Qualitative studies on the metabolism and the toxicological detection of the fentanyl-derived designer drugs 3-methylfentanyl and isofentanyl in rats using liquid chromatography-linear ion trap-mass spectrometry (LC-MS(n)).

The opioid 3-methylfentanyl, a designer drug of the fentanyl type, was scheduled by the Controlled Substance Act due to its high potency and abuse potential. To overcome this regulation, isofentanyl, another designer fentanyl, was synthesized in a clandestine laboratory and seized by the German police. The aims of the presented study were to identify the phase I and phase II metabolites of 3-methylfentanyl and isofentanyl in rat urine, to identify the cytochrome P450 (CYP) isoenzymes involved in their initial metabolic steps, and, finally, to test their detectability in urine. Using liquid chromatography (LC)-linear ion trap-mass spectrometry (MS(n)), nine phase I and five phase II metabolites of 3-methylfentanyl and 11 phase I and four phase II metabolites of isofentanyl could be identified. The following metabolic steps could be postulated for both drugs: N-dealkylation followed by hydroxylation of the alkyl and aryl moiety, hydroxylation of the propanamide side chain followed by oxidation to the corresponding carboxylic acid, and, finally, hydroxylation of the benzyl moiety followed by methylation. In addition, N-oxidation of isofentanyl could also be observed. All hydroxy metabolites were partly excreted as glucuronides. Using recombinant human isoenzymes, CYP2C19, CYP2D6, CYP3A4, and CYP3A5 were found to be involved in the initial metabolic steps. Our LC-MS(n) screening approach allowed the detection of 0.01 mg/L of 3-methylfentanyl and isofentanyl in spiked urine. However, in urine of rats after the administration of suspected recreational doses, the parent drugs could not be detected, but their common nor metabolite, which should therefore be the target for urine screening.

Spectroscopic characterization of 3,4-methylenedioxypyrrolidinobutyrophenone: a new designer drug with α-pyrrolidinophenone structure.

This study presents and discusses the infrared spectroscopic, the nuclear magnetic resonance spectroscopic and mass spectrometric data of the designer drug 3,4 methylenedioxypyrrolidinobutyrophenone (MDPBP), a homolog of 3,4 methylenedioxypyrovalerone (MDPV). MDPBP was first seized in Germany in the year 2009. The structure elucidation of the aliphatic part of MDPBP was carried out by product ion spectrometry of the immonium ion with m/z=112 formed after electron ionization, and by one- and two-dimensional (1)H- and (13)C NMR spectroscopy.

New designer drug alpha-pyrrolidinovalerophenone (PVP): studies on its metabolism and toxicological detection in rat urine using gas chromatographic/mass spectrometric techniques.

The aim of the present study was to identify the metabolites of the new designer drug alpha-pyrrolidinovalerophenone (PVP) in rat urine using GC/MS techniques. Eleven metabolites of PVP could be identified suggesting the following metabolic steps: hydroxylation of the side chain followed by dehydrogenation to the corresponding ketone; hydroxylation of the 2''-position of the pyrrolidine ring followed by dehydrogenation to the corresponding lactam or followed by ring opening to the respective aliphatic aldehyde and further oxidation to the respective carboxylic acid; degradation of the pyrrolidine ring to the corresponding primary amine; and hydroxylation of the phenyl ring, most probably in the 4'-position. The authors' screening procedure for pyrrolidinophenones allowed the detection of PVP metabolites after application of a dose corresponding to a presumed user's dose. In addition, the involvement of nine different human cytochrome P450 (CYP) isoenzymes in the side chain hydroxylation of PVP was investigated and CYP 2B6, 2C19, 2D6, and 3A4 were found to catalyze this reaction.

Metabolism and toxicological detection of the designer drug N-(1-phenylcyclohexyl)-3-methoxypropanamine (PCMPA) in rat urine using gas chromatography-mass spectrometry.

