Designer drugs: a medicinal chemistry perspective

CB 1 Cannabinoid Receptor Agonists Induce Acute Respiratory Depression in Awake Mice

Recreational use of synthetic cannabinoid agonists (i.e., "Spice" compounds) that target the Cannabinoid Type 1 receptor (CB 1 ) can cause respiratory depression in humans. However, Δ 9 -tetrahydrocannabinol (THC), the major psychoactive phytocannabinoid in cannabis, is not traditionally thought to interact with CNS control of respiration, based largely upon sparse labeling of CB1 receptors in the medulla and few reports of clinically significant respiratory depression following cannabis overdose. The respiratory effects of CB 1 agonists have rarely been studied in vivo , suggesting that additional inquiry is required to reconcile the conflict between conventional wisdom and human data. Here we used whole body plethysmography to examine the respiratory effects of the synthetic high efficacy CB 1 agonist CP55,940, and the low efficacy CB 1 agonist Δ 9 -tetrahydrocannabinol in male and female mice. CP55,940 and THC, administered systemically, both robustly suppressed minute ventilation. Both cannabinoids also produced sizable reductions in tidal volume, decreasing both peak inspiratory and expiratory flow - measures of respiratory effort. Similarly, both drugs reduced respiratory frequency, decreasing both inspiratory and expiratory time while markedly increasing expiratory pause, and to a lesser extent, inspiratory pause. Respiratory suppressive effects occurred at lower doses in females than in males, and at many of the same doses shown to produce cardinal behavioral signs of CB 1 activation. We next used RNAscope in situ hybridization to localize CB 1 mRNA to glutamatergic neurons in the medullary pre-Bötzinger Complex, a critical nucleus in controlling respiration. Our results show that, contrary to previous conventional wisdom, CB 1 mRNA is expressed in glutamatergic neurons in a brain region essential for breathing and CB 1 agonists can cause significant respiratory depression.

In silico characterization of ligand-receptor interactions for U-47700, N,N-didesmethyl-U-47700, U-50488 at mu- and kappa-opioid receptors

The increasing misuse of novel synthetic opioids (NSOs) represents a serious public health concern. In this regard, U-47700 (trans-3,4-dichloro-N-[2-(dimethylamino)cyclohexyl]-N-methylbenzamide) and related "U-compounds" emerged on recreational drug markets as synthetic substitutes for illicit heroin and constituents of counterfeit pain medications. While the pharmacology of U-compounds has been investigated using in vitro and in vivo methods, there is still a lack of understanding about the details of ligand-receptor interactions at the molecular level. To this end, we have developed a molecular modeling protocol based on docking and molecular dynamics simulations to assess the nature of ligand-receptor interactions for U-47700, N,N-didesmethyl U-47700, and U-50488 at the mu-opioid receptor (MOR) and kappa-opioid receptor (KOR). The evaluation of ligand-receptor and ligand-receptor-membrane interaction energies enabled the identification of subtle conformational shifts in the receptors induced by ligand binding. Interestingly, the removal of two key methyl groups from U-47700, to form N,N-didesmethyl U-47700, caused a loss of hydrogen bond contact with tryptophan (Trp)229, which may underlie the lower interaction energy and reduced MOR affinity for the compound. Taken together, our results are consistent with the reported biological findings for U-compounds and provide a molecular basis for the MOR selectivity of U-47700 and KOR selectivity of U-50488.

The endocannabinoid system and breathing

Recent changes in cannabis accessibility have provided adjunct therapies for patients across numerous disease states and highlights the urgency in understanding how cannabinoids and the endocannabinoid (EC) system interact with other physiological structures. The EC system plays a critical and modulatory role in respiratory homeostasis and pulmonary functionality. Respiratory control begins in the brainstem without peripheral input, and coordinates the preBötzinger complex, a component of the ventral respiratory group that interacts with the dorsal respiratory group to synchronize burstlet activity and drive inspiration. An additional rhythm generator: the retrotrapezoid nucleus/parafacial respiratory group drives active expiration during conditions of exercise or high CO₂. Combined with the feedback information from the periphery: through chemo- and baroreceptors including the carotid bodies, the cranial nerves, stretch of the diaphragm and intercostal muscles, lung tissue, and immune cells, and the cranial nerves, our respiratory system can fine tune motor outputs that ensure we have the oxygen necessary to survive and can expel the CO₂ waste we produce, and every aspect of this process can be influenced by the EC system. The expansion in cannabis access and potential therapeutic benefits, it is essential that investigations continue to uncover the underpinnings and mechanistic workings of the EC system. It is imperative to understand the impact cannabis, and exogenous cannabinoids have on these physiological systems, and how some of these compounds can mitigate respiratory depression when combined with opioids or other medicinal therapies. This review highlights the respiratory system from the perspective of central versus peripheral respiratory functionality and how these behaviors can be influenced by the EC system. This review will summarize the literature available on organic and synthetic cannabinoids in breathing and how that has shaped our understanding of the role of the EC system in respiratory homeostasis. Finally, we look at some potential future therapeutic applications the EC system has to offer for the treatment of respiratory diseases and a possible role in expanding the safety profile of opioid therapies while preventing future opioid overdose fatalities that result from respiratory arrest or persistent apnea.

