Systemic availability of lipophilic organic UV filters through dermal sunscreen exposure.

BACKGROUND: Chemical UV filters are common components in sunscreens and cosmetic products and used to protect the skin against harmful effects of sunlight like sunburn. However, the effectiveness of sunscreens in the prevention of skin cancer is in some parts still controversial. Meanwhile, questions about negative effects of the chemical UV filters on human health arise and request an effective risk assessment. Real-life exposure data in humans after application of these products are still rare. Thus, we explored whether and to what extent UV filters are absorbed through the skin into the human body. MATERIAL AND METHODS: Plasma and urine samples from 20 healthy volunteers were collected before, during and after a real-life exposure scenario (1st application: 2 mg/cm2; 2nd and 3rd (after 2 and 4 h): 1 mg/cm2 each) using a commercial sunscreen formulation for one day. These samples were analyzed for their content of the currently prominent UV filters octocrylene and avobenzone as well as 2-cyano-3,3-diphenylacrylic acid (CDAA) as the main octocrylene metabolite by using different liquid chromatography electrospray-ionization tandem mass spectrometric procedures. RESULTS: Following dermal sunscreen exposure, avobenzone, octocrylene and CDAA reached concentrations up to 11 µg/L, 25 µg/L and 1352 µg/L in plasma. In urine detection rates of avobenzone and octocrylene were low while CDAA showed a high detection rate and reached up to 5207 µg/g creatinine. Kinetic models could be fitted for octocrylene and CDAA in plasma and CDAA in urine. Concentration peaks were reached between 10 and 16 h after first application and half-life periods were in the range of 1.5 to 2 days. The lipophilic UV filter octocrylene and its metabolite CDAA showed a much slower elimination than other more hydrophilic UV filters. Concordantly, the metabolite CDAA in particular showed a markedly increased renal excretion over the whole sampling period and indicated high internal exposure to OC. DISCUSSION: Real-life sunscreen usage leads to considerable bioavailability of organic UV filters and their metabolites which is rarely seen for other environmental exposures. A combined monitoring of the parent compound and its metabolites is important to fully address internal exposure to the UV filter in humans. Considering the kinetic profiles a prolonged systemic release due to depot formation in skin and a potential accumulation through multi-day exposure is presumed. High in-vivo loads call for a critical toxicological assessment of the UV filters and their metabolites.

Quantification of prominent organic UV filters and their metabolites in human urine and plasma samples.

Monitoring human exposure to chemical UV filters is essential for an accurate assessment of the health risk caused by the resorbed compounds. We developed different procedures for the determination of the prominent UV filters octocrylene (OC), avobenzone (AVO) and 2-ethylhexyl salicylate (EHS) as well as for two OC and EHS metabolites in human urine and OC, AVO and 2-cyano-3,3-diphenylacrylic acid (CDAA) in plasma samples using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Since the development of a multi-method for all analytes proved to be difficult, three different procedures were established for the determination of AVO, OC and its metabolite CDAA in urine and plasma as well as for EHS and its metabolite 5-hydroxy-EHS in urine. The methods have been validated with good sensitivity, precision and accuracy. The procedures were satisfactorily applied to the determination of the target compounds in human samples collected from volunteers after sunscreen application. These new analytical procedures can provide information on the internal exposure to the UV filters OC, AVO and EHS, which has been little studied.

Detection of legal highs in the urine of methadone-treated patient by LC-MS.

Urine tests are the commonly accepted methods to control abstinence and adherence to treatment of patients who undergo methadone maintenance treatment (MMT). Depending on various national guidelines and accessibility of techniques, only selected psychoactive substances are routinely tested in urine of MMT patients. In general, they belong to the few groups of compounds: THC, cocaine, amphetamines, opiates, PCP and benzodiazepines. It is, however, well known that patients enrolled in such replacement programmes take psychoactive substances that are not routinely detected by the toxicology laboratories, to escape unexpected tests. Here, we report semiquantitative detection of legal highs taken by the MMT patient, using high-pressure liquid chromatography coupled to the flowing atmospheric pressure afterglow ion source (LC-FAPA-MS). To demonstrate effectivity of this technique, the data were confirmed by quantitative analysis using LC-ESI-MS/MS. In the analysed sample of MMT patient, a mixture of psychoactive compounds was found, namely 3-MMC (3-methylmethcathinone), pentedrone and methcathinone and determined at the concentrations of 670; 50 and 0.2 µg/mL, respectively. Such fast analytical technique may be useful for the efficient control of substances taken intentionally by MMT patients.

