Identification and quantitation of two benzoylindoles AM-694 and (4-methoxyphenyl)(1-pentyl-1<Emphasis Type="Italic">H</Emphasis>-indol-3-yl)methanone,and three cannabimimetic naphthoylindoles JWH-210, JWH-122, and JWH-019 as adulterants in illegal products obtained via the Internet

During our careful surveillance of unregulated drugs, we found five new compounds used as adulterants in herbal and drug-like products obtained via the Internet. These compounds were identified by liquid chromatography–mass spectrometry, gas chromatography–mass spectrometry, accurate mass spectrometry, and nuclear magnetic resonance spectroscopy. The first compound identified was a benzoylindole AM-694, which is 1-[(5-fluoropentyl)-1H-indol-3-yl]-(2-iodophenyl)methanone (1). The second compound was (4-methoxyphenyl)(1-pentyl-1H-indol-3-yl)methanone (2), which was also classified as a benzoylindole. The three other compounds were identified as naphthoylindoles JWH-210 (4-ethylnaphthalen-1-yl-(1-pentylindol-3-yl)methanone; 3), JWH-122 (4-methylnaphthalen-1-yl-(1-pentylindol-3-yl)methanone; 4), and JWH-019 (1-hexyl-3-(naphthalen-1-oyl)indole; 5). All compounds except compound 2 had been reported to be cannabinoid receptor agonists. For quantitation of the five compounds and previously reported compounds, each product was extracted with methanol under ultrasonication to prepare a test solution for analysis by liquid chromatography with ultraviolet detection. Each compound detected in 43 commercial products showed large variation in content ranging from 4.0 to 359 mg per pack.     

Identification and quantitation of JWH-213, a cannabimimetic indole, as a designer drug in a herbal product

In our survey of designer drugs in the Japanese market, a cannabimimetic indole was identified as a new active compound in a herbal product. The structure of this compound was elucidated by liquid chromatography–photodiode array–mass spectrometry (LC–PDA–MS), gas chromatography–mass spectrometry (GC–MS), high-resolution MS, and nuclear magnetic resonance (NMR) analyses. The compound was finally identified as (4-ethyl-1-naphthalenyl)(2-methyl-1-pentyl-1H-indol-3-yl)methanone (JWH-213), an indole-based cannabinoid receptor ligand. To our knowledge, this is the first finding of JWH-213 as a designer drug in a herbal product. The quantitative LC–PDA analysis showed that the JWH-213 content in the product was 252 mg/pack.     

Identification of a cannabimimetic indole as a designer drug in a herbal product

A cannabimimetic indole has been identified as a new adulterant in a herbal product being sold illegally in Japan for its expected narcotic effect. Liquid chromatography-mass spectrometry and gas chromatography-mass spectrometry analyses indicated that the product contained two major compounds. One was identified as a cannabinoid analog (1RS,3SR)-3-[4-(1,1-dimethyloctyl)-2-hydroxyphenyl]cyclohexan-1-ol (1) by direct comparison with the authentic compound, which we reported previously. The other compound (2) showed a molecular weight of 341 daltons, and accurate mass spectral measurements showed its elemental composition to be C₂₄H₂₃NO. Both mass and nuclear magnetic resonance spectrometric data revealed that 2 was 1-pentyl-3-(1-naphthoyl)indole [or naphthalen-1-yl-(1-pentylindol-3-yl)methanone] being identical to JWH-018, which was synthesized by Wiley and coworkers in 1998. This compound was reported as a potent cannabinoid receptor agonist possessing a pharmacological cannabimimetic activity.     

Identification and quantitation of a benzoylindole (2-methoxyphenyl)(1-pentyl-1H-indol-3-yl)methanone and a naphthoylindole 1-(5-fluoropentyl-1H-indol-3-yl)-(naphthalene-1-yl)methanone (AM-2201) found in illegal products obtained via the Internet and their cannabimimetic effects evaluated by in vitro [35S]GTP��S binding assays