Synthesis of New Ester Derivatives of Salicylic Acid and Evaluation of Their COX Inhibitory Potential

Salicylic acid is an NSAID with serious side effects on the GIS. The side effects of salicylic acid on the GIS are slightly reduced by acetylating salicylic acid. 12 new ester analogs of salicylic acid were synthesized with high yields in this study. The chemical structures of the synthesized compounds were characterized by ¹ H-NMR, ¹³ C-NMR, and HRMS spectra. The inhibitory potential of the compounds was evaluated on COXs by in vitro and in silico studies. The COX2 inhibitory activity of the most potent inhibitor MEST1 (IC₅₀ : 0.048 μM) was found to be much higher than the COX2 inhibitory activity of aspirin (IC₅₀ : 2.60 μM). In docking studies, the strongest inhibitor among the compounds synthesized was predicted to be MEST1, with the lowest binding energy. Docking studies revealed that MEST1 extends from the hydrophobic channel to the top of the cyclooxygenase active site, forming various interactions with residues in the binding pocket.

Proliferation of Novel Synthetic Opioids in Postmortem Investigations After Core-Structure Scheduling for Fentanyl-Related Substances

ABSTRACT

New generations of novel synthetic opioids (NSOs) have emerged to fill a void in the illicit drug markets left by the decline in popularity of fentanyl analogs subsequent to core-structure scheduling of fentanyl-related substances in the United States and China. These new opioids include members of the 2-benzyl benzimidazole (eg, isotonitazene, metonitazene, N -pyrrolidino etonitazene, protonitazene, etodesnitazene), benzimidazolone (eg, brorphine), and cinnamylpiperazine (eg, AP-238, 2-methyl AP-237) subclasses. Novel synthetic opioids continue to be detected in opioid-related fatal overdoses, demonstrating the harms associated with exposure to these drugs. Between January 2020 and December 2021, 384 casework blood samples were reported by our laboratory to contain 1 or more of the prior listed 8 NSOs. Isotonitazene (n = 144), metonitazene (n = 122), and brorphine (n = 91) were the 3 most prevalent substances, with positivity for isotonitazene and brorphine peaking just before the announcement of emergency scheduling. These NSOs have been documented as significant drivers of drug mortality, and this case series described here highlights the challenges medical examiners and coroners face in staying current with emerging drugs. Challenges include regional differences, rapid turnover, short lifecycles, variable toxicology testing, and difficulty in assessing individual drug toxicity in polydrug cases.

Reports of Adverse Events Associated with Use of Novel Psychoactive Substances, 2017-2020: A Review

An important role of modern forensic and clinical toxicologists is to monitor the adverse events of novel psychoactive substances (NPS). Following a prior review from 2013 to 2016, this critical literature review analyzes and evaluates published case reports for NPS from January 2017 through December 2020. The primary objective of this study is to assist in the assessment and interpretation of these cases as well as provide references for confirmation methods. Chemistry, pharmacology, adverse events and user profiles (e.g., polypharmacy) for NPS are provided including case history, clinical symptoms, autopsy findings and analytical results. Literature reviews were performed in PubMed and Google Scholar for publications using search terms such as NPS specific names, general terms (e.g., ‘designer drugs’ and ‘novel psychoactive substances’), drug classes (e.g., ‘designer stimulants’) and outcome-based terms (e.g., ‘overdose’ and ‘death’). Government and website drug surveillance databases and abstracts published by professional forensic science organizations were also searched. Toxicological data and detailed case information were extracted, tabulated, analyzed and organized by drug category. Case reports included overdose fatalities (378 cases), clinical treatment and hospitalization (771 cases) and driving under the influence of drugs (170 cases) for a total of 1,319 cases providing details of adverse events associated with NPS. Confirmed adverse events with associated toxidromes of more than 60 NPS were reported including synthetic cannabinoid, NPS stimulant, NPS hallucinogen, NPS benzodiazepine and NPS opioid cases. Fifty of these NPS were reported for the first time in January 2017 through December 2020 as compared to the previous 4 years surveyed. This study provides insight and context of case findings described in the literature and in digital government surveillance databases and websites during a recent 4-year period. This review will increase the awareness of adverse events associated with NPS use to better characterize international emerging drug threats.

An Update on the Implications of New Psychoactive Substances in Public Health

The emergence of new psychoactive substances has earned a great deal of attention, and several reports of acute poisoning and deaths have been issued involving, for instance, synthetic opiates. In recent years, there have been profound alterations in the legislation concerning consumption, marketing, and synthesis of these compounds; rapid alert systems have also been subject to changes, and new substances and new markets, mainly through the internet, have appeared. Their effects and how they originate in consumers are still mostly unknown, primarily in what concerns chronic toxicity. This review intends to provide a detailed description of these substances from the point of view of consumption, toxicokinetics, and health consequences, including case reports on intoxications in order to help researchers and public health agents working daily in this area.

Amphetamine-type stimulants (ATS) drug classification using shallow one-dimensional convolutional neural network

Amphetamine-type stimulants (ATS) drug analysis and identification are challenging and critical nowadays with the emergence production of new synthetic ATS drugs with sophisticated design compounds. In the present study, we proposed a one-dimensional convolutional neural network (1DCNN) model to perform ATS drug classification as an alternative method. We investigate as well as explore the classification behavior of 1DCNN with the utilization of the existing novel 3D molecular descriptors as ATS drugs representation to become the model input. The proposed 1DCNN model is composed of one convolutional layer to reduce the model complexity. Besides, pooling operation that is a standard part of traditional CNN is not applied in this architecture to have more features in the classification phase. The dropout regularization technique is employed to improve model generalization. Experiments were conducted to find the optimal values for three dominant hyper-parameters of the 1DCNN model which are the filter size, transfer function, and batch size. Our findings found that kernel size 11, exponential linear unit (ELU) transfer function and batch size 32 are optimal for the 1DCNN model. A comparison with several machine learning classifiers has shown that our proposed 1DCNN has achieved comparable performance with the Random Forest classifier and competitive performance with the others.

