Analytical and behavioral characterization of 1-dodecanoyl-LSD (1DD-LSD).

1-Acetyl-N,N-diethyllysergamide (1A-LSD, ALD-52) was first synthesized in the 1950s and found to produce psychedelic effects similar to those of LSD. Evidence suggests that ALD-52 serves as a prodrug in vivo and hydrolysis to LSD is likely responsible for its activity. Extension of the N1-alkylcarbonyl chain gives rise to novel lysergamides, which spurred further investigations into their structure-activity relationships. At the same time, ALD-52 and numerous homologues have emerged as recreational drugs ("research chemicals") that are available from online vendors. In the present study, 1-dodecanoyl-LSD (1DD-LSD), a novel N1-acylated LSD derivative, was subjected to analytical characterization and was also tested in the mouse head-twitch response (HTR) assay to assess whether it produces LSD-like effects in vivo. When tested in C57BL/6J mice, 1DD-LSD induced the HTR with a median effective dose (ED50) of 2.17 mg/kg, which was equivalent to 3.60 µmol/kg. Under similar experimental conditions, LSD has 27-fold higher potency than 1DD-LSD in the HTR assay. Previous work has shown that other homologues such as ALD-52 and 1-propanoyl-LSD also have considerably higher potency than 1DD-LSD in mice, which suggests that hydrolysis of the 1-dodecanoyl moiety may be comparatively less efficient in vivo. Further investigations are warranted to determine whether the increased lipophilicity of 1DD-LSD causes it to be sequestered in fat, thereby reducing its exposure to enzymatic hydrolysis in plasma and tissues. Further clinical studies are also required to assess its activity in humans and to test the prediction that it could potentially serve as a long-acting prodrug for LSD.

Analytical profile of N-ethyl-N-cyclopropyl lysergamide (ECPLA), an isomer of lysergic acid 2,4-dimethylazetidide (LSZ).

Recent investigations have shown that N-ethyl-N-cyclopropyl lysergamide (ECPLA) produces LSD-like behavioral effects in mice, which suggests that it may act as a hallucinogen in humans. Although the use of ECPLA as a recreational drug has been limited, key analytical data that can be used to detect ECPLA are required for future forensic and clinical investigations. ECPLA is an isomer of (2'S,4'S)-lysergic acid 2,4-dimethylazetidide (LSZ), a lysergamide that emerged as a recreational drug in 2013. Several analytical approaches were examined, including single- and tandem mass spectrometry platforms at low and high resolution, gas- and liquid chromatography (GC, LC), nuclear magnetic resonance spectroscopy (NMR), and GC condensed-phase infrared spectroscopy (GC-sIR). ECPLA and LSZ could be differentiated by NMR, GC-sIR, GC, and LC-based methods. The electron ionization mass spectra of ECPLA and LSZ contained ion clusters typically observed with related lysergamides such as m/z 150-155, m/z 177-182, m/z 191-197, m/z 205-208, and m/z 219-224. One of the significant differences in abundance related to these clusters included ions at m/z 196 and m/z 207/208. The base peaks were detected at m/z 221 in both cases followed by the retro-Diels-Alder fragment at m/z 292. Minor but noticeable differences between the two isomers could also be seen in the relative abundance of m/z 98 and m/z 41. Electrospray ionization mass spectra included lysergamide-related ions at m/z 281, 251, 223, 208, 197, 180, and 140. LSZ (but not ECPLA) showed product ions at m/z 267 and m/z 98 under the conditions used.

Prodrugs of New Psychoactive Substances (NPS): A New Challenge.

The concept of a substance acting as a prodrug for an intended drug is not new and has been known and utilized with particular benefits within medicine for efficacy and patient safety. Prodrugs of psychoactive substances are also not particularly new but this has also extended to considerations of prodrugs of new psychoactive substances (NPS). The continuing evolution of NPS has been a constant forensic challenge. In some countries, this constant evolution has led to the introduction of various alternative methods of drug control. Whether for this reason or in the pursuit of user experimentation, prodrugs of NPS have been discussed, developed, and exploited, posing some distinct forensic challenges. This is especially the case within toxicological analysis of biological fluids and for some substances, also forensic chemical analysis, through inherent instability of the prodrug or metabolism in the body. Particular examples of NPS prodrugs include 1-propanoyl-LSD, 1-butanoyl-LSD, 1-acetyl-LSD, and 2C-B-AN. This is in addition to associated substances and medicines that may be used for an intended pharmacological effect. Various prodrugs for stimulant and hallucinogenic substances in particular have appeared in the literature and have been discussed within drug user forums and made available for purchase online. Presently, drug monitoring data from national and international systems indicate that prodrugs are not widely available or problematic. Nevertheless, it is important that there is sufficient awareness of the prodrug concept and potential impact and associated forensic implications, not just for chemical analysis but also for toxicological considerations when a substance has been used.

