Interpreting mono- and poly-SCRA intoxications from an activity-based point of view: JWH-018 equivalents in serum as a comparative measure.

Synthetic cannabinoid receptor agonists (SCRAs) are a class of synthetic drugs that mimic and greatly surpass the effect of recreational cannabis. Acute SCRA intoxications are in general difficult to assess due to the large number of compounds involved, differing widely in both chemical structure and pharmacological properties. The rapid pace of emergence of unknown SCRAs hampers on one hand the timely availability of methods for identification and quantification to confirm and estimate the extent of the SCRA intoxication. On the other hand, lack of knowledge about the harm potential of emerging SCRAs hampers adequate interpretation of serum concentrations in intoxication cases. In the present study, a novel comparative measure for SCRA intoxications was evaluated, focusing on the cannabinoid activity (versus serum concentrations), which can be measured in serum extracts with an untargeted bioassay assessing ex vivo CB1 activity. Application of this principle to a series of SCRA intoxication cases (n = 48) allowed for the determination of activity equivalents, practically entailing a conversion from different SCRA serum concentrations to a JWH-018 equivalent. This allowed for the interpretation of both mono- (n = 34) and poly-SCRA (n = 14) intoxications, based on the intrinsic potential of the present serum levels to exert cannabinoid activity (cf. pharmacological/toxicological properties). A non-distinctive toxidrome was confirmed, showing no relation to CB1 activity. The JWH-018 equivalent was partly related to the poison severity score (PSS) and causality of the clinical intoxication elicited by the SCRA. Altogether, this equivalent concept allows to comparatively and timely interpret (poly-)SCRA intoxications based on CB1 activity.

Effects of Hypericum perforatum (St John's wort) on the pharmacokinetics and pharmacodynamics of rivaroxaban in humans.

AIMS: To investigate the influence of a cytochrome P450 CYP3A4 and efflux transporter P-glycoprotein (P-gp) inducing Hypericum perforatum extract on the pharmacokinetics and pharmacodynamics of rivaroxaban. METHODS: Open-label, nonrandomized, sequential treatment interaction study. Following CYP3A4 and P-gp phenotyping using low-dose midazolam and fexofenadine, 12 healthy volunteers received a single oral dose of 20 mg rivaroxaban and rivaroxaban plasma concentrations and inhibition of the activated coagulation factor X (factor Xa) activity were measured prior to and up to 48 h postdosing. The procedures were repeated after 2 weeks' treatment with the H. perforatum extract. RESULTS: The geometric mean ratios for the area under the concentration-time curve and Cmax of rivaroxaban after/before induction with the H. perforatum extract were 0.76 (90% confidence interval [CI] 0.70, 0.82) and 0.86 (90% CI 0.76, 0.97), respectively. Inhibition of factor Xa activity was reduced with a geometric mean area under the effect-time curve ratio after/before induction of 0.80 (90% CI 0.71, 0.89). No clinically significant differences were found regarding Tmax (median 1.5 vs 1 h, P = .26) and terminal elimination half-life (mean 10.6 vs 10.8 h, P = .93) of rivaroxaban. The H. perforatum extract significantly induced CYP3A4 and P-gp activity, as evidenced by phenotyping. CONCLUSION: The CYP3A4/P-gp inducing H. perforatum extract caused a decrease of rivaroxaban exposure with a proportional decrease of the pharmacodynamic effect. Although the data do not justify a contraindication for the combination or a systematic adjustment of rivaroxaban dosage, avoidance of the combination or laboratory monitoring should be considered in patients taking hyperforin-containing H. perforatum extracts with rivaroxaban.

Clinical value of analytical testing in patients presenting with new psychoactive substances intoxication.

New psychoactive substances (NPS) have emerged worldwide in recent years, posing a threat to public health and a challenge to drug policy. NPS are usually derivatives or analogues of classical recreational drugs designed to imitate their effects while circumventing regulations. This article provides an overview of benefits and limitations of analytical screening in managing patients presenting with acute NPS toxicity. NPS typically cannot be analytically identified with the usual immunoassay tests. To detect NPS using an immunoassay, antibodies specifically binding to the new structures would have to be developed, which is complicated by the rapid change of the NPS market. Activity-based assays could circumvent this problem since no prior knowledge on the substance structure is necessary. However, classical recreational drugs activating the same receptors could lead to false positive results. Liquid or gas chromatography coupled with mass spectrometry is a valuable NPS analysis tool, but its costs (e.g. equipment), run time (results usually within hours vs minutes in case of immunoasssays) and the need for specialized personnel hinder its use in clinical setting, while factors such as lack of reference standards can pose further limitations. Although supportive measures are sufficient in most cases for adequate patient management, the detection and identification of NPS can contribute significantly to public health and safety in cases of e.g. cluster intoxications and outbreaks, and to the investigation of these novel compounds' properties. However, this requires not only availability of the necessary equipment and personnel, but also collaboration between clinicians, authorities and laboratories.