Psychonauts' psychedelics: A systematic, multilingual, web-crawling exercise

Psychedelics alter the perception of reality through agonist or partial agonist interaction with the 2A serotoninergic receptor. They are classified as phenethylamines, tryptamines and lysergamides. These classes, according to the United Nations Office on Drugs and Crime (UNODC) and European Monitoring Centre for Drugs and Drug Addiction (EMCDDA), account for an important percentage of the new psychoactive substances (NPS) current scenario.The paper aimed at: a) identifying and categorising psychedelic molecules from a list of psychonaut websites and NPS online resources; and b) comparing the NPSfinder^Ⓡ results with those from the European and United Nations databases. A crawling software (i.e. 'NPSfinder^Ⓡ') was created to automatically scan, 24/7, a list of URLs and to extract a range of information (chemical/street names, chemical formulae, etc.) to facilitate NPS identification. Data collected were manually analysed and compared with the EMCDDA and UNODC databases.The overall number of psychedelic NPS detected by NPSfinder^Ⓡ (November 2017-February 2020) was 1344, almost ten-times higher than that reported by the UNODC and EMCDDA combined. Of these, 994 previously unknown molecules were identified as (potential) novel psychedelics, suggesting a strong discrepancy between online and real-world NPS scenarios. The results show the interest of psychonauts, and maybe of the much larger community of 'recreational' drug users, towards psychedelics. Moreover, examining online scenario may help in assessing the availability in the real world of psychedelic NPS; understanding drug trends; and in possibly predicting future drug scenarios.

Khat Chewing Practice and Associated Factors among Medical Students in Gondar Town, Ethiopia, 2019

Background:

Globally, khat chewing practice becoming an alarming and common among the youth generation, especially in higher educational institutions. It may also lead to frequent misbehavior, poor academic performance, and memory impairment among students. This study aimed to determine the prevalence of khat chewing practice and associated factors among medical students in Gondar town, Ethiopia, 2019.

Method:

A cross-sectional study was employed on 422 medical students. Data were collected using a self-administered questionnaire and analyzed using SPSS 20 software. Stratified followed by random sampling was employed to select the samples. A multivariable logistic regression model was fitted to identify the predictors. P ⩽ .05 was used to select statistically significant factors.

Result:

The current prevalence of khat chewing practice among medical students was 21.5%. The odds of khat chewing practice was higher among males (AOR = 3.353; 95%CI [1.460-7.701]), Muslims (AOR = 6.390; 95%CI [1.903-21.460]), fifth and 6 year students (AOR = 3.391; 95%CI [1.354-8.488]), smokers (AOR = 5.081; 95%CI [1.898-13.601]), alcohol users (AOR = 4.872; 95%CI [2.094-11.332]), students who had khat chewer close friends (AOR = 30.645; 95%CI [12.261-76.589]).

Conclusion:

Since a significant proportion of students were found to be khat chewers, continuous awareness creation on the impact of khat chewing and counseling services are recommended.

Discovery of novel diarylamides as orally active diuretics targeting urea transporters

Urea transporters (UT) play a vital role in the mechanism of urine concentration and are recognized as novel targets for the development of salt-sparing diuretics. Thus, UT inhibitors are promising for development as novel diuretics. In the present study, a novel UT inhibitor with a diarylamide scaffold was discovered by high-throughput screening. Optimization of the inhibitor led to the identification of a promising preclinical candidate, N-[4-(acetylamino)phenyl]-5-nitrofuran-2-carboxamide (1H), with excellent in vitro UT inhibitory activity at the submicromolar level. The half maximal inhibitory concentrations of 1H against UT-B in mouse, rat, and human erythrocyte were 1.60, 0.64, and 0.13 μmol/L, respectively. Further investigation suggested that 8 μmol/L 1H more powerfully inhibited UT-A1 at a rate of 86.8% than UT-B at a rate of 73.9% in MDCK cell models. Most interestingly, we found for the first time that oral administration of 1H at a dose of 100 mg/kg showed superior diuretic effect in vivo without causing electrolyte imbalance in rats. Additionally, 1H did not exhibit apparent toxicity in vivo and in vitro, and possessed favorable pharmacokinetic characteristics. 1H shows promise as a novel diuretic to treat hyponatremia accompanied with volume expansion and may cause few side effects.

Classics in Chemical Neuroscience: U-47700

U-47700, 3,4-dichloro-N-((1R,2R)-2-(dimethylamino)cyclohexyl)-N-methyl benzamide, is a novel synthetic opioid (NSO), discovered by the Upjohn company in the late 1970s. With potent in vivo activity, ∼10-times greater than that of morphine, U-47700 has become a drug of widespread abuse due to its ease of synthesis and, until recently, lack of robust detection methods by law enforcement. U-47700 has been found in counterfeit oxycodone tablets and is a key ingredient in "gray death." Due to its emergence worldwide in the past 5 years, it is now a Schedule I drug in the United States and similarly designated around the world; moreover, at autopsy, U-47700 was found to have contributed to the death of the pop artist Prince. This Review will capture the >40 year history of U-47700 and go in-depth regarding the synthesis, medicinal chemistry, in vitro/in vivo pharmacology, drug metabolism (from postmortem overdose cases), and societal impact of this DARK Classic in chemical neuroscience.

Designer drugs: a medicinal chemistry perspective (II)

During 2012-2018, the clandestine manufacture of new psychoactive substances (NPS) designed to circumvent substance control regulations increased exponentially worldwide, with concomitant increase in fatalities. This review focuses on three compound classes identified as synthetic opioids, synthetic amphetamines, and synthetic cannabinoids and highlights the medicinal chemistry precedents utilized by clandestine laboratories to develop new NPS with increased brain penetration, longer duration of action, and greater potency. Chemical approaches to illicit drug abuse treatment options, particularly for opioid use disorder, are also discussed.

