Metabolites In Different Matrices Research Articles

2-Fluorodeschloroketamine consumption: About two deaths and a case of self-mutilation.

2-Fluorodeschloroketamine (2-FDCK) is a new psychoactive substance (NPS), close to the ketamine structure. Few cases of 2-FDCK intake are described in the forensic literature, especially concerning death cases. We report here a case of self-mutilation (Case 1) and two forensic deaths linked to 2-FDCK consumption. The second case involved a man found dead in the street, having been stabbed. The third case was a man found dead following a suspected overdose and in an advanced state of putrefaction. For all three cases, biological fluids such as blood and urine were analyzed, as was hair for the two fatal cases. The aim of this study was to identify and quantify 2-FDCK and its main metabolites in different matrices. Biological fluids and hair were analyzed by liquid chromatography coupled with tandem mass spectrometry after decontamination and extraction. Seized products were analyzed by gas chromatography-mass spectrometry and assayed, when possible, by ultra-performance liquid chromatography with diode-array detection. 2-FDCK was detected and quantified in the peripheral blood of Cases 1, 2 and 3 (457, 758 and 5885 µg/L, respectively), as were its main metabolites nor-2-FDCK, dihydro-nor-2-FDCK and dihydro-2-FDCK. In the 1 cm long hair of Cases 2 and 3, 2-FDCK was also detected (approximately 4149 and 79824 pg/mg, respectively). Deschloroketamine (DCK) was found in the biological fluids of Cases 1, 2 and 3 (10, 8 and 350 µg/L, respectively), as well as in hair of Cases 2 and 3 (65 and around 8119 pg/mg, respectively). In Case 3, as a small bag containing DCK powder was seized from his home, we can assume that DCK was taken. On the contrary, to our knowledge, it has not been established that Case 2 took DCK alone, so we can assume that it may be the first case to report DCK from 2-FDCK metabolism in fluids as well as in hair.

Scientific Opinion of the Scientific Panel on Plant Protection Products and their Residues (PPR Panel) on testing and interpretation of comparative in vitro metabolism studies.

EFSA asked the Panel on Plant Protection Products and their residues to deliver a Scientific Opinion on testing and interpretation of comparative in vitro metabolism studies for both new active substances and existing ones. The main aim of comparative in vitro metabolism studies of pesticide active substances is to evaluate whether all significant metabolites formed in the human in vitro test system, as a surrogate of the in vivo situation, are also present at comparable level in animal species tested in toxicological studies and, therefore, if their potential toxicity has been appropriately covered by animal studies. The studies may also help to decide which animal model, with regard to a particular compound, is the most relevant for humans. In the experimental strategy, primary hepatocytes in suspension or culture are recommended since hepatocytes are considered the most representative in vitro system for prediction of in vivo metabolites. The experimental design of 3 × 3 × 3 (concentrations, time points, technical replicates, on pooled hepatocytes) will maximise the chance to identify unique (UHM) and disproportionate (DHM) human metabolites. When DHM and UHM are being assessed, test item‐related radioactivity recovery and metabolite profile are the most important parameters. Subsequently, structural characterisation of the assigned metabolites is performed with appropriate analytical techniques. In toxicological assessment of metabolites, the uncertainty factor approach is the first alternative to testing option, followed by new approach methodologies (QSAR, read‐across, in vitro methods), and only if these fail, in vivo animal toxicity studies may be performed. Knowledge of in vitro metabolites in human and animal hepatocytes would enable toxicological evaluation of all metabolites of concern, and, furthermore, add useful pieces of information for detection and evaluation of metabolites in different matrices (crops, livestock, environment), improve biomonitoring efforts via better toxicokinetic understanding, and ultimately, develop regulatory schemes employing physiologically based or physiology‐mimicking in silico and/or in vitro test systems to anticipate the exposure of humans to potentially hazardous substances in plant protection products.