A Fatality Involving Furanylfentanyl and MMMP, with Presumptive Identification of Three MMMP Metabolites in Urine.

The prevalence of new psychoactive substances (NPS) on the illicit drug market continues to grow, with new analogs being routinely synthesized. Routes of administration for these compounds are also diversifying, and recent research has shown an increase in the incorporation of NPS into vaping liquids. Among the most commonly encountered NPS are the cathinone and fentanyl analogs. Fentanyl analogs in particular have been implicated in a significant number of deaths, usually in combination with other prescription and illicit drugs. We report the case of a 44-year-old male with a history of polysubstance abuse found deceased at his home address. Items located within the vicinity of the deceased were found to contain furanylfentanyl and 2-methyl-4'-(methylthio)-2-morpholinopropiophenone (MMMP also known as MTMP, MMTMP, Irgacure 907 and Caccure 907). Both of these compounds were detected in the post-mortem peripheral blood of the deceased: furanylfentanyl at 1.6 ng/mL and MMMP at 6.7 ng/mL. MMMP is an unrestricted, commercially available photo-initiator used in the printing and polymer industry, which structurally can be classed as a highly modified cathinone. Although MMMP has been found previously in drug seizures, this is the first fatality in which MMMP has been detected. A number of other prescription and illicit drugs were also detected in the blood. MMMP was not detected in the post-mortem urine; however three metabolites, beta-hydroxy-MMMP, beta-hydroxy-MMMP-sulfoxide and beta-hydroxy-MMMP-sulfone, were presumptively identified. The significance of MMMP to the cause of death is uncertain as its pharmacological and toxicological profile is unclear.

[Determination of Methcathinone in Urine by GC-MS].

OBJECTIVES: To establish a method for the analysis of methcathinone in urine by gas chromatography-mass spectrometry （GC-MS）. METHODS: Proadifen hydrochloride （internal standard） and buffer solution （pH=9） were added into the urine samples, and methcathinone was extracted by ethyl acetate. The extract was volatilized in 50 ℃ nitrogen gas flow and the remnant was dissolved by methanol and analysed by GC-MS. RESULTS: The methcathinone in urine showed a good linear relationship in the mass concentration range of 0.02-2.00 µg/mL. The linear equation was y=0.301 9 x+0.018 9 （r=0.999 2）, and the detection limit was 0.01 µg/mL. The recoveries of methcathinone in urine was 96.4%-99.2%, with the intra-day precision of 5.8%-7.6% and the inter-day precision of 6.0%-8.1%. CONCLUSIONS: The method is convenient and sensitive, which can be applied to the forensic identification of methcathinone in urine.

Portable kit for identification and detection of drugs in human urine using surface-enhanced Raman spectroscopy.