Study of the effectiveness of various cannabinoid receptor 1 (CB1) agonists using molecular docking and molecular dynamics modeling

The binding of a series of small organic molecules, acting as agonists of the cannabinoid receptor CB1, was investigated by means of three methods of computational chemistry. Binding modes were predicted by means of molecular docking, and binding free energy was estimated via docking, molecular-mechanics Poisson-Boltzmann surface area method, and multistate Bennett acceptance ratio. No evident correlation was observed for the molecules between the experimental characteristics of affinity and three computed binding free energy estimates. The reasons for the discrepancy were discussed.

Likelihood of depressive symptoms in US older adults by prescribed opioid potency: National Health and Nutrition Examination Survey 2005-2013

OBJECTIVES

To investigate the relationships between depressive symptoms and opioid potency among adults aged 50 years and older reporting use of one or more prescription opioids in the past 30 days.

MATERIALS/DESIGN

Adjusted multiple linear regression models were conducted with 2005-2013 files from a secondary cross-sectional dataset, the National Health and Nutrition Examination Survey (NHANES). Respondents were community-dwelling, noninstitutionalized adults 50 years or older (n = 1036). Predictor variables included a positive screen for minor depression symptoms (Patient Health Questionnaire [PHQ-9] score greater than or equal to 5 and less than or equal to 9), moderate depression symptoms (PHQ-9 greater than or equal to 10 and less than or equal to 14), and severe depression symptoms (PHQ-9 greater than or equal to 15). Criterion variables included weaker-than-morphine analgesics (eg, codeine and tramadol) and morphine-equivalent opioids (eg, morphine and hydrocodone), which served as the reference category, as well as stronger-than-morphine opioid analgesics (eg, fentanyl and oxycodone).

RESULTS

Prevalence rates for symptoms of minor depression, moderate depression, and severe depression were n = 236 (22.8%), n = 135 (13.0%), and n = 122 (11.8%), respectively. Severe depression was significantly associated with high-potency opioid use (odds ratio [OR]: 2.27; confidence interval [CI], 1.16-4.46). In post hoc tests, severe depression remained significantly associated with high-potency opioid use only among respondents without arthritis (OR: 5.80; CI, 1.59-21.13).

CONCLUSIONS

Compared with older adults without depressive symptoms, older adults with severe depressive symptoms are more likely to be taking high-potency opioid medications. Future prescription opioid medication research should prioritize investigations among older adults with pain-related diagnoses, other than arthritis, reporting preexisting or new symptoms of severe depression.

Gas Chromatography-Mass Spectrometry (GC-MS) and Gas Chromatography-Infrared (GC-IR) Analyses of the Chloro-1- n-pentyl-3-(1-naphthoyl)-Indoles: Regioisomeric Cannabinoids

The analytical differentiation of the indole ring regioisomeric chloro-1- n-pentyl-3-(1-naphthoyl)-indoles is described in this report. The regioisomeric chloroindole precursor compounds, N- n-pentyl chloroindole synthetic intermediates, and the target chloro-substituted naphthoylindoles showed the equivalent gas chromatographic elution order based on the position of chlorine substitution on the indole ring. The regioisomeric chloro-1- n-pentyl-3-(1-naphthoyl)-indoles yield electron ionization mass spectra having equivalent major fragments resulting from cleavage of the groups attached to the central indole nucleus. Fragment ions occur at m/z 127 and 155 for the naphthyl and naphthoyl cations common to all indoles having the naphthoyl group substituted at the indole-3 position. Fragments resulting from the loss of the naphthoyl and/or n-pentyl groups from the molecular radical cation yield the cations at m/z 318, 304, 248, and 178. The characteristic (M-17)⁺ fragment ion at m/z 358 resulting from the loss of OH radical is significant in the mass spectra of all these compounds with 1-naphthoyl groups substituted at the indole-3 position. The vapor phase infrared spectra provide a number of characteristic absorption bands to identify the individual isomers.

Synthetic Cathinone Use Among Polysubstance Users: Indirect Indicator of Indiscriminate Drug Taking or Preferred Drug of Abuse?

A survey pertaining to synthetic cathinone (SC) use was completed by 499 polysubstance users enrolled in a residential recovery program in the Southeastern United States. Of the final sample, 28% reported ever SC use. SC-users, compared with nonusers, were more often younger (32.7 vs. 36.0, p = .001), White (93.4% vs. 80.8%, p = .001), and on probation/parole since 2010 (80.9% vs. 70.9%, p = .032). SC-users evidenced extensive drug histories and were less likely to be enrolled in an urban-based program, compared to a rural, Appalachian-based program (73.8% vs. 86.6%, p = .001). Use of synthetic cannabinoids (adjusted odds ratio [AOR] = 1.9, p = .044), kratom (AOR = 1.7, p = .045), and inhalants (AOR = 2.3, p = .001) were significantly associated with SC use. Approximately 23% of SC-users preferred SCs to amphetamines or cocaine; however, only 3.6% ranked SC as their most preferred drug. Past-year SC use declined to 6.6%. Among polysubstance users in this sample, SC use may be a potential indicator of versatile and indiscriminate drug-taking.