Detection of cocaine and its metabolites in whole blood and plasma following a single dose, controlled administration of intranasal cocaine.

The disposition of drugs and their metabolites have been extensively described in the literature, based primarily on the analysis of plasma and urine. However, there are more limited data on their disposition in whole blood, which is often the only specimen available in forensic investigations and cases of driving under the influence of drugs. In this study, we have, for the first time, established pharmacokinetic properties of cocaine (COC) and its metabolites from concurrently collected whole blood and plasma samples, following a single 100 mg dose of cocaine hydrochloride administered via nasal insufflation to seven healthy volunteers. The median Cmax of COC and its major metabolites, benzoylecgonine (BZE) and ecgonine methyl ester (EME), were closely related in whole blood and plasma. The median Cmax for COC in plasma was 379.7 ng/mL (347.5-517.7) and 344.24 ng/mL (271.6-583.2) in whole blood. The median Cmax for BZE in plasma was 441.2 ng/mL (393.6-475. and 371.18 ng/mL (371.1-477.3) in whole blood, EME was 105.5 ng/mL (93.6-151.8) in plasma and 135.5 ng/mL (87.8-183) in whole blood. Calculated medians of the whole blood to plasma ratio of COC (0.76), BZE (0.98) and EME (1.02) of approximately 1, strongly suggesting that the erythrocyte cell wall presents no barrier to COC and its metabolites. Furthermore, whole blood and plasma concentrations of COC were strongly correlated (R2  = 0.0914 R = 0.956, p < 0.0001), as was BZE (R2  = 0.0932 R = 0.965, p < 0.0001) and EME (R2  = 0.0964R = 0.928, p < 0.0001). The minor oxidative metabolite norcocaine (NCOC) was detected in both whole blood and plasma at concentrations between 1 and 5 ng/mL within 60-180 minutes, suggesting that NCOC could be indicator of recent COC administration. Data from this study have shown for the first time that COC and its metabolites BZE and EME are evenly distributed between plasma and whole blood following controlled single-dose intranasal COC administration.

Return of the lysergamides. Part V: Analytical and behavioural characterization of 1-butanoyl-d-lysergic acid diethylamide (1B-LSD).

The psychedelic properties of lysergic acid diethylamide (LSD) have captured the imagination of researchers for many years and its rediscovery as an important research tool is evidenced by its clinical use within neuroscientific and therapeutic settings. At the same time, a number of novel LSD analogs have recently emerged as recreational drugs, which makes it necessary to study their analytical and pharmacological properties. One recent addition to this series of LSD analogs is 1-butanoyl-LSD (1B-LSD), a constitutional isomer of 1-propanoyl-6-ethyl-6-nor-lysergic acid diethylamide (1P-ETH-LAD), another LSD analog that was described previously. This study presents a comprehensive analytical characterization of 1B-LSD employing nuclear magnetic resonance spectroscopy (NMR), low- and high-resolution mass spectrometry platforms, gas- and liquid chromatography (GC and LC), and GC-condensed phase and attenuated total reflection infrared spectroscopy analyses. Analytical differentiation of 1B-LSD from 1P-ETH-LAD was straightforward. LSD and other serotonergic hallucinogens induce the head-twitch response (HTR) in rats and mice, which is believed to be mediated largely by 5-HT2A receptor activation. HTR studies were conducted in C57BL/6J mice to assess whether 1B-LSD has LSD-like behavioral effects. 1B-LSD produced a dose-dependent increase in HTR counts, acting with ~14% (ED50  = 976.7 nmol/kg) of the potency of LSD (ED50  = 132.8 nmol/kg). This finding suggests that the behavioral effects of 1B-LSD are reminiscent of LSD and other serotonergic hallucinogens. The possibility exists that 1B-LSD serves as a pro-drug for LSD. Further investigations are warranted to confirm whether 1B-LSD produces LSD-like psychoactive effects in humans.

