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262 results on '"Henriksen, Gjermund"'

4. Optimization of a Nucleophilic Two-Step Radiosynthesis of 6- O -(2-[ 18 F]fluoroethyl)-6- O -desmethyl-diprenorphine ([ 18 F]FE-DPN) for PET Imaging of Brain Opioid Receptors.

Author

Németh, Enikő, Gyuricza, Barbara, Forgács, Viktória, Cumming, Paul, Henriksen, Gjermund, Marton, János, Bauer, Beate, Mikecz, Pál, and Fekete, Anikó

Subjects
POSITRON emission tomography, BRAIN imaging, OPIOID receptors, RADIOCHEMICAL purification
Abstract

We have established a method for nucleophilic one-pot, two-step radiosynthesis of the popular opioid receptor radioligand 6-O-(2-[18F]fluoroethyl)-6-O-desmethyl-diprenorphine ([18F]FE-DPN) from the novel precursor 6-O-(2-tosyloxyethyl)-6-O-desmethyl- 3-O-trityl-diprenorphine (TE-TDDPN), which we designate as the Henriksen precursor. We undertook an optimization of the synthesis conditions, aiming to enhance the accessibility of [18F]FE-DPN for positron emission tomography (PET) studies of μ-opioid receptors. Herein, we report an optimized direct nucleophilic 18F-fluorination and the deprotection conditions for a fully automated radiosynthesis of [18F]FE-DPN on a modified GE Tracerlab FX FE synthesis panel. Starting from 1–1.5 GBq of [18F]fluoride and applying an Oasis Max 1cc cartridge for fluorine-18 trapping with a reduced amount of K2CO3 (5.06 μmol K+ ion), [18F]FE-DPN ([18F]11) was produced with 44.5 ± 10.6 RCY (decay-corrected), high radiochemical purity (>99%), and a molar activity of 32.2 ± 11.8 GBq/μmol in 60–65 min. [ABSTRACT FROM AUTHOR]

Published
2023
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5. 6-O-(2-[18F]Fluoroethyl)-6-O-Desmethyl-Diprenorphine ([18F]FE-DPN) Preferentially Binds to Mu Opioid Receptors In Vivo

Author

Levinstein, Marjorie R., primary, Ventriglia, Emilya N., additional, Gomez, Juan L., additional, Budinich, Reece C., additional, Marton, János, additional, Henriksen, Gjermund, additional, Holt, Daniel P., additional, Dannals, Robert F., additional, Pomper, Martin G., additional, Zarate, Carlos A., additional, Bonaventura, Jordi, additional, and Michaelides, Michael, additional

Published
2022
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6. Diels-Alder Adducts of Morphinan-6,8-Dienes and Their Transformations

Author

Marton, János, Fekete, Anikó, Cumming, Paul, Hosztafi, Sándor, Mikecz, Pál, and Henriksen, Gjermund

Subjects
Analgesics, Morphine, Naloxone, Organic Chemistry, Receptors, Opioid, mu, Pharmaceutical Science, 610 Medicine & health, Analytical Chemistry, Analgesics, Opioid, Morphinans, Chemistry (miscellaneous), Drug Discovery, Receptors, Opioid, Molecular Medicine, Physical and Theoretical Chemistry
Abstract

6,14-ethenomorphinans are semisynthetic opiate derivatives containing an ethylene bridge between positions 6 and 14 in ring-C of the morphine skeleton that imparts a rigid molecular structure. These compounds represent an important family of opioid receptor ligands in which the 6,14-etheno bridged structural motif originates from a [4 + 2] cycloaddition of morphinan-6,8-dienes with dienophiles. Certain 6,14-ethenomorphinans having extremely high affinity for opioid receptors are often non-selective for opioid receptor subtypes, but this view is now undergoing some revision. The agonist 20R-etorphine and 20R-dihydroetorphine are several thousand times more potent analgesics than morphine, whereas diprenorphine is a high-affinity non-selective antagonist. The partial agonist buprenorphine is used as an analgesic in the management of post-operative pain or in substitution therapy for opiate addiction, sometimes in combination with the non-selective antagonist naloxone. In the context of the current opioid crisis, we communicated a summary of several decades of work toward generating opioid analgesics with lesser side effects or abuse potential. Our summary placed a focus on Diels–Alder reactions of morphinan-6,8-dienes and subsequent transformations of the cycloadducts. We also summarized the pharmacological aspects of radiolabeled 6,14-ethenomorphinans used in molecular imaging of opioid receptors.

