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We present a case of fatal poisoning by 4-F-methcathinone (4-FMC; also called flephedrone), 4-methoxy-α-pyrrolidinopentiophenone (4-MeO-α-PVP), 4-fluoro-α-pyrrolidinopentiophenone (4-F-α-PVP), and α-pyrrolidinohepatanophenone (PV8). In this study, we compared the mass spectra of 4-FMC, 4-MeO-α-PVP, 4-F-α-PVP, PV8, and α-pyrrolidinohexanophenone between LC-ESI-LIT-MS and GC-EI-MS analyses. Subsequently, we applied LC-ESI-LIT-MS for detection and quantification analyses of 4-FMC, 4-MeO-α-PVP, 4-F-α-PVP, and PV8 in human authentic whole blood samples. More specific mass spectra for the target compounds were obtained with the LC-ESI-LIT-MS qualitative analyses than with the GC-EI-MS analyses, indicating that LC-ESI-LIT-MS was more suitable for the qualitative analysis of cathinones. The LC-ESI-LIT-MS validation data showed moderately good linearity and reproducibility for the compounds in the quantitative analyses at the range of 1-500 ng/mL. The detection limits of four cathinones ranged from 0.1 to 1 ng/mL. The concentrations of 4-FMC, 4-MeO-α-PVP, 4-F-α-PVP, and PV8 in heart whole blood samples were 365, 449, 145, and 218 ng/mL, respectively. Those of the 4 cathinones in femoral vein whole blood samples were 397, 383, 127, and 167 ng/mL, respectively. We can then assume that the cause of death was acute poisoning by a combination of 4-FMC, 4-MeO-α-PVP, 4-F-α-PVP, and PV8. In this article, we present a detailed LC-ESI-LIT-MS procedure for detection and quantification analyses of 4-FMC, 4-MeO-α-PVP, 4-F-α-PVP, and PV8 in authentic human whole blood samples.

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Objective: To evaluate antioxidant, cytotoxic, and anti-venom capacity of crude bark extracts of Alstonia parvifolia Merr. Methods: Gas chromatography-mass spectrometry (GC-MS) and energy dispersive X-ray analyses were accomplished to characterize the chemical constituents of Alstonia parvifolia. Biochemical characterization was evaluated using an inhibitory phospholipase A 2 (PLA 2) assay, DPPH, and cytotoxicity assays. Using the constituents listed in the GC-MS analyses, molecular docking was conducted to inspect the binding energies between the chosen compounds and selected PLA 2 isoforms. Results: GC-MS analyses showed that the Alstonia parvifolia crude extract consisted predominantly of acetylmarinobufogenin (14.89%), γ-sitosterol (10.44%), 3-O-methyl-D-glucose (5.88%), 3,5-dimethoxy-4-hydroxyphenylacetic acid (5.30%), (2α,5α)-17-methoxyaspidofractinin-3-one (AFM) (4.08%), and 2,3,5,6,7,8,9-heptahydro-1-phenyl-5-(p-chlorophenylimino)-1H-benzo[e] [1],[4] thiazepine (HPT) (1.37%). The principal elemental components of Alstonia parvifolia were Ca (4.012%) and K (1.496%), as exhibited by energy dispersive X-ray examination. Alstonia parvifolia showed significant free radical scavenging ability (IC 50: 0.287 mg/mL) and was non-cytotoxic to normal HDFn cells (IC 50 >100 μg/mL). Moreover, Alstonia parvifolia was favorably cytotoxic to MCF-7 (IC 50: 4.42 μg/mL), followed by H69PR, HT-29, and THP-1, with IC 50 values of 4.94, 5.07, and 6.27 μg/mL, respectively. Alstonia parvifolia also displayed notable inhibition against PLA 2 activity of Naja philippinensis Taylor venom with IC 50 of (15.2 ± 1.8) μg/mL. Docking and cluster analyses projected negative binding energies from AFM (-6.36 to -9.68 kcal/mol), HPT (-7.38 to -9.77 kcal/ mol), and acetylmarinobufogenin (-7.22 to -9.59 kcal/mol). These calculations were for the particular interactions of Alstonia parvifolia constituents to PLA 2 homologues where the utmost affinity was detected in HPT owing to the dipole interactions with amino acid residues. Conclusions: The bark extract of Alstonia parvifolia shows great potential as an anti-venom agent due to its low cytotoxic profile, remarkable PLA 2 inhibition, and docking binding energies between its bioactive constituents and PLA 2 homologues.

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In the present study a novel analytical procedure for the determination of polybrominated diphenyl ethers in dust samples was developed. The main aim of the research was the selection of the optimum conditions of the matrix solid-phase dispersion before the final determination of polybrominated diphenyl ethers in dust samples. In order to assess the best usefulness of this technique, a favourable ratio of sample amount to the mass of dispersing sorbent, as well as the type of this sorbent used has been tested. The type of sorbent responsible for additional purification (clean-up sorbent) of the extract during matrix solid-phase dispersion was also selected. Gas chromatography coupled with mass spectrometry will be used at the final determination step. Preliminary results indicate that the use of matrix solid-phase dispersion can be a promising alternative to other time-consuming and multi-stage analytical procedures. The proposed method provided satisfactory recoveries (76-119%) and limits of detection: 2.1-4.4 pg µL-1 for tri-heptaBDE in linear range of 5-100 pg µL-1; 480 pg µL-1 for decaBDE in linear range of 500-2000 pg µL-1 from only 0.05 g of a dust sample. Finally, the method was applied to study the content of selected polybrominated diphenyl ethers in real dust samples. Some polybrominated diphenyl ether congeners reached up to (16.3 ±â€¯3.0)·102 ng g-1.

