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This work was financed by the European Regional Development Fund (ERDF) through the Operational Competitiveness Factors Program—COMPETE and by National Funds through FCT—Foundation for Science and Technology within the scope of the project “PTDC/DTPFTO/5651/2014-POCI-01-0145-FEDER-016562” and projects NORTE-01-0145-FEDER-000024, supported by Norte Portugal Regional Operational Program (NORTE2020), under the PORTUGAL 2020 Partnership Agreement, through ERDF and UID/MULTI/04378/2019 from FCT/MEC. We also thank FCT support, through the strategic project UID/MAR/04292/2019 granted to MARE and UID/MULTI/04046/2019 to BioISI. Cristina Amaral thanks FCT for the contract under the funding program (DL 57/2016 – Norma Transitória) and through the Post-doc grant (SFRH/BPD/98304/2013). The authors thank the toxicology sector of the “Laboratório de Polícia Científica da Polícia Judiciária” for providing the smart shop product, within the protocol established with the “Faculdade de Ciências da Universidade de Lisboa” and “Faculdade de Farmácia da Universidade do Porto”. The increasing use of synthetic cannabinoids (SCBs) in recreational settings is becoming a new paradigm of drug abuse. Although SCBs effects mimic those of the Cannabis sativa plant, these drugs are frequently more potent and hazardous. It is known that endocannabinoid signalling plays a crucial role in diverse reproductive events such as placental development. Moreover, the negative impact of the phytocannabinoid Δ9-tetrahydrocannabinol (THC) in pregnancy outcome, leading to prematurity, intrauterine growth restriction and low birth weight is well recognized, which makes women of childbearing age a sensitive group to developmental adverse effects of cannabinoids. Placental trophoblast turnover relies on regulated processes of proliferation and apoptosis for normal placental development. Here, we explored the impact of the SCBs JWH-018, JWH-122 and UR-144 and of the phytocannabinoid THC in BeWo cell line, a human placental cytotrophoblast cell model. All the cannabinoids caused a significant decrease in cell viability without LDH release, though this effect was only detected for the highest concentrations of THC. Moreover, a cell cycle arrest at the G2/M phase was also observed. JWH-018 and JWH-122 increased reactive oxygen species (ROS) production and THC, UR-144 and JWH-122 caused loss of mitochondrial membrane potential. All the compounds were able to induce caspase-9 activation. The involvement of apoptotic pathways was further confirmed through the significant increase in caspase -3/-7 activities. For UR-144, this effect was reversed by the CB1 antagonist AM281, for JWH-018 and THC this effect was mediated by both cannabinoid receptors CB1 and CB2 while for JWH-122 it was cannabinoid receptor-independent. This work demonstrates that THC and SCBs are able to induce apoptotic cell death. Although they may act through different mechanisms and potencies, the studied cannabinoids have the potential to disrupt gestational fundamental events. info:eu-repo/semantics/publishedVersion

The consumption of synthetic cannabinoids (SCs) has significantly increased in the last decade and the analysis of SCs and their metabolites in human specimens is gaining interest in clinical and forensic toxicology. A pilot study has been carried out using a combination of an initial last generation gas chromatography-mass spectrometry (GC-MS) screening method for the determination of JWH-122, JWH-210, UR-144) in oral fluid (OF) of consumers and an ultra-high performance liquid chromatography high resolution mass spectrometry (UHPLC-HRMS) confirmatory method for the quantification of the parent compounds and their metabolites in the same biological matrix. OF samples were simply liquid-liquid extracted before injecting in both chromatographic systems. The developed methods have been successfully validated and were linear from limit of quantification (LOQ) to 50 ng/mL OF. Recovery of analytes was always higher than 70% and matrix effect always lower than 15% whereas intra-assay and inter-assay precision and accuracy were always better than 16%. After smoking 1 mg JWH-122 or UR-144 and 3 mg JWH-210, maximum concentration of 4.00&ndash, 3.14 ng/mL JWH-122, 8.10&ndash, 7.30 ng/mL JWH-210 ng/mL and 7.40 and 6.81 ng/mL UR-144 were measured by GC-MS and UHPLC-HRMS respectively at 20 min after inhalation. Metabolites of JWH 122 and 210 were quantified in OF by UHPLC-HRMS, while that of UR144 was only detectable in traces. Our results provide for the first time information about disposition of these SCs and their metabolites in consumers OF. Last generation GC-MS has proven useful tool to identify and quantify parent SCs whereas UHPLC-HRMS also confirmed the presence of SCs metabolites in the OF of SCs consumers.

