| 1. |
- Concheiro, Marta, et al.
(författare)
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Simultaneous determination of 40 novel psychoactive stimulants in urine by liquid chromatography-high resolution mass spectrometry and library matching
- 2015
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Ingår i: Journal of Chromatography A. - : Elsevier. - 0021-9673 .- 1873-3778. ; 1397, s. 32-42
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Tidskriftsartikel (refereegranskat)abstract
- The emergence of novel psychoactive substances is an ongoing challenge for analytical toxicologists. Different analogs are continuously introduced in the market to circumvent legislation and to enhance their pharmacological activity. Although detection of drugs in blood indicates recent exposure and link intoxication to the causative agent, urine is still the most preferred testing matrix in clinical and forensic settings. We developed a method for the simultaneous quantification of 8 piperazines, 4 designer amphetamines and 28 synthetic cathinones and 4 metabolites, in urine by liquid chromatography coupled to high-resolution mass spectrometry (LC-HRMS). Data were acquired in full scan and data dependent MS2 mode. Compounds were quantified by precursor ion exact mass, and confirmed by product ion spectra library matching, taking into account product ions exact mass and intensities. One-hundred pi, urine was subjected to solid phase cation exchange extraction (SOLA SCX). The chromatographic reverse-phase separation was achieved with gradient mobile phase of 0.1% formic acid in water and in acetonitrile in 20 min. The assay was linear from 2.5 or 5 to 500 mu g/L. Imprecision (n = 15) was less than15.4%, and accuracy (n = 15) 84.2-118.5%. Extraction efficiency was 51.2-111.2%, process efficiency 57.7-104.9% and matrix effect ranged from -41.9% to 238.5% (CV less than 23.3%, except MDBZP CV less than 34%). Authentic urine specimens (n = 62) were analyzed with the method that provides a comprehensive confirmation for 40 new stimulant drugs with specificity and sensitivity.
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| 2. |
- DeFreitas, Laura, et al.
(författare)
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Fast and Sensitive Method for the Determination of 17 Designer Benzodiazepines in Hair by Liquid Chromatography-Tandem Mass Spectrometry
- 2022
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Ingår i: Journal of Analytical Toxicology. - : OXFORD UNIV PRESS INC. - 0146-4760 .- 1945-2403. ; 46:8, s. 852-859
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Tidskriftsartikel (refereegranskat)abstract
- In recent years, identification and analysis of designer benzodiazepines have become a challenge in forensic toxicology. These substances are analogs of the classic benzodiazepines, but their pharmacology is not well known, and many of them have been associated with overdoses and deaths. As a result, there has been a surge in efforts to develop analytical methods to determine these compounds in different biological samples. Our aim was to develop and validate a fast, sensitive and specific method for determining 17 designer benzodiazepines (adinazolam, clobazam, clonazolam, delorazepam, deschloroetizolam, diclazepam, etizolam, flualprazolam, flubromazepam, flubromazolam, flunitrazolam, N-desmethylclobazam, nifoxipam, nitrazolam, meclonazepam, pyrazolam and zolazepam) in hair by liquid chromatography-tandem mass spectrometry (LC-MS-MS). Hair samples were decontaminated and pulverized, and a 20 mg aliquot was incubated in methanol in an ultrasound bath (1 h, 25 degrees C). The supernatant was evaporated and reconstituted in 200 mu L of mobile phase, and the extracts were filtered (nano-filter vials) before injection into LC-MS-MS. All analytes were eluted from the chromatographic column in 8 min, and two multiple-reaction monitoring (MRM) transitions were used to identify each compound. The limits of quantification were 5 or 25 pg/mg depending on the analyte, and the calibration functions were linear to 200 pg/mg. Imprecision was <19.2% (n = 15), and bias was from -13.7 to 18.3% (n = 15). All the analytes yielded high extraction efficiencies >70% and displayed ion suppression between -62.8% and -23.9% (n = 10). The method was applied to 19 authentic cases. Five samples were positive for flualprazolam ( 200 pg/mg) and/or etizolam (47.4-88.5 pg/mg). In conclusion, the present validated method has proven to be fast, sensitive, specific and capable of determining 17 designer benzodiazepines in hair using LC-MS-MS.
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| 3. |
- Kwako, Laura E., et al.