Insights Into the Prevalence and Impacts of Phthalate Esters in Aquatic Ecosystems

Phthalate esters (PEs) are by far the most produced and extensively used synthetic organic chemicals with notable applications in many industrial products such as vinyl upholstery, adhesives, food containers, packaging materials, printing inks, adhesives, cosmetics, paints, pharmaceuticals munitions, and insecticides among other. PEs have long been recognised as ubiquitous organic pollutants of prime environmental concern, with urbanisation amongst the main cause and source of these compounds. Due to their notoriety, these compounds are known to pose devastating effects to living organisms including humans. The presence of PEs and their metabolites in the aquatic ecosystems is of concern primarily due to their endocrine disrupting and carcinogenicity properties. Several research studies have reported prevalence, exposure pathways, toxicity, and impacts of PEs in aquatic ecosystems and humans. Their principal routes of exposure could be direct or indirect, of which the direct route include contact, eating, and drinking contaminated foods, and the indirect route constitute aerosols, leaching and other forms of environmental contamination. PEs find way into water systems through means such as effluent discharges, urban and agricultural land runoff, leaching from waste dumps and other diffuse sources. High-end instrumentation and improved methodologies on the other hand have resulted in increased ability to measure trace levels (μg/L) of PEs and their metabolites in different matrices and ecological compartments of water or aquatic ecosystems such as lakes, oceans, rivers, sediments, wetlands and drinking water samples. In light of the above, this article provides an informed and focused information on the prevalence of phthalate esters in aquatic systems and related effects on living organisms and humans. Furthermore, techniques that have enabled the extraction and analysis of these PEs in aquatic samples are also explained. Future research outlooks and needs are also highlighted in this manuscript. This information will be used to better understand their temporal and spatial distributions in the aquatic systems and aid in devising prudent means to curtail their ecological footprints.

Enantioselective analysis of venlafaxine and its active metabolites: A review on the separation methodologies.

Venlafaxine (VFX) is a serotonin and norepinephrine reuptake inhibitor chiral drug used in therapy as an antidepressant in the form of a racemate consisting of R- and S-VFX. The two enantiomers of VFX exhibit different pharmacological activities: R-VFX inhibits both norepinephrine and serotonin synaptic reuptake, whereas S-VFX inhibits only the serotonin one. R- and S-VFX are metabolized in the liver to the respective R- and S-O-desmethylvenlafaxine (ODVFX), R- and S-N-desmethylvenlafaxine (NDVFX), and R- and S-N,O-didesmethylvenlafaxine (NODVFX). The pharmacological profile of ODVFX is close to that of VFX, whereas the other two chiral metabolites (NDVFX and NODVFX) have lower affinity for the receptor sites. The pharmacokinetics of the VFX enantiomers appear stereoselective, including the metabolism process. In the past 20 years, several studies describing the enantioselective analysis of R- and S-VFX in pharmaceutical formulations and its chiral metabolites in biological matrices were published. These methods encompass liquid chromatography coupled with UV detection, mass spectrometry, or tandem mass spectrometry, and capillary electrophoresis. This paper reviews the published methods used for the determination of the individual enantiomers of VFX and its chiral metabolites in different matrices.

Electrochemical strategies for the detection of forensic drugs

Illicit drugs consumption and trafficking is spread worldwide and remains an increasing challenge for local authorities. Forensic drugs and their metabolites are released into wastewaters due to human excretion after illegal consumption of drugs and occasionally due to disposal of clandestine laboratory wastes into sewage systems, being recently classified as the latest group of ‘emerging pollutants’. Hence, it is essential to have efficient and accurate methods to detect these type of compounds in seized street samples, biological fluids and wastewaters in order to reduce and prevent trafficking and consumption and negative effects on aquatic systems. Electrochemical strategies offer a fast, portable, low-cost and accurate alternative to chromatographic and spectrometric methods, for the analysis of forensic drugs and metabolites in different matrices. Recent electrochemical strategies applied to the detection of illicit drugs in wastewaters, biological fluids and street samples are presented in this review, together with the impact of drug consumption on the environment.