A portable kit was demonstrated for rapid and reliable surface-enhanced Raman scattering (SERS) detection of drugs in human urine. This kit contains two sealed reagent tubes, a packet of standardized SERS substrates, and a mini Raman device. A 3 min pretreatment for separating amphetamines from human urine was developed with an extraction rate of >80% examined by ultraperformance liquid chromatography (UPLC). Simultaneously, highly reproducible two-dimensional (2D) gold nanorod (GNR) arrays were assembled by the use of methoxymercaptopoly(ethylene glycol) (mPEG-SH) capping. Thirty batches of GNR arrays produced the 1001 cm(-1) intensity of methamphetamine (MA) molecules with a relative standard deviation (RSD) of 7.9%, and a 21 × 21 µm(2) area mapping on a 2D GNR array produced a statistical RSD of <10%, implying an excellent reproducibility and uniformity. The detection limit of amphetamines in human urine was at least 0.1 ppm. Moreover, the portable kit was successfully used for detecting MA, 3,4-methylenedioxymethamphetamine (MDMA), and methcathinone (MC) in 30 volunteers' urine samples with various clinical natures, and the dual-analyte detection of MA and MDMA implied a good capability of multiplex analysis. UPLC examination and the SERS recovery test clearly indicated that our pretreatment procedure was sufficient to lower the high background signals caused by complex components in urine and demonstrated the practicability and the resistance to false positives, which is a vital problem for law enforcement applications. The excellent performance of our portable kit promises a great prospective toward a rapid, reliable, and on-spot analyzer, especially for public safety and healthcare.

Metabolism of the designer drug α-pyrrolidinobutiophenone (α-PBP) in humans: identification and quantification of the phase I metabolites in urine.

Urinary phase I metabolites of α-pyrrolidinobutiophenone (α-PBP) in humans were investigated by analyzing urine specimens obtained from drug abusers. Unequivocal identification and accurate quantification of major metabolites were realized using gas chromatography-mass spectrometry and liquid chromatography-tandem mass spectrometry with newly synthesized authentic standards. Two major phase I metabolic pathways were revealed: (1) reduction of the ketone group to 1-phenyl-2-(pyrrolidin-1-yl)butan-1-ol (OH-α-PBP, diastereomers) partly followed by conjugation to its glucuronide and (2) oxidation at the 2″-position of the pyrrolidine ring to α-(2″-oxo-pyrrolidino)butiophenone (2″-oxo-α-PBP) via the putative intermediate α-(2″-hydroxypyrrolidino)butiophenone (2″-OH-α-PBP). Of the phase I metabolites retaining the structural characteristics of the parent drug, OH-α-PBP was the most abundant in all specimens examined. Comparison of the phase I metabolism of α-PBP and α-pyrrolidinovalerophenone (α-PVP) suggested a relationship between the aliphatic side chain length and the metabolic pathways in α-pyrrolidinophenones: the shorter aliphatic side chain (1) led to more extensive metabolism via reduction of the ketone group than via the oxidation at the 2″-position of the pyrrolidine ring and (2) influenced the isomeric ratio of a pair of diastereomers.

Elucidation of the metabolites of the novel psychoactive substance 4-methyl-N-ethyl-cathinone (4-MEC) in human urine and pooled liver microsomes by GC-MS and LC-HR-MS/MS techniques and of its detectability by GC-MS or LC-MS(n) standard screening approaches.

4-methyl-N-ethcathinone (4-MEC), the N-ethyl homologue of mephedrone, is a novel psychoactive substance of the beta-keto amphetamine (cathinone) group. The aim of the present work was to study the phase I and phase II metabolism of 4-MEC in human urine as well as in pooled human liver microsome (pHLM) incubations. The urine samples were worked up with and without enzymatic cleavage, the pHLM incubations by simple deproteinization. The metabolites were separated and identified by gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-high resolution-tandem mass spectrometry (LC-HR-MS/MS). Based on the metabolites identified in urine and/or pHLM, the following metabolic pathways could be proposed: reduction of the keto group, N-deethylation, hydroxylation of the 4-methyl group followed by further oxidation to the corresponding 4-carboxy metabolite, and combinations of these steps. Glucuronidation could only be observed for the hydroxy metabolite. These pathways were similar to those described for the N-methyl homologue mephedrone and other related drugs. In pHLM, all phase I metabolites with the exception of the N-deethyl-dihydro isomers and the 4-carboxy-dihydro metabolite could be confirmed. Glucuronides could not be formed under the applied conditions. Although the taken dose was not clear, an intake of 4-MEC should be detectable in urine by the GC-MS and LC-MS(n) standard urine screening approaches at least after overdose.

Analytical condition setting a crucial step in the quantification of unstable polyphenols in acidic conditions: analyzing prenylflavanoids in biological samples by liquid chromatography-electrospray ionization triple quadruple mass spectrometry.

