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Tada T, Mizuno Y, Shibata Y, Yasui H, Kuge Y. Application of copper (I) selective ligands for PET imaging of reactive oxygen species through metabolic trapping. Nucl Med Biol 2024; 134-135:108914. [PMID: 38733873 DOI: 10.1016/j.nucmedbio.2024.108914] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Revised: 03/29/2024] [Accepted: 04/24/2024] [Indexed: 05/13/2024]
Abstract
INTRODUCTION Reactive oxygen species (ROS) are attractive targets for clinical PET imaging. In this study, we hypothesized that PET imaging of ROS would be possible by using chelating ligands (L) that form stable complexes with copper (I) but not with copper (II), based on metabolic trapping. Namely, when [64Cu][CuI(L)2]+ is oxidized by ROS, the oxidized complex will release [64Cu]Cu2+. Then, the released [64Cu]Cu2+ will be trapped inside the cell, resulting in PET signal depending on the redox potential of ROS. To examine the potential of this novel molecular design for ROS imaging, we synthesized copper (I) complexes with bicinchoninic acid (BCA) disodium salt and bathocuproinedisulfonic acid (BCS) disodium salt and evaluated their reactivity with several kinds of ROS. In addition, the cellular uptake of [64Cu][CuI(BCS)2]3- and the stability of [64Cu][CuI(BCS)2]3- in a biological condition were also evaluated. METHODS [64Cu]Cu2+ was reduced to [64Cu]Cu+ by ascorbic acid and coordinated with BCA and BCS in the acetate buffer to synthesize [64Cu][CuI(BCA)2]3- and [64Cu][CuI(BCS)2]3-. The radiochemical yields were determined by thin-layer chromatography (TLC). After [64Cu][CuI(BCS)2]3- was incubated with hydroxyl radical, lipid peroxide, superoxide, and hydrogen peroxide, the percentage of released [64Cu]Cu2+ from the parent complex was evaluated by TLC. HT-1080 human fibrosarcoma cells were treated with 0.1 % Dimethyl sulfoxide (control), imidazole ketone erastin (IKE), or IKE + ferrostatin-1 (Fer-1). Then, the uptake of [64Cu][CuI(BCS)2]3- to HT-1080 cells in each group was evaluated as %Dose/mg protein. Lastly, [64Cu][CuI(BCS)2]3- was incubated in human plasma, and its intact ratio was determined by TLC. RESULTS The radiochemical yield of [64Cu][CuI(BCS)2]3- (86 ± 1 %) was higher than that of [64Cu][CuI(BCA)2]3- (44 ± 3 %). [64Cu][CuI(BCA)2]3- was unstable and partially decomposed on TLC. After [64Cu][CuI(BCS)2]3- was reacted with hydroxyl radical, lipid peroxide, and superoxide, 67 ± 2 %, 44 ± 13 %, and 22 ± 3 % of total radioactivity was detected as [64Cu]Cu2+, respectively. On the other hand, the reaction with hydrogen peroxide did not significantly increase the ratio of [64Cu]Cu2+ (4 ± 1 %). These results suggest that [64Cu][CuI(BCS)2]3- could be used for detecting high-redox-potential ROS such as hydroxyl radical and lipid peroxide with high selectivity. The cellular uptake values of [64Cu][CuI(BCS)2]3- in the control, IKE, and Fer-1 group were 42 ± 2, 54 ± 2, and 47 ± 5 %Dose/mg protein (n = 3), respectively, suggesting the ROS specific uptake of [64Cu][CuI(BCS)2]3-. On the other hand, the intact ratio after the incubation of [64Cu][CuI(BCS)2]3- in human plasma was 9 ± 5 %. CONCLUSION PET imaging of ROS would be possible by using a copper (I) selective ligand, based on metabolic trapping. Although improvement of the membrane permeability and the stability of copper (I) complexes is required, the present results pave the way for the development of novel 64Cu-labeled complexes for PET imaging of ROS.
