1
|
Ludwig FA, Laurini E, Schmidt J, Pricl S, Deuther-Conrad W, Wünsch B. [ 18F]Fluspidine-A PET Tracer for Imaging of σ 1 Receptors in the Central Nervous System. Pharmaceuticals (Basel) 2024; 17:166. [PMID: 38399380 PMCID: PMC10892410 DOI: 10.3390/ph17020166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Revised: 01/18/2024] [Accepted: 01/25/2024] [Indexed: 02/25/2024] Open
Abstract
σ1 receptors play a crucial role in various neurological and neurodegenerative diseases including pain, psychosis, Alzheimer's disease, and depression. Spirocyclic piperidines represent a promising class of potent σ1 receptor ligands. The relationship between structural modifications and σ1 receptor affinity and selectivity over σ2 receptors led to the 2-fluoroethyl derivative fluspidine (2, Ki = 0.59 nM). Enantiomerically pure (S)-configured fluspidine ((S)-2) was prepared by the enantioselective reduction of the α,β-unsaturated ester 23 with NaBH4 and the enantiomerically pure co-catalyst (S,S)-24. The pharmacokinetic properties of both fluspidine enantiomers (R)-2 and (S)-2 were analyzed in vitro. Molecular dynamics simulations revealed very similar interactions of both fluspidine enantiomers with the σ1 receptor protein, with a strong ionic interaction between the protonated amino moiety of the piperidine ring and the COO- moiety of glutamate 172. The 18F-labeled radiotracers (S)-[18F]2 and (R)-[18F]2 were synthesized in automated syntheses using a TRACERlab FX FN synthesis module. High radiochemical yields and radiochemical purity were achieved. Radiometabolites were not found in the brains of mice, piglets, and rhesus monkeys. While both enantiomers revealed similar initial brain uptake, the slow washout of (R)-[18F]2 indicated a kind of irreversible binding. In the first clinical trial, (S)-[18F]2 was used to visualize σ1 receptors in the brains of patients with major depressive disorder (MDD). This study revealed an increased density of σ1 receptors in cortico-striato-(para)limbic brain regions of MDD patients. The increased density of σ1 receptors correlated with the severity of the depressive symptoms. In an occupancy study with the PET tracer (S)-[18F]2, the selective binding of pridopidine at σ1 receptors in the brain of healthy volunteers and HD patients was shown.
Collapse
Affiliation(s)
- Friedrich-Alexander Ludwig
- Institute of Radiopharmaceutical Cancer Research, Department of Neuroradiopharmaceuticals, Helmholtz-Zentrum Dresden-Rossendorf, D-04318 Leipzig, Germany; (F.-A.L.); (W.D.-C.)
| | - Erik Laurini
- Molecular Biology and Nanotechnology Laboratory (MolBNL@UniTS), DEA, University of Trieste, 34127 Trieste, Italy; (E.L.); (S.P.)
| | - Judith Schmidt
- Institut für Pharmazeutische und Medizinische Chemie, Universität Münster, Corrensstraße 48, D-48149 Münster, Germany;
| | - Sabrina Pricl
- Molecular Biology and Nanotechnology Laboratory (MolBNL@UniTS), DEA, University of Trieste, 34127 Trieste, Italy; (E.L.); (S.P.)
- Department of General Biophysics, Faculty of Biology and Environmental Protection, University of Lodz, 90-136 Lodz, Poland
| | - Winnie Deuther-Conrad
- Institute of Radiopharmaceutical Cancer Research, Department of Neuroradiopharmaceuticals, Helmholtz-Zentrum Dresden-Rossendorf, D-04318 Leipzig, Germany; (F.-A.L.); (W.D.-C.)
| | - Bernhard Wünsch
- Institut für Pharmazeutische und Medizinische Chemie, Universität Münster, Corrensstraße 48, D-48149 Münster, Germany;
- GRK 2515, Chemical Biology of Ion Channels (Chembion), Universität Münster, Corrensstraße 48, D-48149 Münster, Germany
| |
Collapse
|
2
|
Ning C, Rui KH, Wei Y, Shi M. Rh(i)-catalyzed dimerization of ene-vinylidenecyclopropanes for the construction of spiro[4,5]decanes and mechanistic studies. Chem Sci 2022; 13:7310-7317. [PMID: 35799819 PMCID: PMC9214856 DOI: 10.1039/d1sc06986a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Accepted: 05/31/2022] [Indexed: 07/22/2023] Open
Abstract
Rh(i) complex catalyzed dimerization of ene-vinylidenecyclopropanes took place smoothly to construct a series of products containing spiro[4,5]decane skeletons featuring a simple operation procedure, mild reaction conditions, and good functional group tolerance. In this paper, the combination of experimental and computational studies reveals a counterion-assisted Rh(i)-Rh(iii)-Rh(v)-Rh(iii)-Rh(i) catalytic cycle involving tandem oxidative cyclometallation/reductive elimination/selective oxidative addition/selective reductive elimination/reductive elimination steps; in addition, a pentavalent spiro-rhodium intermediate is identified as the key intermediate in this dimerization reaction upon DFT calculation.