Published
2022
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7. 6-O-(2-[18F]Fluoroethyl)-6-O-Desmethyl-Diprenorphine ([18F]FE-DPN) Preferentially Binds to Mu Opioid Receptors In Vivo.

Author

Levinstein, Marjorie R., Ventriglia, Emilya N., Gomez, Juan L., Budinich, Reece C., Marton, János, Henriksen, Gjermund, Holt, Daniel P., Dannals, Robert F., Pomper, Martin G., Zarate Jr, Carlos A., Bonaventura, Jordi, and Michaelides, Michael

Subjects
OPIOID receptors, RADIOACTIVE tracers, POSITRON emission tomography, BRAIN physiology, NUCLEOPHILIC reactions
Abstract

Purpose: 6-O-(2-[18F]Fluoroethyl)-6-O-desmethyl-diprenorphine ([18F]FE-DPN) is regarded as a non-selective opioid receptor radiotracer. Procedure: Here, we report the first characterization of [18F]FE-DPN synthesized from the novel precursor, 6-O-(2-tosyloxyethoxy)-6-O-desmethyl-3-O-trityl-diprenorphine (TE-TDDPN), using a one-pot, two-step nucleophilic radiosynthesis to image opioid receptors in rats and mice using positron emission tomography. Results: We also show that [18F]FE-DPN and [3H]DPN exhibit negligible brain uptake in mu opioid receptor (MOR) knockout mice. Conclusions: Taken together with prior findings, our results suggest that [18F]FE-DPN and [3H]DPN preferentially bind to MOR in rodents in vivo. [ABSTRACT FROM AUTHOR]

Published
2023
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12. 4-Anilidopiperidine Derivatives for in vivo Imaging of μ-Opioid Receptors

Author

Marton Janos, Berenyi Sandor, Henriksen Gjermund, Glaenzel Brita, and Sipos Attila

Subjects
Thesaurus (information retrieval), Opioid, Chemistry, Organic Chemistry, medicine, 4-anilidopiperidine, Receptor, Biochemistry, Neuroscience, Preclinical imaging, medicine.drug
Abstract

A method for gram scale preparation of 2-fluoropropionyl-carfentanil was established, starting from 4-phenylamino-1-benzyl-4-piperidinecarboxylic acid. 2-Fluoropropionyl-carfentanil carboxylic acid and 2-chloropropionyl-carfentanil as precursors were synthesized for the radiosynthesis of 11C and/or 18F labelled 2-fluoropropionyl-carfentanil derivatives via two separate reaction routes. Conformational analysis of 2-fluoropropionyl-carfentanil was performed using computational methods. Calculated 1H and 13C-NMR shifts are presented.

Published
2020
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13. Two-pot Oxidative Preparation of Dicarboxylic Acid Containing Cellulose for the Removal of Beryllium (Be2+) from Aqueous Solution

Author

Cumming Paul, Li Jiping, M. Siddeeg Saifeldin, Katoch Ashish, Alam Intyaz, Fan Mingliang, A. Tahoon Mohamed, Singh Manjinder, Tolga Özdemir Vedat, Yayayürük Onur, Mert Tuğaç Himmet, Aggarwal Geeta, Arar Özgür, Kumar Kashyap Pankaj, Kaur Malkiet, B. Rebah Faouzi, Shabbir Muhamad, Kumar Sushil, Verma Sonia, Mangipudi Parthasarathi, Henriksen Gjermund, Yadav Arvind, Arora Monika, Marton Janos, Baranwal Somesh, Bauer Beate, S. Alsaiari Norah, Erdem Yayayürük Aslı, Arora Dhingra Gitika, Kumar Pradeep, Nagpal Manju, Ratan Ram, and Singh Pathania Akashdeep

