Direct detection of the psychoactive substance MT-45 in human tissue samples by probe electrospray ionization-tandem mass spectrometry

Arterial thromboxane A2-induced transient contraction after IL-1β exposure

The involvement of thromboxane A2 (TXA2) in systemic inflammation and infection is well recognized. However, there are few reports on the involvement of prostanoids in warm shock (the initial pathology of sepsis). Previous studies showed that interleukin (IL)-1β causes a rapid inducible nitric oxide synthase/nitric oxide (iNOS/NO)-mediated relaxation in peripheral blood vessels during warm shock. Furthermore, a transient contraction was seen before this relaxation occurred. The present study aimed to elucidate the mechanism of this transient contraction. We measured isometric tension changes in the superior mesenteric arteries from normal male Wistar rats by adding IL-1β at the point of maximum contraction by phenylephrine (Ph). The same study was performed for each vessel pretreated with various inhibitors, including SQ29548, a TXA2 receptor antagonist, 30 min before Ph contraction. In addition, the concentration of thromboxane B2 (TXB2) in SMA was measured by probe electrospray ionization. Treatment of endothelial vessels with cyclooxygenase 1 (COX1)/2 inhibitors SC560/NS398 and TXA2 receptor antagonist SQ29548 suppressed IL-1β–induced transient contractions. This transient contraction reaction was derived from TXA2. Additionally, gene expression of COX2/TXA2 synthetase and the concentration of TXB2 were significantly increased in IL-1β-exposed vessels. It was demonstrated for the first time in inflamed blood vessels that endothelial cell-derived COX2/TXA2 is induced before iNOS and causes transient contractions. TXA2 may be considered an early sign of warm shock or as a biological defense mechanism in the early stages of septic shock.

Developments in high-resolution mass spectrometric analyses of new psychoactive substances

The proliferation of new psychoactive substances (NPS) has necessitated the development and improvement of current practices for the detection and identification of known NPS and newly emerging derivatives. High-resolution mass spectrometry (HRMS) is quickly becoming the industry standard for these analyses due to its ability to be operated in data-independent acquisition (DIA) modes, allowing for the collection of large amounts of data and enabling retrospective data interrogation as new information becomes available. The increasing popularity of HRMS has also prompted the exploration of new ways to screen for NPS, including broad-spectrum wastewater analysis to identify usage trends in the community and metabolomic-based approaches to examine the effects of drugs of abuse on endogenous compounds. In this paper, the novel applications of HRMS techniques to the analysis of NPS is reviewed. In particular, the development of innovative data analysis and interpretation approaches is discussed, including the application of machine learning and molecular networking to toxicological analyses.

Endothelium-Independent Relaxation of Vascular Smooth Muscle Induced by Persimmon-Derived Polyphenol Phytocomplex in Rats

The vasorelaxant effect of polyphenols is well known, and the mortality rate due to coronary artery disease is low in people who consume polyphenol-containing foods. We aimed to elucidate the mechanism by which polyphenols derived from persimmon juice (PJ) and persimmon leaves (PLs) induce vasorelaxation and suppress vasocontraction in the superior mesenteric arteries isolated from male Sprague Dawley rats. Vasocontraction was induced with 1 µM phenylephrine, and polyphenol-induced vasorelaxation was expressed as a percentage of the previous tone induced by phenylephrine. PJ powder (100 mg/L) induced higher levels of vasorelaxation (mean ± standard error of the mean, 88.6% ± 4.4%) than PLs powder (1 g/L; 72.0% ± 10.8%). Nitric oxide pathway inhibitors (NG-nitro-L-arginine methyl ester + carboxy-PTIO) did not affect persimmon-derived polyphenol-induced vasorelaxation, whereas potassium chloride, tetraethylammonium, and potassium-channel inhibitors did. Vasorelaxation was endothelium independent with both extracts. Phenylephrine-induced vasocontraction was suppressed by pretreatment with PJ and PLs powder, even when inositol triphosphate-mediated Ca²⁺ release and extracellular Ca²⁺ influx were inhibited. These results suggest that persimmon-derived polyphenol phytocomplex cause vasorelaxation and inhibit vasocontraction through hyperpolarization of smooth muscle cells. Persimmon-derived polyphenols may be able to prevent cardiovascular diseases caused by abnormal contraction of blood vessels.