The use of synthetic cannabinoids (SCs), which escape conventional detection systems, may be a good alternative to elude routine drug analysis for cannabis. The detection of these drugs in urine is unusual due to their complete and fast metabolism, therefore requiring alternative strategies. In this work, an investigation has been made on SCs consumption by minors (less than 18 years old) in juvenile offenders' centres. 667 urine samples (from 127 minors) were collected after their permits with stay at home. We also studied the SCs from 7 herbal blends available at the smartshop frequented by the minors. Both, urine and herbal blends, were analysed by liquid chromatography coupled to high resolution mass spectrometry. The analysis of urine confirmed the absence of more than 200 SCs investigated. Thus, the focus was made on metabolites reported for those SCs identified in the herbal blends collected from the smart-shop. The major metabolites of XLR-11 and UR-144 (N-pentanoic acid and N-(5-hydroxypentyl)) were found in several urine samples. Apart from the main metabolites included in the initial searching, a thorough investigation of more metabolites for these SCs was additionally performed, including MS/MS experiments for the tentative identification of compounds detected in the urine samples. The 16 samples positive to the XLR-11 metabolites were assigned to 6 minors, only 2 of which had recognized consumption. On the basis of the results obtained, preventive and therapeutic interventions must be implemented to reduce the consumption of psychoactive substances and to improve the risk-perception of these substances by minors.

Background: `Herbal mixtures` containing synthetic cannabinoid receptor agonists (SCRAs) are promoted as legal alternative to marihuana and are easily available via the Internet. Keeping analytical methods for the detection of these SCRAs up-to-date is a continuous challenge for clinicians and toxicologists due to the high diversity of the chemical structures and the frequent emergence of new compounds. Since many SCRAs are extensively metabolized, analytical methods used for urine testing require previous identification of the major metabolites of each compound. Objective: The aim of this study was to identify the in vivo major metabolites of nine SCRAs (AM-694, AM-2201, JWH-007, JWH-019, JWH-203, JWH-307, MAM-2201, UR-144, XLR-11) for unambiguous detection of a drug uptake by analysis of urine samples. Method: Positive urine samples from patients of hospitals, detoxification and therapy centers as well as forensic-psychiatric clinics were analyzed by means of liquid chromatography-tandem mass spectrometry (LC-MS/MS) and liquid chromatography-quadrupol time-of-flight mass spectrometry (LC-qToF-MS) for investigation of the in vivo major metabolites. Results: For all investigated SCRAs, monohydroxylation, dihydroxylation and/or formation of the N-pentanoic acid metabolites were among the most abundant metabolites detected in human urine samples. Substitution of the fluorine atom was observed to be an important metabolic reaction for compounds carrying an N-(5-fluoropentyl) chain. Dealkylated metabolites were not detected in vivo. Conclusion: The investigated metabolites facilitate the reliable detection of drug uptake by analysis of urine samples. For distinction between uptake of the fluorinated and the non-fluorinated analogs, the N-(4-hydroxypentyl) metabolite of the non-fluorinated analog was identified as a useful analytical target and consumption marker.