Collapse
Affiliation(s)
- Chao Ning
- Key Laboratory for Advanced Materials and Institute of Fine Chemicals, Key Laboratory for Advanced Materials, Feringa Nobel Prize Scientist Joint Research Center, School of Chemistry & Molecular Engineering, East China University of Science and Technology Meilong Road No. 130 Shanghai 200237 China
| | - Kang-Hua Rui
- Key Laboratory for Advanced Materials and Institute of Fine Chemicals, Key Laboratory for Advanced Materials, Feringa Nobel Prize Scientist Joint Research Center, School of Chemistry & Molecular Engineering, East China University of Science and Technology Meilong Road No. 130 Shanghai 200237 China
| | - Yin Wei
- State Key Laboratory of Organometallic Chemistry, Center for Excellence in Molecular Synthesis, University of Chinese Academy of Sciences, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences 345 Lingling Road Shanghai 200032 China
| | - Min Shi
- Key Laboratory for Advanced Materials and Institute of Fine Chemicals, Key Laboratory for Advanced Materials, Feringa Nobel Prize Scientist Joint Research Center, School of Chemistry & Molecular Engineering, East China University of Science and Technology Meilong Road No. 130 Shanghai 200237 China
- State Key Laboratory of Organometallic Chemistry, Center for Excellence in Molecular Synthesis, University of Chinese Academy of Sciences, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences 345 Lingling Road Shanghai 200032 China
| |
Collapse
|
3
|
Bechthold E, Schreiber JA, Ritter N, Grey L, Schepmann D, Daniliuc C, González-Cano R, Nieto FR, Seebohm G, Wünsch B. Synthesis of tropane-based σ1 receptor antagonists with antiallodynic activity. Eur J Med Chem 2022; 230:114113. [DOI: 10.1016/j.ejmech.2022.114113] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 01/08/2022] [Accepted: 01/08/2022] [Indexed: 11/03/2022]
|
4
|
Systematic asymmetric analog synthesis of fluspidine, a σ1 receptor ligand, to improve ligand affinity. Tetrahedron Lett 2021. [DOI: 10.1016/j.tetlet.2021.153250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
5
|
Torres-Gómez H, Daniliuc C, Schepmann D, Laurini E, Pricl S, Wünsch B. Propellanes as Rigid Scaffolds for the Stereodefined Attachment of σ-Pharmacophoric Structural Elements to Achieve σ Affinity. Int J Mol Sci 2021; 22:ijms22115685. [PMID: 34073622 PMCID: PMC8199339 DOI: 10.3390/ijms22115685] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Revised: 05/20/2021] [Accepted: 05/22/2021] [Indexed: 01/07/2023] Open
Abstract
Following the concept of conformationally restriction of ligands to achieve high receptor affinity, we exploited the propellane system as rigid scaffold allowing the stereodefined attachment of various substituents. Three types of ligands were designed, synthesized and pharmacologically evaluated as σ1 receptor ligands. Propellanes with (1) a 2-methoxy-5-methylphenylcarbamate group at the "left" five-membered ring and various amino groups on the "right" side; (2) benzylamino or analogous amino moieties on the "right" side and various substituents at the left five-membered ring and (3) various urea derivatives at one five-membered ring were investigated. The benzylamino substituted carbamate syn,syn-4a showed the highest σ1 affinity within the group of four stereoisomers emphasizing the importance of the stereochemistry. The cyclohexylmethylamine 18 without further substituents at the propellane scaffold revealed unexpectedly high σ1 affinity (Ki = 34 nM) confirming the relevance of the bioisosteric replacement of the benzylamino moiety by the cyclohexylmethylamino moiety. Reduction of the distance between the basic amino moiety and the "left" hydrophobic region by incorporation of the amino moiety into the propellane scaffold resulted in azapropellanes with particular high σ1 affinity. As shown for the propellanamine 18, removal of the carbamate moiety increased the σ1 affinity of 9a (Ki = 17 nM) considerably. Replacement of the basic amino moiety by H-bond forming urea did not lead to potent σ ligands. According to molecular dynamics simulations, both azapropellanes anti-5 and 9a as well as propellane 18 adopt binding poses at the σ1 receptor, which result in energetic values correlating well with their different σ1 affinities. The affinity of the ligands is enthalpy driven. The additional interactions of the carbamate moiety of anti-5 with the σ1 receptor protein cannot compensate the suboptimal orientations of the rigid propellane and its N-benzyl moiety within the σ1 receptor-binding pocket, which explains the higher σ1 affinity of the unsubstituted azapropellane 9a.