Disubstituted piperazine analogues of trifluoromethylphenylpiperazine and methylenedioxybenzylpiperazine: analytical differentiation and serotonin receptor binding studies

A series of N,N-disubstituted piperazines were synthesized containing the structural elements of both methylenedioxybenzylpiperazine (MDBP) and trifluoromethylphenylpiperazine (TFMPP) in a single molecule. These six potential designer drug molecules having a regioisomeric relationship were compared in gas chromatography-mass spectrometry (GC-MS), gas chromatography-infrared spectroscopy and serotonin receptor affinity studies. These compounds were separated by capillary gas chromatography on an Rxi®-17Sil MS stationary phase film and the elution order appears to be determined by the position of aromatic ring substitution. The majority of electron ionization mass spectral fragment ions occur via processes initiated by one of the two nitrogen atoms of the piperazine ring. The major electron ionization mass spectrometry (EI-MS) fragment ions observed in all six of these regioisomeric substances occur at m/z = 364, 229, 163 and 135. The relative intensity of the various fragment ions is also equivalent in each of the six EI-MS spectra. The vapour phase infrared spectra provide a number of absorption bands to differentiate among the six individual compounds on this regioisomeric set. Thus, the mass spectra place these compounds into a single group and the vapour phase infrared spectra differentiate among the six regioisomeric possibilities. All of the TFMPP-MDBP regioisomers displayed significant binding to 5-HT_2B receptors and in contrast to 3-TFMPP, most of these TFMPP-MDBP isomers did not show significant binding at 5-HT₁ receptor subtypes. Only the 3-TFMPP-3,4-MDBP (Compound 5) isomer displayed affinity comparable to 3-TFMPP at 5-HT_1A receptors (K_i = 188 nmol/L).

Behavioral and Pharmacokinetic Profile of Indole-Derived Synthetic Cannabinoids JWH-073 and JWH-210 as Compared to the Phytocannabinoid Δ9-THC in Rats

Synthetic cannabinoid compounds are marketed as “legal” marijuana substitutes, even though little is known about their behavioral effects in relation to their pharmacokinetic profiles. Therefore, in the present study we assessed the behavioral effects of systemic treatment with the two synthetic cannabinoids JWH-073 and JWH-210 and the phytocannabinoid Δ⁹-THC on locomotor activity, anxiety-like phenotype (in the open field) and sensorimotor gating (measured as prepulse inhibition of the acoustic startle response, PPI), in relation to cannabinoid serum levels. Wistar rats were injected subcutaneously (sc.) with JWH-073 (0.1, 0.5, or 5 mg/kg), JWH-210 (0.1, 0.5, or 5 mg/kg), Δ⁹-THC (1 or 3 mg/kg) or vehicle (oleum helanti) in a volume of 0.5 ml/kg and tested in the open field and PPI. Although JWH-073, JWH-210, Δ⁹-THC (and its metabolites) were confirmed in serum, effects on sensorimotor gating were absent, and locomotor activity was only partially affected. Δ⁹-THC (3 mg/kg) elicited an anxiolytic-like effect as suggested by the increased time spent in the center of the open field (p < 0.05). Our results further support the potential anxiolytic-like effect of pharmacological modulation of the endocannabinoid system.

GC-MS and GC-IR Analyses of the Methoxy-1-n-pentyl-3-(1-naphthoyl)-indoles: Regioisomeric Designer Cannabinoids

The indole ring regioisomeric methoxy-1-n-pentyl-3-(1-naphthoyl)-indoles represent indole ring-substituted analogs of the synthetic cannabinoid JWH-018. The electron ionization mass spectra show equivalent regioisomeric major fragments resulting from cleavage of the groups attached to the central indole nucleus. The characteristic (M-17)+ fragment ion at m/z 354 resulting from the loss of OH group is significant in the mass spectra of all four compounds. Fragmentation of the naphthoyl and/or pentyl groups yields the cations at m/z 314, 300, 244 and 216. The vapor-phase infrared spectra provide a number of characteristic absorption bands to identify the individual isomers. Gas chromatographic separations on a capillary column containing a film of trifluoropropylmethyl polysiloxane (Rtx-200) provided excellent resolution of these compounds, their precursor indoles and intermediate pentylindoles. The elution order appears related to the degree of crowding of indole ring substituents.

The role of nonmuscle myosin II in polydrug memories and memory reconsolidation

Using pharmacologic and genetic approaches targeting actin or the actin-driving molecular motor, nonmuscle myosin II (NMII), we previously discovered an immediate, retrieval-independent, and long-lasting disruption of methamphetamine- (METH-) and amphetamine-associated memories. A single intrabasolateral amygdala complex infusion or systemic administration of the NMII inhibitor Blebbistatin (Blebb) is sufficient to produce this disruption, which is selective, having no retrieval-independent effect on memories for fear, food reward, cocaine, or morphine. However, it was unclear if Blebb treatment would disrupt memories of other stimulants and amphetamine class drugs, such as nicotine (NIC) or mephedrone (MEPH; bath salts). Moreover, many individuals abuse multiple drugs, but it was unknown if Blebb could disrupt polydrug memories, or if the inclusion of another substance would render Blebb no longer able to disrupt METH-associated memories. Therefore, the present study had two primary goals: (1) to determine the ability of Blebb to disrupt NIC- or MEPH-associated memories, and (2) to determine the ability of METH to modify other unconditioned stimulus (US) associations’ susceptibility to Blebb. To this end, using the conditional place preference model, mice were conditioned to NIC and MEPH alone or METH in combination with NIC, morphine, or foot shock. We report that, unlike METH, there was no retrieval-independent effect of Blebb on NIC- or MEPH-associated memories. However, similar to cocaine, reconsolidation of the memory for both drugs was disrupted. Further, when combined with METH administration, NIC- and morphine-, but not fear-, associated memories were rendered susceptible to disruption by Blebb. Given the high rate of polydrug use and the resurgence of METH use, these results have important implications for the treatment of substance use disorder.

