 (part of the AM cannabinoid series) is an analgesic drug which is a cannabinoid receptor agonist. It is a derivative of HU-210 which has been substituted with a 6β-(3-hydroxyprop-1-ynyl) group. This adds a "southern" aliphatic hydroxyl group to the molecule as seen in the CP-series of nonclassical cannabinoid drugs, and so AM-938 represents a hybrid structure between the classical and nonclassical cannabinoid families, with the 6-hydroxyalkyl chain rigidified with a triple bond. This gives AM-938 a greater degree of selectivity, so while it is still a potent agonist at both CB1 and CB2, it is reasonably selective for CB2, with a Ki of 0.3 nM at CB2 and 1.2 nM at CB1, a selectivity of around four-fold.
AM-4030 is an analgesic drug which is a cannabinoid receptor agonist. It is a derivative of HU-210 which has been substituted with a 6β-((E)-3-hydroxyprop-1-enyl) group. This adds a "southern" aliphatic hydroxyl group to the molecule as seen in the CP-series of nonclassical cannabinoid drugs, and so AM-4030 represents a hybrid structure between the classical and nonclassical cannabinoid families, with the 6-hydroxyalkyl chain rigidified with a double bond with defined stereochemistry. This gives AM-4030 a greater degree of selectivity, so while it is still a potent agonist at both CB1 and CB2, it is reasonably selective for CB1, with a Ki of 0.7nM at CB1 and 8.6nM at CB2, a selectivity of around 12x. Resolution of the enantiomers of AM-4030 yields an even more potent compound, although with less selectivity, with the (−) enantiomer AM-4030a having a Ki of 0.6nM at CB1 and 1.1nM at CB2.
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.
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-1221 is a drug that acts as a potent and selective agonist for the cannabinoid receptor CB2, with a Ki of 0.28 nM at CB2 and 52.3 nM at the CB1 receptor, giving it around 180 times selectivity for CB2. The 2-methyl and 6-nitro groups on the indole ring both tend to increase CB2 affinity while generally reducing affinity at CB1, explaining the high CB2 selectivity of AM-1221. However, despite this relatively high selectivity for CB2, its CB1 affinity is still too strong to make it useful as a truly selective CB2 agonist, so the related compound AM-1241 is generally preferred for research purposes.
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.
AM-2233 is a drug that acts as a highly potent full agonist for the cannabinoid receptors, with a Ki of 1.8 nM at CB1 and 2.2 nM at CB2 as the active (R) enantiomer. It was developed as a selective radioligand for the cannabinoid receptors and has been used as its 131I derivative for mapping the distribution of the CB1 receptor in the brain. AM-2233 was found to fully substitute for THC in rats, with a potency lower than that of JWH-018 but higher than WIN 55,212-2.
AM-1248 is a drug that acts as a moderately potent agonist for both the cannabinoid receptors CB1 and CB2, but with some dispute between sources over its exact potency and selectivity. Replacing the 3-(1-naphthoyl) group found in many indole derived cannabinoid ligands, with an adamantoyl group, generally confers significant CB2 selectivity, but reasonable CB1 affinity and selectivity is retained when an N-methylpiperidin-2-ylmethyl substitution is used at the indole 1-position. The related compound 1-pentyl-3-(1-adamantoyl)indole was identified as having been sold as a cannabinoid designer drug in Hungary in 2011, along with another synthetic cannabinoid AM-679.
AM-1220 is a drug that acts as a potent and moderately selective agonist for the cannabinoid receptor CB1, with around 19 times selectivity for CB1 over the related CB2 receptor. It was originally invented in the early 1990s by a team led by Thomas D'Ambra at Sterling Winthrop, but has subsequently been researched by many others, most notably the team led by Alexandros Makriyannis at the University of Connecticut. The (piperidin-2-yl)methyl side chain of AM-1220 contains a stereocenter, so there are two enantiomers with quite different potency, the (R)-enantiomer having a Ki of 0.27 nM at CB1 while the (S)-enantiomer has a much weaker Ki of 217 nM.
AM-2389 is a classical cannabinoid derivative which acts as a potent and reasonably selective agonist for the CB1 receptor, with a Ki of 0.16 nM, and 26× selectivity over the related CB2 receptor. It has high potency in animal tests of cannabinoid activity, and a medium duration of action. Replacing the 1',1'-dimethyl substitution of the dimethylheptyl side chain of classical cannabinoids with cyclopropyl or cyclopentyl results in higher potency than cyclobutyl, but only the cyclobutyl derivatives show selectivity for CB1 over CB2. High selectivity for CB1 over CB2 is difficult to achieve (cf. AM-906, AM-1235), as almost all commonly used CB1 agonists have similar or greater affinity for CB2 than CB1, and the only truly highly selective CB1 agonists known as of 2012 are eicosanoid derivatives such as O-1812.
AM-1714 (part of the AM cannabinoid series) is a drug that acts as a reasonably selective agonist of the peripheral cannabinoid receptor CB2, with sub-nanomolar affinity and 490x selectivity over the related CB1 receptor. In animal studies it has both analgesic and anti-allodynia effects. The 9-methoxy derivative AM-1710 has similar CB2 affinity but only 54x selectivity over CB1.