Analysing and quantifying chronic stress-associated endogenous steroids in hair samples.

In previous studies, various steroids have been associated with stress and have therefore been quantified to investigate stress-related questions. Since the main stress-related steroid cortisol follows a circadian rhythm, often hair is analysed to quantify this steroid. Further, hair analysis gives the unique possibility of long-time monitoring by analysing a certain segment of hair, since hair grows on average 1 cm per month. Hair is a difficult matrix due to the complex sample preparation with many steps including washing and grinding, followed by various extraction steps. Additionally, steroids are endogenous and are therefore present in the hair matrix. Hence, no analyte free matrix is available, which is needed for the quantification via external calibrators. To overcome this problem, the so-called surrogate methods can be used, for which a 13 C3 labelled or deuterated reference compound of the steroid of interest is used for quantification. In the present study, a surrogate method was developed and fully validated for the quantitative analysis of seven steroids in human hair. Validation experiments showed that the method is further suitable for semi-quantitative analysis of estradiol. However, it is not suitable for the analysis of androsterone and DHEAS. The method was successfully used to analyse steroids in a comprehensive study of 360 adolescent hair samples, enabling research into stress markers.

Metabolite markers for three synthetic tryptamines N-ethyl-N-propyltryptamine, 4-hydroxy-N-ethyl-N-propyltryptamine, and 5-methoxy-N-ethyl-N-propyltryptamine.

N-Ethyl-N-propyltryptamine (EPT), 4-hydroxy-N-ethyl-N-propyltryptamine (4-OH-EPT), and 5-methoxy-N-ethyl-N-propyltryptamine (5-MeO-EPT) are new psychoactive substances classified as tryptamines, sold online. Many tryptamines metabolize rapidly, and identifying the appropriate metabolites to reveal intake is essential. While the metabolism of 4-OH-EPT and 5-MeO-EPT are not previously described, EPT is known to form metabolites by indole ring hydroxylation among others. Based on general knowledge of metabolic patterns, 5-MeO-EPT is also expected to form ring hydroxylated EPT (5-OH-EPT). In the present study, the aim was to characterize the major metabolites of EPT, 4-OH-EPT, and 5-MeO-EPT, to provide markers for substance identification in forensic casework. The tryptamines were incubated with pooled human liver microsomes at 37°C for up to 4 h. The generated metabolites were separated and detected by ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry analysis. The major in vitro EPT metabolites were formed by hydroxylation, N-dealkylation, and carbonylation. In comparison, 4-OH-EPT metabolism was dominated by double bond formation, N-dealkylation, hydroxylation, and carbonylation in vitro and hydroxylation or carbonylation combined with double bond loss, carbonylation, N-dealkylation, and hydroxylation in vivo. 5-MeO-EPT was metabolized by O-demethylation, hydroxylation, and N-dealkylation in vitro. The usefulness of the characterized metabolites in forensic casework was demonstrated by identification of unique metabolites for 4-OH-EPT in a human postmortem blood sample with suspected EPT or 4-OH-EPT intoxication.

On the complex relationship between resilience and hair cortisol levels in adolescence despite parental physical abuse: a fourth wave of resilience research.

Introduction: To understand the family's role in adolescents' mental health development and the connection to neurodevelopmental disorders related to experienced parental physical abuse, we first explored resilience pathways longitudinally and secondly, connected the identified patterns to adolescents' hair cortisol levels that are rooted in the hypothalamic-pituitary-adrenal axis as the main stress response system and connected brain structure alterations. Methods: We analyzed longitudinal online questionnaire data for three consecutive high school years (from seventh to ninth grade) and four survey waves from a representative sample of n = 1609 high school students in Switzerland on violence-resilience pathways. Furthermore, we collected students' hair samples from a subsample of n = 229 at survey wave 4. About 30% of the participating adolescents had been physically abused by their parents. Out of the overall sample, we drew a subsample of adolescents with parental abuse experiences (survey wave 1 n = 509; survey wave 2 n = 506; survey wave 3 n = 561; survey wave 4 n = 560). Results: Despite the odds, about 20-30% of adolescents who have experienced parental physical abuse escaped the family violence cycle and can be called resilient. By applying a person-oriented analytical approach via latent class and transition analysis, we longitudinally identified and compared four distinct violence-resilience patterns. We identified violence resilience as a multidimensional latent construct, which includes hedonic and eudaimonic protective and risk indicators. Because resilience should not solely be operationalized based on the lack of psychopathology, our latent construct included both feeling good (hedonic indicators such as high levels of self-esteem and low levels of depression/anxiety and dissociation) and doing well (eudaimonic indicators such as high levels of self-determination and self-efficacy as well as low levels of aggression toward peers). Discussion: The present study confirmed that higher cortisol levels significantly relate to the comorbid pattern (internalizing and externalizing symptoms), and further confirmed the presence of lasting alterations in brain structures. In this way, we corroborated the insight that when studying the resilience pathways and trajectories of abused adolescents, biological markers such as hair cortisol significantly enhance and deepen the understanding of the longitudinal mechanisms of psychological markers (e.g., self-determination, self-esteem, self-efficacy) that are commonly applied in questionnaires.