The topic of this paper relates to the study of cases involving the use of new psychoactive substances (NPS) from the classes of synthetic cannabinoids and cathinones, analyzed from multiple viewpoints including clinical and medico-legal perspectives. The paper investigates three fatal cases in which UR-144 and UR-144 with pentedrone identified in the bodies of victims during post-mortem examinations were responsible for the tragic consequences and proved to be the indirect cause of death. The victims were men aged 16, 22 and 40 years who used drugs, for example they smoked marijuana or its substitutes in the form of synthetic cannabinoids. In addition, all of them had behavioural problems. On account of emotional imbalance attributable probably to the presence of UR-144 (in one case) and a mixture of UR-144 and pentedrone (in the other two cases), two men committed suicide by jumping from a height and hanging, and one man had fatal accidental poisoning with pentedrone which was used to enhance the effect of previously used UR-144. The presence of UR-144 and pentedrone in the post-mortem material was analyzed by liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS-MS). The results of toxicological tests were analyzed with a focus on possible tragic side effects caused by the presence of UR-144 and UR-144 with pentedrone in the body.Temat niniejszej pracy wpisuje się w nurt badawczy dotyczący przypadków przyjmowania nowych substancji psychoaktywnych (NSP) z grupy syntetycznych kannabinoidów i katynonów, rozpatrywanych z różnych punktów widzenia, w tym w aspekcie klinicznym i medyczno-prawnym. Analiza obejmuje trzy przypadki śmiertelne, w których obecność UR-144 oraz UR-144 z pentedronem w organizmie ofiar, wykazana w toku badań pośmiertnych, zaważyła na tragicznych konsekwencjach, stając się pośrednią przyczyną zgonu. Ofiarami byli mężczyźni w wieku 16, 22 i 40 lat przyjmujący narkotyki, w tym palący marihuanę lub jej zamienniki w postaci syntetycznych kannabinoidów, którzy dodatkowo mieli problemy behawioralne. W wyniku zaburzenia równowagi emocjonalnej spowodowanej zażyciem UR-144 (w jednym przy­padku) lub mieszaniny UR-144 i pentedronu (w dwóch przypadkach) w dwóch przypadkach doszło do zamachów samobójczych w postaci skoku z wysokości i powieszenia, a w jednym do przypadkowego zatrucia śmiertelnego pentedronem zażytym w celu wzmocnienia efektu działania wcześniej przyjętego UR-144. Oznaczenie UR-144 i pentedronu w badanym materiale sekcyjnym przeprowadzono metodą chromatografii cieczowej sprzężoną z tandemową spektrometrią mas z jonizacją poprzez rozpylanie w polu elektrycznym (LC-ESI-MS-MS). Wyniki badań toksykologicznych analizowano w kontekście możliwych tragicznych efektów ubocznych obecności UR-144 oraz UR-144 z pentedronem w organizmie człowieka.

© 2018, American Association of Pharmaceutical Scientists. The number of new psychoactive substances keeps on rising despite the controlling efforts by law enforcement. Although metabolism of the newly emerging drugs is continuously studied to keep up with the new additions, the exact structures of the metabolites are often not identified due to the insufficient sample quantities for techniques such as nuclear magnetic resonance (NMR) spectroscopy. The aim of the study was to characterise several metabolites of the synthetic cannabinoid (1-pentyl-1H-indol-3-yl) (2,2,3,3-tetramethylcyclopropyl) methanone (UR-144) by NMR spectroscopy after the incubation with the fungus Cunninghamella elegans. UR-144 was incubated with C. elegans for 72 h, and the resulting metabolites were chromatographically separated. Six fractions were collected and analysed by NMR spectroscopy. UR-144 was also incubated with human liver microsomes (HLM), and the liquid chromatography-high resolution mass spectrometry analysis was performed on the HLM metabolites with the characterised fungal metabolites as reference standards. Ten metabolites were characterised by NMR analysis including dihydroxy metabolites, carboxy and hydroxy metabolites, a hydroxy and ketone metabolite, and a carboxy and ketone metabolite. Of these metabolites, dihydroxy metabolite, carboxy and hydroxy metabolites, and a hydroxy and ketone metabolite were identified in HLM incubation. The results indicate that the fungus is capable of producing human-relevant metabolites including the exact isomers. The capacity of the fungus C. elegans to allow for NMR structural characterisation by enabling production of large amounts of metabolites makes it an ideal model to complement metabolism studies.