During our careful surveillance of unregulated drugs in January to February 2011, we found two new compounds used as adulterants in herbal products obtained via the Internet. These compounds were identified by liquid chromatography?Cmass spectrometry, gas chromatography-mass spectrometry, accurate mass spectrometry, and nuclear magnetic resonance spectroscopy. The first compound identified was a benzoylindole (2-methoxyphenyl)(1-pentyl-1H-indol-3-yl)methanone (1), which is a positional isomer of (4-methoxyphenyl)(1-pentyl-1H-indol-3-yl)methanone (RCS-4, 4). The second compound was 1-(5-fluoropentyl-1H-indol-3-yl)-(naphthalene-1-yl)methanone (AM-2201, 2). The compound 2 has been reported to be a cannabinoid receptor agonist. Because the cannabimimetic effects of compounds 1 and 4 have not been reported to date, their biological activities were evaluated by measuring the activation of [³⁵S] guanosine-5??-O-(3-thio)-triphosphate binding to guanine nucleotide-binding proteins, together with those of other synthetic cannabimimetic compounds. For quantitation of the above two compounds (1 and 2) and previously identified compounds (AM-694, 3; JWH-122, 5; RCS-4, 4), each product was extracted with methanol under ultrasonication to prepare a sample solution for analysis by liquid chromatography with ultraviolet detection. Each of four commercial products contained some of cannabimimetic indoles 1?C5; their contents ranged from 14.8 to 185 mg per pack.     

Identification and quantitation of two new naphthoylindole drugs-of-abuse, (1-(5-hydroxypentyl)-1H-indol-3-yl)(naphthalen-1-yl)methanone (AM-2202) and (1-(4-pentenyl)-1H-indol-3-yl)(naphthalen-1-yl)methanone, with other synthetic cannabinoids in unregulated “herbal” products circulated in the Tokyo area

During our continual surveillance of unregulated drugs in May–June 2011, we found two new compounds as adulterants in herbal products obtained at shops in the Tokyo area. These compounds were identified by liquid chromatography–mass spectrometry, gas chromatography–mass spectrometry, accurate mass spectrometry, and nuclear magnetic resonance spectroscopy. The first compound identified was a naphthoylindole (1-(5-hydroxypentyl)-1H-indol-3-yl)(naphthalen-1-yl)methanone (AM-2202, 1), which is a side-chain hydroxyl analogue of JWH-018. The second compound was (1-(4-pentenyl)-1H-indol-3-yl)(naphthalen-1-yl)methanone (2), which is side-chain double bond analogue of JWH-018. This is the first report to identify 1 and 2 in a commercial “herbal” product to our knowledge. For quantitation of the above compounds 1 and 2, and chemical analysis for previously reported compounds (AM-2201, 3; JWH-203, 4; JWH-019, 7; JWH-210, 8; mitragynine, 9), each product was extracted with methanol under ultrasonication to prepare solutions for analysis by liquid chromatography with ultraviolet detection. For the sake of identifying JWH-203 (4) and its positional isomers [JWH-203-3-chloroisomer (5) and 4-chloroisomer (6)] correctly, simultaneous liquid chromatography analysis on fluorocarbon-bonded silica gel column was performed. And a case report of commercially available products containing synthetic cannabinoids 7 and 8, and a natural occurring alkaloid 9, was also shown. Each of 6 commercially circulated products contained compounds 1–4 and 7–9; the amounts of the compounds ranged from 4.1 to 222 mg per pack.     

Identification and quantitation of cannabimimetic compound JWH-250 as an adulterant in products obtained via the Internet

During our careful survey of unregulated drugs in Tokyo, a new compound was disclosed as an adulterant in herbal and powder products. This compound was found to have a molecular weight of 335 by liquid chromatography-mass spectrometry and gas chromatography-mass spectrometry, and the accurate mass measurement suggested an elementary composition of C₂₂H₂₆NO₂. Using these mass data together with those obtained by nuclear magnetic resonance analysis, the compound was identified as 1-pentyl-3-(2-methoxyphenylacetyl)indole (JWH-250), which had been reported by Huffman and coworkers in 2005. This compound was classified as a phenylacetylindole and a cannabinoid receptor agonist. For quantitation of the compound in herbal and powder products, each product was extracted with methanol under ultrasonication to prepare the solution for analysis by liquid chromatography with ultraviolet detection. The contents of JWH-250 in five products ranged from 77.4 to 165 mg per pack.     