Syntheses and analytical characterizations of the research chemical 1-[1-(2-fluorophenyl)-2-phenylethyl]pyrrolidine (fluorolintane) and five of its isomers.

A number of substances based on the 1,2-diarylethylamine template have been investigated for various potential clinical applications whereas others have been encountered as research chemicals sold for non-medical use. Some of these substances have transpired to function as NMDA receptor antagonists that elicit dissociative effects in people who use these substances recreationally. 1-[1-(2-Fluorophenyl)-2-phenylethyl]pyrrolidine (fluorolintane, 2-F-DPPy) has recently appeared as a research chemical, which users report has dissociative effects. One common difficulty encountered by stakeholders confronting the appearance of new psychoactive substances is the presence of positional isomers. In the case of fluorolintane, the presence of the fluorine substituent on either the phenyl and benzyl moieties of the 1,2-diarylethylamine structure results in a total number of six possible racemic isomers, namely 2-F-, 3-F-, and 4-F-DPPy (phenyl ring substituents) and 2"-F-, 3"-F-, and 4"-F-DPPy (benzyl ring substituents). The present study reports the chemical syntheses and comprehensive analytical characterizations of the two sets of three positional isomers. These studies included various low- and high-resolution mass spectrometry platforms, gas- and liquid chromatography (GC and LC), nuclear magnetic resonance (NMR) spectroscopy and GC-condensed phase and attenuated total reflection infrared spectroscopy analyses. The differentiation between each set of three isomers was possible under a variety of experimental conditions including GC chemical ionization triple quadrupole tandem mass spectrometric analysis of the [M + H - HF]+ species. The latter MS method was particularly helpful as it revealed distinct formations of product ions for each of the six investigated substances.

The United Kingdom and Ireland association of forensic toxicologists forensic toxicology laboratory guidelines (2018).

In 2010, the United Kingdom and Ireland Association of Forensic Toxicologists (UKIAFT) created forensic toxicology laboratory guidelines. This represents a revision of those guidelines as a result of the changing toxicological and technical landscape.

The analytical challenges of cyclopropylfentanyl and crotonylfentanyl: An approach for toxicological analysis.

New psychoactive substances (NPS) are increasingly being seen in forensic casework globally and encompass a number of types of drugs including "designer opioids", especially fentanyl analogues, which are of particular concern due to their high potency and significant risk of toxicity. They are often sold as heroin or mixed with other illicit drugs and therefore users may be unaware they are taking such hazardous compounds. Two fentanyl analogues that have recently been detected are cyclopropylfentanyl and crotonylfentanyl. In order to accurately determine the prevalence of such compounds in clinical and forensic casework, including potential toxicity, they need to be correctly identified using definitive and defensible techniques. Cyclopropylfentanyl and crotonylfentanyl are structural isomers, and it has previously been highlighted that these 2 compounds are analytically difficult to specifically identify owing to their similarity in structure and chromatographic behaviour. To further investigate in an attempt to overcome this problem, analysis of certified reference material using high performance liquid chromatography with diode array UV detection (HPLC-DAD), liquid chromatography-tandem mass spectrometry (LC-MS/MS), and liquid chromatography-quadrupole time-of-flight-mass spectrometry (LC-QToF-MS) has been performed. Whilst the compounds were shown to have an identical mass-spectral fragmentation pattern, they had different UV spectra. This was coupled with a discernible difference in retention time with the HPLC conditions applied, allowing differentiation of the 2 compounds. Using this approach, cyclopropylfentanyl was positively identified and subsequently quantified in 4 fatalities with the exclusion of crotonylfentanyl.

A Series of Deaths Involving Carfentanil in the UK and Associated Post-mortem Blood Concentrations.

The potent opioid and veterinary drug, carfentanil has recently entered the illicit drug market, especially in relation to heroin and cocaine. Recent publications have reported carfentanil concentrations found in fatalities occurring in the USA. This article presents the toxicological findings in seven heroin/cocaine cases occurring in the UK within a short period of time where carfentanil was detected and measured. Carfentanil was detected along with other drugs in all cases with no alcohol detected in the post-mortem blood in any of the cases. Of the other drugs detected, of particular note, cannabinoids were detected in three, cocaine in four, other opioids (methadone, dihydrocodeine and tramadol) in four and benzodiazepines were detected in four of the seven fatalities. A high concentration of ketamine and norketamine was found in one case. Morphine and its glucuronide metabolites were also measured where detected in six of the seven cases. The carfentanil concentrations were found to be between 0.22 and 3.3 ng/mL (mean 0.93, median 0.66 ng/mL) in post-mortem femoral blood. In one case where aortic and ventricular post-mortem blood was submitted for analysis in addition to femoral blood, comparative concentrations of 1.05 (aortic), 0.57 (ventricular) and 0.50 (femoral) ng/mL were found. The concentrations support the necessity to ensure laboratory detection methods for carfentanil and subsequent measurement are appropriate as concentrations below 0.3 ng/mL may be present in post-mortem blood. The concentrations also support the notion that there is no particular "toxic" or "fatal" post-mortem blood carfentanil concentration associated with its use.