Recently, use of novel synthetic cannabinoids has increased greatly despite worldwide efforts to regulate these drugs. XLR-11 ((1-[5'-fluoropentyl]indol-3-yl)-(2,2,3,3-tetramethylcyclopropyl)methanone), a fluorinated synthetic cannabinoid with a tetramethylcyclopropyl moiety, has been frequently abused since 2012. XLR-11 produces a number of metabolites in common with its non-fluorinated parent analogue, UR-144 ((1-pentylindol-3-yl)-(2,2,3,3-tetramethylcyclopropyl)methanone). Therefore, it is essential to develop effective urinary markers to distinguish between these drugs. In this study, we investigated the metabolic profile of authentic human urine specimens from suspected users of XLR-11 using liquid chromatography-quadrupole time-of-flight mass spectrometry. Furthermore, we quantified four potential XLR-11 metabolites by using commercially available reference standards. In vitro metabolism of XLR-11 and UR-144 using human liver microsomes was also investigated to compare patterns of production of hydroxypentyl metabolites. Urine samples were prepared with and without enzymatic hydrolysis, and subjected to solid-phase extraction. We identified 19 metabolites generated by oxidative defluorination, hydroxylation, carboxylation, dehydrogenation, glucuronidation, and combinations of these reactions. Among the identified metabolites, 12 were generated from a cyclopropyl ring-opened XLR-11 degradation product formed during smoking. The XLR-11 metabolite with a hydroxylated 2,4-dimethylpent-1-ene moiety was detected in most specimens after hydrolysis and could be utilized as a specific marker for XLR-11 intake. Quantitative results showed that the concentration ratio of 5- and 4-hydroxypentyl metabolites should also be considered as a useful marker for differentiating between the abuse of XLR-11 and UR-144.

Synthetic cannabinoid (SC) designer drugs featuring bioisosteric fluorine substitution are identified by forensic chemists and toxicologists with increasing frequency. Although terminal fluorination of N-pentyl indole SCs is sometimes known to improve cannabinoid type 1 (CB1) receptor binding affinity, little is known of the effects of fluorination on functional activity of SCs. This study explores the in vitro functional activities of SC designer drugs JWH-018, UR-144, PB-22, and APICA, and their respective terminally fluorinated analogues AM-2201, XLR-11, 5F-PB-22, and STS-135 at human CB1 and CB2 receptors using a FLIPR membrane potential assay. All compounds demonstrated agonist activity at CB1 (EC50 = 2.8–1959 nM) and CB2 (EC50 = 6.5–206 nM) receptors, with the fluorinated analogues generally showing increased CB1 receptor potency (∼2–5 times). Additionally, the cannabimimetic activities and relative potencies of JWH-018, AM-2201, UR-144, XLR-11, PB-22, 5F-PB-22, APICA, and STS-135 in vivo were evaluated in rats using biotelemetry. All SCs dose-dependently induced hypothermia and reduced heart rate at doses of 0.3–10 mg/kg. There was no consistent trend for increased potency of fluorinated SCs over the corresponding des-fluoro SCs in vivo. Based on magnitude and duration of hypothermia, the SCs were ranked for potency (PB-22 > 5F-PB-22 = JWH-018 > AM-2201 > APICA = STS-135 = XLR-11 > UR-144).

