Detection and identification of the designer benzodiazepine flubromazepam and preliminary data on its metabolism and pharmacokinetics

The appearance of pyrazolam in Internet shops selling ‘research chemicals’ in 2012 marked the beginning of designer benzodiazepines being sold as recreational drugs or ‘self medication’. With recent changes in national narcotics laws in many countries, where two uncontrolled benzodiazepines (phenazepam and etizolam), which were marketed by pharmaceutical companies in some countries, were scheduled, clandestine laboratories seem to turn to poorly characterized research drug candidates as legal substitutes. Following the appearance of pyrazolam, it comes with no surprise that recently, flubromazepam (7‐bromo‐5‐(2‐fluorophenyl)‐1,3‐dihydro‐2H‐1,4‐benzodiazepin‐2‐one), a second designer benzodiazepine, was offered on the market. In this article, this new compound was characterized using nuclear magnetic resonance, gas chromatography‐mass spectrometry (GC–MS), liquid chromatography–mass spectrometry (LC–MS/MS) and liquid chromatography quadrupole time‐of‐flight MS (LC–Q–ToF–MS). Additionally, a study was carried out, in which one of the authors consumed 4 mg of flubromazepam to gain preliminary data on the pharmacokinetic properties and the metabolism of this compound. For this purpose, serum as well as urine samples were collected for up to 31 days post‐ingestion and analyzed applying LC–MS/MS and LC–Q‐ToF‐MS techniques. On the basis of this study, flubromazepam appears to have an extremely long elimination half‐life of more than 100 h. One monohydroxylated compound and the debrominated compound could be identified as the predominant metabolites, the first allowing a detection of a consumption for up to 28 days post‐ingestion when analyzing urine samples in our case. Additionally, various immunochemical assays were evaluated, showing that the cross‐reactivity of the used assay seems not to be sufficient for safe detection of the applied dose in urine samples, bearing the risk that it could be misused in drug‐withdrawal settings or in other circumstances requiring regular drug testing. Furthermore, it may be used in drug‐facilitated crimes without being detected. Copyright © 2013 John Wiley & Sons, Ltd.     

Beobachtungen von Diffusionsprozessen im Schichtensystem Silber-Zinksulfid mit dem Photoemissions-Elektronenmikroskop

By means of the photoemission electron microscope Balzers Metioscope KE 3 the diffusion processes were investigated which occur at elevated temperatures in a system of silver and zincsulfide coatings. At 150 °C the formation of Ag₂S at the surface of the silver film can be seen (high emitting round spots on bright background) and at 240 °C one can observe the diffusion of silver through the zincsulfide film (high emitting small spots on dark background). On heating coagulation process of the silver particles takes place in the boundary zone near the silver layer. With increasing temperatures the mobility of these particles becames high enough to allow them to migrate into the silver layer.     

Conformational adaptation and selective adatom capturing of tetrapyridyl-porphyrin molecules on a copper (111) surface

We present a combined low-temperature scanning tunneling microscopy and near-edge X-ray adsorption fine structure study on the interaction of tetrapyridyl-porphyrin (TPyP) molecules with a Cu(111) surface. A novel approach using data from complementary experimental techniques and charge density calculations allows us to determine the adsorption geometry of TPyP on Cu(111). The molecules are centered on "bridge" sites of the substrate lattice and exhibit a strong deformation involving a saddle-shaped macrocycle distortion as well as considerable rotation and tilting of the meso-substituents. We propose a bonding mechanism based on the pyridyl-surface interaction, which mediates the molecular deformation upon adsorption. Accordingly, a functionalization by pyridyl groups opens up pathways to control the anchoring of large organic molecules on metal surfaces and tune their conformational state. Furthermore, we demonstrate that the affinity of the terminal groups for metal centers permits the selective capture of individual iron atoms at low temperature.     

Self-assembly and conformation of tetrapyridyl-porphyrin molecules on Ag(111)

We present a low-temperature scanning tunneling microscopy (STM) study on the supramolecular ordering of tetrapyridyl-porphyrin (TPyP) molecules on Ag(111). Vapor deposition in a wide substrate temperature range reveals that TPyP molecules easily diffuse and self-assemble into large, highly ordered chiral domains. We identify two mirror-symmetric unit cells, each containing two differently oriented molecules. From an analysis of the respective arrangement it is concluded that lateral intermolecular interactions control the packing of the layer, while its orientation is induced by the coupling to the substrate. This finding is corroborated by molecular mechanics calculations. High-resolution STM images recorded at 15 K allow a direct identification of intramolecular features. This makes it possible to determine the molecular conformation of TPyP on Ag(111). The pyridyl groups are alternately rotated out of the porphyrin plane by an angle of 60 degrees.     

Characterization and in vitro phase I microsomal metabolism of designer benzodiazepines — an update comprising adinazolam,cloniprazepam, fonazepam, 3‐hydroxyphenazepam,metizolam and nitrazolam

