Development of a mass spectrometric hydroxyl-position determination method for the hydroxyindole metabolites of JWH-018 by GC-MS/MS

Separation and Characterization of Synthetic Cannabinoid Metabolite Isomers Using SLIM High-Resolution Ion Mobility-Tandem Mass Spectrometry (HRIM-MS/MS)

Synthetic cannabinoids, a subclass of new psychoactive substances (NPS), are laboratory-made substances that are chemically similar to those found naturally in the cannabis plant. Many of these substances are illicitly manufactured and have been associated with severe health problems, prompting a need to develop analytical methods capable of characterizing both known and previously undetected compounds. This work focuses on a novel Structures for Lossless Ion Manipulations (SLIM) IM-MS approach to the differentiation and structural characterization of synthetic cannabinoid metabolites, specifically MDA-19/BUTINACA, JWH-018, and JWH-250 isomer groups. These different compound classes are structurally very similar, differing only in the position of one or a few functional groups; this yielded similarity in measured collision cross section (CCS) values. However, the high resolution of SLIM IM provided adequate separation of many of these isomers, such as sodiated JWH-250 metabolites N-4-OH, N-5-OH, and 5-OH, which displayed CCS of 187.5, 182.5, and 202.3 Å2, respectively. In challenging cases where baseline separation was precluded due to nearly identical CCS, such as for JWH-018 isomers, simple derivatization by dansyl chloride selectively reacted with the 6-OH compound to provide differentiation of all isomers using a combination of CCS and m/z. Finally, the opportunity to use this method for structural elucidation of unknowns was demonstrated by using SLIM IM mobility-aligned MS/MS fragmentation. Different MDA-19/BUTINACA isomers were first mobility separated and could then be individually activated, yielding unique fragments for both targeted identification and structural determination. Overall, the described SLIM IM-MS/MS workflow provides significant potential as a rapid screening tool for the characterization of emerging NPS such as synthetic cannabinoids and their metabolites.

Recent bionalytical methods for the determination of new psychoactive substances in biological specimens

One of the problems associated with the consumption of new psychoactive substances is that in most scenarios of acute toxicity the possibility of quick clinical action may be impaired because many screening methods are not responsive to them, and laboratories are not able to keep pace with the appearance of new substances. For these reasons, developing and validating new analytical methods is mandatory in order to efficiently face those problems, allowing laboratories to be one step ahead. The goal of this work is to perform a critical review regarding bionalytical methods that can be used for the determination of new psychoactive substances (phenylethylamines, cathinones, synthetic cannabinoids, opioids, benzodiazepines, etc), particularly concerning sample preparation techniques and associated analytical methods.

In vitro and in vivo pharmacological evaluation of the synthetic cannabinoid receptor agonist EG-018

Synthetic cannabinoid receptor agonists (SCRAs) possess high abuse liability and complex toxicological profiles, making them serious threats to public health. EG-018 is a SCRA that has been detected in both illicit products and human samples, but it has received little attention to date. The current studies investigated EG-018 at human CB₁ and CB₂ receptors expressed in HEK293 cells in [³H]CP55,940 competition binding, [³⁵S]GTPγS binding and forskolin-stimulated cAMP production. EG-018 was also tested in vivo for its ability to produce cannabimimetic and abuse-related effects in the cannabinoid tetrad and THC drug discrimination, respectively. EG-018 exhibited high affinity at CB₁ (21 nM) and at CB₂ (7 nM), but in contrast to typical SCRAs, behaved as a weak partial agonist in [³⁵S]GTPγS binding, exhibiting lower efficacy but greater potency, than that of THC at CB₁ and similar potency and efficacy at CB₂. EG-018 inhibited forskolin-stimulated cAMP with similar efficacy but lower potency, compared to THC, which was likely due to high receptor density facilitating saturation of this signaling pathway. In mice, EG-018 (100 mg/kg, 30 min) administered intraperitoneally (i.p.) did not produce effects in the tetrad or drug discrimination nor did it shift THC's ED₅₀ value in drug discrimination when administered before THC, suggesting EG-018 has negligible occupancy of brain CB₁ receptors following i.p. administration. Following intravenous (i.v.) administration, EG-018 (56 mg/kg) produced hypomotility, catalepsy, and hypothermia, but only catalepsy was blocked by the selective CB₁ antagonist rimonabant (3 mg/kg, i.v.). Additional studies of EG-018 and its structural analogues could provide further insight into how cannabinoids exert efficacy through the cannabinoid receptors.

The chemistry and pharmacology of synthetic cannabinoid SDB-006 and its regioisomeric fluorinated and methoxylated analogs

Synthetic cannabinoids are the largest and most structurally diverse class of new psychoactive substances, with manufacturers often using isomerism to evade detection and circumvent legal restriction. The regioisomeric methoxy- and fluorine-substituted analogs of SDB-006 (N-benzyl-1-pentyl-1H-indole-3-carboxamide) were synthesized and could not be differentiated by gas chromatography-mass spectrometry (GC-MS), but were distinguishable by liquid chromatography-quadrupole time-of-flight-MS (LC-QTOF-MS). In a fluorescence-based plate reader membrane potential assay, SDB-006 acted as a potent agonist at human cannabinoid receptors (CB1 EC50 = 19 nM). All methoxy- and fluorine-substituted analogs showed reduced potency compared to SDB-006, although the 2-fluorinated analog (EC50 = 166 nM) was comparable to known synthetic cannabinoid RCS-4 (EC50 = 146 nM). Using biotelemetry in rats, SDB-006 and RCS-4 evoked comparable reduction in body temperature (~0.7°C at a dose of 10 mg/kg), suggesting lower potency than the recent synthetic cannabinoid AB-CHMINACA (>2°C, 3 mg/kg).

Rapid screening and identification of novel psychoactive substances using PaperSpray interfaced to high resolution mass spectrometry

The simple and rapid detection and identification of designer drugs is of substantial importance to forensic scientists and law enforcement. Although synthetic cathinones, cannabinoids, and other common novel psychoactive substances (NPS) are produced for purposes that do not include human consumption, they are regularly abused. The analysis of these compounds is often achieved using mass spectrometry, but can be complicated by the lack of spectral libraries and the scarcity of simple and reliable sample introduction techniques. PaperSpray® ionization is a new, automated technique for rapid analysis of samples, without chromatography or prior purification. Matrix, such as powder or plant material, is dissolved or extracted with common solvents and deposited directly on disposable PaperSpray® cartridges for high-throughput, automated analysis. The combination of PaperSpray® sample introduction and High Resolution Accurate Mass Spectrometry (HRAM) provides a powerful and simple tool for identification of new substances, without requiring reference standards.