Subjects
chemistry.chemical_classification, Behavior, Aqueous solution, chemistry.chemical_element, Water, Oxidative phosphorylation, water treatment, Analytical Chemistry, chemistry.chemical_compound, Dicarboxylic acid, chemistry, biopolymer, regeneration, cellulose diacetate, Sorption, ion-exchange, Beryllium, Cellulose, Biosorbents, Nuclear chemistry
Abstract

Background: Cellulose is one of the most abundant, non-toxic, and renewable natural biopolymers. The presence of hydroxyl groups in cellulose leads to further modification of it. Preparation and modification of cellulose-based sorbents and their applications on water treatment gained traction in recent years. Objective: A low-cost and eco-friendly biosorbent was designed and fabricated by introducing the acetate functional groups into cellulose for removing Beryllium (Be2+) from an aqueous solution. The sorption of Be2+ on acetate containing cellulose was evaluated for varying sorbent doses and initial solution pH values. Methods: The sorbent was prepared by a two-step oxidation process. In the initial step, cellulose reacted with NaIO4 and aldehyde groups were introduced to the cellulose. In the second step, newly obtained aldehyde groups were oxidized to create acetate groups. Results: The kinetics of the sorption process showed that Be2+ uptake reached equilibrium in 3 minutes. The sorption isotherm was well fitted in the Langmuir model, and the maximum sorption capacity was 4.54 mg/g. Moreover, the thermodynamic studies demonstrated that Be2+ sorption was spontaneous and exothermic. Furthermore, the prepared sorbent can be regenerated by using 0.1 M HCl or H2SO4 solutions. Conclusion: It is concluded that the removal of Be2+ is pH-dependent and it is favorable at high solution pH. The kinetics of the prepared sorbent were rapid and equilibrium attained in 3 minutes. The prepared sorbent can be regenerated with 0.1 M acid solution with > 99% efficiency., Ege University Scientific Re-search Projects Coordination Unit [FLP-2018-20310], This study is supported by Ege University Scientific Re-search Projects Coordination Unit (Project Number: FLP-2018-20310) .

Published
2022

20. A new precursor for the radiosynthesis of 6-o-(2-[18F]fluoroethyl)-6-odesmethyl-diprenorphine ([18F]FE-DPN) by nucleophilic radiofluorination

Author

Marton, János, Cumming, Paul, Bauer, Beate, Henriksen, Gjermund, Marton, János, Cumming, Paul, Bauer, Beate, and Henriksen, Gjermund

Abstract

We present the preparation of the new precursor 6-O-(2-tosyloxyethoxy)-6-O-desmethyl-3O-trityl-diprenorphine (TE-TDDPN) for a one-pot, two-step nucleophilic radiosynthesis of 6-O-(2[18F]fluoroethyl-6-O-desmethyl-diprenorphine ([18F]FE-DPN). The route to the precursor consists of a five-step synthesis starting from diprenorphine. We also provide alternative synthesis routes for the cold reference standard and the complete1H-and13C-NMR assignment of the prepared derivatives.