New Method of Analysis of Nitrofurans and Nitrofuran Metabolites in Different Biological Matrices Using UHPLC-MS/MS.

IntroductionThe major difficulty in analysis of nitrofurans in feed, feed water, and food of animal origin is that nitrofurans have low molecular weights and fast metabolism. The principal goal of this study was to prepare a procedure for the determination of nitrofurans and their metabolites by a single method in different types of feed, feed water, and food of animal origin.Material and MethodsTwo-gram samples were subjected to hydrolysis and derivatisation processes by addition of hydrochloric acid and 2-nitrobenzaldehyde. After incubation the sample was purified by solid phase extraction technique. Nitrofurans were analysed using ultra-high-pressure liquid chromatography-MS/MS (UHPLC-MS/MS).ResultsThe results of validation fulfil the requirement of the confirmatory criteria according to the European Commission Decision 2002/657/EC regarding apparent recoveries (88.9%–107.3%), repeatability (2.9%–9.4%) and within-laboratory reproducibility (4.4%–10.7%).ConclusionThe method can be successfully applied to monitor nitrofurans and their metabolites in different matrices.

Rapid Quantification of Major Volatile Metabolites in Fermented Food and Beverages Using Gas Chromatography-Mass Spectrometry.

Here we present a method for the accurate quantification of major volatile metabolites found in different food and beverages, including ethanol, acetic acid and other aroma compounds, using gas chromatography coupled to mass spectrometry (GC-MS). The method is combined with a simple sample preparation procedure using sodium chloride and anhydrous ethyl acetate. The GC-MS analysis was accomplished within 4.75 min, and over 80 features were detected, of which 40 were positively identified using an in-house and a commercial mass spectrometry (MS) library. We determined different analytical parameters of these metabolites including the limit of detection (LOD), limit of quantitation (LOQ) and range of quantification. In order to validate the method, we also determined detailed analytical characteristics of five major fermentation end products including ethanol, acetic acid, isoamyl alcohol, ethyl-L-lactate and, acetoin. The method showed very low technical variability for the measurements of these metabolites in different matrices (<3%) with an excellent accuracy (100 ± 5%), recovery (100 ± 10%), reproducibility and repeatability [Coefficient of variation (CV) 1–10%)]. To demonstrate the applicability of the method, we analysed different fermented products including balsamic vinegars, sourdough, distilled (whisky) and non-distilled beverages (wine and beer).

Pharmacokinetics, Metabolism, Distribution and Excretion of Carfilzomib in Rats.