Pharmacology, prevalence in Germany, and analytical data of cyclobutylmethyl- and norbornylmethyl-type synthetic cannabinoid receptor agonists.

Synthetic cannabinoid receptor agonists (SCRAs) are distributed on the drug market to produce THC-like effects while evading routine drug testing and legislation. The cyclobutylmethyl (CBM) and norbornylmethyl (NBM) side chain specifically circumvented the German legislation and led to the emergence of exploratory SCRAs in 2019-2021. The NBM SCRAs were detected post-amendment of the new psychoactive substances act in 2020, which scheduled all CBM SCRAs. All six SCRAs are full agonists at the cannabinoid receptor 1 compared with Δ9 -tetrahydrocannabinol and CP-55,940. The CBM SCRAs showed binding affinities of Ki : 29.4-0.65 nm and potencies of EC50 : 483-40.1 nm (CBMICA << CBMINACA < CBMeGaClone). The norbornyl derivatives exhibited high affinities (Ki : 1.87-0.25 nm), with indazole being the most affine. Functional activity data confirmed that the indazole derivative tends to be the most potent of all three NBM SCRAs (EC50 : 169-1.78 nm). The sterically demanding NBM side chain increased the affinity and activity of almost all core structures. Future studies should be conducted on similarly voluminous side chain moieties. The 'life cycle' of all SCRAs on the drug market was less than a year. Notably, Cumyl-CBMICA was the most prevalent while also having the weakest cannabimimetic properties. Quantification of Cumyl-CBMICA during peak consumption in late 2019 and early 2020 revealed an increase in the concentration on the herbal material, which, together with forum entries and blog posts, corroborates the low in vitro cannabimimetic properties. Seizure prevalence data indicate that almost all SCRAs continue to be identified in 2022, potentially due to remaining stocks.

Investigation of the µ- and κ-opioid receptor activation by eight new synthetic opioids using the [35 S]-GTPγS assay: U-47700, isopropyl U-47700, U-49900, U-47931E, N-methyl U-47931E, U-51754, U-48520, and U-48800.

In 2009, new synthetic opioids appeared on the new psychoactive substances market. This class of new psychoactive substances generally poses a health risk due to the high affinity and potency of most of these compounds for the opioid receptors. It is known that overdoses can lead to respiratory depression and result in death. However, for many new synthetic opioids, data on toxicological and toxicokinetic properties are scarce. In the present study, eight U-opioids were investigated for their structure activity relationships at the µ- and κ-opioid receptors using a [35 S]-GTPγS assay. The potencies of the investigated U-opioids were lower than those of the reference compounds (µ-opioid receptor: hydromorphone, fentanyl; κ-opioid receptor: U-69593, U-50488). At the µ-opioid receptor, U-47700 showed the highest potency with an EC50 value of 111 nM, and at the κ-opioid receptor, U-51754 was found to be the most potent compound with an EC50 value of 120 nM. The following structural features were advantageous for activating the µ-opioid receptor: two chlorine substituents in 3,4-position at the aromatic ring, the absence of the methylene group between the amide group and the aromatic ring, a methyl group at the amide nitrogen, and/or a dimethylamine residue at the amine nitrogen of the cyclohexane ring. Further, the following structural features were beneficial for κ-opioid receptor activation: a methylene group between the amide group and the aromatic ring, a pyrrolidine residue at the amine nitrogen of the cyclohexane ring, a methyl group at the amide nitrogen, and/or a chlorine substitution at the 3,4-position of the aromatic ring.

Structure-activity relationships of valine, tert-leucine, and phenylalanine amino acid-derived synthetic cannabinoid receptor agonists related to ADB-BUTINACA, APP-BUTINACA, and ADB-P7AICA.