Comparison between human liver microsomes and the fungus Cunninghamella elegans for biotransformation of the synthetic cannabinoid JWH-424 having a bromo-naphthyl moiety analysed by high-resolution mass spectrometry

Purpose

JWH-424, (8-bromo-1-naphthyl)(1-pentyl-1H-indol-3-yl)methanone, is a synthetic cannabinoid, which is a brominated analogue of JWH-018, one of the best-known synthetic cannabinoids. Despite the structural similarity to JWH-018, little is known about JWH-424 including its metabolism. The aim of the study was to compare human liver microsomes (HLM) and the fungus Cunninghamella elegans as the metabolism catalysts for JWH-424 to better understand the characteristic actions of the fungus in the synthetic cannabinoid metabolism.

Methods

JWH-424 was incubated with HLM for 1 h and Cunninghamella elegans for up to 72 h. The HLM incubation mixtures were diluted with methanol and fungal incubation mixtures were extracted with dichloromethane and reconstituted in methanol before analyses by liquid chromatography–high-resolution mass spectrometry (LC-HRMS).

Results

HLM incubation resulted in production of ten metabolites through dihydrodiol formation, hydroxylation, and/or ipso substitution of the bromine with a hydroxy group. Fungal incubation led to production of 23 metabolites through carboxylation, dihydrodiol formation, hydroxylation, ketone formation, glucosidation and/or sulfation.

Conclusions

Generally, HLM models give good predictions of human metabolites and structural analogues are metabolised in a similar fashion. However, major hydroxy metabolites produced by HLM were those hydroxylated at naphthalene instead of pentyl moiety, the major site of hydroxylation for JWH-018. Fungal metabolites, on the other hand, had undergone hydroxylation mainly at pentyl moiety. The metabolic disagreement suggests the necessity to verify the human metabolites in authentic urine samples, while H9 and H10 (hydroxynaphthalene), H8 (ipso substitution), F22 (hydroxypentyl), and F17 (dihydroxypentyl) are recommended for monitoring of JWH-424 in urinalysis.

     

Identification of two new-type synthetic cannabinoids, N-(1-adamantyl)-1-pentyl-1H-indole-3-carboxamide (APICA) and N-(1-adamantyl)-1-pentyl-1H-indazole-3-carboxamide (APINACA), and detection of five synthetic cannabinoids, AM-1220, AM-2233, AM-1241, CB-13 (CRA-13), and AM-1248, as designer drugs in illegal products

Two new-type synthetic cannabinoids, N-(1-adamantyl)-1-pentyl-1H-indole-3-carboxamide (APICA, 1) and N-(1-adamantyl)-1-pentyl-1H-indazole-3-carboxamide (APINACA, 2), have been identified as designer drugs in illegal products being sold in Japan. The identification was based on liquid chromatography-mass spectrometry (LC-MS), gas chromatography-mass spectrometry (GC-MS), high-resolution MS and nuclear magnetic resonance (NMR) analyses. Both mass and NMR spectrometric data revealed that 1 was 1-pentyl-N-tricyclo[3.3.1.1^3,7]dec-1-yl-1H-indole-3-carboxamide, and 2 was 1-pentyl-N-tricyclo[3.3.3.1.^3,7]dec-1-yl)-1H-indazole-3-carboxamide. Although many of the synthetic cannabinoids detected in illegal products, such as JWH-018, have a 3-carbonyl indole moiety, compounds 1 and 2 are a new type of synthetic cannabinoid having an amide and an adamantyl group, and 2 also has an indazole group in place of an indole group. There has been no synthetic, chemical, or biological information about 1 or 2 until now, making this the first report of these cannabimimetic compounds (1 and 2) as designer drugs. In addition, five synthetic cannabinoids, AM-1220, AM-2233, AM-1241, CB-13 (CRA-13), and AM-1248, are also described herein as newly distributed designer drugs in Japan.     