The interest in studying hops and beer prenylflavanoids, isoxanthohumol, xanthohumol, and 8-prenylnaringenin, has increased in recent years due to their biological activity as strong phytoestrogens and potent cancer chemopreventive agents. However, prenylflavanoids behave differently from most polyphenols, since they are unstable at acidic pH. To our knowledge, no published studies to date have considered the degradation of these compounds during analytical processes. In the present work, a new sensitive and specific method based on solid phase extraction and liquid chromatography coupled to electrospray ionization triple quadruple mass spectrometry (LC-ESI-MS/MS) was developed and validated. The new method was optimized to avoid degradation of the selected analytes, isoxanthohumol, xanthohumol, and 8-prenylnaringenin, throughout the analytical process and to reduce the urine matrix effect in LC-ESI-MS/MS assays. It was concluded that a neutral pH (pH 7.0) is necessary for the analysis of prenylflavanoids, in order to maintain the stability of compounds for at least 24 h. The addition of ascorbic acid to the media improved stability, calibration curves, coefficients of correlation, accuracy, and precision parameters. Mix-mode cation exchange sorbent yielded the best matrix effect factors and recoveries. Method validation results showed appropriate intraday and interday accuracy and precision (<15%). Recovery of isoxanthohumol, xanthohumol, and 8-prenylnaringenin was 97.1% ± 0.03, 105.8% ± 0.05, and 105.4% ± 0.04, respectively, and matrix effect factors were nearly 100%. The stability assay showed that analytes were stable for at least 24 h. The method was applied to quantify 10 human samples of urine and was able to quantify prenylflavanoids in urine after the consumption of a single dose of beer (330 mL).

Simultaneous determination of 4-substituted cathinones (4-MMC, 4-MEC and 4-FMC) in human urine by HPLC-DAD.

This study developed a selective and rapid high-performance liquid chromatography-diode array detection method for the confirmation of different cathinone derivates in human urine. Samples were prepared by solid-phase extraction (SPE) using procaine hydrochloride as the internal standard. The chromatographic separation was performed on a Kinetex PFP column using isocratic elution. The mobile phase was composed of a mixture of acetonitrile (33%, v/v) and 0.005M ammonium trifluoroacetate buffer (67%, v/v; pH 4.93 ± 0.03) with a flow rate of 0.350 mL/min. The diode array detection was performed at 262 nm. The method was linear over the concentration range of 25-2,400 ng/mL. Intra-day and inter-day precision values for cathinones were less than 1.26% (relative standard deviation). The limit of detection for any compounds extracted from human urine by the optimized SPE method was 40 ng/mL and the limit of quantification was 100 ng/mL in the urine. The recovery rate of SPE was between 71 and 82% with a lower relative standard deviation than 2.35%.

Psychosis from a bath salt product containing flephedrone and MDPV with serum, urine, and product quantification.

INTRODUCTION: The use of designer drugs commonly marketed as bath salts or plant food has risen dramatically in recent years. Several different synthetic cathinones have been indentified in these products, including mephedrone, 3,4-methylenedioxypyrovalerone (MDPV), and 4-fluoromethcathinone (flephedrone). We report a case of bath salt intoxication with quantitative MDPV and flephedrone levels in a patient's serum and urine, and from the bath salt product. CASE REPORT: A 23-year-old male with a prior psychiatric history arrived via EMS for bizarre behavior, suicidality, and hallucinations after reportedly insufflating a bath salt. He was found to have MDPV levels of 186 and 136 ng/mL in his serum and urine, respectively, and flephedrone levels of 346 and 257 ng/mL in the serum and urine, respectively. The white powder in question was found to contain 143 µg MDPV and 142 µg flephedrone per milligram powder. His psychosis and agitation resolved with lorazepam, droperidol, and observation in the emergency department. DISCUSSION: Agitation, psychosis, movement disorders, tachycardia, and hypertension have all been attributed to the use of MDPV; there are no prior reports detailing clinical experience with flephedrone. Considering that our patient's serum flephedrone levels were twofold higher than his MDPV level, it is likely flephedrone contributed to his clinical toxicity. This case suggests the possibility that fluorinated cathinones, such as flephedrone, may have altered metabolism and/or elimination which may affect their course of clinical toxicity. This case highlights the evolving composition of synthetic cathinones found in bath salt products.