Synthetic cannabinoid receptor agonists (SCRAs) remain one the most prevalent classes of new psychoactive substances (NPS) worldwide, and examples are generally poorly characterised at the time of first detection. We have synthesised a systematic library of amino acid-derived indole-, indazole-, and 7-azaindole-3-carboxamides related to recently detected drugs ADB-BUTINACA, APP-BUTINACA and ADB-P7AICA, and characterised these ligands for in vitro binding and agonist activity at cannabinoid receptor subtypes 1 and 2 (CB1 and CB2), and in vivo cannabimimetic activity. All compounds showed high affinity for CB1 (K i 0.299-538 nM) and most at CB2 (K i = 0.912-2190 nM), and most functioned as high efficacy agonists of CB1 and CB2 in a fluorescence-based membrane potential assay and a ßarr2 recruitment assay (NanoBiT®), with some compounds being partial agonists in the NanoBiT® assay. Key structure-activity relationships (SARs) were identified for CB1/CB2 binding and CB1/CB2 functional activities; (1) for a given core, affinities and potencies for tert-leucinamides (ADB-) > valinamides (AB-) ≫ phenylalaninamides (APP-); (2) for a given amino acid side-chain, affinities and potencies for indazoles > indoles ≫ 7-azaindoles. Radiobiotelemetric evaluation of ADB-BUTINACA, APP-BUTINACA and ADB-P7AICA in mice demonstrated that ADB-BUTINACA and ADB-P7AICA were cannabimimetic at 0.1 mg kg-1 and 10 mg kg-1 doses, respectively, as measured by pronounced decreases in core body temperature. APP-BUTINACA failed to elicit any hypothermic response up to the maximally tested 10 mg kg-1 dose, yielding an in vivo potency ranking of ADB-BUTINACA > ADB-P7AICA > APP-BUTINACA.

Determination of the Cross-Reactivity of the Biological Metabolite (-)-trans-Δ9-Tetrahydrocannabinol-Carboxylic Acid-Glucuronide (THC-COOH-Gluc) for Cannabinoid Immunoassays.

The highest concentrated metabolite of (-)-trans-Δ9-tetrahydrocannabinol (THC) in urine, the main psychoactive constituent of Cannabis sativa, is 11-nor-9-carboxy-(-)-trans-Δ9-tetrahydrocannabinol-ß-D-glucuronide [(-)-trans-THC-COOH-Gluc]. Even though reference standards for THC, 11-hydroxy-THC (11-OH-THC) and THC-COOH are commercially available as the biological (-)-trans-stereoisomers, the reference standard of THC-COOH-Gluc is only available as the racemic 11-nor-9-carboxy-(±)-cis-Δ9-tetrahydrocannabinol-ß-D-glucuronide. This poses the problem for immunoassays, because different stereoisomers may have different cross-reactivity (CR). The aim of the current study was to extract the biological stereoisomer (-)-trans-THC-COOH-Gluc from a urine sample of two marihuana consumers by solid-phase extraction with a Chromabond® C18 cartridge. The cannabinoids in the obtained extract were quantified by Liquid-chromatography coupled to tandem mass spectrometry (LC-MS-MS) and used after dilution for further testing of the CR of (-)-trans-THC-COOH-Gluc with a homogenous enzyme immunoassay assay (hEIA) (Urine HEIA® Cannabinoids (THC), Immunalysis™, Pomona, CA, USA). The CR was determined as the measured HEIA® signal (ng/mL) per THC-COOH-Gluc concentration (ng/mL) in percentage. Results showed that the CR (determined in concentration ratios) is concentration dependent and is 72-87% in the calibration range (20-50 ng/mL). At the cut-off of the hEIA (40 ng/mL), the CR was determined to be 75%. With a molecular weight quotient of 1.51 (MWTHC-COOH-Gluc/MWTHC-COOH = 520.568 g/mol/344.451 g/mol), this means that CR (in molar ratios) is 106-131%. This finding is important, since the major metabolite of THC in urine is (-)-trans-THC-COOH-Gluc and not (-)-trans-THC-COOH, which is used for calibration and no hydrolysis is performed during the determination by hEIA.

Pharmacological and metabolic characterization of the novel synthetic opioid brorphine and its detection in routine casework.