A large number of new psychoactive substances are available at the illicit drug market and the synthetic cannabinoids (SCs) are among the substances that have led to serious side effects and death. Knowledge about common concentrations of these drugs are however sparse. Concentrations of APINACA and 5F-APINACA in biological matrixes have previously not been reported, and concentrations of UR-144 and its degradant product in blood samples from driving under the influence of drug (DUID) cases have not been published. The aims of this study were to report concentrations of APINACA, 5F-APINACA, UR-144 and UR-144 degradant from DUID cases analyzed at the Norwegian Institute of Public Health (NIPH), and also previously unpublished concentrations of AM-2201 in cases from our Institute. We have further summarized all the former published studies where concentrations of SCs have been reported, to compare with the results from these newer SCs. In whole blood from one driver we have found 5F-APINACA and from three drivers both APINACA and 5F-APINACA in concentrations from 0.24 to 24.5 and 0.9 to 6.5 μg/L, respectively, and UR-144 in two cases in concentrations of 0.22 and 0.47 μg/L. UR-144 degradant in a concentration of 0.15 μg/L was found in one of the cases. A summary of the literature reveals major deficiencies regarding concentrations of most of the SCs. The SCs most frequently detected in DUID cases were (n≥8) AM-2201, JWH-122, JWH-018 and JWH-210. In intoxication cases AM-2201 (n=517) was the most often detected SC, followed by JWH-122, JWH-210, UR-144, JWH-018, and MAM-2201 (n>100). Four studies regarding concentrations in autopsy cases have been published, and concentrations of four different SCs have been reported (JWH-018, JWH-073, JWH-210, AM-2201 and the metabolites of AM-2201; 4-OH-pentyl, JWH-018 5-OH-pentyl and JWH-018 pentanoic acid). Pharmacokinetic data are only available for JWH-018 (n=3), JWH-073 (n=1) and the metabolites of AM-2201; 4-OH-pentyl, 6-OH-indole, JWH-018 5-OH-pentyl and JWH-018 pentanoic acid (n=1).

Synthetic cannabinoids (SCs) continue to be the largest group of new psychoactive substances (NPS) monitored by the European Monitoring Center of Drugs and Drugs of Abuse (EMCDDA). The identification and subsequent prohibition of single SCs has driven clandestine chemists to produce analogues of increasing structural diversity, intended to evade legislation. That structural diversity, combined with the mostly unknown metabolic profiles of these new SCs, poses a big challenge for the conventional targeted analytical assays, as it is difficult to screen for "unknown" compounds. Therefore, an alternative screening method, not directly based on the structure but on the activity of the SC, may offer a solution for this problem. We generated stable CB1 and CB2 receptor activation assays based on functional complementation of a split NanoLuc luciferase and used these to test an expanded set of recent SCs (UR-144, XLR-11, and their thermal degradation products; AB-CHMINACA and ADB-CHMINACA) and their major phase I metabolites. By doing so, we demonstrate that several major metabolites of these SCs retain their activity at the cannabinoid receptors. These active metabolites may prolong the parent compound's psychotropic and physiological effects and may contribute to the toxicity profile. Utility of the generated stable cell systems as a first -line screening tool for SCs in urine was also demonstrated using a relatively large set of authentic urine samples. Our data indicate that the stable CB reporter assays detect CB receptor, activation by extracts of urine in which SCs (or their metabolites) are present at low- or subnanomolar (ng/mL) level. Hence, the developed assays do not only allow activity profiling of SCs and their metabolites, it may also serve as a screening tool, complementing targeted and untargeted analytical assays and preceding analytical (mass spectrometry based) confirmation.

The case reports for 18 driving cases positive for the synthetic cannabinoid substances XLR-11 and/or UR-144 are discussed. Eleven of these cases had drug recognition expert evaluations performed. Slurred speech, lack of convergence and body and eyelid tremors were the most consistently noted interview characteristic. Pulse and blood pressure of the subjects were within the expected range. Most of the drivers contacted demonstrated poor driving; however, their performance on the standardized field sobriety tests yielded inconsistent diagnostic information. All cases were negative for other commonly detected drugs that affect the central nervous system, although one case was additionally positive for other synthetic cannabinoids. Of the studied cases, six were positive for only UR-144, whereas eight contained only XLR-11. Four cases were found to have both.