Studies on the metabolism and the toxicological detection of the phencyclidine-derived designer drug N-(1-phenylcyclohexyl)-3-methoxypropanamine (PCMPA) in rat urine are described using gas chromatographic-mass spectrometric (GC-MS) techniques. Based on the identified metabolites, the following metabolic pathways could be postulated: N-dealkylation, O-demethylation partially followed by oxidation of the resulting alcohol to the corresponding carboxylic acid, hydroxylation of the cyclohexyl ring at different positions, and aromatic hydroxylation. The formed metabolites were identical to those of the homologue N-(1-phenylcyclohexyl)-3-ethoxypropanamine (PCEPA) with exception of the mono hydroxyl metabolites of PCEPA. All PCMPA metabolites were partially excreted in conjugated form. An intake of a common drug users' dose of PCMPA could be detected in rat urine by the authors' systematic toxicological analysis (STA) procedure using full-scan GC-MS after acid hydrolysis, liquid-liquid extraction and microwave-assisted acetylation. The STA should be suitable for proof of an intake of PCMPA also in human urine assuming similar metabolism.

Metabolism and toxicological detection of a new designer drug, N-(1-phenylcyclohexyl)propanamine, in rat urine using gas chromatography-mass spectrometry.

Studies are described on the metabolism and the toxicological detection of the phencyclidine-derived designer drug N-(1-phenylcyclohexyl)-propanamine (PCPR) in rat urine using gas chromatographic-mass spectrometric techniques. The identified metabolites indicated that PCPR was metabolized by hydroxylation of the cyclohexyl ring at different positions, hydroxylation of the phenyl ring, N-dealkylation, and combinations of these steps. Parts of the metabolites were excreted in conjugated form. The authors' systematic toxicological analysis (STA) procedure using full-scan GC-MS after acid hydrolysis, liquid-liquid extraction and microwave-assisted acetylation allowed the detection of an intake of a common drug users' dose of PCPR in rat urine. Assuming similar metabolism in humans, the STA should be suitable for proof of an intake of PCPR in human urine.

New designer drugs N-(1-phenylcyclohexyl)-2-ethoxyethanamine (PCEEA) and N-(1-phenylcyclohexyl)-2-methoxyethanamine (PCMEA): Studies on their metabolism and toxicological detection in rat urine using gas chromatographic/mass spectrometric techniques.

Studies are described on the metabolism and the toxicological detection of the phencyclidine-derived designer drugs N-(1-phenylcyclohexyl)-2-ethoxyethanamine (PCEEA) and N-(1-phenylcyclohexyl)-2-methoxyethanamine (PCMEA) in rat urine using gas chromatographic/mass spectrometric (GC/MS) techniques. The identified metabolites indicated that PCEEA and PCMEA were transformed to the same metabolites by N-dealkylation and O-dealkylation partially followed by oxidation of the resulting alcohol to the respective carboxylic acid and hydroxylation of the cyclohexyl ring at different positions and combinations of those. Finally, aromatic hydroxylation of the O-dealkylated metabolites was partially followed by hydroxylation of the cyclohexyl ring at different positions. All metabolites were partially excreted in conjugated form. The authors' systematic toxicological analysis (STA) procedure using full-scan GC/MS after acid hydrolysis, liquid-liquid extraction and microwave-assisted acetylation allowed the detection of an intake of a common drug users' dose both of PCEEA and PCMEA in rat urine. Assuming similar metabolism in humans, the STA should be suitable for proof of an intake of PCEEA and PCMEA in human urine, although their differentiation is not possible due to common metabolites.

Determination of delta13 CV-PDB and delta15NAIR values of cocaine from a big seizure in Germany by stable isotope ratio mass spectrometry.

In this study, delta(13)C(V- PDB) and delta(15)N(AIR) values of 132 cocaine samples from a big seizure in Germany in 2002 were determined using elemental analyser isotope ratio mass spectrometry. The 1.2 tons of cocaine were packed in 1 kg packages and the cocaine bricks inside these packages showed certain logos. Twenty different logos could be identified. Results show a large variability among some samples, for delta(15)N(AIR) values ranging from-17 to -2 per thousand. Furthermore, the possibility of linking samples with the same logo was checked. The results show that, in general, there is no relationship between the determined isotope ratio and a certain logo.