Designer benzodiazepines represent an emerging class of new psychoactive substances. While other classes of new psychoactive substances such as cannabinoid receptor agonists and designer stimulants are mainly consumed for hedonistic reasons, designer benzodiazepines may also be consumed as ‘self‐medication’ by persons suffering from anxiety or other psychiatric disorders or as stand‐by ‘antidote’ by users of stimulant and hallucinogenic drugs. In the present study, five benzodiazepines (adinazolam, cloniprazepam, fonazepam, 3‐hydroxyphenazepam and nitrazolam) and one thienodiazepine (metizolam) offered as ‘research chemicals’ on the Internet were characterized and their main in vitro phase I metabolites tentatively identified after incubation with pooled human liver microsomes. For all compounds, the structural formula declared by the vendor was confirmed by nuclear magnetic resonance spectroscopy, gas chromatography–mass spectrometry (MS), liquid chromatography MS/MS and liquid chromatography quadrupole time‐of‐flight MS analysis. The detected in vitro phase I metabolites of adinazolam were N‐desmethyladinazolam and N‐didesmethyladinazolam. Metizolam showed a similar metabolism to other thienodiazepines comprising monohydroxylations and dihydroxylation. Cloniprazepam was metabolized to numerous metabolites with the main metabolic steps being N‐dealkylation, hydroxylation and reduction of the nitro function. It has to be noted that clonazepam is a metabolite of cloniprazepam, which may lead to difficulties when interpreting analytical findings. Nitrazolam and fonazepam both underwent monohydroxylation and reduction of the nitro function. In the case of 3‐OH‐phenazepam, no in vitro phase I metabolites were detected. Formation of licensed benzodiazepines (clonazepam after uptake of cloniprazepam) and the sale of metabolites of prescribed benzodiazepines (fonazepam, identical to norflunitrazepam, and 3‐hydroxyphenazepam) present the risk of incorrect interpretation of analytical findings. Copyright © 2016 John Wiley & Sons, Ltd.     

Identification and structural characterization of the synthetic cannabinoid 3‐(1‐adamantoyl)‐1‐pentylindole as an additive in ‘herbal incense’

Since the end of 2010, more than 20 synthetic cannabimimetics have been identified in ‘Spice’ products, demonstrating the enormous dynamic in this field. In an effort to cope with the problem, many countries have already undertaken legal measures by putting some of these compounds under control. Nevertheless, once a number of compounds were scheduled, they were soon replaced by other synthetic cannabinoids. In this article, we report the identification of a new – and due to its substitution pattern rather uncommon – cannabimimetic found in several ‘herbal incense’ products. The GC–EI mass spectrum first led to misidentification as the alpha‐methyl‐derivative of JWH‐250. However, since both substances show different retention indices, thin‐layer chromatography was used to isolate the unknown compound. After application of nuclear magnetic resonance spectroscopy, high‐resolution MS and GC–MS/MS techniques, the compound was identified as 3‐(1‐adamantoyl)‐1‐pentylindole, a derivative of JWH‐018 carrying an adamantoyl moiety instead of a naphthoyl group. This finding supports that the listing of synthetic cannabinoids as prohibited substances triggers the appearance of compounds with uncommon substituents. Moreover, it emphasizes the necessity of being aware of the risk of misidentification when using techniques sometimes providing only limited structural information like GC–MS. Copyright © 2012 John Wiley & Sons, Ltd.     

In-Situ Growth of Gadolinium Phthalocyaninato Sandwich Complexes on the Ag(111) Surface

We report a low-temperature scanning tunneling microscopy investigation of the in-situ growth of gadolinium phthalocyaninato complexes by combined deposition of free-base phthalocyanines and gadolinium atoms on a smooth Ag(111) substrate. A careful control of the stoichiometry allows the expression of a multilevel structurecomposed of irregularly distributed Gd_x-1(Pc)_x complexes, x=2–5, thus paving new avenues for surface-confined columnar growth.     

Discriminative response of surface-confined metalloporphyrin molecules to carbon and nitrogen monoxide

The binding of small gas molecules to metalloporphyrins is of both fundamental scientific and technological interest. It plays a key role in the transport of respiratory gases, catalytic processes in biological systems, and artificial nanostructures for sensing. Here, we present a detailed molecular-level investigation regarding the interaction of nitrogen monoxide (NO) and carbon monoxide (CO) with metallo-tetraphenylporphyrin (M-TPP, M = Co, Fe) arrays, anchored on a noble metal Ag(111) surface, providing M-TPP species with a distinct saddle-shape conformation. Scanning tunneling microscopy and spectroscopy experiments reveal that the impact of CO and NO is strikingly different on both species. In the case of CO, the M-TPP core can be dressed by either one or two carbon monoxide ligands, whereby the porphyrin geometric and electronic structure remains nearly unaffected. In contrast, following NO exposure exclusively a mononitrosyl species evolves. The NO axial ligation induces a relaxation of the adsorption-induced molecular deformation and markedly modifies the electronic structure of the porphyrin.     

LC/ESI-MS/MS method for quantification of 28 synthetic cannabinoids in neat oral fluid and its application to preliminary studies on their detection windows

Serum and urine samples are commonly used for the analysis of synthetic cannabinoids in biofluids; however, their utilization as analytical matrices for drug abstinence control features some substantial drawbacks. While for blood collection invasive sampling is inevitable, the urinary analysis of synthetic cannabinoids is limited by the lack of available reference standards of the respective major metabolites. Moreover, the long detectability of synthetic cannabinoids in both matrices hampers the identification of a recent synthetic cannabinoid use. This article describes the development, validation and application of an LC/ESI-MS/MS method for the quantification of 28 synthetic cannabinoids in neat oral fluid (OF) samples. OF samples were prepared by protein precipitation using ice-cold acetonitrile. Chromatographic separation was achieved by gradient elution on a Luna Phenyl Hexyl column (50?×?2 mm, 5 μm), while detection was carried out on a QTrap 4000 instrument in positive ionization mode. The limits of detection ranged from 0.02 to 0.40 ng/mL, whereas the lower limits of quantification ranged from 0.2 to 4.0 ng/mL. The method was applied to authentic samples collected during two preliminary studies in order to obtain insights into the general detectability and detection windows of synthetic cannabinoids in this matrix. The results indicate that synthetic cannabinoids are transferred from the blood stream into OF and vice versa only at a very low rate. Therefore, positive OF samples are due to contamination of the oral cavity during smoking. As these drug-contaminations could be detected up to approximately 2 days, neat oral fluid appears to be well suited for detection of a recent synthetic cannabinoid use.