Availability and consumption of synthetic cannabinoids have risen recently in the USA and Europe. These drugs have adverse effects, including acute psychosis and bizarre behavior. In 2012, the United States Drug Enforcement Agency permanently banned five of the synthetic cannabinoids and in 2013, temporarily added XLR11, UR-144 and AKB48 to Schedule I of the Controlled Substances Act. As synthetic cannabinoid strains are added to the Schedule I list, new strains are being introduced into the market. XLR11 and UR-144 are two of the most recent additions to the synthetic cannabinoid drug class. To test collected oral fluid samples for XLR11 and UR-144, we developed a bioanalytical method that initially purifies the sample with solid-phase extraction and then quantitatively identifies the drugs with ultra-high-performance liquid chromatography-tandem mass spectrometry. The method was validated according to United States Food and Drug Administration guidelines and Scientific Working Group for Forensic Toxicology guidelines and the validation data showed that the method is an accurate, precise, robust and efficient method suited for high-throughput toxicological screening applications. We tested human subject samples with the developed method and found the presence of parent drugs (XLR11 and UR-144), their metabolites and their pyrolysis products in oral fluid.

UR-144 [(1-pentyl-1H-indol-3-yl)(2,2,3,3-tetramethylcyclopropyl)methanone] is a synthetic cannabinoid, which has been detected in many herbal blends, resinous samples and powders seized from the Polish drug market since the beginning of 2012. This paper presents the case of intoxication by this substance. A complete picture of the symptoms observed by a witness, paramedics and medical doctors are given. In the analysis of powder residues from the plastic bag seized from the intoxicated person by gas chromatography-mass spectrometry (GC-MS), UR-144 and its major pyrolysis product [1-(1-pentyl-1H-indol-3-yl)-3-methyl-2-(propan-2-yl)but-3-en-1-one] were detected. Both substances were also identified in a blood sample collected on admission of the patient to hospital using liquid chromatography-triple quadrupole tandem mass spectrometry (LC-QqQ-MS). Blood concentration of UR-144 was 6.1 ng/mL. A urine sample collected at the same time was analyzed by liquid chromatography-quadruple time-of-flight tandem mass spectrometry (LC-QTOF-MS). The parent substance and its pyrolysis products were not detected in urine, while their five metabolites were found. The experiments allowed the location of derivative groups to be established, and thus elucidate rough structures of the metabolites; a dihydroxylated metabolite of UR-144 and mono-, dihydroxylated and carboxylated metabolites of its pyrolysis product were identified.

UR-144 [(1-pentyl-1H-indol-3-yl)(2,2,3,3-tetramethylcyclopropyl)methanone] is a synthetic cannabinoid, which has been detected in many 'legal highs', seized from the global drug market since the beginning of 2012. It has gained popularity as a 'legal' alternative to classic cannabis in countries where it was not controlled. Despite the widespread distribution of this substance, the data on its effects on the human body are scarce. Therefore, this paper describes the results of analysis and observed effects in 39 cases in which UR-144 was determined in blood. Symptoms were noted from the blood sampling forms filled out by the representative doctor. The determined concentrations of UR-144 were in the range of trace amounts (LOD-0.15ng/mL; LOQ-0.5ng/mL) up to 17ng/mL. The most common observed effects included slurred speech, dilated pupils, sluggish and abnormal pupillary reaction, cheerful behaviour, poor coordination, and staggering. Less frequently observed were: verbosity, narrow pupils, loss of consciousness, pale or reddened facial skin, blackout, euphoria, agitation, hallucinations, hindered communication, shaking hands, seizures, convulsions, somnolence, delayed movements, redness of the conjunctiva, and tachycardia. The discussed cases show the effects observed after UR-144 use. This study can assist in the recognition of possible effects caused by this substance.

Ongoing changes in the synthetic cannabinoid drug market create the need for relevant targeted immunoassays for rapid screening of biological samples. We describe the validation and performance characteristics of an enzyme-linked immunosorbent assay designed to detect use of one of the most prevalent synthetic cannabinoids in urine, UR-144, by targeting its pentanoic acid metabolite. Fluorinated UR-144 (XLR-11) has been demonstrated to metabolize to this common product. The assay has significant cross-reactivity with UR-144-5-OH, UR-144-4-OH and XLR-11-4-OH metabolites, but