Metabolism and toxicological detection of the designer drug 4-iodo-2,5-dimethoxy-amphetamine (DOI) in rat urine using gas chromatography-mass spectrometry.

The amphetamine-derived designer drug 4-iodo-2,5-dimethoxy-amphetamine (DOI) is an upcoming substance on the illicit drug market. In the current study, the identification of its metabolites in rat urine and their toxicological detection in the authors' systematic toxicological analysis (STA) procedure were examined. DOI is extensively metabolized by O-demethylation and beside small amounts of parent compound it was found to be excreted mainly in form of metabolites. The STA procedure using full-scan GC-MS allowed proving an intake of a common drug users' dose of DOI by detection of the two O-demethyl metabolite isomers in rat urine. Assuming similar metabolism, the described STA procedure should be suitable for proof of an intake of DOI in human urine.

Mass spectral and NMR spectral data of two new designer drugs with an alpha-aminophenone structure: 4'-methyl-alpha-pyrrolidinohexanophenone and 4'-methyl-alpha-pyrrolidinobutyrophenone.

This study presents and discusses the nuclear magnetic resonance (NMR) spectroscopic and mass spectroscopic data of the new designer drug 4'-methyl-alpha-pyrrolidinobutyrophenone (MPBP) and its homolog 4'-methyl-alpha-pyrrolidinohexanophenone (MPHP) which were seized in 2004 and 2000 in Germany for the first time. The structure elucidation of the aliphatic part of MPBP was carried out by product ion spectroscopy of the immonium ion formed after electron ionization as well as with 1H and 13C NMR. Product ion spectroscopy of immonium ions again proved to be a powerful tool to determine the structure of designer drugs and to distinguish between isobaric structures of the alkyl-amino moiety.

Studies on the toxicological detection of the designer drug 4-bromo-2,5-dimethoxy-beta-phenethylamine (2C-B) in rat urine using gas chromatography-mass spectrometry.

The phenethylamine-derived designer drug 4-bromo-2,5-dimethoxy-beta-phenethylamine (2C-B) is known to be extensively metabolized in various species including humans. In rat urine, 2C-B was found to be excreted mainly via its metabolites. In the current study, the toxicological detection of these metabolites in the authors' systematic toxicological analysis (STA) procedure was examined. The STA procedure using full-scan GC-MS allowed proving an intake of a common drug abusers' dose of 2C-B by detection of the O-demethyl deaminohydroxy and two isomers of the O-demethyl metabolites in rat urine. Assuming similar metabolism, the described STA procedure should be suitable for proof of an intake of 2C-B in human urine.

New designer drug N-(1-phenylcyclohexyl)-3-ethoxypropanamine (PCEPA): studies on its metabolism and toxicological detection in rat urine using gas chromatographic/mass spectrometric techniques.

Studies are described on the metabolism and toxicological detection of the phencyclidine-derived designer drug N-(1-phenylcyclohexyl)-3-ethoxypropanamine (PCEPA) in rat urine using gas chromatographic/mass spectrometric techniques. The identified metabolites indicated that PCEPA was metabolized by N-dealkylation, O-deethylation partially followed by oxidation of the resulting alcohol to the corresponding carboxylic acid, hydroxylation of the cyclohexyl ring at different positions of PCEPA, N-dealkyl PCEPA, O-deethyl PCEPA, and of the corresponding carboxylic acids. Finally, aromatic hydroxylation of PCEPA, the corresponding carboxylic acids, and O-deethyl PCEPA, the latter partially followed by oxidation to the corresponding carboxylic acid and hydroxylation of the cyclohexyl ring could be observed. All metabolites were partially excreted in the conjugated form. The authors' systematic toxicological analysis (STA) procedure using full-scan GC/MS after acid hydrolysis, liquid-liquid extraction, and microwave-assisted acetylation allowed the detection in rat urine of an intake of a common drug users' dose of PCEPA. Assuming a similar metabolism in humans, the STA in human urine should be suitable as proof of intake of PCEPA.