Syntheses, analytical and pharmacological characterizations of the 'legal high' 4-[1-(3-methoxyphenyl)cyclohexyl]morpholine (3-MeO-PCMo) and analogues.

New psychoactive substances (NPS) are commonly referred to as 'research chemicals', 'designer drugs' or 'legal highs'. One NPS class is represented by dissociative anesthetics, which include analogues of the arylcyclohexylamine phencyclidine (PCP), ketamine and diphenidine. A recent addition to the NPS market was 4-[1-(3-methoxyphenyl)cyclohexyl]morpholine (3-MeO-PCMo), a morpholine analogue of 3-MeO-PCP. Although suspected to have dissociative effects in users, information about its pharmacological profile is not available. From clinical and forensic perspectives, detailed analytical data are needed for identification, especially when facing the presence of positional isomers, as these are frequently unavailable commercially. This study presents the analytical and pharmacological characterization of 3-MeO-PCMo along with five additional analogues, namely the 2- and 4-MeO-PCMo isomers, 3,4-methylenedioxy-PCMo (3,4-MD-PCMo), 3-Me-PCMo and PCMo. All six arylcyclohexylmorpholines were synthesized and characterized using chromatographic, mass spectrometric and spectroscopic techniques. The three positional isomers could be differentiated and the identity of 3-MeO-PCMo obtained from an internet vendor was verified. All six compounds were also evaluated for affinity at 46 central nervous system receptors including the N-methyl-d-aspartate receptor (NMDAR), an important target for dissociative anesthetics such as PCP and ketamine. In vitro binding studies using (+)-[3-3 H]-MK-801 in rat forebrain preparations revealed moderate affinity for NMDAR in the rank order of 3-Me >3-MeO > PCMo >3,4-MD > 2-MeO > 4-MeO-PCMo. 3-MeO-PCMo was found to have moderate affinity for NMDAR comparable to that of ketamine, and had an approximate 12-fold lower affinity than PCP. These results support the anecdotal reports of dissociative effects from 3-MeO-PCMo in humans.

Return of the lysergamides. Part IV: Analytical and pharmacological characterization of lysergic acid morpholide (LSM-775).

Lysergic acid diethylamide (LSD) is perhaps one of the best-known psychoactive substances and many structural modifications of this prototypical lysergamide have been investigated. Several lysergamides were recently encountered as 'research chemicals' or new psychoactive substances (NPS). Although lysergic acid morpholide (LSM-775) appeared on the NPS market in 2013, there is disagreement in the literature regarding the potency and psychoactive properties of LSM-775 in humans. The present investigation attempts to address the gap of information that exists regarding the analytical profile and pharmacological effects of LSM-775. A powdered sample of LSM-775 was characterized by X-ray crystallography, nuclear magnetic resonance spectroscopy (NMR), gas chromatography mass spectrometry (GC-MS), high mass accuracy electrospray MS/MS, high performance liquid chromatography (HPLC) diode array detection, HPLC quadrupole MS, and GC solid-state infrared analysis. Screening for receptor affinity and functional efficacy revealed that LSM-775 acts as a nonselective agonist at 5-HT1A and 5-HT2A receptors. Head twitch studies were conducted in C57BL/6J mice to determine whether LSM-775 activates 5-HT2A receptors and produces hallucinogen-like effects in vivo. LSM-775 did not induce the head twitch response unless 5-HT1A receptors were blocked by pretreatment with the antagonist WAY-100,635 (1 mg/kg, subcutaneous). These findings suggest that 5-HT1A activation by LSM-775 masks its ability to induce the head twitch response, which is potentially consistent with reports in the literature indicating that LSM-775 is only capable of producing weak LSD-like effects in humans.

Further evidence for GHB naturally occurring in common non-alcoholic beverages.