Published
2021

38. Enhancement of Astroglial Aerobic Glycolysis by Extracellular Lactate-Mediated Increase in cAMP

Author

Vardjan, Nina, Chowdhury, Helena H., Horvat, Anemari, Velebit, Jelena, Malnar, Maja, Muhič, Marko, Kreft, Marko, Krivec, Špela G., Bobnar, Saša T., Miš, Katarina, Pirkmajer, Sergej, Offermanns, Stefan, Henriksen, Gjermund, Storm-mathisen, Jon, Bergersen, Linda H., Zorec, Robert, Vardjan, Nina, Chowdhury, Helena H., Horvat, Anemari, Velebit, Jelena, Malnar, Maja, Muhič, Marko, Kreft, Marko, Krivec, Špela G., Bobnar, Saša T., Miš, Katarina, Pirkmajer, Sergej, Offermanns, Stefan, Henriksen, Gjermund, Storm-mathisen, Jon, Bergersen, Linda H., and Zorec, Robert

Published
2018

40. Enhancement of Astroglial Aerobic Glycolysis by Extracellular Lactate-Mediated Increase in cAMP

Author

Vardjan, Nina, primary, Chowdhury, Helena H., additional, Horvat, Anemari, additional, Velebit, Jelena, additional, Malnar, Maja, additional, Muhič, Marko, additional, Kreft, Marko, additional, Krivec, Špela G., additional, Bobnar, Saša T., additional, Miš, Katarina, additional, Pirkmajer, Sergej, additional, Offermanns, Stefan, additional, Henriksen, Gjermund, additional, Storm-Mathisen, Jon, additional, Bergersen, Linda H., additional, and Zorec, Robert, additional

Published
2018
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41. A New Precursor for the Radiosynthesis of 6-O-(2-[18F]Fluoroethyl)-6-Odesmethyl- diprenorphine ([18F]FE-DPN) by Nucleophilic Radiofluorination

Author

Marton, János, Cumming, Paul, Bauer, Beate, and Henriksen, Gjermund

Abstract

We present the preparation of the new precursor 6-O-(2-tosyloxyethoxy)-6-O-desmethyl-3- O-trityl-diprenorphine (TE-TDDPN) for a one-pot, two-step nucleophilic radiosynthesis of 6-O-(2- [18F]fluoroethyl-6-O-desmethyl-diprenorphine ([18F]FE-DPN). The route to the precursor consists of a five-step synthesis starting from diprenorphine. We also provide alternative synthesis routes for the cold reference standard and the complete 1H- and 13C-NMR assignment of the prepared derivatives.

Published
2021
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43. FIBT versus florbetaben and PiB: a preclinical comparison study with amyloid-PET in transgenic mice

Author

Yousefi, Behrooz H., von Reutern, Boris, Scheruebl, Daniela, Manook, Andre, Schwaiger, Markus, Grimmer, Timo, Henriksen, Gjermund, Foerster, Stefan, Drzezga, Alexander, Wester, Hans-Juergen, Yousefi, Behrooz H., von Reutern, Boris, Scheruebl, Daniela, Manook, Andre, Schwaiger, Markus, Grimmer, Timo, Henriksen, Gjermund, Foerster, Stefan, Drzezga, Alexander, and Wester, Hans-Juergen

Abstract

Background: Over the last decade, an increasing number of studies have been published on the use of amyloid-beta (A beta) PET imaging with different F-18-radiopharmaceuticals for clinical characterization of Alzheimer's disease (AD) in different stages. However, distinct study cohorts and different quantification techniques allow only for an indirect comparison between the different tracers. Thus, the aim of this study was the direct intra-individual in vivo comparison of different A beta-targeted radiopharmaceuticals for PET imaging, including the newly developed agent [F-18]FIBT. Methods: A small group of four animals of a well-characterized APP/PS1 transgenic (tg) mouse model of AD and gender-matched control (ctl) animals underwent a sequential and standardized PET imaging regimen for direct comparison of [F-18]FIBT, [F-18]florbetaben, and [C-11]PiB. The quantitative PET imaging data were cross-validated with the cerebral A beta plaque load as quantified ex vivo on histological sections. Results: We found that FIBT (2-(p-methylaminophenyl)-7-(2-[F-18] fluoroethoxy) imidazo[2,1-b]benzothiazole) compares favorably to florbetaben as a high-contrasting PET radiopharmaceutical for imaging A beta pathology. The excellent pharmacokinetics of FIBT in combination with its high-binding affinity towards A beta resulted in feasible high-contrast imaging of A beta with high global cortex to cerebellum standard uptake value ratio (SUVR) in 24-month-old tg mice (tg 1.68 +/- 0.15 vs. ctl 0.95 +/- 0.02). The SUVRs in transgenic versus control animals (SUVRtg/SUVRctl) for FIBT (1.78 +/- 0.16) were similar to the ratios as observed in humans (SUVRAD/SUVRctl) for the established gold standard Pittsburgh compound B (PiB) (1.65 +/- 0.41). Conclusions: This head-to-head PET tracer comparison study in mice indicated the good imaging properties of [F-18]FIBT, such as high initial brain uptake, fast clearance of the brain, and high binding affinity towards A beta as directly compared to t