Designer drug 2,4,5-trimethoxyamphetamine (TMA-2): studies on its metabolism and toxicological detection in rat urine using gas chromatographic/mass spectrometric techniques.

Studies are described on the metabolism and the toxicological detection of the amphetamine-derived designer drug 2,4,5-trimethoxyamphetamine (TMA-2) in rat urine using gas chromatographic/mass spectrometric (GC/MS) techniques. The identified metabolites indicated that TMA-2 was metabolized by oxidative deamination to the corresponding ketone followed by reduction to the corresponding alcohol, O-demethylation followed by oxidative deamination, and finally O,O-bis-demethylation. All metabolites carrying hydroxy groups were found to be partly excreted in urine as glucuronides and/or sulfates. The authors' systematic toxicological analysis (STA) procedure using full-scan GC/MS after acid hydrolysis, liquid-liquid extraction, and microwave-assisted acetylation allowed the detection, in rat urine, of an intake of TMA-2 that corresponds to a common drug users' dose. Assuming similar metabolism, the described STA procedure in human urine should be suitable as proof of an intake of TMA-2.

Designer drugs 2,5-dimethoxy-4-bromo-amphetamine (DOB) and 2,5-dimethoxy-4-bromo-methamphetamine (MDOB): studies on their metabolism and toxicological detection in rat urine using gas chromatographic/mass spectrometric techniques.

Studies are described on the metabolism and the toxicological analysis of the amphetamine-derived designer drug 2,5-dimethoxy-4-bromo-amphetamine (DOB) and its corresponding N-methyl analogue 2,5-dimethoxy-4-bromo-methamphetamine (MDOB) in rat urine using gas chromatographic/mass spectrometric techniques. The identified metabolites indicated that DOB was metabolized by O-demethylation followed by oxidative deamination to the corresponding ketone as well as deamination followed by reduction to the corresponding alcohol. Other metabolic pathways were O,O-bisdemethylation or hydroxylation of the side chain followed by O-demethylation and deamination to the corresponding alcohol. The expected oxo compound after deamination could not be detected. All metabolites carrying hydroxy groups were found to be partly excreted in the conjugated form. MDOB underwent O-demethylation, O,O-bisdemethylation, or hydroxylation of the side chain followed by O-demethylation. Additional N-demethylation to DOB occurred, including the above-mentioned metabolites. Again, all metabolites carrying hydroxy groups were found to be partly excreted in the conjugated form. The authors' systematic toxicological analysis (STA) procedure using full-scan GC/MS after acid hydrolysis, liquid-liquid extraction, and microwave-assisted acetylation allowed the detection of an intake of a dose of DOB and MDOB in rat urine that corresponds to a common drug user's dose. Assuming a similar metabolism, the described STA procedure in human urine should be suitable as proof of an intake of DOB and MDOB.

Studies on the metabolism and toxicological detection of the new designer drug 4'-methyl-alpha-pyrrolidinobutyrophenone (MPBP) in rat urine using gas chromatography-mass spectrometry.

The aim of the presented study was to identify the metabolites of the new designer drug 4'-methyl-alpha-pyrrolidinobutyrophenone (MPBP) in rat urine using GC-MS techniques. After enzymatic hydrolysis, extraction and various derivatizations, seven metabolites of MPBP could be identified suggesting the following metabolic steps: oxidation of the 4'-methyl group to the corresponding alcohol and further oxidation to the respective carboxy compound, hydroxylation of the pyrrolidine ring followed by dehydrogenation to the corresponding lactam or reduction of the keto group to the 1-dihydro compound. A previously published GC-MS-based screening procedure for pyrrolidinophenones involving enzymatic hydrolysis and mixed-mode solid-phase extraction of urine samples allowed detection of MPBP metabolites. Assuming similar metabolism and dosages in humans, an intake of MPBP should be detectable via its metabolites in urine.

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.