GHB has been implicated in many cases of suspected surreptitious administration with the purpose of increasing victim vulnerability to sexual assault. Low amounts of endogenous (or naturally occurring) GHB, which do not reach pharmacologically active levels, have been detected in alcoholic and non-alcoholic beverages. Due to the continued requirement to obtain data on the presence of endogenous GHB in various beverage types, GHB concentrations were measured in a series of non-alcoholic beverages. Tonic water and lemon flavoured tonic water beverages were analysed at 0, 24 and 96h after the bottle opening using gas chromatography coupled to tandem mass spectrometry (GC-MS/MS) on an Agilent 6890/7000C Triple Quadrupole. GHB was detected in all beverages at very low amounts ranging from 89 to 145ng/mL (0.089-0.145mg/L) and did not demonstrate a general trend of variation for concentration along the tested time span (96h). The presented data provide additional evidence for the endogenous nature of GHB in non-alcoholic beverages at very low concentrations, which are many orders of magnitude lower than those described to produce any pharmacological effect on the subject. However, when considering a case of alleged drug-facilitated sexual assault, a low level of GHB detected in a drink may be related both to a surreptitiously GHB administration with subsequent dilution for concealment or to the presence of endogenous GHB. On this basis, a comprehensive analysis of all the available information, including circumstantial data demonstrating possible attempts to conceal GHB administration and an assessment of levels of endogenous GHB in the suspected beverage type, is of the utmost importance for a proper interpretation of the toxicological results.

Return of the lysergamides. Part III: Analytical characterization of N6 -ethyl-6-norlysergic acid diethylamide (ETH-LAD) and 1-propionyl ETH-LAD (1P-ETH-LAD).

The psychoactive properties of lysergic acid diethylamide (LSD) have fascinated scientists across disciplines and the exploration of other analogues and derivatives has been motivated by deepening the understanding of ligand-receptor interactions at the molecular level as well as by the search for new therapeutics. Several LSD congeners have appeared on the new psychoactive substances (NPS) market in the form of blotters or powders. Examples include 1-propionyl-LSD (1P-LSD), AL-LAD, and LSZ. The absence of analytical data for novel compounds is a frequent challenge encountered in clinical and toxicological investigations. Two newly emerging lysergamides, namely N6 -ethyl-6-norlysergic acid diethylamide (ETH-LAD) and 1P-ETH-LAD, were characterized by gas chromatography-mass spectrometry (GC-MS), low and high mass accuracy electrospray MS(/MS), GC solid-state infrared analysis, high performance liquid chromatography diode array detection as well as nuclear magnetic resonance spectroscopy. Limited analytical data for ETH-LAD were previously available, whereas information about 1P-ETH-LAD has not previously been encountered in the scientific literature. This study extends the characterization of lysergamides distributed on the NPS market, which will help to make analytical data available to clinicians, toxicologists, and other stakeholders who are likely to encounter these substances. The analysis of a test incubation of 1P-ETH-LAD with human serum at 37°C by LC single quadrupole MS at various time points (0-6 h, once per hour and one measurement after 24 h) revealed the formation of ETH-LAD, suggesting that 1P-ETH-LAD might serve as a pro-drug. 1P-ETH-LAD was still detectable in serum after 24 h. Copyright © 2017 John Wiley & Sons, Ltd.

Determining the Toxicological Significance of Pregabalin in Fatalities.

Pregabalin has become more widely prescribed and abused in recent years but is still not always included in laboratory analysis. An LC-MS-MS method has been developed and applied to measure pregabalin in 93 postmortem cases, including drug-related deaths, alternative causes of death, and fatalities where pregabalin was likely to have contributed to death. Other drugs or alcohol was detected, and the most common drug types (in decreasing frequency) were antidepressants, opioids, benzodiazepines, opiates, alcohol, antipsychotics, cocaine, cardiac drugs, amphetamines, cannabis, anticonvulsants, and antihistamines. New psychoactive substances (methoxphenidine and synthetic cannabinoids) were only found in two cases. The results provide further data to assist in evaluating the significance of postmortem pregabalin concentrations and a toxicologically significant concentration of 25 mg/L is proposed. Pregabalin, especially with concomitant use of other CNS depressant drugs, presents a significant toxicological risk and existing laboratory protocols should be reviewed for their suitability to detect pregabalin.