(författare)
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The Corticotropin Releasing Hormone-1 (CRH1) Receptor Antagonist Pexacerfont in Alcohol Dependence: A Randomized Controlled Experimental Medicine Study
- 2015
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Ingår i: Neuropsychopharmacology. - : Nature Publishing Group: Open Access Hybrid Model Option A. - 0893-133X .- 1740-634X. ; 40:5, s. 1053-1063
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Tidskriftsartikel (refereegranskat)abstract
- Extensive preclinical data implicate corticotropin-releasing hormone (CRH), acting through its CRH1 receptor, in stress- and dependence-induced alcohol seeking. We evaluated pexacerfont, an orally available, brain penetrant CRH1 antagonist for its ability to suppress stress-induced alcohol craving and brain responses in treatment seeking alcohol-dependent patients in early abstinence. Fifty-four anxious alcohol-dependent participants were admitted to an inpatient unit at the NIH Clinical Center, completed withdrawal treatment, and were enrolled in a double-blind, randomized, placebo-controlled study with pexacerfont (300 mg/day for 7 days, followed by I 00 mg/day for 23 days). After reaching steady state, participants were assessed for alcohol craving in response to stressful or alcohol-related cues, neuroendocrine responses to these stimuli, and functional magnetic resonance imaging (fMRI) responses to alcohol-related stimuli or stimuli with positive or negative emotional valence. A separate group of 10 patients received open-label pexacerfont following the same dosing regimen and had cerebrospinal fluid sampled to estimate central nervous system exposure. Pexacerfont treatment had no effect on alcohol craving, emotional responses, or anxiety. There was no effect of pexacerfont on neural responses to alcohol-related or affective stimuli. These results were obtained despite drug levels in cerebrospinal fluid (CSF) that predict close to 90% central CRH1 receptor occupancy. CRH1 antagonists have been grouped based on their receptor dissociation kinetics, with pexacerfont falling in a category characterized by fast dissociation. Our results may indicate that antagonists with slow offset are required for therapeutic efficacy. Alternatively, the extensive preclinical data on CRH1 antagonism as a mechanism to suppress alcohol seeking may not translate to humans.
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| 4. |
- Swortwood, Madeleine J., et al.
(författare)
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First metabolic profile of PV8, a novel synthetic cathinone, in human hepatocytes and urine by high-resolution mass spectrometry
- 2016
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Ingår i: Analytical and Bioanalytical Chemistry. - : SPRINGER HEIDELBERG. - 1618-2642 .- 1618-2650. ; 408:18, s. 4845-4856
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Tidskriftsartikel (refereegranskat)abstract
- Novel psychoactive substances (NPS) are ever changing on the drug market, making it difficult for toxicology laboratory methods to stay current with so many new drugs. Recently, PV8, a synthetic pyrrolidinophenone, was detected in seized products in Japan (2013), The Netherlands (2014), and Germany (2014). There are no controlled PV8 administration studies, and no pharmacodynamic and pharmacokinetic data. The objective was to determine PV8s metabolic stability in human liver microsome (HLM) incubation and its metabolism following human hepatocyte incubation and high-resolution mass spectrometry (HRMS) with a Thermo Scientific Q-Exactive. Data were acquired with a full-scan data-dependent mass spectrometry method. Scans were thoroughly data mined with different data processing algorithms and analyzed in WebMetaBase. PV8 exhibited a relatively short 28.8 min half-life, with an intrinsic 24.2 mu L/min/mg microsomal clearance. This compound is predicted to be an intermediate clearance drug with an estimated human 22.7 mL/min/kg hepatic clearance. Metabolic pathways identified in vitro included: hydroxylation, ketone reduction, carboxylation, N-dealkylation, iminium formation, dehydrogenation, N-oxidation, and carbonylation. The top three in vitro metabolic pathways were di-hydroxylation amp;gt; ketone reduction amp;gt; gamma-lactam formation. Authentic urine specimen analyses revealed the top three metabolic pathways were aliphatic hydroxylation amp;gt; ketone reduction + aliphatic hydroxylation amp;gt; aliphatic carboxylation, although the most prominent peak was parent PV8. These data provide useful urinary metabolite targets (aliphatic hydroxylation, aliphatic hydroxylation + ketone reduction, aliphatic carboxylation, and di-hydroxylation) for forensic and clinical testing, and focus reference standard companies synthetic efforts to provide commercially available standards needed for PV8 biological specimen testing.
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| 5. |
- Swortwood, Madeleine J., et al.
(författare)
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In vitro, in vivo and in silico metabolic profiling of -pyrrolidinopentiothiophenone, a novel thiophene stimulant
- 2016
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Ingår i: Bioanalysis. - : FUTURE SCI LTD. - 1757-6180 .- 1757-6199. ; 8:1, s. 65-82
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Tidskriftsartikel (refereegranskat)abstract
- Background: Little or no pharmacological or toxicological data are available for novel psychoactive substances when they first emerge, making their identification and interpretation in biological matrices challenging. Materials & methods: A new synthetic cathinone, alpha-pyrrolidinopentiothiophenone (alpha-PVT), was incubated with hepatocytes and samples were analyzed using liquid chromatography coupled to a Q Exactive(TM) Orbitrap mass spectrometer. Authentic urine specimens from suspected -PVT cases were also analyzed. Scans were data mined with Compound Discoverer for identification and structural elucidation of metabolites. Results/conclusion: Seven alpha-PVT metabolites were identified in hepatocyte incubations, and in the authentic urine samples, also with an additional monohydroxylated product and a glucuronide of low intensity. alpha-PVT dihydroxypyrrolidinyl, alpha-PVT 2-ketopyrrolidinyl, alpha-PVT hydroxythiophenyl and alpha-PVT thiophenol had the most intense in vivo signals.
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