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Differentiation among regioisomers of synthetic cannabinoids in forensic drug analysis is a crucial issue, since all isomers are not regulated by law. New equivalent analogs obtained via minor modification of their preexisting molecules keep on emerging. Isomers formed via substitutional exchange are also a cause for concern. This study is focused on the isomeric molecules that stem from minor modifications of 5F-PB-22. The analytical properties of these molecules and methods of differentiation are reported. Scan mode analysis using gas chromatography-electron ionization-mass spectrometry (GC-EI-MS) was performed using the authentic 5F-PB-22 standard, five regioisomeric quinolinyl ester indoles, and five regioisomeric isoquinolinyl ester indoles. Because it was not possible to separate 5F-PB-22 from the 5-hydroxyquinoline isomer using GC and all analytes showed similar EI mass spectra, liquid chromatography (LC)-tandem mass spectrometry analysis was performed. Using LC, a successful separation of 5F-PB-22 from all isomers could be achieved. Based on the electrospray ionization-mass spectra, the protonated molecular ion at m/z 377.2 was selected as the precursor ion for the regioisomeric and structural isomeric differentiation. Collision-induced dissociation provides relative intensity differences in the product ions among the isomers, enabling mass spectrometric differentiation of the isomers. To our knowledge, this is the first report on mass spectrometric differentiation of 5F-PB-22 and its ten isomers.

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Nitrocellulose (NC) is one of the most common ingredients in explosive mixtures, however because of its non-volatility, its detection using Gas Chromatography-Electron Ionization-Mass Spectrometry (GC-EI-MS) has not been achieved until today. A rapid method for the identification of NC in bulk explosives using GC-EI-MS was developed. The sample preparation is simple and takes place in a test tube, employing standard equipment of a forensics laboratory. The protocol was optimized and applied to seven, both high and low, commercial explosives, which contained the substance of interest. Moreover, three explosives in the absence of NC were tested to cross check for false positives. Fourteen different standard explosive substances that are usually found in explosive mixtures were then employed in order to monitor the effect of the method on these compounds and check for interferences. Results showed that NC was detected, by its trimethylsilyl (TMS) derivatives, in all the explosive mixtures analyzed and no false positives were observed. The proposed method showed selectivity for NC, as it had no interference coming from other ingredients of explosive mixtures. The protocol introduced offers considerable improvement in identifying the individual components of an explosive mixture and contributes in successful classification of explosives.

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Cholesterol hydroperoxides (ChOOHs) are included as lipid peroxidation products in the skin exposed to ultraviolet (UV) light irradiation. They may exert physicochemical actions affecting biomembrane rigidity because cholesterol is one of the major components of cell membranes. We investigated the distribution of isomeric ChOOHs in heterogeneous cell membranes with different lipid profiles using mouse fibroblast NIH-3T3 cells as a model of the dermis. Before and after UVA irradiation in the presence of hematoporphyrin, cell membranes were partitioned to microdomains (lipid rafts and caveolae) containing a higher amount of cholesterol and non-microdomains (containing a lower amount of cholesterol) by ultracentrifugation. By a combination of diphenylpyrenylphosphine-thin-layer chromatography blotting analyses and gas chromatography-electron ionization-mass spectrometry/selected ion monitoring analyses, ChOOH isomers were determined as their trimethylsilyloxyl derivatives. Cholesterol 5α-, 7α- and 7ß-hydroperoxide were found as isomeric ChOOHs before irradiation. The amounts of the three ChOOH isomers increased significantly after photoirradiation for 2h. No difference was observed between microdomains and non-microdomains with regard to the ratio of the amounts of isomeric ChOOHs to that of cholesterol, suggesting that these ChOOH isomers were distributed equally in both parts depending on cholesterol content. When cells were treated with a purified mixture of ChOOH isomers, cell membranes incorporated ChOOHs into microdomains as well as non-microdomains evenly. Cellular matrix metalloproteinase-9 (MMP-9) activity was elevated by treatment with the purified mixture of ChOOH isomers. These results strongly suggest that ChOOHs accumulate in cell membranes irrespective of the heterogeneous microstructure and promote MMP activity if dermal cells are exposed to photodynamic actions.

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A novel method was established for the qualitative and quantitative determination of fatty acids in Channel Catfish muscle by gas chromatography-electron ionization-mass spectrometry (GC-EI-MS) after supercritical carbon dioxide fluid extraction (SFE-CO_2). The extraction parameters for the methodology were optimized). The optimal conditions were extraction pressure of 25 MPa at 45 ℃ and extraction time of 100 min at the rate of carbon dioxide 30 L/h. The fatty acids in the muscle oil were derived by boron-trifluoride method). The saponification time was 10 min, and the esterication time was 20 min. The obtained fatty acid methylesters were separated by gas chromatography using a HP-Innowax capillary column, and were detected by electron) ionization) mass spectrometry. Full scan mode and SIM mode were used for the qualitative and quantitative analysis), respectively. In the SIM mode, saturated fatty acids were determined with m/z 74, mono-unsaturated) fatty acids were determined with m/z 55, double-unsaturated fatty acids were determined with m/z 67, and polyunsaturated fatty acids were determined with m/z 79. The detection limits of 14 fatty acids were 2.2-20.0 μg/L(S/N=3)), and the quantitative limits were 7.39-59.85 μg/L(S/N=10). The recoveries fell in the range from 90.0% to 111.2%(n=4), and the relative standard deviation was between) 2.0% and 5.9%. This effective, sensitive and reproducible method can be used for the determination of fatty acids in Channel Catfish muscle sample.