New cathinone-derived designer drugs 3-bromomethcathinone and 3-fluoromethcathinone: studies on their metabolism in rat urine and human liver microsomes using GC-MS and LC-high-resolution MS and their detectability in urine.

3-Bromomethcathinone (3-BMC) and 3-Fluoromethcathinone (3-FMC) are two new designer drugs, which were seized in Israel during 2009 and had also appeared on the illicit drug market in Germany. These two compounds were sold via the Internet as so-called "bath salts" or "plant feeders." The aim of the present study was to identify for the first time the 3-BMC and 3-FMC Phase I and II metabolites in rat urine and human liver microsomes using GC-MS and LC-high-resolution MS (HR-MS) and to test for their detectability by established urine screening approaches using GC-MS or LC-MS. Furthermore, the human cytochrome-P450 (CYP) isoenzymes responsible for the main metabolic steps were studied to highlight possible risks of consumption due to drug-drug interaction or genetic variations. For the first aim, rat urine samples were extracted after and without enzymatic cleavage of conjugates. The metabolites were separated and identified by GC-MS and by LC-HR-MS. The main metabolic steps were N-demethylation, reduction of the keto group to the corresponding alcohol, hydroxylation of the aromatic system and combinations of these steps. The elemental composition of the metabolites identified by GC-MS could be confirmed by LC-HR-MS. Furthermore, corresponding Phase II metabolites were identified using the LC-HR-MS approach. For both compounds, detection in rat urine was possible within the authors' systematic toxicological analysis using both GC-MS and LC-MS(n) after a suspected recreational users dose. Following CYP enzyme kinetic studies, CYP2B6 was the most relevant enzyme for both the N-demethylation of 3-BMC and 3-FMC after in vitro-in vivo extrapolation.

Doping control analysis of metamfepramone and two major metabolites using liquid chromatography-tandem mass spectrometry.

The sympathomimetic agent metamfepramone (2-dimethylamino-1-phenylpropan-1-one, dimethylpropion) is widely used for the treatment of the common cold or hypotonic conditions. Due to its stimulating properties and its rapid metabolism resulting in major degradation products such as methylpseudoephedrine and methcathinone, it has been considered relevant for doping controls by the World Anti-Doping Agency (WADA). The rapid degradation of the active drug complicates the detection of metamfepramone itself but the metabolites methylpseudoephedrine and methcathinone can be monitored, and the finding of the latter in particular allows the inference of a metamfepramone administration. In order to improve sports drug testing procedures, metamfepramone, methylpseudoephedrine and methcathinone were characterized using electrospray ionization-high resolution/high accuracy mass spectrometry, and a method employing liquid chromatography/tandem mass spectrometry was established that allowed the analysis of these three analytes by direct injection of 2 microL of urine specimens. The assay was validated with regard to specificity, lower limits of detection (2-10 ng mL(-1)), intraday and interday precision (3-17%) and ion suppression/enhancement effects. The developed procedure has been used to verify or falsify suspicious signals observed in routine screening procedures based on gas chromatography/mass spectrometry and yielded an adverse analytical finding concerning a metamfepramone administration in an authentic doping control sample. Although the active drug was not detected, the indicative metabolites methylpseudoephedrine and methcathinone were considered sufficient to infer the application of the prohibited drug.

Rapid GC-MS confirmation of amphetamines in urine by extractive acylation.