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Affiliation(s)
- Tetsuro Tada
- Graduate School of Biomedical Science and Engineering, Hokkaido University, Hokkaido 060-0815, Japan
| | - Yuki Mizuno
- Central Institute of Isotope Science, Hokkaido University, Hokkaido 060-0815, Japan; Global Center for Biomedical Science and Engineering, Hokkaido University, Hokkaido 060-0815, Japan.
| | - Yuki Shibata
- Central Institute of Isotope Science, Hokkaido University, Hokkaido 060-0815, Japan
| | - Hironobu Yasui
- Faculty of Veterinary Medicine, Hokkaido University, Hokkaido 060-0818, Japan; One Health Research Center, Hokkaido University, Hokkaido 060-0818, Japan
| | - Yuji Kuge
- Central Institute of Isotope Science, Hokkaido University, Hokkaido 060-0815, Japan; Global Center for Biomedical Science and Engineering, Hokkaido University, Hokkaido 060-0815, Japan
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Tosato M, Franchi S, Isse AA, Del Vecchio A, Zanoni G, Alker A, Asti M, Gyr T, Di Marco V, Mäcke H. Is Smaller Better? Cu 2+/Cu + Coordination Chemistry and Copper-64 Radiochemical Investigation of a 1,4,7-Triazacyclononane-Based Sulfur-Rich Chelator. Inorg Chem 2023; 62:20621-20633. [PMID: 37115633 PMCID: PMC10731632 DOI: 10.1021/acs.inorgchem.3c00621] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Indexed: 04/29/2023]
Abstract
The biologically triggered reduction of Cu2+ to Cu+ has been postulated as a possible in vivo decomplexation pathway in 64/67Cu-based radiopharmaceuticals. In an attempt to hinder this phenomenon, we have previously developed a family of S-containing polyazamacrocycles based on 12-, 13-, or 14-membered tetraaza rings able to stabilize both oxidation states. However, despite the high thermodynamic stability of the resulting Cu2+/+ complexes, a marked [64Cu]Cu2+ release was detected in human serum, likely as a result of the partially saturated coordination sphere around the copper center. In the present work, a new hexadentate macrocyclic ligand, 1,4,7-tris[2-(methylsulfanyl)ethyl)]-1,4,7-triazacyclononane (NO3S), was synthesized by hypothesizing that a smaller macrocyclic backbone could thwart the observed demetalation by fully encapsulating the copper ion. To unveil the role of the S donors in the metal binding, the corresponding alkyl analogue 1,4,7-tris-n-butyl-1,4,7-triazacyclononane (TACN-n-Bu) was considered as comparison. The acid-base properties of the free ligands and the kinetic, thermodynamic, and structural properties of their Cu2+ and Cu+ complexes were investigated in solution and solid (crystal) states through a combination of spectroscopic and electrochemical techniques. The formation of two stable mononuclear species was detected in aqueous solution for both ligands. The pCu2+ value for NO3S at physiological pH was 6 orders of magnitude higher than that computed for TACN-n-Bu, pointing out the significant stabilizing contribution arising from the Cu2+-S interactions. In both the solid state and solution, Cu2+ was fully embedded in the ligand cleft in a hexacoordinated N3S3 environment. Furthermore, NO3S exhibited a remarkable ability to form a stable complex with Cu+ through the involvement of all of the donors in the coordination sphere. Radiolabeling studies evidenced an excellent affinity of NO3S toward [64Cu]Cu2+, as quantitative incorporation was achieved at high apparent molar activity (∼10 MBq/nmol) and under mild conditions (ambient temperature, neutral pH, 10 min reaction time). Human serum stability assays revealed an increased stability of [64Cu][Cu(NO3S)]2+ when compared to the corresponding complexes formed by 12-, 13-, or 14-membered tetraaza rings.
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Affiliation(s)
- Marianna Tosato
- Department
of Chemical Sciences, University of Padova, 35131 Padova, Italy
| | - Sara Franchi
- Department
of Chemical Sciences, University of Padova, 35131 Padova, Italy
| | | | | | - Giordano Zanoni
- Department
of Chemical Sciences, University of Padova, 35131 Padova, Italy
| | - André Alker
- Roche
Pharmaceutical Research and Early Development, Roche Innovation Center Basel F. Hoffmann-La Roche, 4058 Basel, Switzerland
| | - Mattia Asti
- Radiopharmaceutical
Chemistry Section, Nuclear Medicine Unit, AUSL-IRCCS Reggio Emilia, 42122 Reggio Emilia, Italy
| | - Thomas Gyr
- Division
of Radiopharmaceutical Chemistry, Clinic of Radiology and Nuclear
Medicine, University Hospital Basel, 4031 Basel, Switzerland
| | - Valerio Di Marco
- Department
of Chemical Sciences, University of Padova, 35131 Padova, Italy
| | - Helmut Mäcke
- Department
of Nuclear Medicine, University Hospital
Freiburg, D-79106 Freiburg, Germany
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Tosato M, Pelosato M, Franchi S, Isse AA, May NV, Zanoni G, Mancin F, Pastore P, Badocco D, Asti M, Di Marco V. When ring makes the difference: coordination properties of Cu 2+/Cu + complexes with sulfur-pendant polyazamacrocycles for radiopharmaceutical applications. NEW J CHEM 2022. [DOI: 10.1039/d2nj01032a] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The Cu2+/+ complexes formed by sulfur-containing polyazamacrocycles were studied in aqueous solution using potentiometry, UV-Vis, NMR, EPR, and cyclic voltammetry.