New cannabimimetic indazole derivatives, N-(1-amino-3-methyl-1-oxobutan-2-yl)-1-pentyl-1H-indazole-3-carboxamide (AB-PINACA) and N-(1-amino-3-methyl-1-oxobutan-2-yl)-1-(4-fluorobenzyl)-1H-indazole-3-carboxamide (AB-FUBINACA) identified as designer drugs in illegal products

Two new cannabimimetic indazole derivatives, N-(1-amino-3-methyl-1-oxobutan-2-yl)-1-pentyl-1H-indazole-3-carboxamide (AB-PINACA, 1) and N-(1-amino-3-methyl-1-oxobutan-2-yl)-1-(4-fluorobenzyl)-1H-indazole-3-carboxamide (AB-FUBINACA, 2), have been identified as designer drugs in illegal products. These identifications were based on liquid chromatography–mass spectrometry, gas chromatography–mass spectrometry, high-resolution mass spectrometry, and nuclear magnetic resonance spectroscopy. Because there have been neither chemical nor pharmacological data about compound 1 until now, this is the first report of this compound. Compound 2 was reported as a potent cannabinoid CB₁ receptor modulator when synthesized by Pfizer in 2009; but this is the first report of its detection in illegal products.     

[1-(Tetrahydropyran-4-ylmethyl)-1H-indol-3-yl]-(2,2,3,3-tetramethylcyclopropyl)methanone: a new synthetic cannabinoid identified on the drug market

A new synthetic cannabinoid, [1-(tetrahydropyran-4-ylmethyl)-1H-indol-3-yl]-(2,2,3,3-tetramethylcyclopropyl)methanone, was identified in several resinous samples seized by law enforcement officers in Poland. Its identification was based on liquid chromatography–electrospray ionization–quadrupole time-of-flight–mass spectrometry, gas chromatography–electron ionization–mass spectrometry, one-dimensional and two-dimensional nuclear magnetic resonance spectroscopy, and Fourier-transform infrared spectroscopy. The reported substance was first developed by Abbott Laboratories and patented under the name “A-834,735”. It is a potent agonist of both CB₁ and CB₂ receptors. Although A-834,735 shows moderate selectivity to CB₂ receptor, it exhibits a CB₁ affinity similar to that of ?⁹-tetrahydrocannabinol. The drug has recently become available in online shops. To our knowledge, this is the first report to disclose a synthetic cannabinoid containing a (tetrahydropyran-4-yl)methyl structure in products seized from the drug market.     

Two new-type cannabimimetic quinolinyl carboxylates, QUPIC and QUCHIC, two new cannabimimetic carboxamide derivatives, ADB-FUBINACA and ADBICA, and five synthetic cannabinoids detected with a thiophene derivative α-PVT and an opioid receptor agonist AH-7921 identified in illegal products

We identified two new-type cannabimimetic quinolinyl carboxylates, quinolin-8-yl 1-pentyl-(1H-indole)-3-carboxylate (QUPIC, 1) and quinolin-8-yl 1-(cyclohexylmethyl)-1H-indole-3-carboxylate (QUCHIC, 2); and two new cannabimimetic carboxamide derivatives, N-(1-amino-3,3-dimethyl-1-oxobutan-2-yl)-1-(4-fluorobenzyl)-1H-indazole-3-carboxamide (ADB-FUBINACA, 3) and N-(1-amino-3,3-dimethyl-1-oxobutan-2-yl)-1-pentyl-1H-indole-3-carboxamide (ADBICA, 4), as designer drugs in illegal products. Compound 3 was reported to have a potent affinity for cannabinoid CB₁ receptor by Pfizer in 2009, but this is the first report of its detection in illegal products. No chemical or pharmacological data for compounds 1, 2, and 4 have appeared until now, making this the first report on these compounds. We also detected synthetic cannabinoids, APICA N-(5-fluoropentyl) analog (5), APINACA N-(5-fluoropentyl) analog (6), UR-144 N-(5-chloropentyl) analog (7), JWH-122 N-(5-chloropentyl) analog (8), and AM-2201 4-methoxynaphthyl analog (4-MeO-AM-2201, 9) herein as newly distributed designer drugs in Japan. It is of interest that compounds 1 and 2 were detected with their synthetic component, 8-quinolinol (10). A stimulant thiophene analog, α-pyrrolidinovalerothiophenone (α-PVT, 11), and an opioid receptor agonist, 3,4-dichloro-N-([1-(dimethylamino)cyclohexyl]methyl)benzamide (AH-7921, 12), were also detected as new types of designer drugs coexisting with several synthetic cannabinoids and cathinone derivatives in illegal products.     