Dopaminergic neurotoxic effects of 3-TFMPP derivatives

Designer drugs are synthetically formulated to mimic the psychostimulatory effects of an original controlled/illegal drug of abuse. Designer drugs have similar chemical structure or functional analog as compared to existing controlled psychostimulatory drugs. There is a substantial rise in the production and use of designer drugs globally. Piperazine designer drugs were synthesized as an alternative to MDMA and have shown to induce numerous toxic effects leading to huge health, safety, law enforcement & monetary problems, and lethality. Currently, there are very few studies on the dopaminergic neurotoxicity of 1-(3-trifluoromethylphenyl) piperazine (3-TFMPP) and its derivatives (structural congeners). N27 rat dopaminergic neurons are valid cells to investigate the neurotoxic effects and establish the neurotoxic mechanisms of various substances. In the current study, we studied the time and dose-dependent neurotoxicity mechanisms of dopaminergic neurotoxicity of 3-TFMPP (parent compound) and its derivatives (2-TFMPP, 4-TFMPP). TFMPP derivatives-induced significant neurotoxicity (induced dopaminergic neuronal death. TFMPP derivatives-induced oxidative stress, mitochondrial dysfunction, apoptosis and decreased tyrosine hydroxylase expression. If the use of designer drugs are not strictly regulated and restricted around the world, this can lead to numerous central and peripheral disorders leading to a liability to the current and future society.

Pharmacotoxicology of Non-fentanyl Derived New Synthetic Opioids

A class of opioid agonists not structurally related to fentanyl, derived from research publications of pharmaceutical companies or patents within the United States and abroad are contributing to the current opioid epidemic. Novel synthetic opioids (NSOs) created to circumvent drug control laws such as U-47700, U-49900, AH-7921, or MT-45 have no recognized therapeutic use, are clandestinely manufactured and sold on conventional or dark web. We herein provide a review of the pharmacological properties available on most of these substances trying to provide a better knowledge on these compounds, particularly with respect to toxicity and dangerous adverse effects in users. Indeed, these NSOs share not only a great potency of action and receptor affinity with respect to natural or synthetic opiates (e.g., morphine, heroin, and methadone) but also a non-negligible toxicity leading to intoxications and fatalities, posing a serious harm to public health and society.

Geographic Variability of Active Ingredients in Spice as an Indicator of Mechanisms of Distribution and Manufacture Within Alaska

Designer drugs, like Spice, are synthetic psychoactive analogs of illegal substances with understudied health effects since they have traditionally been sold in packages labeled "not for human consumption" and the molecular structures can be specifically altered to circumvent legislation. Recent legislation has focused on regulating packaging and has reduced, but not eliminated, the distribution of Spice in Alaska. Legally obtained Spice samples from three geographic regions in Alaska were analyzed using liquid injection gas chromatography-mass spectrometry (GC-MS). Most (70%) of the samples contained illegal cannabinoids that have been regulated by the Drug Enforcement Agency and 47% contained multiple active ingredients. We hypothesized that the heterogeneity of the active ingredients between brands and across regions could be used to indicate small- or larger-scale manufacturing, and the results indicate multiple manufacturing scales. Evidence for small-scale manufacturing included inconsistent packaging, several of which contained similar active ingredient profiles in different brands purchased from a single store. Evidence for large-scale production was also found with some brands having consistent active ingredient profiles across regions. This study provides preliminary data for the geographic variability of active ingredients in Spice as an indicator of mechanisms of manufacture and distribution to inform legislators and law enforcement and help prioritizing resource allocation in an effort to quell Spice use in Alaska.

Gestational Exposure to the Synthetic Cathinone Methylenedioxypyrovalerone Results in Reduced Maternal Care and Behavioral Alterations in Mouse Pups

The member of synthetic cathinone family, methylenedioxypyrovalerone (MDPV), is a frequently used psychoactive drug of abuse. The objective of our study was to determine the effect of MDPV (administered from the 8th to the 14th day of gestation) on the behavior of neonatal and adolescent mice, as well as its effect on maternal care. We measured maternal care (pup retrieval test, nest building), locomotor activity (open field test), and motor coordination (grip strength test) of dams, whereas on pups we examined locomotor activity at postnatal day 7 and day 21 (open field test) and motor coordination on day 21 (grip strength test). On fresh-frozen brain samples of the dams we examined the expression of two important peptides implicated in the regulation of maternal behavior and lactation: tuberoinfundibular peptide 39 (TIP39) mRNA in the thalamic posterior intralaminar complex, and amylin mRNA in the medial preoptic nucleus. We detected decreased birth rate and survival of offspring, and reduced maternal care in the drug-treated animals, whereas there was no difference between the motility of treated and control mothers. Locomotor activity of the pups was increased in the MDPV treated group both at 7 and 21 days of age, while motor coordination was unaffected by MDPV treatment. TIP39 and amylin were detected in their typical location but failed to show a significant difference of expression between the drug-treated and control groups. The results suggest that chronic systemic administration of the cathinone agent MDPV to pregnant mice can reduce birth rate and maternal care, and it also enhances motility (without impairment of motor coordination) of the offspring.