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

R,S-4'-Methoxy-alpha-pyrrolidinopropiophenone (MOPPP) 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 MOPPP 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 GC-MS. Analysis of urine samples of rats treated with MOPPP revealed that MOPPP [limit of detection (S/N 3) was 100 ng/ml] was completely metabolized by demethylation of the methoxy group, hydroxylation of the pyrrolidine ring with subsequent dehydrogenation to the corresponding lactam and/or oxidative desamination to the corresponding diketo compounds. To some extent, the demethylated MOPPP metabolites were hydroxylated with partial subsequent methylation in position 3'. The hydroxy groups were found to be partly conjugated. Based on these data, MOPPP could be detected in urine via its metabolites by full-scan GC-MS using MS for screening and library search for identification by comparison of the spectra with reference spectra.

Metabolism and toxicological detection of the new designer drug 3',4'-methylenedioxy-alpha-pyrrolidinopropiophenone studied in urine using gas chromatography-mass spectrometry.

R,S-3',4'-Methylenedioxy-alpha-pyrrolidinopropiophenone (MDPPP) 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 MDPPP 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 GC-MS. Analysis of urine samples of rats treated with MDPPP revealed that MDPPP was completely metabolized by demethylenation of the methylenedioxy group followed by partial 3'-methylation of the resulting catechol, oxidative desamination to the corresponding diketo compounds and/or hydroxylation of the pyrrolidine ring with subsequent dehydrogenation to the corresponding lactam. The hydroxy groups were found to be partly conjugated. Based on these data, MDPPP 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.

New designer drug 4'-methyl-alpha-pyrrolidinohexanophenone: studies on its metabolism and toxicological detection in urine using gas chromatography-mass spectrometry.

R,S-4'-Methyl-alpha-pyrrolidinohexanophenone (MPHP) is a new designer drug which has appeared on the illicit drug market. The aim of this study was to identify the MPHP 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 GC-MS. Analysis of urine samples of rats treated with MPHP revealed that MPHP was completely metabolized by hydroxylation of the tolyl methyl group followed by dehydrogenation to the corresponding carboxylic acid, hydroxylation of the side chain, hydroxylation of the pyrrolidine ring with subsequent dehydrogenation to the corresponding lactam and/or reduction of the keto group. The carboxy and/or hydroxy groups were found to be only partly conjugated. Based on these data, MPHP could be detected in urine via its metabolites by GC-MS using mass chromatography for screening and library search for identification.

Studies on the metabolism and toxicological detection of the new designer drug 4'-methyl-alpha-pyrrolidinopropiophenone in urine using gas chromatography-mass spectrometry.

4'-Methyl-alpha-pyrrolidinopropiophenone (MPPP) is a new designer drug which has appeared on the illicit drug market. The aim of our study was to identify the MPPP metabolites and to develop a toxicological detection procedure in urine using solid-phase extraction, ethylation and GC-MS. In urine samples of rats treated with MPPP, MPPP was found to be completely metabolized by oxidative desamination, hydroxylation of the 4'-methyl group followed by oxidation finally to the corresponding carboxy compound and/or by hydroxylation of the pyrrolidine ring followed by dehydrogenation to the corresponding lactam. The carboxy groups were found to be partly conjugated. Based on these data, MPPP could be detected in urine via its metabolites by GC-MS using mass chromatography for screening and library search for identification.

Studies on the metabolism and toxicological detection of the new designer drug N-benzylpiperazine in urine using gas chromatography-mass spectrometry.

Studies are described on the metabolism and on the toxicological analysis of the piperazine-like designer drug N-benzylpiperazine (BZP, scene name "A2") in rat and human urine using gas chromatography-mass spectrometry (GC-MS). The identified metabolites indicated that BZP was hydroxylated at the aromatic ring and that the piperazine moiety is metabolically degraded. Our systematic toxicological analysis (STA) procedure using full-scan GC-MS after acid hydrolysis, liquid-liquid extraction and microwave-assisted acetylation allowed the detection of the parent compound as well as of the above mentioned metabolites in rat urine after single administration of a dose calculated from the doses commonly taken by drug users. It has also proved to be applicable in authentic clinical or forensic cases. However, it should be considered that BZP is also a metabolite of the medicament piberaline.