Identification of (1-pentylindol-3-yl)-(2,2,3,3-tetramethylcyclopropyl)methanone and its 5-pentyl fluorinated analog in herbal incense seized for drug trafficking

Four herbal incense products were seized from suspected drug abusers in Korea. The major ingredients in the herbal incense samples were purified, and their structures were elucidated using gas chromatography–electron ionization–mass spectrometry (GC–EI–MS), liquid chromatography–time-of-flight–mass spectrometry (LC–TOF–MS), and 1D and 2D nuclear magnetic resonance (NMR) spectroscopy. As a result, ingredients in the herbal incense were identified as (1-pentylindol-3-yl)-(2,2,3,3-tetramethylcyclopropyl)methanone and its 5-pentyl fluorinated analog [1-(5-fluoropentyl)indol-3-yl]-(2,2,3,3-tetramethylcyclopropyl)methanone. The former is being sold via the Internet as a "research chemical" named UR-144, and the latter is sold as 5F-UR-144. UR-144 is a selective full agonist of CB₂ cannabinoid receptor, and was first developed by Abbott Laboratories as an analgesic. It exhibits analgesic activity against both neuropathic and inflammatory pain associated mainly with the CB₂ receptor, but shows less psychotropic effects associated with the CB₁ receptor. Fluorination of the N-pentyl side chain of cannabimimetic compounds increases their cannabinoid receptor affinity such as with AM-2201, which shows both increased analgesic and psychotropic effects simultaneously. UR-144 and 5F-UR-144 can be classified as research chemicals based on their analgesic effects, but in practice are abused as psychotropic agents and can cause unexpected toxic effects. Thus, the trade and diversion of these chemicals should be monitored carefully for possible abuse. To our knowledge, this is the first report disclosing cyclopropylcarbonylindoles in herbal products.     

Two new synthetic cannabinoids, AM-2201 benzimidazole analog (FUBIMINA) and (4-methylpiperazin-1-yl)(1-pentyl-1H-indol-3-yl)methanone (MEPIRAPIM), and three phenethylamine derivatives, 25H-NBOMe 3,4,5-trimethoxybenzyl analog, 25B-NBOMe, and 2C-N-NBOMe, identified in illegal products

Two new types of synthetic cannabinoids, an AM-2201 benzimidazole analog (FUBIMINA, 1) and (4-methylpiperazin-1-yl)(1-pentyl-1H-indol-3-yl)methanone (MEPIRAPIM, 2), and three newly emerged phenethylamine derivatives, 25B-NBOMe (3), 2C-N-NBOMe (4), and a 25H-NBOMe 3,4,5-trimethoxybenzyl analog (5), were detected in illegal products distributed in Japan. The identification was based on liquid chromatography–mass spectrometry (LC–MS) and gas chromatography–mass spectrometry (GC–MS), high-resolution MS, and nuclear magnetic resonance analyses. Different from the representative synthetic cannabinoids, such as JWH-018, which have a naphthoylindole moiety, compounds 1 and 2 were completely new types of synthetic cannabinoids; compound 1 had a benzimidazole group in place of an indole group, and compound 2 had a 4-methylpiperazine group in place of the naphthyl group. Compounds 3 and 4 were N-o-methoxybenzyl derivatives of 2,5-dimethoxyphenethylamines (25-NBOMe series), which had been previously detected in European countries, but have newly emerged in Japan. Compound 5 had an N-trimethoxybenzyl group in place of an N-o-methoxybenzyl group. Data on the chemistry and pharmacology of compounds 1, 2, and 5 have never been reported to our knowledge.     

Hyperreflexia induced by XLR-11 smoke is caused by the pyrolytic degradant

Purpose

Some of the synthetic cannabinoids, often found in recreational drugs of the herbal form, reportedly induce a generalized seizure in drug abusers immediately after smoking. However, it is still unclear what elicits the sensorimotor responses, particularly in the case of hyperreflexia or excitatory behavior during the synthetic cannabinoid exposure. The purpose of this study was to explore the mechanism underlying the hyperreflexia induced by smoke intoxication of XLR-11 [(1-(5-fluoropentyl)-1H-indol-3-yl)(2,2,3,3-tetramethylcyclopropyl)methanone].