Solid-phase microextraction- probe electrospray ionization devices for screening and quantitating drugs of abuse in small amounts of biofluids

Probe electrospray ionization (PESI) is an ambient ionization mass spectrometry technique (AIMS) that is primarily used in qualitative studies, though researchers have recently combined it with sample preparation for the quantitative analysis of various analytes in biological matrices. This study presents a method that integrates solid-phase microextraction with PESI for direct coupling to a triple quadrupole mass spectrometer, and examines its ability to quantitate drugs of abuse. Intra- and inter-probe reproducibility experiments were conducted to assess the stability and reproducibility of the extraction-phase-coated PESI probes (coating length: 2 mm; coating thickness: 6.5 μm). This research is the first documented instance wherein highly sensitive determinations were successfully attained using these microextraction and micro-desorption techniques in conjunction with small volumes of sample and extraction phase. A mixture consisting of IPA/H₂O (1/1 v/v) + 0.1% FA was determined to be the optimal desorption solvent for SPME-PESI-MS/MS, as it facilitated high analyte enrichment in a picolitre of the solvent, which acted at the same time as efficient electrospray media. Furthermore, a method of quantifying drugs of abuse in 30 μL of plasma without matrix modification was also developed. This method had an intra-day accuracy within the 80-120% range for all eight drugs of abuse at concentrations of 3, 30, and 90 pg μL^-1; the exception to this result was lorazepam at 30 pg μL^-1, which had an intra-day accuracy of 122%. The lower limit of quantification (LLOQ) for fentanyl and nordiazepam was pg μL^-1; the LLOQ for buprenorphine, codeine, diazepam, lorazepam, and propranolol was 5 pg μL^-1; and the LLOQ of oxazepam was 10 pg μL^-1.

Molecularly Imprinted Polymer-Coated Probe Electrospray Ionization Mass Spectrometry Determines Phorbol Esters and Deoxyphorbol Metabolites in Jatropha curcas Leaves

In this study, a molecularly imprinted polymer-coated probe electrospray ionization mass spectrometry (MIPCPESI-MS) method was developed for detection of phorbol esters (PEs) and deoxyphorbol metabolites in Jatropha curcas leaves. Such an approach was established by sticking on a metallic needle a molecularly imprinted polymer to particularly design a MIP-coated probe for selective sampling and ionization of PEs and deoxyphorbol metabolites. By a subsequent application of a high voltage and methanol, as spray solvent, ESI was generated for direct and rapid analysis under ambient and open-air conditions. MIP-coated probe exhibited a high sampling capacity of the PEs and its metabolites in methanolic extracts of J. curcas leaves compared with the non-imprinted polymer (NIP)-coated probe. MIPCPESI-MS allowed the detection of phorbol 12,13-diacetate (PDA) from J. curcas leaves with minimal sample preparation, and with detection limit and quantification reaching 0.28 μg/mL and 0.92 μg/mL, respectively. Also, good linearity was obtained with R² > 0.99 and precision and accuracy values between 4.06-13.49% and - 1.60 to - 15.26%, respectively. The current method was successfully applied to screening methanolic extracts of six different J. curcas leaf genotypes (three toxic and three non-toxic). PDA and three PE deoxyphorbol metabolites were identified only from toxic genotypes, in which PDA was determined with concentration ranging from 222.19 ± 23.55 to 528.23 ± 19.72 μg/g. All these findings support that the MIPCPESI-MS method developed here has a high potential for the analysis of PEs in plant extracts enabling differentiation of toxic and non-toxic genotypes earlier in the leaves.

Organ distribution of diclazepam, pyrazolam and 3-fluorophenmetrazine

The organ distribution of 3-fluorophenmetrazine (3-FPM), pyrazolam, diclazepam as well as its main metabolites delorazepam, lormetazepam and lorazepam, was investigated. A solid phase extraction (SPE) and a QuEChERS (acronym for quick, easy, cheap, effective, rugged and safe) - approach were used for the extraction of the analytes from human tissues, body fluids and stomach contents. The detection was performed on a liquid chromatography-tandem mass spectrometry system (LCMS/MS). The analytes of interest were detected in all body fluids and tissues. Results showed femoral blood concentrations of 10 μg/L for 3-FPM, 28 μg/L for pyrazolam, 1 μg/L for diclazepam, 100 μg/L for delorazepam, 6 μg/L for lormetazepam, and 22 μg/L for lorazepam. Tissues (muscle, kidney and liver) and bile exhibited higher concentrations of the mentioned analytes than in blood. Additional positive findings in femoral blood were for 2-fluoroamphetamine (2-FA, approx. 89 μg/L), 2-flourometamphetamine (2-FMA, hint), methiopropamine (approx. 2.2 μg/L), amphetamine (approx. 21 μg/L) and caffeine (positive). Delorazepam showed the highest ratio of heart (C) and femoral blood (P) concentration (C/P ratio = 2.5), supported by the concentrations detected in psoas muscle (430 μg/kg) and stomach content (approx. 210 μg/L, absolute 84 μg). The C/P ratio indicates that delorazepam displays susceptibility for post-mortem redistribution (PMR), supported by the findings in muscle tissue. 3-FPM, pyrazolam, diclazepam, lorazepam and lormetazepam did apparently not exhibit any PMR. The cause of death, in conjunction with autopsy findings was concluded as a positional asphyxia promoted by poly-drug intoxication by arising from designer benzodiazepines and the presence of synthetic stimulants.

