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.
JWH-018 (1-pentyl-3-(1-naphthoyl)indole, NA-PIMO or AM-678) is an analgesic chemical from the naphthoylindole family that acts as a full agonist at both the CB1 and CB2 cannabinoid receptors, with some selectivity for CB2. It produces effects in animals similar to those of tetrahydrocannabinol (THC), a cannabinoid naturally present in cannabis, leading to its use in synthetic cannabis products that in some countries are sold legally as "incense blends".
Synthetic cannabinoids are a class of designer drug molecules that bind to the same receptors to which cannabinoids in cannabis plants attach. These novel psychoactive substances should not be confused with synthetic phytocannabinoids or synthetic endocannabinoids from which they are in many aspects distinct.
AB-001 (1-pentyl-3-(1-adamantoyl)indole) is a designer drug that was found as an ingredient in synthetic cannabis smoking blends in Ireland in 2010 and Hungary and Germany in 2011. It is unclear who AB-001 was originally developed by, but it is structurally related to compounds such as AM-1248 and its corresponding 1-(tetrahydropyran-4-ylmethyl) analogue, which are known to be potent cannabinoid agonists with moderate to a high selectivity for CB2 over CB1. The first published synthesis and pharmacological evaluation of AB-001 revealed that it acts as a full agonist at CB1 (EC50 = 35 nM) and CB2 receptors (EC50 = 48 nM). However, AB-001 was found to possess only weak cannabimimetic effects in rats at doses up to 30 mg/kg, making it less potent than the carboxamide analogue APICA, which possesses potent cannabimimetic activity at doses of 3 mg/kg.
Cannabipiperidiethanone is a synthetic cannabinoid that has been found as an ingredient of "herbal" synthetic cannabis blends sold in Japan, alongside JWH-122 and JWH-081.
MAM-2201 is a drug that presumably acts as a potent agonist for the cannabinoid receptors. It had never previously been reported in the scientific or patent literature, and was first identified by laboratories in the Netherlands and Germany in June 2011 as an ingredient in synthetic cannabis smoking blends. Like RCS-4 and AB-001, MAM-2201 thus appears to be a novel compound invented by "research chemical" suppliers specifically for grey-market recreational use. Structurally, MAM-2201 is a hybrid of two known cannabinoid compounds JWH-122 and AM-2201, both of which had previously been used as active ingredients in synthetic cannabis blends before being banned in many countries.
AB-FUBINACA (AMB-FUBINACA) is a psychoactive drug that acts as a potent agonist for the cannabinoid receptors, with Ki values of 0.9 nM at CB1 and 23.2 nM at CB2 and EC50 values of 1.8 nM at CB1 and 3.2 nM at CB2. It was originally developed by Pfizer in 2009 as an analgesic medication but was never pursued for human use. In 2012, it was discovered as an ingredient in synthetic cannabinoid blends in Japan, along with a related compound AB-PINACA, which had not previously been reported.
AB-PINACA is a compound that was first identified as a component of synthetic cannabis products in Japan in 2012.
QUCHIC is a designer drug offered by online vendors as a cannabimimetic agent, and was first detected being sold in synthetic cannabis products in Japan in early 2013, and subsequently also in New Zealand. The structure of QUCHIC appears to use an understanding of structure-activity relationships within the indole class of cannabimimetics, although its design origins are unclear. QUCHIC, along with QUPIC, represents a structurally unique synthetic cannabinoid chemotype since it contains an ester linker at the indole 3-position rather than the precedented ketone of JWH-018 and its analogues, or the amide of SDB-001 and its analogues.
AB-CHMINACA is an indazole-based synthetic cannabinoid. It is a potent agonist of the CB1 receptor (Ki = 0.78 nM) and CB2 receptor (Ki = 0.45 nM) and fully substitutes for Δ9-THC in rat discrimination studies, while being 16x more potent. Continuing the trend seen in other cannabinoids of this generation, such as AB-FUBINACA and AB-PINACA, it contains a valine amino acid amide residue as part of its structure, where older cannabinoids contained a naphthyl or adamantane residue.
