9 research outputs found

    Design and cytotoxic evaluation of new annonaceous acetogenin analogues

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    Analogues of annonaceous acetogenins were built up from 5-iodofuran-2-carbaldehyde and undec-10-ynoic acid or undec-10-ynol by a Sonogashira reaction, followed by a Grignard reaction and a mercury catalysed hydratisation. The cytotoxicity was evaluated with MTT assay ((3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide colorimetric assay for measuring cellular proliferation) against HL cells and at the National Cancer Institute (NCI)

    Analysis of 3,4-Methylenedioxymethamphetamine (MDMA) and its Metabolites in Plasma and Urine by HPLC-DAD and GC-MS

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    In Europe, the compound 3,4-methylenedioxymethamphetamine (MDMA, Ecstasy, Adam), in addition to cannabis, is the most abused illicit drug at all-night "techno” parties. Methods for the determination of MDMA and its metabolites, 4-hydroxy-3-methoxymethamphetamine (HMMA), 3,4-dihydroxymethamphetamine (HHMA), 3,4-methylenedioxyamphetamine (MDA), 4-hydroxy-3-methoxyamphetamine (HMA), and 3,4-dihydroxyamphetamine (HHA), in biological fluids were established. Plasma and urine samples were collected from two patients in a controlled clinical study over periods of 9 and 22 h, respectively. MDMA and MDA were determined in plasma and urine by reversed-phase high-performance liquid chromatography with diode array detection (HPLC-DAD) after solid-phase extraction on cation-exchange columns. Acidic or enzymatic hydrolysis was necessary to detect HMMA, HMA, HHMA, and HHA, which are mainly excreted as glucuronides. Gas chromatography-mass spectrometry (GC-MS) was used for confirmation. Sample extraction and on-disc derivatization with heptafluorobutyric anhydride (HFBA) were performed on Toxi-Lab SPEC solid-phase extraction concentrators. After administration of a single oral dose of 1.5 mg/kg body weight MDMA, peak plasma levels of 331 ng/mL MDMA and 15 ng/mL MDA were measured after 2 h and 6.3 h, respectively. Peak concentrations of 28.1 µg/mL MDMA in urine appeared after 21.5 h. Up to 2.3 µg/mL MDA, 35.1 µg/mL HMMA, and 2.1 µg/mL HMA were measured within 16-21.5 h. Conjugated HMMA and HHMA are the main urinary metabolites of MDM

    The EnMAP imaging spectroscopy mission towards operations

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    EnMAP (Environmental Mapping and Analysis Program) is a high-resolution imaging spectroscopy remote sensing mission that was successfully launched on April 1st, 2022. Equipped with a prism-based dual-spectrometer, EnMAP performs observations in the spectral range between 418.2 nm and 2445.5 nm with 224 bands and a high radiometric and spectral accuracy and stability. EnMAP products, with a ground instantaneous field-of-view of 30 m x 30 m at a swath width of 30 km, allow for the qualitative and quantitative analysis of surface variables from frequently and consistently acquired observations on a global scale. This article presents the EnMAP mission and details the activities and results of the Launch and Early Orbit and Commissioning Phases until November 1st, 2022. The mission capabilities and expected performances for the operational Routine Phase are provided for existing and future EnMAP users

    Analysis of 3,4-Methylenedioxymethamphetamine (MDMA) and its Metabolites in Plasma and Urine by HPLC-DAD and GC-MS

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    In Europe, the compound 3,4-methylenedioxymethamphetamine (MDMA, Ecstasy, Adam), in addition to cannabis, is the most abused illicit drug at all-night “techno” parties. Methods for the determination of MDMA and its metabolites, 4-hydroxy-3-methoxymethamphetamine (HMMA), 3,4-dihydroxymethamphetamine (HHMA), 3,4-methylenedioxyamphetamine (MDA), 4-hydroxy-3-methoxyamphetamine (HMA), and 3,4-dihydroxyamphetamine (HHA), in biological fluids were established. Plasma and urine samples were collected from two patients in a controlled clinical study over periods of 9 and 22 h, respectively. MDMA and MDA were determined in plasma and urine by reversed-phase high-performance liquid chromatography with diode array detection (HPLC-DAD) after solid-phase extraction on cation-exchange columns. Acidic or enzymatic hydrolysis was necessary to detect HMMA, HMA, HHMA, and HHA, which are mainly excreted as glucuronides. Gas chromatography-mass spectrometry (GC-MS) was used for confirmation. Sample extraction and on-disc derivatization with heptafluorobutyric anhydride (HFBA) were performed on Toxi-Lab SPEC solid-phase extraction concentrators. After administration of a single oral dose of 1.5 mg/kg body weight MDMA, peak plasma levels of 331 ng/mL MDMA and 15 ng/mL MDA were measured after 2 h and 6.3 h, respectively. Peak concentrations of 28.1 µg/mL MDMA in urine appeared after 21.5 h. Up to 2.3 µg/mL MDA, 35.1 µg/mL HMMA, and 2.1 µg/mL HMA were measured within 16–21.5 h. Conjugated HMMA and HHMA are the main urinary metabolites of MDMA

    Increasing the Efficiency of Ligands for FK506-Binding Protein 51 by Conformational Control

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    The design of efficient ligands remains a key challenge in drug discovery. In the quest for lead-like ligands for the FK506-binding protein 51 (FKBP51), we designed two new classes of bicyclic sulfonamides to probe the contribution of conformational energy in these ligands. The [4.3.1] scaffold had consistently higher affinity compared to the [3.3.1] or monocyclic scaffolds, which could be attributed to better preorganization of two key recognition motifs. Surprisingly, the binding of the rigid [4.3.1] scaffold was enthalpy-driven and entropically disfavored compared to the flexible analogues. Cocrystal structures at atomic resolution revealed that the sulfonamide nitrogen in the bicyclic scaffolds can accept an unusual hydrogen bond from Tyr(113) that mimics the putative FKBP transition state. This resulted in the first lead-like, functionally active ligand for FKBP51. Our work exemplifies how atom-efficient ligands can be achieved by careful conformational control even in very open and thus difficult binding sites such as FKBP51

    Increasing the Efficiency of Ligands for FK506-Binding Protein 51 by Conformational Control

    No full text
    The design of efficient ligands remains a key challenge in drug discovery. In the quest for lead-like ligands for the FK506-binding protein 51 (FKBP51), we designed two new classes of bicyclic sulfonamides to probe the contribution of conformational energy in these ligands. The [4.3.1] scaffold had consistently higher affinity compared to the [3.3.1] or monocyclic scaffolds, which could be attributed to better preorganization of two key recognition motifs. Surprisingly, the binding of the rigid [4.3.1] scaffold was enthalpy-driven and entropically disfavored compared to the flexible analogues. Cocrystal structures at atomic resolution revealed that the sulfonamide nitrogen in the bicyclic scaffolds can accept an unusual hydrogen bond from Tyr<sup>113</sup> that mimics the putative FKBP transition state. This resulted in the first lead-like, functionally active ligand for FKBP51. Our work exemplifies how atom-efficient ligands can be achieved by careful conformational control even in very open and thus difficult binding sites such as FKBP51

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    V. Anhang

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