Application of probe electrospray ionization-tandem mass spectrometry to ultra-rapid determination of glufosinate and glyphosate in human serum

Glufosinate and glyphosate, which are non-selective herbicides that include an amino acid moiety in their structures, are frequently used worldwide to control unwanted vegetation. Unfortunately, these readily available herbicides are also used by people to commit suicide, and thus represent important chemicals of interest in the fields of clinical medicine and forensics. Because of the high water solubility of these herbicides, most analytical methods for their detection require a derivatization step, which results in longer analysis times. Therefore, derivatization-based methods do not currently contribute to judgements on treatment decisions in emergency medicine. In this study, we addressed this limiting factor by developing an ultra-rapid and simple analytical technique using a combination of probe electrospray ionization (PESI) and tandem mass spectrometry (MS/MS), which gives quantitative results within 0.3 min. Herbicide standards were added to human serum that was then subjected to analysis (N = 5 per concentration). The analysis was repeated daily over eight consecutive days. The limit of detection (LOD) was 0.59 μg/mL for glufosinate and 0.20 μg/mL for glyphosate. The limit of quantitation (LOQ), i.e., the lowest point on the calibration curves, was 1.56 μg/mL for both the herbicides. The matrix effects were observed at three different concentrations (between 95.7%-104% for glufosinate, and between 90.7%-95.7% for glyphosate). When applied to samples taken from actual poisoning cases (six samples for each herbicide), the present method gave almost the same quantitative values as those obtained by conventional high-performance liquid chromatography with fluorescence detection. Thus, we believe that PESI-MS/MS could emerge as a rapid diagnosis method in the clinical emergency field.

Novel synthetic opioids - toxicological aspects and analysis

Over the past few years, there has been an emerging number of new psychoactive drugs. These drugs are frequently mentioned as "legal highs", "herbal highs", "bath salts" and "research chemicals". They are mostly sold and advertised on online forums and on the dark web. The emerging new psychoactive substances are designed to mimic the effects of psychoactive groups, which are often abused drugs. Novel synthetic opioids are a new trend in this context and represent an alarming threat to public health. Given the wide number of fatalities related to these compounds reported within the last few years, it is an important task to accurately identify these compounds in biologic matrices in order to administer an effective treatment and reverse the respiratory depression caused by opioid related substances. Clinicians dealing with fentanyl intoxication cases should consider that it could, in fact, be a fentanyl analogue. For this reason, it is a helpful recommendation to include synthetic opioids in the routine toxicological screening procedures, including analysis in alternative matrices, if available, to investigate poly-drug use and possible tolerance to opioids. To address this public health problem, better international collaboration, effective legislation, effective investigation, control of suspicious "research chemicals" online forums and continuous community alertness are required. This article aims to review diverse reported fatalities associated with new synthetic opioids describing them in terms of pharmacology, metabolism, posology, available forms, as well as their toxic effects, highlighting the sample procedures and analytical techniques available for their detection and quantification in biological matrices.

An ultra-rapid drug screening method for acetaminophen in blood serum based on probe electrospray ionization-tandem mass spectrometry

Poisoning incidents caused by drugs, accidental ingestion of poisons, attempted suicide, homicide, and exposure to toxic compounds occur frequently every year across the globe. This raises the need to rapidly identify toxic agents in poisoned patients in a clinical emergency setting. In addition, determining drug/poison concentration is undoubtedly necessary to arrive at a toxicological treatment plan. The purpose of this study was to develop an ultra-rapid drug screening method for the clinical treatment of poisoning. Probe electrospray ionization (PESI), one of the ambient ionization techniques, is able to detect compounds from various biological materials almost directly. We applied the PESI technique to the rapid detection of acetaminophen (APAP). Blood serum samples were diluted 100-fold with 10 mM ammonium formate/ethanol (1:1 v/v) solution including deuterium-labeled internal standards (IS; APAP-d4). Only 10 μL of the diluted sample was used for measurement. The tandem mass spectrometer (MS/MS) equipped with a PESI was used in selected reaction monitoring mode for the quantitation of APAP; the measurement time was only 18 s. Transitions were set at 152 > 110 for quantitation, 152 > 65 for qualifier, and 156 > 114 for IS (APAP-d4). All measurements were conducted in positive mode. The calibration curve (1/x²) was linear over the range of 1.56–200 μg/mL (r² = 0.998), and the limit of detection and quantitation were 0.37 μg/mL and 1.56 μg/mL, respectively. The accuracy (bias) and precision (RSD%) of the method were within an acceptable range (−0.15–2.8% and 2.3–6.1%, respectively) and matrix effect at 3 concentrations (95.1–104%) indicated that PESI-MS/MS is only slightly affected by matrices. In real forensic cases, quantitative values of APAP determined by the PESI-MS/MS were almost identical to those determined by the liquid chromatography-MS/MS method. Since PESI-MS/MS is a simple, reliable, and rapid determination method for toxic agents with virtually no need for blood serum pretreatment, it would be highly suitable for poisoning cases in clinical emergency settings. In the future, a method for simultaneous rapid determination of multiple toxic agents will be developed.