After their first emergence in 2009, Novel synthetic opioids (NSO) have become an emerging class of New Psychoactive Substances (NPS) on the market for these new drugs. So far, 67 NSO have been reported to the Early Warning system of the European Monitoring Centre for Drugs and Drug Addiction (EMCDDA). It is presumed that NSO mainly target the four known opioid receptors, i.e. the µ-opioid (MOR), the δ-opioid (DOR), the κ-opioid (KOR) and nociceptin receptors and that their consumption can result in serious adverse effects such as massive respiratory depression or death. In the present study we investigated the in vivo and in vitro metabolism of brorphine, a NSO that was first identified on the NPS market in August 2019 in the United States, using both a pooled human liver microsome assay and real forensic case samples. For the detection of metabolites LC-HR-MS/MS was used and quantification of brorphine was performed using an LC-MS/MS method. Additionally, we pharmacologically characterized brorphine regarding its activation of the MOR and KOR via G protein recruitment using the [35S]-GTPγS assay. In forensic urine samples, 14 distinct metabolites were identified, whereas in blood only four metabolites could be found. The pooled human liver microsome assay generated six distinct in vitro phase I metabolites. The most prominent in vivo metabolite was formed by N-oxydation, whereas the main in vitro metabolite was formed by hydroxylation. The pharmacological characterization at the MOR and KOR revealed brorphine to be a potent MOR agonist and a weak, partial KOR agonist in the [35S]-GTPγS assay.

New synthetic cannabinoids carrying a cyclobutyl methyl side chain: Human Phase I metabolism and data on human cannabinoid receptor 1 binding and activation of Cumyl-CBMICA and Cumyl-CBMINACA.

Synthetic cannabinoids (SCs) represent a large group of new psychoactive substances (NPS), sustaining a high prevalence on the drug market since their first detection in 2008. Cumyl-CBMICA and Cumyl-CBMINACA, the first representatives of a new subclass of SCs characterized by a cyclobutyl methyl (CBM) moiety, were identified in July 2019 and February 2020. This work aimed at evaluating basic pharmacological characteristics and human Phase I metabolism of these compounds. Human Phase I metabolites were tentatively identified by liquid chromatography-quadrupole time-of-flight mass spectrometry (LC-QToF-MS) of urine samples and confirmed by a pooled human liver microsome (pHLM) assay. The basic pharmacological evaluation was performed by applying a competitive ligand binding assay and a functional activation assay (GTPγS) using cell membranes carrying the human cannabinoid receptor 1 (hCB1 ). Investigation of the human Phase I metabolism resulted in the identification of specific urinary markers built by monohydroxylation or dihydroxylation. Although Cumyl-CBMICA was primarily hydroxylated at the indole ring, hydroxylation of Cumyl-CBMINACA mainly occurred at the CBM moiety. Both substances acted as agonists at the hCB1 receptor, although substantial differences could be observed. Cumyl-CBMINACA showed higher binding affinity (Ki = 1.32 vs. 29.3 nM), potency (EC50 = 55.4 vs. 497 nM), and efficacy (Emax = 207% vs. 168%) than its indole counterpart Cumyl-CBMICA. This study confirms that substitution of an indole by an indazole core tends to increase in vitro potency, which is potentially reflected by higher in vivo potency. The emergence and disappearance of SCs distributed via online shops carrying a CBM moiety once more demonstrate the "cat-and-mouse" game between manufacturers and legislation.

Systematic evaluation of a panel of 30 synthetic cannabinoid receptor agonists structurally related to MMB-4en-PICA, MDMB-4en-PINACA, ADB-4en-PINACA, and MMB-4CN-BUTINACA using a combination of binding and different CB1 receptor activation assays-Part II: Structure activity relationship assessment via a ß-arrestin recruitment assay.

Synthetic cannabinoid receptor agonists (SCRAs) are the second largest class of new psychoactive substances (NPS) and are associated with serious adverse effects and even death. Despite this, little pharmacological data are available for many of the most recent SCRAs. This study consists of three different parts, aiming to systematically evaluate a panel of 30 SCRAs using binding and different in vitro human cannabinoid 1 receptor (CB1 ) activation assays. The present Part II investigated the SCRA analogs for their CB1 activation via a ß-arrestin recruitment assay. The panel was systematically designed to include key structural sub-features of recent SCRAs. Thus, the 4-pentenyl tail of MMB-4en-PICA and MDMB-4en-PINACA was retained while incorporating varying head groups from other prevalent SCRAs, including amides and esters of L-valine, L-tert-leucine, and L-phenylalanine, and adamantyl and cumyl moieties. All 30 SCRAs activated CB1 , with indazoles generally showing the greatest potency (EC50 = 1.88-281 nM), followed by indoles (EC50 = 11.5-2293 nM), and the corresponding 7-azaindoles (EC50 = 62.4-9251 nM). Several subunit-linked structure-activity relationships were identified: (i) tert-leucine-functionalized SCRAs were more potent than the corresponding valine derivatives; (ii) no major difference in potency or efficacy was observed between tert-leucine/valine-derived amides and the corresponding methyl esters; however, phenylalanine analogs were affected by this change; and (iii) minor structural changes to the 4-pentenyl substituent had little influence on activity. These findings elucidate structural features that modulate the CB1 activation potential of currently prevalent SCRAs and a systematic panel of analogs, some of which may appear in NPS markets in future.