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Affiliation(s)
- Marianna Tosato
- Department of Chemical Sciences, University of Padova, 35131 Padova, Italy
| | - Matteo Pelosato
- Department of Chemical Sciences, University of Padova, 35131 Padova, Italy
| | - Sara Franchi
- Department of Chemical Sciences, University of Padova, 35131 Padova, Italy
| | | | - Nóra Veronica May
- Centre for Structural Science, Research Centre for Natural Sciences, 1117 Budapest, Hungary
| | - Giordano Zanoni
- Department of Chemical Sciences, University of Padova, 35131 Padova, Italy
| | - Fabrizio Mancin
- Department of Chemical Sciences, University of Padova, 35131 Padova, Italy
| | - Paolo Pastore
- Department of Chemical Sciences, University of Padova, 35131 Padova, Italy
| | - Denis Badocco
- Department of Chemical Sciences, University of Padova, 35131 Padova, Italy
| | - Mattia Asti
- Radiopharmaceutical Chemistry Section, Nuclear Medicine Unit, AUSL-IRCCS di Reggio Emilia, 42122 Reggio Emilia, Italy
| | - Valerio Di Marco
- Department of Chemical Sciences, University of Padova, 35131 Padova, Italy
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Tosato M, Dalla Tiezza M, May NV, Isse AA, Nardella S, Orian L, Verona M, Vaccarin C, Alker A, Mäcke H, Pastore P, Di Marco V. Copper Coordination Chemistry of Sulfur Pendant Cyclen Derivatives: An Attempt to Hinder the Reductive-Induced Demetalation in 64/67Cu Radiopharmaceuticals. Inorg Chem 2021; 60:11530-11547. [PMID: 34279088 PMCID: PMC8389837 DOI: 10.1021/acs.inorgchem.1c01550] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The Cu2+ complexes formed by a series of cyclen derivatives bearing sulfur pendant arms, 1,4,7,10-tetrakis[2-(methylsulfanyl)ethyl]-1,4,7,10-tetraazacyclododecane (DO4S), 1,4,7-tris[2-(methylsulfanyl)ethyl]-1,4,7,10-tetraazacyclododecane (DO3S), 1,4,7-tris[2-(methylsulfanyl)ethyl]-10-acetamido-1,4,7,10-tetraazacyclododecane (DO3SAm), and 1,7-bis[2-(methylsulfanyl)ethyl]-4,10-diacetic acid-1,4,7,10-tetraazacyclododecane (DO2A2S), were studied in aqueous solution at 25 °C from thermodynamic and structural points of view to evaluate their potential as chelators for copper radioisotopes. UV-vis spectrophotometric out-of-cell titrations under strongly acidic conditions, direct in-cell UV-vis titrations, potentiometric measurements at pH >4, and spectrophotometric Ag+-Cu2+ competition experiments were performed to evaluate the stoichiometry and stability constants of the Cu2+ complexes. A highly stable 1:1 metal-to-ligand complex (CuL) was found in solution at all pH values for all chelators, and for DO2A2S, protonated species were also detected under acidic conditions. The structures of the Cu2+ complexes in aqueous solution were investigated by UV-vis and electron paramagnetic resonance (EPR), and the results were supported by relativistic density functional theory (DFT) calculations. Isomers were detected that differed from their coordination modes. Crystals of [Cu(DO4S)(NO3)]·NO3 and [Cu(DO2A2S)] suitable for X-ray diffraction were obtained. Cyclic voltammetry (CV) experiments highlighted the remarkable stability of the copper complexes with reference to dissociation upon reduction from Cu2+ to Cu+ on the CV time scale. The Cu+ complexes were generated in situ by electrolysis and examined by NMR spectroscopy. DFT calculations gave further structural insights. These results demonstrate that the investigated sulfur-containing chelators are promising candidates for application in copper-based radiopharmaceuticals. In this connection, the high stability of both Cu2+ and Cu+ complexes can represent a key parameter for avoiding in vivo demetalation after bioinduced reduction to Cu+, often observed for other well-known chelators that can stabilize only Cu2+.