Collapse
Affiliation(s)
- Héctor Torres-Gómez
- Department of Chemistry and Pharamcy, Institut für Pharmazeutische und Medizinische Chemie, Westfälische Wilhelms-Universität Münster, Corrensstraße 48, D-48149 Münster, Germany; (H.T.-G.); (D.S.)
| | - Constantin Daniliuc
- Department of Chemistry and Pharamcy, Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, Corrensstraße 40, D-48149 Münster, Germany;
| | - Dirk Schepmann
- Department of Chemistry and Pharamcy, Institut für Pharmazeutische und Medizinische Chemie, Westfälische Wilhelms-Universität Münster, Corrensstraße 48, D-48149 Münster, Germany; (H.T.-G.); (D.S.)
| | - Erik Laurini
- Molecular Biology and Nanotechnology Laboratory (MolBNL@UniTS), Department of Engineering and Architecture, University of Trieste, 34127 Trieste, Italy; (S.P.); (E.L.)
| | - Sabrina Pricl
- Molecular Biology and Nanotechnology Laboratory (MolBNL@UniTS), Department of Engineering and Architecture, University of Trieste, 34127 Trieste, Italy; (S.P.); (E.L.)
- Department of General Biophysics, Faculty of Biology and Environmental Protection, University of Lodz, 90-236 Lodz, Poland
| | - Bernhard Wünsch
- Department of Chemistry and Pharamcy, Institut für Pharmazeutische und Medizinische Chemie, Westfälische Wilhelms-Universität Münster, Corrensstraße 48, D-48149 Münster, Germany; (H.T.-G.); (D.S.)
- GRK 2515, Chemical Biology of Ion Channels (Chembion), Westfälische Wilhelms-Universität Münster, D-48149 Münster, Germany
- Correspondence: ; Tel.: +49-251-833-3311; Fax: +49-251-833-2144
| |
Collapse
|
6
|
Yao H, Wang Y, Razi MK. An asymmetric Salamo-based Zn complex supported on Fe 3O 4 MNPs: a novel heterogeneous nanocatalyst for the silyl protection and deprotection of alcohols under mild conditions. RSC Adv 2021; 11:12614-12625. [PMID: 35423821 PMCID: PMC8696965 DOI: 10.1039/d1ra01185e] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Accepted: 03/12/2021] [Indexed: 12/20/2022] Open
Abstract
In this study, a magnetic asymmetric Salamo-based Zn complex (H2L = salen type di-Schiff bases)-supported on the surface of modified Fe3O4 (Fe3O4@H2L-Zn) as a new catalyst was designed and characterized via numerous analytical techniques such as FT-IR spectroscopy, XRD, EDS, ICP-AES, SEM, TEM, TGA and VSM. An efficient and sustainable synthetic protocol has been presented for the synthesis of silyl ether substructures via the silyl protection of alcohols under mild conditions. The synthetic protocol involves a two-component solvent-free reaction between various hydroxyl-bearing substrates and hexamethyldisilazane (HMDS) as an inexpensive silylating agent using Fe3O4@H2L-Zn MNPs as a magnetically separable, recyclable and reusable heterogeneous catalyst. Fe3O4@H2L-Zn MNPs were also applied for the removal of silyl protecting groups from hydroxyl functions using water in CH2Cl2 under green conditions. The catalyst demonstrated good to excellent catalytic yield efficiency for both the reactions compared to the commercial metal-based catalysts under green conditions for a wide range of substrates.
Collapse
Affiliation(s)
- Hongyan Yao
- Dean's Office, Hebi Polytechnic Hebi 458030 China
| | - Yongsheng Wang
- School of Physical Science Education, Henan Polytechnic University Jiaozuo 454003 China
| | - Maryam Kargar Razi
- Faculty of Chemistry, North Branch of Tehran, Islamic Azad University Tehran Iran
| |
Collapse
|
7
|
Ashraf MA, Liu Z, Li C, Zhang D. Recent advances in catalytic silylation of hydroxyl‐bearing compounds: A green technique for protection of alcohols using Si–O bond formations. Appl Organomet Chem 2020. [DOI: 10.1002/aoc.6131] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Muhammad Aqeel Ashraf
- School of Forestry Henan Agricultural University Zhengzhou 450002 China
- School of Environmental Studies China University of Geosciences Wuhan 430074 China
| | - Zhenling Liu
- School of Management Henan University of Technology Zhengzhou 450001 China
| | - Cheng Li
- School of Forestry Henan Agricultural University Zhengzhou 450002 China
| | - Dangquan Zhang
- School of Forestry Henan Agricultural University Zhengzhou 450002 China
| |
Collapse
|