Return of the lysergamides. Part II: Analytical and behavioural characterization of N6 -allyl-6-norlysergic acid diethylamide (AL-LAD) and (2'S,4'S)-lysergic acid 2,4-dimethylazetidide (LSZ).

Lysergic acid N,N-diethylamide (LSD) is perhaps one of the most intriguing psychoactive substances known and numerous analogs have been explored to varying extents in previous decades. In 2013, N6 -allyl-6-norlysergic acid diethylamide (AL-LAD) and (2'S,4'S)-lysergic acid 2,4-dimethylazetidide (LSZ) appeared on the 'research chemicals'/new psychoactive substances (NPS) market in both powdered and blotter form. This study reports the analytical characterization of powdered AL-LAD and LSZ tartrate samples and their semi-quantitative determination on blotter paper. Included in this study was the use of nuclear magnetic resonance (NMR) spectroscopy, gas chromatography-mass spectrometry (GC-MS), low and high mass accuracy electrospray MS(/MS), high performance liquid chromatography diode array detection and GC solid-state infrared analysis. One feature shared by serotonergic psychedelics, such as LSD, is the ability to mediate behavioural responses via activation of 5-HT2A receptors. Both AL-LAD and LSZ displayed LSD-like responses in male C57BL/6 J mice when employing the head-twitch response (HTR) assay. AL-LAD and LSZ produced nearly identical inverted-U-shaped dose-dependent effects, with the maximal responses occurring at 200 µg/kg. Analysis of the dose responses by nonlinear regression confirmed that LSZ (ED50 = 114.2 nmol/kg) was equipotent to LSD (ED50 = 132.8 nmol/kg) in mice, whereas AL-LAD was slightly less potent (ED50 = 174.9 nmol/kg). The extent to which a comparison in potency can be translated directly to humans requires further investigation. Chemical and pharmacological data obtained from NPS may assist research communities that are interested in various aspects related to substance use and forensic identification. Copyright © 2016 John Wiley & Sons, Ltd.

Return of the lysergamides. Part I: Analytical and behavioural characterization of 1-propionyl-d-lysergic acid diethylamide (1P-LSD).

1-Propionyl-d-lysergic acid diethylamide hemitartrate (1P-LSD) has become available as a 'research chemical' in the form of blotters and powdered material. This non-controlled derivative of d-lysergic acid diethylamide (LSD) has previously not been described in the published literature despite being closely related to 1-acetyl-LSD (ALD-52), which was developed in the 1950s. This study describes the characterization of 1P-LSD in comparison with LSD using various chromatographic and mass spectrometric methods, infrared and nuclear magnetic resonance spectroscopy. An important feature common to LSD and other serotonergic hallucinogens is that they produce 5-HT2A -receptor activation and induce the head-twitch response (HTR) in rats and mice. In order to assess whether 1P-LSD displays LSD-like properties and activates the 5-HT2A receptor, male C57BL/6 J mice were injected with vehicle (saline) or 1P-LSD (0.025-0.8 mg/kg, IP) and HTR assessed for 30 min using magnetometer coil recordings. It was found that 1P-LSD produced a dose-dependent increase in HTR counts, and that it had ~38% (ED50 = 349.6 nmol/kg) of the potency of LSD (ED50 = 132.8 nmol/kg). Furthermore, HTR was abolished when 1P-LSD administration followed pretreatment with the selective 5-HT2A receptor antagonist M100907 (0.1 mg/kg, SC), which was consistent with the concept that the behavioural response was mediated by activation of the 5-HT2A receptor. These results indicate that 1P-LSD produces LSD-like effects in mice, consistent with its classification as a serotonergic hallucinogen. Nevertheless, the extent to which 1P-LSD might show psychoactive effects in humans similar to LSD remains to be investigated. Copyright © 2015 John Wiley & Sons, Ltd.

Syntheses and analytical characterizations of N-alkyl-arylcyclohexylamines.