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Affiliation(s)
- Marianna Tosato
- Department of Chemical Sciences, University of Padova, via Marzolo 1, 35131 Padova, Italy
| | - Marco Dalla Tiezza
- Department of Chemical Sciences, University of Padova, via Marzolo 1, 35131 Padova, Italy
| | - Nóra V May
- Centre for Structural Science, Research Centre for Natural Sciences, Magyar tudósok Körútja 2, 1117 Budapest, Hungary
| | - Abdirisak Ahmed Isse
- Department of Chemical Sciences, University of Padova, via Marzolo 1, 35131 Padova, Italy
| | - Sonia Nardella
- Department of Chemical Sciences, University of Padova, via Marzolo 1, 35131 Padova, Italy.,Department of Pharmaceutical Sciences, University of Padova, via Marzolo 8, 35131 Padova, Italy
| | - Laura Orian
- Department of Chemical Sciences, University of Padova, via Marzolo 1, 35131 Padova, Italy
| | - Marco Verona
- Department of Pharmaceutical Sciences, University of Padova, via Marzolo 8, 35131 Padova, Italy
| | - Christian Vaccarin
- Department of Pharmaceutical Sciences, University of Padova, via Marzolo 8, 35131 Padova, Italy
| | - André Alker
- Roche Pharmaceutical Research and Early Development, Roche Innovation Center Basel F. Hoffmann-La Roche, Grenzacherstrasse 124, 4058 Basel, Switzerland
| | - Helmut Mäcke
- Department of Nuclear Medicine, University Hospital Freiburg, Hugstetterstrasse 55, D-79106 Freiburg, Germany
| | - Paolo Pastore
- Department of Chemical Sciences, University of Padova, via Marzolo 1, 35131 Padova, Italy
| | - Valerio Di Marco
- Department of Chemical Sciences, University of Padova, via Marzolo 1, 35131 Padova, Italy
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5
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Shuvaev S, Suturina EA, Rotile NJ, Astashkin A, Ziegler CJ, Ross AW, Walker TL, Caravan P, Taschner IS. Revisiting dithiadiaza macrocyclic chelators for copper-64 PET imaging. Dalton Trans 2020; 49:14088-14098. [PMID: 32970072 PMCID: PMC7967274 DOI: 10.1039/d0dt02787a] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Synthesis and characterisation of a dithiadiaza chelator NSNS2A, as well as copper complexes thereof are reported in this paper. Solution structures of copper(i/ii) complexes were calculated using density functional theory (DFT) and validated by both NMR and EPR spectroscopy. DFT calculations revealed a switch in the orientation of tetragonal distortion upon protonation, which might be responsible for poor stability of the Cu(II)NSNS2A complex in aqueous media, whilst the same switch in tetragonal distortion was experimentally observed by changing the solvent. The chelator was radiolabeled with 64Cu and evaluated using PET/MRI in rats. Despite a favorable redox potential to stabilize the cuprous state in vivo, the 64Cu(II)NSNS2A complex showed suboptimal stability compared to its tetraazamacrocyclic analogue, 64Cu(TE2A), with a significant 64Cu uptake in the liver.
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Affiliation(s)
- Sergey Shuvaev
- A. A. Martinos Center for Biomedical Imaging and the Institute for Innovation in Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, USA.
| | | | - Nicholas J Rotile
- A. A. Martinos Center for Biomedical Imaging and the Institute for Innovation in Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, USA.
| | - Andrei Astashkin
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ 85721, USA
| | | | - Alana W Ross
- A. A. Martinos Center for Biomedical Imaging and the Institute for Innovation in Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, USA.
| | - Tia L Walker
- Department of Chemistry, Indiana University Northwest, Gary, IN 46408, USA.
| | - Peter Caravan
- A. A. Martinos Center for Biomedical Imaging and the Institute for Innovation in Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, USA.
| | - Ian S Taschner
- Department of Chemistry, Indiana University Northwest, Gary, IN 46408, USA.