Abstract 2754Poster Board II-730 Introduction:Carfilzomib, a tetrapeptide epoxyketone that selectively and irreversibly inhibits the 20S proteasome, has demonstrated a favorable safety profile and anti-tumor efficacy in phase II trials in patients with multiple myeloma [1, 2]. In this study, we characterized the pharmacokinetics (PK), metabolism, distribution and excretion of carfilzomib in Sprague Dawley rats. Methods:In vivo studies were conducted following single intravenous (IV) administrations of carfilzomib to rats. For pharmacokinetic evaluations, plasma samples were collected pre-dose and from 0.1 to 60 minutes post-dose. Biliary excretion was evaluated in bile-duct cannulated rats with bile collection for 8 hours. Urine was collected for 24 hours post-dose for evaluation of renal excretion. Metabolism was studied in plasma, bile and urine samples collected from rats treated with carfilzomib and following in vitro incubations of carfilzomib with hepatocytes and tissue homogenates of lung, heart and kidney from rats. Liquid chromatography with tandem mass spectrometric detection was used in determination of carfilzomib and metabolites in different matrices. Noncompartmental analysis was used in calculation of pharmacokinetic parameters. Results:(1) Carfilzomib was rapidly cleared from the plasma compartment following bolus IV administration with a terminal half life of less than 20 minutes. The plasma clearance was 229, 195 and 296 mL/min/kg, the Cmax (the maximum concentration) was 16.4, 39.3 and 42.9 μM and the AUClast (area under the plasma concentration vs time curve) was 12.6, 28.5 and 37.6 min*μmol/L, at the dose levels of 2, 4 and 8 mg/kg, respectively. At all dose levels, the clearance was much higher than rat hepatic flow. When carfilzomib was given as 30-minute intravenous infusion at 8 mg/kg, the steady state concentration of 1.5 μM was reached within 15 minutes and was 28-fold lower than the Cmax with IV bolus at the equivalent dose. Other PK parameters (clearance, AUC and t1/2) were comparable between bolus and infusion dosing. Rapid and potent proteasome inhibition in blood and tissues (brain excepted) was observed following either bolus or infusion administration, demonstrating wide tissue distribution of carfilzomib. (2) Carfilzomib was rapidly metabolized not only in rat hepatocytes, but also in incubations with tissue homogenates of rat lung, kidney and liver as well as in rat blood, indicating that carfilzomib could be metabolized in tissues and in blood in vivo following IV administration to rats. These results suggested that the high clearance was due to extrahepatic metabolism of carfilzomib in vivo. In plasma, urine and bile collected from rats treated with carfilzomib, as well as in incubations of carfilzomib with rat hepatocytes and tissue homogenates, the most abundant metabolites were found to be peptide fragments and the diol of carfilzomib. These results indicated that peptidase cleavage and epoxide hydrolysis were the principal pathways of metabolism and that P450-mediated mechanisms were not significant in the overall metabolism of carfilzomib. (3) Carfilzomib was eliminated mainly in the form of metabolites following intravenous dosing to rats via renal and biliary excretions. Conclusions:Carfilzomib is rapidly cleared and widely distributed following IV administrations to rats. Metabolism of carfilzomib is mediated by plasma and tissue resident peptidases and epoxide hydrolases. The irreversible mechanism of proteasome inhibition by carfilzomib overcomes clearance mechanisms and enables equivalent proteasome inhibition with both bolus and infusion administration. These data support ongoing efforts to study the effect of infusion administration of carfilzomib in patients with myeloma.[1] S. Jagennath, et al. (2008) Blood 112(11): Abstract #864.[2] R. Vij, et al., (2008) Blood 112(11): Abstract #865. Disclosures:Yang:Proteolix Inc: Employment, Equity Ownership. Fang:Proteolix Inc: Employment, Equity Ownership. Wang:Proteolix, Inc.: Employment, Equity Ownership. Jiang:Proteolix Inc: Employment, Equity Ownership. Muchamuel:Proteolix Inc: Employment, Equity Ownership. Lee:Proteolix, Inc.: Employment, Equity Ownership. Kirk:Proteolix Inc: Employment, Equity Ownership. Zhao:Proteolix Inc: Employment, Equity Ownership. Bennett:Proteolix: Employment, Equity Ownership. Molineaux:Proteolix Inc: Employment, Equity Ownership.

Recent advances in the application of capillary electrophoresis with mass spectrometric detection

This review gives an overview of applications of CE coupled to MS detection published in the literature of the last three years. The works discussed in this paper comprise a wide range of different fields of application. These include important sections such as the analysis of biomolecules, the analysis of pharmaceuticals and their metabolites in different matrices, environmental analysis, and also investigations on the composition of technical products.

The determination of pesticide residues and metabolites using supercritical fluid extraction

Supercritical fluid extraction (SFE) has become a promising alternative technique in the recent years for solid and semi-solid matrices, due to its advantages over classical solvent extraction (especially Soxhlet extraction). This paper briefly presents the strategy for the development of an SFE method, before reviewing the main results concerning pesticides and their metabolites in different matrices.