Systematic evaluation of a panel of 30 synthetic cannabinoid receptor agonists structurally related to MMB-4en-PICA, MDMB-4en-PINACA, ADB-4en-PINACA, and MMB-4CN-BUTINACA using a combination of binding and different CB1 receptor activation assays. Part III: The G protein pathway and critical comparison of different assays.

The present work is the last of a three-part study investigating a panel of 30 systematically designed synthetic cannabinoid receptor agonists (SCRAs) including features such as the 4-pentenyl tail and varying head groups including amides and esters of l-valine (MMB, AB), l-tert-leucine (ADB), and l-phenylalanine (APP), as well as adamantyl (A) and cumyl moieties (CUMYL). Here, we evaluated these SCRAs for their capacity to activate the human cannabinoid receptor 1 (CB1 ) via indirect measurement of G protein recruitment. Furthermore, we comparatively evaluated the results obtained from three in vitro assays, based on the recruitment of ß-arrestin 2 (ßarr2 assay) or Gαi protein (mini-Gαi assay), or binding of [35 S]-GTPγS. The observed efficacies (Emax ) varied depending on the conducted assay. Statistical analysis suggests that the population means of the relative intrinsic activity (RAi ) significantly differ for the [35 S]-GTPγS assay and the other two assays, but the population means of the ßarr2 and mini-Gαi assays were not statistically different. Our data suggest that differences observed between the ßarr2 and mini-Gαi assays are the best predictor for 'biased agonism' towards ßarr or G protein recruitment in our study. SCRAs carrying an ADB or MPP moiety as a head group tended to produce elevated Emax values in the ßarr2 assay, which might result in a tendency of these compounds to cause pronounced tolerance in users-a hypothesis that should be evaluated further by future studies. In general, a comparison of efficacies derived from different assays is difficult and should only be conducted very cautiously.

Systematic evaluation of a panel of 30 synthetic cannabinoid receptor agonists structurally related to MMB-4en-PICA, MDMB-4en-PINACA, ADB-4en-PINACA, and MMB-4CN-BUTINACA using a combination of binding and different CB1 receptor activation assays: Part I-Synthesis, analytical characterization, and binding affinity for human CB1 receptors.

Synthetic cannabinoid receptor agonists (SCRAs) are one of the largest and most structurally diverse classes of new psychoactive substances (NPS). Despite this, pharmacological data are often lacking following the identification of a new SCRA in drug markets. In this first of a three-part series, we describe the synthesis, analytical characterization, and binding affinity of a proactively generated, systematic library of 30 indole, indazole, and 7-azaindole SCRAs related to MMB-4en-PICA, MDMB-4en-PINACA, ADB-4en-PINACA, and MMB-4CN-BUTINACA featuring a 4-pentenyl (4en-P), butyl (B/BUT), or 4-cyanobutyl (4CN-B/BUT) tail and a methyl l-valinate (MMB), methyl l-tert-leucinate (MDMB), methyl l-phenylalaninate (MPP), l-valinamide (AB), l-tert-leucinamide (ADB), l-phenylalaninamide (APP), adamantyl (A), or cumyl head group. Competitive radioligand binding assays demonstrated that the indazole core conferred the highest CB1 binding affinity (Ki = 0.17-39 nM), followed by indole- (Ki = 0.95-160 nM) and then 7-azaindole-derived SCRAs (Ki = 5.4-271 nM). Variation of the head group had the greatest effect on binding, with tert-leucine amides and methyl esters (Ki = 0.17-14 nM) generally showing the greatest affinities, followed by valine derivatives (Ki = 0.72-180 nM), and then phenylalanine derivatives (Ki = 2.5-271 nM). Adamantyl head groups (Ki = 8.8-59 nM) were suboptimal for binding, whereas the cumyl analogues consistently conferred high affinity (Ki = 0.62-36 nM). Finally, both butyl (Ki = 3.1-163 nM) and 4-cyanobutyl (Ki = 5.5-44 nM) tail groups were less favorable for CB1 binding than their corresponding 4-pentenyl counterparts (Ki = 0.72-25 nM).

NNL-3: A Synthetic Intermediate or a New Class of Hydroxybenzotriazole Esters with Cannabinoid Receptor Activity?