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Fu RG, Wang Y, Xia F, Zhang HL, Sun Y, Yang DW, Wang YW, Yin P. Synthesis of 2-Amino-5-acylthiazoles by a Tertiary Amine-Promoted One-Pot Three-Component Cascade Cyclization Using Elemental Sulfur as a Sulfur Source. J Org Chem 2019; 84:12237-12245. [PMID: 31480831 DOI: 10.1021/acs.joc.9b02032] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
A novel one-pot three-component cascade cyclization strategy for the synthesis of 2-amino-5-acylthiazoles using enaminones, cyanamide, and elemental sulfur has been developed. The reported methods have demonstrated good tolerance of various functional groups. Up to 28 2-amino-5-acylthiazole compounds bearing diverse structural differences were successfully synthesized from easily obtained starting materials with moderate to excellent yields. Our method provides an effective way for the access of valuable and potentially bioactive 2-amino-5-acylthiazole derivatives.
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Affiliation(s)
- Rong-Geng Fu
- Key Laboratory for Quality Evaluation of Bulk Herbs of Hunan Province, Hunan Key Laboratory of Druggability and Preparation Modification for Traditional Chinese Medicine and TCM and Ethnomedicine Innovation & Development International Laboratory, School of Pharmacy , Hunan University of Chinese Medicine , Changsha 410208 , People's Republic of China
| | - Yong Wang
- Key Laboratory for Quality Evaluation of Bulk Herbs of Hunan Province, Hunan Key Laboratory of Druggability and Preparation Modification for Traditional Chinese Medicine and TCM and Ethnomedicine Innovation & Development International Laboratory, School of Pharmacy , Hunan University of Chinese Medicine , Changsha 410208 , People's Republic of China
| | - Fei Xia
- Key Laboratory for Quality Evaluation of Bulk Herbs of Hunan Province, Hunan Key Laboratory of Druggability and Preparation Modification for Traditional Chinese Medicine and TCM and Ethnomedicine Innovation & Development International Laboratory, School of Pharmacy , Hunan University of Chinese Medicine , Changsha 410208 , People's Republic of China
| | - Hao-Lin Zhang
- Key Laboratory for Quality Evaluation of Bulk Herbs of Hunan Province, Hunan Key Laboratory of Druggability and Preparation Modification for Traditional Chinese Medicine and TCM and Ethnomedicine Innovation & Development International Laboratory, School of Pharmacy , Hunan University of Chinese Medicine , Changsha 410208 , People's Republic of China
| | - Yuan Sun
- Department of Chemistry and Biochemistry , The Ohio State University , Columbus , Ohio 43210 , United States
| | - Duo-Wen Yang
- Key Laboratory for Quality Evaluation of Bulk Herbs of Hunan Province, Hunan Key Laboratory of Druggability and Preparation Modification for Traditional Chinese Medicine and TCM and Ethnomedicine Innovation & Development International Laboratory, School of Pharmacy , Hunan University of Chinese Medicine , Changsha 410208 , People's Republic of China
| | - Ye-Wei Wang
- Key Laboratory for Quality Evaluation of Bulk Herbs of Hunan Province, Hunan Key Laboratory of Druggability and Preparation Modification for Traditional Chinese Medicine and TCM and Ethnomedicine Innovation & Development International Laboratory, School of Pharmacy , Hunan University of Chinese Medicine , Changsha 410208 , People's Republic of China
| | - Peng Yin
- Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education), College of Chemistry and Chemical Engineering , Hunan Normal University , Changsha , Hunan 410081 , People's Republic of China
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7
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Younes A, Montavon G, Gouin SG, André-Joyaux E, Peumery R, Chalopin T, Alliot C, Mokili M, Champion J, Deniaud D. Investigation of a new “N2S2O2” chelating agent with high Po(iv) affinity. Chem Commun (Camb) 2017; 53:6492-6495. [DOI: 10.1039/c7cc03198j] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A water-soluble complexing agent for 210-polonium decorporation was designed and synthesised with a high conditional stability constant.
