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Brendan Twamley

6 papers in the library · 154 citations · publishing 2014-2018

Papers

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

Drug Testing and Analysis June 5, 2017 Simon D. Brandt, Pierce V. Kavanagh, Brendan Twamley et al. 56 citations

Lysergic acid morpholide (LSM-775), a structural relative of LSD, appeared on the market for new psychoactive substances in 2013, but its potency and psychoactive effects in humans have been disputed. This investigation characterized a powdered sample using multiple analytical techniques and tested its receptor activity. LSM-775 acted as a nonselective agonist at 5-HT1A and 5-HT2A receptors. In head twitch studies with C57BL/6J mice, LSM-775 did not induce the head twitch response unless 5-HT1A receptors were blocked by the antagonist WAY-100,635 (1 mg/kg, subcutaneous). The findings suggest that activation of 5-HT1A receptors by LSM-775 masks its hallucinogen-like effects, consistent with reports that it produces only weak LSD-like effects in humans.

Characterization of a novel and potentially lethal designer drug (±)‐cis‐para‐methyl‐4‐methylaminorex (4,4'‐DMAR, or ‘Serotoni’)

Drug Testing and Analysis May 19, 2014 Simon D. Brandt, Michael H. Baumann, John S. Partilla et al. 37 citations

A new designer drug, para-methyl-4-methylaminorex (4,4'-DMAR), was linked to 26 deaths in Europe in 2013. Laboratory analysis of samples from online vendors identified the (±)-cis isomer in at least 18 cases. The drug acts as a potent releaser at dopamine, norepinephrine, and serotonin transporters, with EC50 values of 8.6 nM, 26.9 nM, and 18.5 nM respectively. Its potency at dopamine and norepinephrine transporters rivaled that of d-amphetamine and aminorex, but it was far more potent at the serotonin transporter. This broad activity predicts serious side effects including psychosis, agitation, hyperthermia, and cardiovascular stimulation, especially at high doses or with other stimulants.

Synthesis, characterization and monoamine transporter activity of the new psychoactive substance mexedrone and its N‐methoxy positional isomer, N‐methoxymephedrone

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.

Synthesis, characterization, and monoamine transporter activity of the new psychoactive substance 3′,4′‐methylenedioxy‐4‐methylaminorex (MDMAR)

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.

Test purchase, identification and synthesis of 2-amino-1-(4-bromo-2, 5-dimethoxyphenyl)ethan-1-one (bk-2C-B).

Drug testing and analysis June 1, 2015 John D Power, Pierce Kavanagh, John O'Brien et al. 12 citations

A substance called bk-2C-B, a cathinone analogue of the psychoactive phenethylamine 2C-B, has become available from online retailers. Its identity was confirmed through multiple analytical methods, including nuclear magnetic resonance spectroscopy, gas and liquid chromatography, and high-resolution mass spectrometry. The compound was also synthesized using the Delépine reaction. Gas chromatography-mass spectrometry showed potential for artificial formation of byproducts, but these were not seen with liquid chromatography. Analysis revealed the purchased material was a mixture of hydrochloride and hydrobromide salts, suggesting a specific synthetic route, and X-ray crystallography showed it exists as polymorphs.

Synthesis, analytical characterization, and monoamine transporter activity of the new psychoactive substance 4‐methylphenmetrazine (4‐MPM), with differentiation from its ortho‐ and meta‐ positional isomers

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.