Amphetamine and related derivatives are widely abused central- and psychostimulants. Detection of certain derivatives, such as methcathinone, by commonly available immunoassay screening techniques is insufficient. Multi-analyte confirmations for amphetamine type stimulants are therefore required, but traditional gas chromatography-mass spectrometry methods necessitate lengthy analytical procedures with prolonged sample turn-around times. A validated rapid GC-MS assay for urinary confirmation of amphetamine, methamphetamine, methcathinone, ephedrine, norephedrine, methylenedioxyamphetamine, methylenedioxymethamphetamine, methylenedioxyethylamphetamine and N-methyl-1-(3,4 methylenedioxyphenyl)-2-butanamine is reported. The method entailed in situ derivatization of urine specimens by extractive acylation with pentafluoropropionic anhydride, followed by rapid chromatography on a microbore capillary column. Analytes were separated in less than 3 min and quantified simultaneously by selected-ion monitoring using stable isotope substituted internal standards. The total instrument cycle-time was 6 min per sample. The limits of detection were between 1.5 ng/mL and 6.25 ng/mL for the various analytes. Intermediate precision and accuracy were in the range of 6.3-13.8% and 90.5-107.3% for the respective analytes at the lower limit of quantitation, and between 5.8-12.6% and 95.4-103.1% for the high control. Long-term storage of methcathinone positive specimens at -20 degrees C proved insufficient stability of this analyte. The proposed assay is precise and accurate for confirmation of amphetamine and derivatives in urine. The complementary approach of extractive-derivatization and fast GC-MS analysis is especially applicable in routine clinical settings where reduced sample turn-around times are required. Further investigation of cathinone as a possible metabolite of methcathinone is warranted, based on results from analyzed authentic urine samples.

Qualitative confirmation procedure for ephedrines as acetonide derivatives in doping urine samples by gas chromatography/electron ionization mass spectrometry.

Ephedrines are sympathomimetic amines which have central nervous system stimulating properties and, for this reason, some of them are forbidden in sport by the World Antidoping Agency (WADA). They are screened and quantitated in urine by several published techniques and confirmed by gas chromatography/mass spectrometry (GC/MS). In this paper, a simple and easy confirmation procedure for norpseudoephedrine, norephedrine, ephedrine and pseudoephedrine in human urine by GC/electron ionization (EI)-MS is described. After the addition of diphenylamine as internal standard, a liquid-liquid extraction procedure under alkaline conditions with tert-butyl methyl ether was applied to the samples. The analytes were derivatized with acetone and pyridine to form the correspondent oxazolidine derivatives (acetonide). The EI mass spectra of all the studied substances have many diagnostic ions with relative abundance in accordance with WADA requirements and show great structural information content. The fragmentation of theses derivatives is discussed.

Microbial and dietary factors associated with the 8-prenylnaringenin producer phenotype: a dietary intervention trial with fifty healthy post-menopausal Caucasian women.

Hop-derived food supplements and beers contain the prenylflavonoids xanthohumol (X), isoxanthohumol (IX) and the very potent phyto-oestrogen (plant-derived oestrogen mimic) 8-prenylnaringenin (8-PN). The weakly oestrogenic IX can be bioactivated via O-demethylation to 8-PN. Since IX usually predominates over 8-PN, human subjects may be exposed to increased doses of 8-PN. A dietary intervention trial with fifty healthy post-menopausal Caucasian women was undertaken. After a 4 d washout period, participants delivered faeces, blank urine and breath samples. Next, they started a 5 d treatment with hop-based supplements that were administered three times per d and on the last day, a 24 h urine sample was collected. A semi-quantitative FFQ was used to estimate fat, fibre, alcohol, caffeine and theobromine intakes. The recoveries of IX, 8-PN and X in the urine were low and considerable inter-individual variations were observed. A five-fold increase in the dosage of IX without change in 8-PN concentration resulted in a significant lower IX recovery and a higher 8-PN recovery. Classification of the subjects into poor (60%), moderate (25%) and strong (15%) 8-PN producers based on either urinary excretion or microbial bioactivation capacity gave comparable results. Recent antibiotic therapy seemed to affect the 8-PN production negatively. A positive trend between methane excretion and 8-PN production was observed. Strong 8-PN producers consumed less alcohol and had a higher theobromine intake. From this study we conclude that in vivo O-demethylation of IX increases the oestrogenic potency of hop-derived products.