Synthetic cannabinoid receptor agonists (SCRAs) remain a prolific class of new psychoactive substances (NPS) and continue to expand rapidly. Despite the recent identification of hydroxybenzotriazole (HOBt) containing SCRAs in synthetic cannabis samples, there is currently no information regarding the pharmacological profile of these NPS with respect to human CB1 and CB2 receptors. In the current study, a series consisting of seven HOBt indole-, indazole-, and 7-azaindole-carboxylates bearing a range of N-alkyl substituents were synthesized and pharmacologically evaluated. Competitive binding assays at CB1 and CB2 demonstrated that all analogues except a 2-methyl-substituted derivative had low affinity for CB1 (Ki = 3.80-43.7 µM) and CB2 (Ki = 2.75-18.2 µM). A fluorometric functional assay revealed that 2-methylindole- and indole-derived HOBt carboxylates were potent and efficacious agonists of CB1 (EC50 = 12.0 and 63.7 nM; Emax = 118 and 120%) and CB2 (EC50 = 10.9 and 321 nM; Emax = 91 and 126%). All other analogues incorporating indazole and 7-azaindole cores and bearing a range of N1-substituents showed relatively low potency for CB1 and CB2. Additionally, a reporter assay monitoring ß-arrestin 2 (ßarr2) recruitment to the receptor revealed that the 2-methylindole example was the most potent and efficacious at CB1 (EC50 = 131 nM; Emax = 724%) and the most potent at CB2 (EC50 = 38.2 nM; Emax = 51%). As with the membrane potential assay, the indazole and other indole HOBt carboxylates were considerably less potent at both receptors, and analogues comprising a 7-azaindole core showed little activity. Taken together, these data suggest that NNL-3 demonstrates little CB1 receptor activity and is unlikely to be psychoactive in humans. NNL-3 is likely an unintended SCRA manufacturing byproduct. However, the synthesis of NNL-3 analogues proved simple and general, and some of these showed potent cannabimetic profiles in vitro, indicating that HOBt esters of this type may represent an emerging class of SCRA NPS.

Cannabidiol and tetrahydrocannabinol concentrations in commercially available CBD E-liquids in Switzerland.

Cannabidiol (CBD) rich hemp and hemp products low in Δ9-tetrahydrocannabinol (THC) (less than 1%) are legally available in Switzerland. Besides herbs for smoking and oils, liquids (e-liquids) for smoking in electronic cigarettes (e-cigs) have recently appeared on the market. These e-liquids are available with different CBD concentrations and can be flavoured. The aim of the current study was to investigate 20 e-liquids legally available in Switzerland for their contents using Fourier-transform infrared spectroscopy (FTIR) as a preliminary step followed by gas-chromatography coupled to mass spectrometry to identify potential cannabinoids, natural plant compounds and flavours. Quantification of CBD, cannabidiol carboxylic acid (CBD-acid), cannabinol (CBN), Δ9-tetrahydrocannabinol (THC), and Δ9-tetrahydrocannabinol carboxylic acid A (THC-acid) was performed by a validated method with ultra-high-pressure-liquid chromatography coupled to a diode array detector (UHPLC-DAD). FTIR analysis could confirm that for all investigated samples the e-liquid matrix consisted of 1,2-propanediol and glycerol. The qualitative GC-MS could identify ten phytocannabinoids including the quantified analytes, six natural plant compounds and five flavours. All analysed samples had a total THC content below 0.1059% (by weight), hence meeting the legal requirements of both Switzerland (<1%) and the European Union (<0.2%). The total CBD content ranged from 0.182 to 3.346% and differed in ten out of 20 samples from the CBD content presented by the manufacturer by more than 10% relative CBD. Furthermore, two of the analysed samples contained only 0.348% and 0.182% total CBD despite being labelled as "CBD rich". Seven of the 20 samples contained the correct CBD content (in the range of the labelled CBD content ± 10%). In conclusion, a deviation in the determined total CBD content from the labelled CBD content could be observed for half of the analysed samples, meaning that consumers cannot rely on the manufacturers' information. It is remarkable, that currently no official regulations for providing correct information of CBD content or any external product control is available in Switzerland and in most other countries.

Scheduling of new psychoactive substance the Swiss way: A review and critical analysis.

Since the introduction of the European Early Warning System in 2005, >700 new psychoactive substances (NPS) have been listed. This review article presents for the first time the Swiss narcotic law in perspective of scheduling of NPS, and compares it to the regulations of the German speaking neighbours Austria and Germany. The Swiss way is a fast and effective way for scheduling NPS, with the purpose to restrict drug trafficking and for controlling the NPS drug market: the legal basis for scheduling substances of abuse is the "Law about narcotics and psychotropic substances" (BetmG, SR 812.121), which includes the "narcotic law directory (BetmVV-EDI, SR 812.121.11) suitable for listing all controlled substances. The BetmVV-EDI, SR 812.121.11 contains seven indices, with index e specifically designed for the fast scheduling of NPS. Newly appearing NPS can either be controlled under a structure analogues definition or by listing single substances. The list of single substances is updated at least once per year, and structure analogues definitions can be implemented, in order to keep track with new developments on the NPS market. The latest version from November 30th 2018 contains ten different structure analogue definitions and 207 single substances. Requirements to list NPS are their appearance on the NPS market, suspected psychotropic effects and their suggestions by Forensic professionals. As soon as substances are newly placed, on Schedule I of the 1961 Convention or Schedule II of the 1971 Convention by the Commission on Narcotic Drugs of the World Health Organization they can easily be transferred from index e to index a-d of the BetmVV-EDI, SR 812.121.11. The Austrian law uses a structure analogue and single substances approach (introduced in 2012, one update in 2016), whereas the German NPS law (established in 2016, no update yet) only lists two structure-analogue-definitions. All three legislations have defined which core structures, kinds and sites of substitutions are regulated.

