Drug Testing and Analysis
April 15, 2015
Gavin McLaughlin, Noreen Morris, Pierce V. Kavanagh et al.
32 citations
Three powdered samples sold online as the 'research chemical' 2-methoxydiphenidine (2-MXP) were analytically characterized and compared with synthesized isomers. Gas chromatography, high-performance liquid chromatography, mass spectrometry, nuclear magnetic resonance spectroscopy, infrared spectroscopy, and thin layer chromatography all confirmed the samples were 2-MXP. The three positional isomers (2-, 3-, and 4-MXP) could be differentiated, notably by distinct stability differences observed during in-source collision-induced dissociation of the protonated molecule under HPLC selected-ion monitoring. Additionally, matrix assisted inlet ionization Orbitrap mass spectrometry detected the protonated molecule of 2-MXP directly from a tablet surface after adding 3-nitrobenzonitrile as matrix.
Neuropharmacology
October 12, 2017
Felix P. Mayer, Nadine V. Burchardt, Ann M. Decker et al.
30 citations
Three isomers of the new psychoactive substance 3-fluorophenmetrazine (2-FPM, 3-FPM, and 4-FPM) inhibit dopamine and norepinephrine transporters with potencies comparable to cocaine (IC50 values below 2.5 μM) but show much weaker effects at the serotonin transporter (IC50 values above 80 μM). They also induce efflux of monoamines via all three transporters, an effect enhanced by the ionophore monensin. These compounds act as monoamine releasers with marked potency at catecholamine transporters implicated in abuse and addiction.
Drug Testing and Analysis
July 15, 2014
Jason Wallach, Pierce V. Kavanagh, Gavin McLaughlin et al.
26 citations
Diphenidine, a dissociative agent sold as a 'research chemical,' and its isomer 2,2-DEP can be distinguished using gas chromatography-mass spectrometry by their unique iminium ions. The study synthesized and characterized both compounds and their pyrrolidine analogues. Two vendor samples confirmed diphenidine. In rat hippocampal slices, diphenidine (30 μM) reduced NMDA-mediated electrical signals to a similar extent as ketamine (30 μM), indicating it acts on the same receptor. This suggests 1,2-diphenylethylamines are emerging alternatives to arylcyclohexylamine-type dissociatives like PCP and methoxetamine.
Drug Testing and Analysis
August 15, 2016
Gavin McLaughlin, Noreen Morris, Pierce V. Kavanagh et al.
23 citations
Mexedrone, a derivative of mephedrone that appeared in 2015, was synthesized and analytically characterized. It was a weak non-selective uptake blocker at dopamine, norepinephrine, and serotonin transporters with IC50 values in the low micromolar range, and lacked releasing activity at dopamine and norepinephrine transporters but showed weak releasing activity at serotonin transporters (EC50 = 2.5 μM). Its isomer, N-methoxymephedrone, acted as a weak uptake blocker and a fully efficacious substrate-type releasing agent across all three transporters with EC50 values in the low micromolar range. A synthesis by-product, α-chloromethylmephedrone, was inactive in all assays.
Drug Testing and Analysis
October 20, 2014
Gavin McLaughlin, Noreen Morris, Pierce V. Kavanagh et al.
18 citations
A newly emerged psychoactive substance, 3,4-methylenedioxy-4-methylaminorex (MDMAR), was synthesized and characterized. Analysis of vendor-sourced MDMAR found it to be predominantly the cis-isomer (90%), which could artificially convert to the trans-isomer under certain liquid chromatography conditions. Both MDMAR isomers, along with cis- and trans-4,4'-DMAR, were more potent than MDMA in releasing dopamine and norepinephrine in rat brain tissue. While cis-4,4'-DMAR, cis-MDMAR, and trans-MDMAR fully released serotonin, trans-4,4'-DMAR acted as a serotonin uptake blocker. The high potency of these analogues at monoamine transporters may indicate potential for serious side-effects at high doses.
Drug Testing and Analysis
April 19, 2018
Gavin McLaughlin, Michael H. Baumann, Pierce V. Kavanagh et al.
8 citations
Two new psychoactive substances, 4-methylphenmetrazine (4-MPM) and 3-methylphenmetrazine (3-MPM), have appeared on the recreational drug market following the earlier emergence of 3-fluorophenmetrazine. Analytical characterization of vendor samples confirmed the presence of 4-MPM in two samples and 3-MPM in one sample. In vitro transporter assays using rat brain synaptosomes tested the isomers' ability to inhibit uptake or stimulate release of dopamine, norepinephrine, and serotonin. The findings suggest that 2-MPM and 3-MPM will exhibit stimulant properties similar to phenmetrazine, whereas 4-MPM may display entactogen properties more similar to MDMA. Combining test purchases, analytical characterization, targeted synthesis, and pharmacological evaluation provides an effective approach for generating data on emerging substances.