Comparing rewarding and reinforcing properties between 'bath salt' 3,4-methylenedioxypyrovalerone (MDPV) and cocaine using ultrasonic vocalizations in rats

Abuse of synthetic psychostimulants like synthetic cathinones has risen in recent years. 3,4-Methylenedioxypyrovalerone (MDPV) is one such synthetic cathinone that demonstrates a mechanism of action similar to cocaine. Compared to cocaine, MDPV is more potent at blocking dopamine and norepinephrine reuptake and is readily self-administered by rodents. The present study compared the rewarding and reinforcing properties of MDPV and cocaine using systemic injection dose-response and self-administration models. Fifty kilohertz ultrasonic vocalizations (USVs) were recorded as an index of positive affect throughout experiments. In Experiment 1, MDPV and cocaine dose-dependently elicited 50-kHz USVs upon systemic injection, but MDPV increased USVs at greater rates and with greater persistence relative to cocaine. In Experiment 2, latency to begin MDPV self-administration was shorter than latency to begin cocaine self-administration, and self-administered MDPV elicited greater and more persistent rates of 50-kHz USVs versus cocaine. MDPV-elicited 50-kHz USVs were sustained over the course of drug load-up whereas cocaine-elicited USVs waned following initial infusions. Notably, we observed a robust presence of context-elicited 50-kHz USVs from both MDPV and cocaine self-administering rats. Collectively, these data suggest that MDPV has powerfully rewarding and reinforcing effects relative to cocaine at one-tenth doses. Consistent with prior work, we additionally interpret these data in supporting that MDPV has significant abuse risk based on its potency and subjectively positive effects. Future studies will be needed to better refine therapeutic strategies targeted at reducing the rewarding effects of cathinone analogs in efforts to ultimately reduce abuse liability.

Role of monoaminergic systems and ambient temperature in bath salts constituent 3,4-methylenedioxypyrovalerone (MDPV)-elicited hyperthermia and locomotor stimulation in mice

3,4-Methylenedioxypyrovalerone (MDPV) is a common constituent of illicit bath salts products, and in vitro studies implicate monoamine transporters as mediators of its pharmacological effects. Locomotor and thermoregulatory effects of MDPV depend on ambient temperature, so the current studies aimed to gauge the involvement of dopamine (DA), norepinephrine (NE), and serotonin (5-HT) in MDPV-induced locomotor stimulation and hyperthermia in the mouse at different ambient temperatures. Mice were pretreated with the selective 5-HT-reuptake inhibitor fluoxetine (3 mg/kg), the NE-reuptake inhibitor desipramine (3 mg/kg), the DA-reuptake inhibitor bupropion (10 mg/kg), or saline, followed by 10 mg/kg MDPV while thermoregulation and locomotor activity were monitored via radiotelemetry. In other studies, mice were pretreated for three days with saline, 100 mg/kg of the tryptophan hydroxylase inhibitor para-chlorophenylalanine (p-CPA), or 100 mg/kg of the tyrosine hydroxylase inhibitor α-methyl-para-tyrosine (α-MPT) before receiving 10 mg/kg MDPV on the fourth day. All manipulations were conducted at both 20 °C and 28 °C ambient temperatures. MDPV increased locomotor activity under both ambient conditions and modestly increased core body temperature at 20 °C; however, neither pretreatment with monoamine reuptake inhibitors nor monoamine synthesis inhibitors significantly altered these effects. At 28 °C, MDPV induced a more pronounced hyperthermic effect which was attenuated by bupropion, desipramine, or fluoxetine pretreatment, but not by the monoamine synthesis inhibitors. These results suggest that MDPV may have a more complex pharmacological profile than suggested by in vitro studies, perhaps extending beyond interactions with monoamine transporters. A more thorough binding profile of MDPV at various brain recognition sites should be developed. This article is part of the Special Issue entitled 'Designer Drugs and Legal Highs.'

Apparent Affinity Estimates and Reversal of the Effects of Synthetic Cannabinoids AM-2201, CP-47,497, JWH-122, and JWH-250 by Rimonabant in Rhesus Monkeys

Synthetic cannabinoids have been prohibited due to abuse liability and toxicity. Four such synthetic cannabinoids, AM-2201 ([1-(5-fluoropentyl)indol-3-yl]-naphthalen-1-ylmethanone), CP-47,497 (2-[(1R,3S)-3-hydroxycyclohexyl]-5-(2-methyloctan-2-yl)phenol), JWH-122 [(4-methylnaphthalen-1-yl)-(1-pentylindol-3-yl)methanone], and JWH-250 [2-(2-methoxyphenyl)-1-(1-pentylindol-3-yl)ethanone], were tested for their capacity to produce CB1 receptor-mediated discriminative stimulus effects in two groups of rhesus monkeys. One group (n = 4) discriminated Δ9-tetrahydrocannabinol (∆9-THC; 0.1 mg/kg i.v.), and a second group (n = 4) discriminated the cannabinoid antagonist rimonabant (1 mg/kg i.v.) while receiving 1 mg/kg/12 hours of ∆9-THC. AM-2201, JWH-122, CP-47,497, JWH-250, and ∆9-THC increased ∆9-THC lever responding. Duration of action was 1-2 hours for AM-2201, JWH-122, and JWH-250 and 4-5 hours for CP-47,497 and ∆9-THC. Rimonabant (1 mg/kg) surmountably antagonized the discriminative stimulus effects of all cannabinoid agonists; the magnitude of rightward shift was 10.6-fold for AM-2201, 10.7-fold for JWH-122, 11.0-fold for CP-47,497, and 15.7-fold for JWH-250. The respective pKB values were not significantly different: 6.61, 6.65, 6.66, and 6.83. In ∆9-THC-treated monkeys discriminating rimonabant, AM-2201 (0.1 and 0.32 mg/kg), JWH-122 (0.32 and 1 mg/kg), JWH-250 (1 and 3.2 mg/kg), and CP-47,497 (0.32, 1, and 3.2 mg/kg) produced not only rate-decreasing effects that were reversed by rimonabant, but also dose-dependent, rightward shifts in the rimonabant discrimination dose-effect function. These results show striking similarity in the CB1 receptor mechanism mediating the subjective effects of AM-2201, JWH-122, JWH-250, and CP-47,497. For products containing AM-2201 and JWH-122, a short duration of action could lead to more frequent use; moreover, inattention to differences in potency among synthetic cannabinoids could underlie unexpected toxicity. Rapid reversal of effects by intravenous rimonabant has potential value in emergency situations.