Published
2015

45. Comparison of [11C]Choline ([11C]CHO) and S(+)-β-Methyl-[11C]Choline ([11C]SMC) as Imaging Probes for Prostate Cancer in a PC-3 Prostate Cancer Xenograft Model

Author

Schwarzenböck, Sarah Marie, primary, Gertz, Jana, additional, Souvatzoglou, Michael, additional, Kurth, Jens, additional, Sachs, David, additional, Nawroth, Roman, additional, Treiber, Uwe, additional, Schuster, Tibor, additional, Senekowitsch-Schmidtke, Reingard, additional, Schwaiger, Markus, additional, Ziegler, Sibylle Ilse, additional, Henriksen, Gjermund, additional, Wester, Hans-Jürgen, additional, and Krause, Bernd Joachim, additional

Published
2014
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46. Synthesis and Evaluation of Three Structurally Related 18F-Labeled Orvinols of Different Intrinsic Activities: 6-O-[18F]Fluoroethyl-diprenorphine ([18F]FDPN), 6-O-[18F]Fluoroethyl-buprenorphine ([18F]FBPN), and 6-O-[18F]Fluoroethyl-phenethyl-orvinol ([18F]FPEO)

Author

Schoultz, Bent W., primary, Hjørnevik, Trine, additional, Reed, Brian J., additional, Marton, János, additional, Coello, Christopher S., additional, Willoch, Frode, additional, and Henriksen, Gjermund, additional

Published
2014
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47. Voxel-Based Analysis of Amyloid-Burden Measured with [C-11]PiB PET in a Double Transgenic Mouse Model of Alzheimer's Disease

Author

von Reutern, Boris, Gruenecker, Barbara, Yousefi, Behrooz H., Henriksen, Gjermund, Czisch, Michael, Drzezga, Alexander, von Reutern, Boris, Gruenecker, Barbara, Yousefi, Behrooz H., Henriksen, Gjermund, Czisch, Michael, and Drzezga, Alexander

Abstract

The purpose of this study is to validate the feasibility of a voxel-based analysis of in vivo amyloid-beta positron emission tomography (PET) imaging studies in transgenic mouse models of Alzheimer's disease. We performed [C-11]PiB PET imaging in 20 APP/PS1 mice and 16 age-matched controls, and histologically determined the individual amyloid-beta plaque load. Using SPM software, we performed a voxel-based group comparison plus a regression analysis between PiB retention and actual plaque load, both thresholded at p (FWE) < 0.05. In addition, we carried out an individual ROI analysis in every animal. The automated voxel-based group comparison allowed us to identify voxels with significantly increased PiB retention in the cortical and hippocampal regions in transgenic animals compared to controls. The voxel-based regression analysis revealed a significant association between this signal increase and the actual cerebral plaque load. The validity of these results was corroborated by the individual ROI-based analysis. Voxel-based analysis of in vivo amyloid-beta PET imaging studies in mouse models of Alzheimer's disease is feasible and allows studying the PiB retention patterns in whole brain maps. Furthermore, the selected approach in our study also allowed us to establish a quantitative relation between tracer retention and actual plaque pathology in the brain in a voxel-wise manner.

Published
2013

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