5F-ADB (also known as MDMB-5F-PINACA and 5F-MDMB-PINACA) is an indazole-based synthetic cannabinoid from the indazole-3-carboxamide family, which has been used as an active ingredient in synthetic cannabis products and has been sold online as a designer drug. 5F-ADB is a potent agonist of the CB1 receptor, though it is unclear whether it is selective for this target. 5F-ADB was first identified in November 2014 from post-mortem samples taken from an individual who had died after using a product containing this substance. Subsequent testing identified 5F-ADB to have been present in a total of ten people who had died from unexplained drug overdoses in Japan between September 2014 and December 2014. 5F-ADB is believed to be extremely potent based on the very low levels detected in tissue samples, and appears to be significantly more toxic than earlier synthetic cannabinoid drugs that had previously been sold.
THJ-2201 is an indazole-based synthetic cannabinoid that presumably acts as a potent agonist of the CB1 receptor and has been sold online as a designer drug.
AB-CHFUPYCA is a compound that was first identified as a component of synthetic cannabis products in Japan in 2015. The name "AB-CHFUPYCA" is an acronym of its systematic name N-(1-Amino-3-methyl-1-oxoButan-2-yl)-1-(CycloHexylmethyl)-3-(4-FlUorophenyl)-1H-PYrazole-5-CarboxAmide. There are two known regioisomers of AB-CHFUPYCA: 3,5-AB-CHMFUPPYCA (pictured) and 5,3-AB-CHMFUPPYCA. The article[1] refers to both 3,5-AB-CHMFUPPYCA and 5,3-AB-CHMFUPPYCA as AB-CHMFUPPYCA isomers, so AB-CHMFUPPYCA and AB-CHFUPYCA are not names for a unique chemical structure.
NM-2201 (also known as CBL-2201 and NA-5F-PIC) is an indole-based synthetic cannabinoid that presumably has similar properties to the closely related 5F-PB-22 and NNE1, which are both full agonists and unselectively bind to CB1 and CB2 receptors with low nanomolar affinity.
QMPSB is an arylsulfonamide-based synthetic cannabinoid that has been sold as a designer drug.
NE-CHMIMO (CHM-018) is an indole-based synthetic cannabinoid that is presumed to be a potent agonist of the CB1 receptor and has been sold online as a designer drug. NE-CHMIMO is the 1-cyclohexylmethyl (instead of 1-pentyl) analogue of the first-generation synthetic cannabinoid JWH-018. The corresponding cyclohexylmethyl derivative of JWH-081 had also been reported several months earlier.
CUMYL-4CN-BINACA (also known as CUMYL-CYBINACA or SGT-78) is an indazole-3-carboxamide based synthetic cannabinoid that has been sold online as a designer drug. It is a potent agonist for cannabinoid receptors CB1 and CB2, with in vitro EC50 values of 0.58 nM and 6.12 nM, respectively. In mice, CUMYL-4CN-BINACA produces hypothermic and pro-convulsant effects via the CB1 receptor, and anecdotal reports suggest it has an active dose of around 0.1 mg in humans.
MDMB-4en-PINACA is an indazole-based synthetic cannabinoid that has been sold online as a designer drug. MDMB-4en-PINACA was first identified in Europe in 2017. In 2021, MDMB-4en-PINACA was the most common synthetic cannabinoid identified by the Drug Enforcement Administration in the United States. MDMB-4en-PINACA differs from 5F-MDMB-PINACA due to replacement of 5-fluoropentyl with a pent-4-ene moiety (4-en).
ADB-BINACA (also known as ADMB-BZINACA using EMCDDA naming standards) 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.
ADB-HEXINACA is a cannabinoid designer drug that has been found as an ingredient in some synthetic cannabis products, first appearing in early 2021. It is a longer chain homologue of previously encountered synthetic cannabinoid compounds such as ADB-BUTINACA and ADB-PINACA. The pharmacology of ADB-HEXINACA and numerous analogues at CB1 and CB2 receptors has been reported.