Synthetic cannabinoid induced acute respiratory depression: Case series and literature review

Synthetic Cannabinoids are a street drug that is widely attainable and cheap compared to natural cannabis, and has variable potency and unpredictable effects with no commercially available diagnostic test to confirm its presence. Similar to natural cannabis, Synthetic Cannabinoid intoxication can present in several ways with the most common emergency room presentations to be of neurologic and psychiatric manifestation. The respiratory depressive effect of Synthetic Cannabinoids has not been well documented in medical literature.

We report four patients admitted in the Intensive Care Unit with acute respiratory failure necessitating endotracheal intubation after use of Synthetic Cannabinoid. All patients had a reversal of respiratory failure in less than 24 h, three patients had a complicated course due to aspiration pneumonia. All four patients exhibited aggressive behavior, with two of them diagnosed with Bipolar Disorder and Cocaine Use Disorder.

The effect of Synthetic Cannabinoids in peripheral receptors such as chemoreceptors and baroreceptors can increase bronchial airway resistance. It is postulated that CB1 receptor stimulation could be one of the possible mechanisms of synthetic cannabinoid-induced respiratory depression. Chemical gases released after its inhalation may also cause damage to the bronchiolar epithelium and has the potential to disrupt the protective surfactant layer in the alveoli, which then could interfere with effective gas exchange leading to hypoxia and acidosis. The stimulation of CB1 receptors have a series of downstream signaling effects in the G protein-coupled pathway and mitogen-activated protein kinase (MAPK) pathway, causing suppression of both excitatory and inhibitory neuronal activity. The aforementioned molecular changes in the central nervous system after CB1 receptor stimulation could impact respiration.

The use of Synthetic Cannabinoids can cause respiratory depression in individuals without an underlying pulmonary disease and adds to the growing number of literature about the presentation and debilitating adverse events from its consumption. Although there is no specific toxidrome associated with it, clinicians should have a high index of suspicion with its use especially in patients presenting with a history of drug overdose.

The synthetic cannabinoid WIN-55,212 induced-apoptosis in cytotrophoblasts cells by a mechanism dependent on CB1 receptor

The endocannabinoid system has evolved as a key regulator in several pathological and physiological processes, including placentation, decidualization and implantation. In addition, it is known that Cannabis and cannabinoids negatively affect female reproduction. Although, the biological action of synthetic cannabinoids, such as WIN-55,212, in human fertility and pregnancy outcome remain to be unveiled. A tight balance between proliferation, differentiation and apoptosis of trophoblast cells is required for placental development and pregnancy outcome. Therefore, in this work, the effects of the synthetic cannabinoid WIN-55,212 in placental cytotrophoblast cells were explored. For that, it was used a human choriocarcinoma cell line, BeWo cells, and primary cultures of human cytotrophoblasts isolated from term placentas. Results demonstrate that this synthetic cannabinoid induces cell cycle arrest. We also observed that cell viability loss was associated with a disruption of mitochondrial membrane potential and activation of caspases -9 and -3/-7 independently of reactive oxygen species (ROS) production or recruitment of the endoplasmic reticulum stress marker CHOP. Moreover, these effects were prevented by pre-incubation with a selective cannabinoid receptor 1 (CBR1) antagonist (AM281). Thus, our results provide strong evidences of the apoptotic process induced by WIN-55,212 through the activation of the CBR1, which may reveal the impact of cannabinoids consumption during placental development.

Disruption of hippocampal synaptic transmission and long-term potentiation by psychoactive synthetic cannabinoid 'Spice' compounds: comparison with Δ9 -tetrahydrocannabinol

There has been a marked increase in the availability of synthetic drugs designed to mimic the effects of marijuana. These cannabimimetic drugs, sold illicitly as 'Spice' and related products, are associated with serious medical complications in some users. In vitro studies suggest that synthetic cannabinoids in these preparations are potent agonists at central cannabinoid CB1 receptors (CB1Rs), but few investigations have delineated their cellular effects, particularly in comparison with the psychoactive component of marijuana, Δ9 -tetrahydrocannabinol (Δ9 -THC). We compared the ability of three widely abused synthetic cannabinoids and Δ9 -THC to alter glutamate release and long-term potentiation in the mouse hippocampus. JWH-018 was the most potent inhibitor of hippocampal synaptic transmission (EC50 ~15 nM), whereas its fluoropentyl derivative, AM2201, inhibited synaptic transmission with slightly lower potency (EC50 ~60 nM). The newer synthetic cannabinoid, XLR-11, displayed much lower potency (EC50 ~900 nM) that was similar to Δ9 -THC (EC50 ~700 nM). The effects of all compounds occurred via activation of CB1Rs, as demonstrated by reversal with the selective antagonist/inverse agonist AM251 or the neutral CB1R antagonist PIMSR1. Moreover, AM2201 was without effect in the hippocampus of transgenic mice lacking the CB1R. Hippocampal slices exposed to either synthetic cannabinoids or Δ9 -THC exhibited significantly impaired long-term potentiation (LTP). We find that, compared with Δ9 -THC, the first-generation cannabinoids found in Spice preparations display higher potency, whereas a recent synthetic cannabinoid is roughly equipotent with Δ9 -THC. The disruption of synaptic function by these synthetic cannabinoids is likely to lead to profound impairments in cognitive and behavioral function.