Metabolism of the recently encountered designer drug, methylone, in humans and rats.

The urinary metabolites of methylone in humans and rats were investigated by analysing urine specimens from its abuser and after administrating to rats with gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-electrospray ionization mass spectrometry (LC-ESI MS), using authentic standards. The time-course excretion profiles of methylone and its three metabolites in rats were further investigated after a single intraperitoneal dosing of 5 mg kg-1 methylone hydrochloride. Two major metabolic pathways were revealed for both humans and rats as follows: (1) side-chain degradation by N-demethylation to the corresponding primary amine methylenedioxycathinone (MDC), partly conjugated; and (2) demethylenation followed by O-methylation of either a 3- or 4-OH group on the benzene ring to produce 4-hydroxy-3-methoxymethcathinone (HMMC) or 3-hydroxy-4-methoxymethcathinone (3-OH-4-MeO-MC), respectively, mostly conjugated. Of these metabolites, HMMC was the most abundant in humans and rats. The cumulative amount of urinary HMMC excreted within the first 48 h in rats was approximately 26% of the dose, and the amount of the parent methylone was not more than 3%. These results demonstrate that the analysis of HMMC will be indispensable for proof of the use of methylone in forensic urinalysis.

High-performance liquid chromatographic determination of xanthohumol in rat plasma, urine, and fecal samples.

Xanthohumol (XN) is the major prenylated flavonoid in hop plants and as such a constituent of beer. Pharmacological studies have shown that XN possesses marked antioxidant and antiproliferative effects. In order to study the resorption and metabolism of this compound, reversed-phase high-performance liquid chromatography is used for the determination of XN in rat plasma, urine, and feces. In session one, rats receive either oral or intravenous (iv) administration (20 mg/kg body weight) of XN. In session two, rats receive oral administration of 50, 100, 200, 400, and 500 mg/kg body weight XN for bioavailability studies at various dose levels. Plasma, urine, and feces are collected at varying time points and assayed for their XN content. Plasma levels of XN fell rapidly within 60 min after iv administration; no XN is detected in plasma after oral administration in either session. XN and its metabolites are excreted mainly in feces within 24 h of administration. The method is a reliable tool for performing studies of XN in different biological material.

Metabolism of the new designer drug alpha-pyrrolidinopropiophenone (PPP) and the toxicological detection of PPP and 4'-methyl-alpha-pyrrolidinopropiophenone (MPPP) studied in rat urine using gas chromatography-mass spectrometry.

R,S-alpha-pyrrolidinopropiophenone (PPP) is a new designer drug with assumed amphetamine-like effects which has appeared on the illicit drug market. The aim of this study was to identify the PPP metabolites using solid-phase extraction, ethylation or acetylation as well as to develop a toxicological detection procedure in urine using solid-phase extraction, trimethylsilylation and gas chromatography-mass spectrometry (GC-MS). Analysis of urine samples of rats treated with PPP revealed that PPP was extensively metabolized by hydroxylation of the pyrrolidine ring with subsequent dehydrogenation to the corresponding lactam, hydroxylation of the aromatic ring in position 4' or double dealkylation of the pyrrolidine ring to the corresponding primary amine (cathinone) partly followed by reduction of the keto group to the corresponding secondary alcohol (norephedrines). As cathinone and the norephedrine diastereomers are also formed after intake of other drugs of abuse or medicaments, special attention must be paid to the detection of the unequivocal metabolite 2"-oxo-PPP as an unambiguous proof for the intake of PPP. The hydroxy groups were found to be partly conjugated. Based on these data, PPP could be detected in urine via its metabolites by full-scan GC-MS using mass chromatography for screening and library search for identification by comparison of the spectra with reference spectra. The same toxicological detection procedure can be applied to other designer drugs of the pyrrolidinophenone type, like MOPPP, MDPPP, MPHP, and MPPP. The detection of the latter will also be presented here.