Investigating the ability of the microbial model Cunninghamella elegans for the metabolism of synthetic tryptamines.

Tryptamines can occur naturally in plants, mushrooms, microbes, and amphibians. Synthetic tryptamines are sold as new psychoactive substances (NPS) because of their hallucinogenic effects. When it comes to NPS, metabolism studies are of crucial importance, due to the lack of pharmacological and toxicological data. Different approaches can be taken to study in vitro and in vivo metabolism of xenobiotica. The zygomycete fungus Cunninghamella elegans (C. elegans) can be used as a microbial model for the study of drug metabolism. The current study investigated the biotransformation of four naturally occurring and synthetic tryptamines [N,N-Dimethyltryptamine (DMT), 4-hydroxy-N-methyl-N-ethyltryptamine (4-HO-MET), N,N-di allyl-5-methoxy tryptamine (5-MeO-DALT) and 5-methoxy-N-methyl-N-isoporpoyltryptamine (5-MeO-MiPT)] in C. elegans after incubation for 72 hours. Metabolites were identified using liquid chromatography-high resolution-tandem mass spectrometry (LC-HR-MS/MS) with a quadrupole time-of-flight (QqTOF) instrument. Results were compared to already published data on these substances. C. elegans was capable of producing all major biotransformation steps: hydroxylation, N-oxide formation, carboxylation, deamination, and demethylation. On average 63% of phase I metabolites found in the literature could also be detected in C. elegans. Additionally, metabolites specific for C. elegans were identified. Therefore, C. elegans is a suitable complementary model to other in vitro or in vivo methods to study the metabolism of naturally occurring or synthetic tryptamines.

Study of the in vitro and in vivo metabolism of the tryptamine 5-MeO-MiPT using human liver microsomes and real case samples.

The synthetic tryptamine 5-methoxy-N-methyl-N-isopropyltryptamine (5-MeO-MiPT) has recently been abused as a hallucinogenic drug in Germany and Switzerland. This study presents a case of 5-MeO-MiPT intoxication and the structural elucidation of metabolites in pooled human liver microsomes (pHLM), blood, and urine. Microsomal incubation experiments were performed using pHLM to detect and identify in vitro metabolites. In August 2016, the police encountered a naked man, agitated and with aggressive behavior on the street. Blood and urine samples were taken at the hospital and his premises were searched. The obtained blood and urine samples were analyzed for in vivo metabolites of 5-MeO-MiPT using liquid chromatography-high resolution tandem mass spectrometry (LC-HRMS/MS). The confiscated pills and powder samples were qualitatively analyzed using Fourier transform infrared (FTIR), gas chromatography-mass spectrometry (GC-MS), LC-HRMS/MS, and nuclear magnetic resonance (NMR). 5-MeO-MiPT was identified in 2 of the seized powder samples. General unknown screening detected cocaine, cocaethylene, methylphenidate, ritalinic acid, and 5-MeO-MiPT in urine. Seven different in vitro phase I metabolites of 5-MeO-MiPT were identified. In the forensic case samples, 4 phase I metabolites could be identified in blood and 7 in urine. The 5 most abundant metabolites were formed by demethylation and hydroxylation of the parent compound. 5-MeO-MiPT concentrations in the blood and urine sample were found to be 160 ng/mL and 3380 ng/mL, respectively. Based on the results of this study we recommend metabolites 5-methoxy-N-isopropyltryptamine (5-MeO-NiPT), 5-hydroxy-N-methyl-N-isopropyltryptamine (5-OH-MiPT), 5-methoxy-N-methyl-N-isopropyltryptamine-N-oxide (5-MeO-MiPT-N-oxide), and hydroxy-5-methoxy-N-methyl-N-isopropyltryptamine (OH-5-MeO-MiPT) as biomarkers for the development of new methods for the detection of 5-MeO-MiPT consumption, as they have been present in both blood and urine samples.