Synthetic indole-derived cannabinoids have become commonly used recreational drugs and continue to be abused despite their adverse consequences. As compounds that were identified early in the epidemic (e.g., naphthoylindoles) have become legally banned, new compounds have appeared on the drug market. Two tetramethylcyclopropyl ketone indoles, UR-144 [(1-pentyl-1H-indol-3-yl)-(2,2,3,3-tetramethylcyclopropyl)methanone] and XLR-11 [(1-(5-fluoropentyl)-1H-indol-3-yl)-(2,2,3,3-tetramethylcyclopropyl)methanone], recently have been identified in confiscated products. These compounds are structurally related to a series of CB2-selective compounds explored by Abbott Labs. The purpose of the present study was to evaluate the extent to which UR-144 and XLR-11 shared cannabinoid effects with Δ9-tetrahydrocannabinol (Δ9-THC). Indices of in vitro and in vivo activity at cannabinoid receptors were assessed. Similar to other psychoactive cannabinoid agonists, XLR-11 and UR-144 showed low nanomolar (< 30) affinity for CB1 and CB2 receptors, activated these receptors as full agonists, and produced dose-dependent effects that were blocked by rimonabant in mice, including antinociception, hypothermia, catalepsy and suppression of locomotor activity. The potency of both compounds was several-fold greater than Δ9-THC. XLR-11 and UR-144 also substituted for Δ9-THC in a Δ9-THC discrimination procedure in mice, effects that were attenuated by rimonabant. Analysis of urine from mice treated with the compounds revealed that both were extensively metabolized, with predominant urinary excretion as glucuronide conjugates. Together, these results demonstrate that UR-144 and XLR-11 share a pharmacological profile of in vitro and in vivo effects with Δ9-THC and other abused indole-derived cannabinoids and would be predicted to produce Δ9-THC-like subjective effects in humans.

Studies on the pyrolysis of the synthetic cannabinoid agonist UR-144 ((1-pentyl-1H-indol-3-yl)(2,2,3,3-tetramethylcyclopropyl)methanone) have shown that its major pyrolysis product is a tetramethylcyclopropane ring-opened alkene. Considering that smoking is a common way of ingesting synthetic cannabimimetics, the presence of the metabolites of this pyrolysis product would be expected in biological fluids. Using GC-MS and LC-MS-MS methods, a series of phase I metabolites of UR-144 and its pyrolysis product were detected in the urine samples from patients admitted to hospital with suspected drug intoxication. The metabolites were tentatively identified as the products of mono-hydroxylation, di-hydroxylation, mono-hydroxylation with formation of the carbonyl group on the N-alkyl chain, carboxylation and N-dealkylation with mono-hydroxylation. In the case of the UR-144 pyrolysis product, metabolites with hydration of the aliphatic double bond were also identified. The parent compounds were detected as trace amounts in some urine samples, and the hydrated derivative of the UR-144 pyrolysis product was detected in the majority of samples. The detection of mono-hydroxylated metabolites of UR-144 (LC-MS-MS) and mono-hydroxylated/with hydration metabolites of the UR-144 pyrolysis product (GC-MS) was found to be the most useful method of establishing UR-144 ingestion.

Several 3-acylindoles with high affinity for the CB(2) cannabinoid receptor and selectivity over the CB(1) receptor have been prepared. A variety of 3-acyl substituents were investigated, and the tetramethylcyclopropyl group was found to lead to high affinity CB(2) agonists (5, 16). Substitution at the N1-indole position was then examined. A series of aminoalkylindoles was prepared and several substituted aminoethyl derivatives were active (23-27, 5) at the CB(2) receptor. A study of N1 nonaromatic side chain variants provided potent agonists at the CB(2) receptor (16, 35-41, 44-47, 49-54, and 57-58). Several polar side chains (alcohols, oxazolidinone) were well-tolerated for CB(2) receptor activity (41, 50), while others (amide, acid) led to weaker or inactive compounds (55 and 56). N1 aromatic side chains also afforded several high affinity CB(2) receptor agonists (61, 63, 65, and 69) but were generally less potent in an in vitro CB(2) functional assay than were nonaromatic side chain analogues.