Methods

Locomotor activity and body temperature of mice were measured using an implanted Nano-Tag device. The intensity of catalepsy was determined by the bar test. The extracellular dopamine levels in the nucleus accumbens and glutamate levels in the hippocampus were measured by in vivo microdialysis using electrochemical detector-coupled high-performance liquid chromatography and by in vivo enzyme-based biosensor method, respectively.

Results

Mice exposed to the smoke of XLR-11 exhibited hyperreflexia at the very early phase, followed by hypothermia and catalepsy. The XLR-11 smoke contained XLR-11 and XLR-11 degradant at a ratio of approximately 1:25. Mice treated intraperitoneally with XLR-11 degradant at a dose comparable to the smoke inhalation experiment showed a hyperreflexic effect immediately after the treatment, but XLR-11 showed no such effect. The effects of XLR-11 degradant were significantly suppressed by pretreatment with AM-251, a CB₁ receptor antagonist. Extracellular dopamine and glutamate levels showed no evidence of involvement in the XLR-11 degradant-induced hyperreflexia; on the other hand gabapentin, a GABAergic antiepileptic, significantly suppressed the enhanced locomotor activity.

Conclusions

The hyperreflexic effect of XLR-11 degradant is mediated by the CB₁ receptor and possibly by GABAergic function.

     

Identification of the cannabimimetic AM-1220 and its azepane isomer (N-methylazepan-3-yl)-3-(1-naphthoyl)indole in a research chemical and several herbal mixtures

Recently, a large number of synthetic cannabinoids have been identified in herbal mixtures. Moreover, an even higher number of cannabimimetic compounds are currently distributed as research chemicals on a gram to kilogram scale via several online trading platforms. As this situation leads to a large number of new cannabimimetics and the occurrence of isobaric substances, the analysis of such compounds using mass spectroscopy (MS) involves the risk of incorrect assignments of mass spectra. In certain cases, this leads to considerable analytical challenges. In the majority of cases, these challenges can only be mastered by combining multiple analytical techniques. We purchased a so-called research chemical advertised as the cannabimimetic compound [(N-methylpiperidin-2-yl)methyl]-3-(1-naphthoyl)indole (AM-1220) via an Internet platform. Analysis of the microcrystalline substance using gas chromatography (GC)–MS indicated the presence of pure AM-1220. However, after further purity testing utilizing thin-layer chromatography we were surprised to see an additional spot indicating a mixture of two substances with highly similar physicochemical properties. After isolation, high-resolution mass spectroscopy (HR-MS) revealed an elemental composition of C₂₆H₂₆N₂O for both substances, proving the presence of two isobaric substances. Moreover, GC–MS and LC-HR-MS/MS experiments indicated two naphthoylindoles featuring different heterocyclic substituents at the indole nitrogen. Nuclear magnetic resonance spectroscopy verified the presence of the highly potent cannabimimetic AM-1220 and its azepane isomer. Interestingly, only a few weeks after purchasing the powder we also detected both substances in a similar proportion in several herbal mixtures for the first time.     

In vitro and in vivo metabolisms of 1-pentyl-3-(4-methyl-1-naphthoyl)indole (JWH-122)

1-Pentyl-3-(4-methyl-1-naphthoyl)indole (JWH-122) is an agonist of the cannabinoid receptors CB₁ and CB₂. In this study, the phase I and phase II metabolisms of JWH-122 were investigated using two models. In vitro studies using incubations of JWH-122 with human liver microsomes were performed to obtain metabolites of the drug at the initial step; 11 classes of metabolites were found and analyzed by liquid chromatography–mass spectrometry (LC–MS) and liquid chromatography–tandem mass spectrometry (LC–MS–MS). Hydroxylation(s) on the naphthalene moiety and/or the indole moiety of the molecule took place as such or in combination with dehydrogenation or cleavage of the N-pentyl side chain. Furthermore, dihydrodiol metabolites were formed probably via epoxide formation on the naphthalene moiety, irrespective of the combination with hydroxylation(s). A metabolite carrying a carboxyl group on the N-pentyl side chain was also detected. As the second step of the study, in vivo experiments using chimeric mice were performed; the mice were orally administered JWH-122, and their urine samples were collected, subjected to enzymatic hydrolysis, and analyzed by LC–MS and LC–MS–MS. The urine samples without hydrolysis were also analyzed for their molecular formulae in the conjugated forms by LC–high resolution MS. The in vivo model using chimeric mice confirmed most metabolite classes and clarified the phase II metabolism of JWH-122. It was concluded that all metabolites formed in vivo were excreted conjugated as glucuronide or sulfate, with conjugation rates above 50 %.     