The rise in new psychoactive substances that are available as 'research chemicals' (RCs) remains a significant forensic and legislative challenge. A number of arylcyclohexylamines have attracted attention as RCs and continue to be encountered, including 3-MeO-PCP, 3-MeO-PCE and 3-MeO-PCPr. These compounds are commonly perceived as ketamine-like dissociative substances and are believed to act predominantly via antagonism of the N-methyl-D-aspartate (NMDA) receptor. To aid in the identification of newly emerging substances of abuse, the current studies were performed. The syntheses of fifteen N-alkyl-arylcyclohexylamines are described. Analytical characterizations were performed via gas chromatography and high performance liquid chromatography coupled to multiple forms of mass spectrometry as well as nuclear magnetic resonance spectroscopy, ultraviolet diode array detection and infrared spectroscopy. The series consisted of the N-alkyl derivatives (N-methyl, N-ethyl, N-propyl) of phenyl-substituted and isomeric 2-, 3- and 4-methoxy phenylcyclohexylamines, as well as the N-alkyl derivatives obtained from 3-methylphenyl and 2-thienyl moieties. In addition to the presentation of a range of previously unreported data, it was also found that positional isomers of aryl methoxyl-substituted arylcyclohexylamines were readily distinguishable under a variety of analytical conditions. Copyright © 2015 John Wiley & Sons, Ltd.

Test purchase, synthesis, and characterization of 2-methoxydiphenidine (MXP) and differentiation from its meta- and para-substituted isomers.

The structurally diverse nature of the 1,2-diphenylethylamine template provides access to a range of substances for drug discovery work but some have attracted attention as 'research chemicals'. The most recent examples include diphenidine, i.e. 1-(1,2-diphenylethyl)piperidine and 2-methoxydiphenidine, i.e. 1-[1-(2-methoxyphenyl)-2-phenylethyl]piperidine (MXP, methoxyphenidine, 2-MXP) that have been associated with uncompetitive N-methyl-D-aspartate (NMDA) receptor antagonist activity. Analytical challenges encountered during chemical analysis include the presence of positional isomers. Three powdered samples suspected to contain 2-MXP were obtained from three Internet retailers in the United Kingdom and subjected to analytical characterization by gas chromatography (GC) and high performance liquid chromatography (HPLC) coupled to various forms of mass spectrometry (MS). Nuclear magnetic resonance spectroscopy, infrared spectroscopy and thin layer chromatography were also employed. This was supported by the synthesis of all three isomers (2-, 3- and 4-MXP) by two different synthetic routes. The analytical data obtained for the three purchased samples were consistent with the synthesized 2-MXP standard and the differentiation between the isomers was possible. Distinct stability differences were observed for all three isomers during in-source collision-induced dissociation of the protonated molecule when employing detection under HPLC selected-ion monitoring detection, which added to the ability to differentiate between them. Furthermore, the analysis of a 2-MXP tablet by matrix assisted inlet ionization Orbitrap mass spectrometry confirmed that it was possible to detect the protonated molecule of 2-MXP directly from the tablet surface following addition of 3-nitrobenzonitrile as the matrix.

Analytical characterization of bioactive N-benzyl-substituted phenethylamines and 5-methoxytryptamines.

RATIONALE: Substances based on the N-(2-methoxybenzyl)phenethylamine template ('NBOMe' derivatives) play an important role in medicinal research but some of these derivatives have also appeared as 'research chemicals' for recreational use which has attracted attention worldwide. A major challenge associated with newly emerging substances includes the lack of analytical data and the ability to correctly identify positional isomers. METHODS: Six N-benzylphenethylamines based on the 2,5-dimethoxy-4-iodophenethylamine structure ('25I') and twelve substituted N-benzyl-5-methoxytryptamines ('5MT') have been prepared and extensively characterized. Techniques used for characterization were gas chromatography/ion trap mass spectrometry in electron and chemical ionization mode, liquid chromatography/diode array detection (DAD), infrared spectroscopy, electrospray high mass accuracy quadrupole time-of-flight tandem mass spectrometry, and triple quadrupole tandem mass spectrometry. RESULTS: The characterization of 18 'NBOMe' compounds provided a comprehensive collection of chromatographic and spectral data. Four groups of three positional isomers, i.e. 25I-NB2OMe, 25I-NB3OMe, 25I-NB4OMe, 25I-NB2B, 25I-NB3B, 25I-NB4B and their 5-methoxytryptamine counterparts, were included and assessed for ability to obtain differentiation. Six meta-substituted N-benzyl derivatives of 5-methoxytryptamine (CF3, F, CH3, Cl, I, SCH3) were also studied. CONCLUSIONS: The implementation of mass spectral techniques was helpful for the differentiation between isomers, for example, when considering the difference in a number of ion ratios. This was considered beneficial in cases where chromatographic separation was only partially achieved under liquid chromatography (LC) conditions. The use of LC/DAD analysis was also found to be valuable for this particular purpose, which confirmed the integrative value of complementary techniques used in areas related to forensic toxicology.