Evaluation of carboxamide-type synthetic cannabinoids as CB<Subscript>1</Subscript>/CB<Subscript>2</Subscript> receptor agonists: difference between the enantiomers

Recently, carboxamide-type synthetic cannabinoids have been distributed globally as new psychoactive substances (NPS). Some of these compounds possess asymmetric carbon, which is derived from an amide moiety composed of amino acid derivatives (i.e., amides or esters of amino acids). In this study, we synthesized both enantiomers of synthetic cannabinoids, N-(1-amino-3-methyl-1-oxobutan-2-yl)-1-(2-fluorobenzyl)-1H-indazole-3-carboxamide (AB-FUBINACA 2-fluorobenzyl isomer), N-(1-amino-1-oxo-3-phenylpropan-2-yl)-1-(cyclohexylmethyl)-1H-indazole-3-carboxamide (APP-CHMINACA), ethyl [1-(5-fluoropentyl)-1H-indazole-3-carbonyl]valinate (5F-EMB-PINACA), ethyl [1-(4-fluorobenzyl)-1H-indazole-3-carbonyl]valinate (EMB-FUBINACA), and methyl 2-[1-(4-fluorobenzyl)-1H-indole-3-carboxamido]-3,3-dimethylbutanoate (MDMB-FUBICA), which were reported as NPS found in Europe from 2014 to 2015, to evaluate their activities as CB₁/CB₂ receptor agonists. With the exception of (R) MDMB-FUBICA, all of the tested enantiomers were assumed to be agonists of both CB₁ and CB₂ receptors, and the EC₅₀ values of the (S)-enantiomers for the CB₁ receptors were about five times lower than those of (R)-enantiomers. (R) MDMB-FUBICA was shown to function as an agonist of the CB₂ receptor, but lacks CB₁ receptor activity. To the best of our knowledge, this is the first report to show that the (R)-enantiomers of the carboxamide-type synthetic cannabinoids have the potency to activate CB₁ and CB₂ receptors. The findings presented here shed light on the pharmacological properties of these carboxamide-type synthetic cannabinoids in forensic cases.     

The 2-alkyl-2<Emphasis Type="Italic">H</Emphasis>-indazole regioisomers of synthetic cannabinoids AB-CHMINACA,AB-FUBINACA,AB-PINACA,and 5F-AB-PINACA are possible manufacturing impurities with cannabimimetic activities

Indazole-derived synthetic cannabinoids (SCs) featuring an alkyl substituent at the 1-position and l-valinamide at the 3-carboxamide position (e.g., AB-CHMINACA) have been identified by forensic chemists around the world, and are associated with serious adverse health effects. Regioisomerism is possible for indazole SCs, with the 2-alkyl-2H-indazole regioisomer of AB-CHMINACA recently identified in SC products in Japan. It is unknown whether this regiosiomer represents a manufacturing impurity arising as a synthetic byproduct, or was intentionally synthesized as a cannabimimetic agent. This study reports the synthesis, analytical characterization, and pharmacological evaluation of commonly encountered indazole SCs AB-CHMINACA, AB-FUBINACA, AB-PINACA, 5F-AB-PINACA and their corresponding 2-alkyl-2H-indazole regioisomers. Both regioisomers of each SC were prepared from a common precursor, and the physical properties, ¹H and ¹³C nuclear magnetic resonance spectroscopy, gas chromatography–mass spectrometry, and ultraviolet–visible spectroscopy of all SC compounds are described. Additionally, AB-CHMINACA, AB-FUBINACA, AB-PINACA, and 5F-AB-PINACA were found to act as high potency agonists at CB₁ (EC₅₀ = 2.1–11.6 nM) and CB₂ (EC₅₀ = 5.6–21.1 nM) receptors in fluorometric assays, while the corresponding 2-alkyl-2H-indazole regioisomers demonstrated low potency (micromolar) agonist activities at both receptors. Taken together, these data suggest that 2-alkyl-2H-indazole regioisomers of AB-CHMINACA, AB-FUBINACA, AB-PINACA, and 5F-AB-PINACA are likely to be encountered by forensic chemists and toxicologists as the result of improper purification during the clandestine synthesis of 1-alkyl-1H-indazole regioisomers, and can be distinguished by differences in gas chromatography–mass spectrometry fragmentation pattern.     

5F-Cumyl-PINACA in ‘e-liquids’ for electronic cigarettes: comprehensive characterization of a new type of synthetic cannabinoid in a trendy product including investigations on the in vitro and in vivo phase I metabolism of 5F-Cumyl-PINACA and its non-fluorinated analog Cumyl-PINACA

Purpose

In recent years e-liquids used in electronic cigarettes have become an attractive alternative to smoking tobacco. A new trend is the use of e-liquids containing synthetic cannabinoids (SCs) instead of smoking cannabis or herbal mixtures laced with SCs. In the frame of a systematic monitoring of the online market of ‘legal high’ products, e-liquids from online retailers who also sell herbal blends were bought.

Methods

The products were analyzed by gas chromatography-mass spectrometry. In some of the e-liquids an unknown compound was detected which was identified as the SC 5F-Cumyl-PINACA (1-(5-fluoropentyl)-N-(2-phenylpropan-2-yl)-1H-indazole-3-carboxamide) by nuclear magnetic resonance analysis. To investigate the phase I metabolism of this new class of compounds, 5F-Cumyl-PINACA and its non-fluorinated analog Cumyl-PINACA were incubated with pooled human liver microsomes (pHLM). Cumyl-PINACA was additionally ingested orally (0.6 mg) by a volunteer in a controlled self-experiment. To assess the relative potency of Cumyl-PINACA a set of SCs were characterized using a cAMP assay.

Results

Metabolism of 5F-Cumyl-PINACA and Cumyl-PINACA showed similarities with AM-2201 and JWH-018. The main metabolites were formed by hydroxylation at the N-pentyl side chain. The main metabolites detected in the volunteer’s urine sample were the same as in the pHLM assay. All SCs tested with the cAMP assay were full agonists at the CB₁ receptor. Cumyl-PINACA was the most potent SC among the tested compounds and showed an EC₅₀ value of 0.06 nM.

Conclusions

The increasing popularity of e-liquids particularly among young people, and the extreme potency of the added SCs, pose a serious threat to public health. To our knowledge, this is the first report describing the tentative identification of human in vivo metabolites of Cumyl-PINACA and 5F-Cumyl-PINACA.

     

Identification of (1<Emphasis Type="Italic">H</Emphasis>-indol-3-yl)(2,2,3,3-tetramethylcyclopropyl)methanone (DP-UR-144) in a herbal drug product that was commercially available in the Tokyo metropolitan area

We encountered during our investigation a case of herbal drug products commercially available in the Tokyo metropolitan area in 2014, in which a small unknown peak was detected, along with the intense peak of FUB-144, by liquid chromatography–ultraviolet detection. The present study was conducted to identify and clarify the pharmacological characteristics of the compound present in this small peak. We isolated a compound using a silica gel column from the peak, which was then identified to have a molecular weight of 241 Da by liquid chromatography–mass spectrometry and gas chromatography–mass spectrometry. The accurate mass measurement suggested an elementary composition of C₁₆H₁₉NO. Using these mass data together with those obtained by the nuclear magnetic resonance analysis, the compound was finally identified as (1H-indol-3-yl)(2,2,3,3-tetramethylcyclopropyl)methanone (despentyl-UR-144; DP-UR-144). In addition, this compound was revealed to have affinities for cannabinoid receptors CB₁ and CB₂ with EC₅₀s of 2.36 × 10^?6 and 2.79 × 10^?8 M, respectively. To our knowledge, there is no information in the scientific literature on structural or pharmacological properties of this chemical. These results suggest that the components present in small amounts can contribute to the effects of a major component in their mother product, if they have sufficient pharmacological activities, and, therefore, even such small amounts of components should be precisely characterized and well evaluated to control illegal and potentially illegal drug products.