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8
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Le Fur M, Beyler M, Le Poul N, Lima LMP, Le Mest Y, Delgado R, Platas-Iglesias C, Patinec V, Tripier R. Improving the stability and inertness of Cu(ii) and Cu(i) complexes with methylthiazolyl ligands by tuning the macrocyclic structure. Dalton Trans 2016; 45:7406-20. [PMID: 27041505 DOI: 10.1039/c6dt00385k] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
A tacn based ligand bearing two methylthiazolyl arms (no2th) was synthesized with the aim to find ligands forming very stable and inert complexes with Cu(ii) and Cu(i) in aqueous medium for radiopharmaceutical applications. The no2th ligand was efficiently prepared following the orthoamide intermediate synthesis. The complexes with Cu(2+) and Zn(2+) were obtained and analyzed by X-ray diffraction. The [Cu(no2th)](2+) complex presents a pentacoordinated distorted square pyramidal coordination geometry, while the metal ion in [Zn(no2th)](2+) adopts a hexacoordinated distorted trigonal prismatic geometry involving the coordination of a perchlorate counter ion. The acid-base properties of no2th have been studied using potentiometric titrations, and the stability constants of Cu(2+) and Zn(2+) complexes were determined by potentiometric and UV-vis titrations using H4edta as a competitor ligand. The stability constant determined for the Cu(2+) complex is rather high (log KCuL = 20.77 and pCu = 17.15), and moreover no2th exhibits a high selectivity for copper(ii) in relation to zinc(ii). The kinetics of the copper(ii) complexation process is very fast even in acidic medium. In addition, the [Cu(no2th)](2+) complex was found to be inert under rather harsh conditions (up to 2 M HCl and 60 °C), displaying a very high half-life time of about 15 days in 2 M HCl at 90 °C. The electrochemical reduction of the copper(ii) complex in water leads to the reversible formation of a stable copper(i) species. Spectroscopic studies performed by NMR, UV-vis and EPR, assisted by theoretical calculations, show that the [Cu(no2th)](2+) complex presents a structure in solution similar to that observed in the solid state. When compared to its cyclam di-N-methylthiazolyl counterpart, the results reported in this paper unambiguously show that replacing the cyclam unit by a tacn moiety improves the stability and inertness of its Cu(ii) and Cu(i) complexes.
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Affiliation(s)
- Mariane Le Fur
- Université de Bretagne Occidentale, UMR-CNRS 6521, SFR ScInBioS, Faculté des Sciences et Techniques, 6 avenue Victor le Gorgeu, C.S. 93837, 29238 Brest Cedex 3, France.
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9
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Rodríguez-Rodríguez A, Halime Z, Lima LMP, Beyler M, Deniaud D, Le Poul N, Delgado R, Platas-Iglesias C, Patinec V, Tripier R. Cyclams with Ambidentate Methylthiazolyl Pendants for Stable, Inert, and Selective Cu(II) Coordination. Inorg Chem 2015; 55:619-32. [DOI: 10.1021/acs.inorgchem.5b01779] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Aurora Rodríguez-Rodríguez
- UFR des
Sciences et Techniques, Université de Bretagne Occidentale, UMR-CNRS 6521, 6 avenue Victor le Gorgeu, C.S. 93837, 29238 Brest Cedex 3, France
| | - Zakaria Halime
- UFR des
Sciences et Techniques, Université de Bretagne Occidentale, UMR-CNRS 6521, 6 avenue Victor le Gorgeu, C.S. 93837, 29238 Brest Cedex 3, France
| | - Luís M. P. Lima
- Instituto de Tecnologia Química e Biológica
António Xavier, Universidade Nova de Lisboa, Av. da República, 2780-157 Oeiras, Portugal
| | - Maryline Beyler
- UFR des
Sciences et Techniques, Université de Bretagne Occidentale, UMR-CNRS 6521, 6 avenue Victor le Gorgeu, C.S. 93837, 29238 Brest Cedex 3, France
| | - David Deniaud
- UFR Sciences et Techniques, Université de Nantes, UMR-CNRS 6230, 2, rue de la Houssinière, BP 92208, 44322 Nantes Cedex 3, France
| | - Nicolas Le Poul
- UFR des
Sciences et Techniques, Université de Bretagne Occidentale, UMR-CNRS 6521, 6 avenue Victor le Gorgeu, C.S. 93837, 29238 Brest Cedex 3, France
| | - Rita Delgado
- Instituto de Tecnologia Química e Biológica
António Xavier, Universidade Nova de Lisboa, Av. da República, 2780-157 Oeiras, Portugal
| | - Carlos Platas-Iglesias
- Grupo QUICOOR, Centro de Investigaciones
Científicas Avanzadas (CICA) and Departamento de Química
Fundamental, Facultade de Ciencias, Universidade da Coruña, Campus
da Zapateira-Rúa da Fraga 10, 15008 A Coruña, Spain
| | - Véronique Patinec
- UFR des
Sciences et Techniques, Université de Bretagne Occidentale, UMR-CNRS 6521, 6 avenue Victor le Gorgeu, C.S. 93837, 29238 Brest Cedex 3, France
| | - Raphaël Tripier
- UFR des
Sciences et Techniques, Université de Bretagne Occidentale, UMR-CNRS 6521, 6 avenue Victor le Gorgeu, C.S. 93837, 29238 Brest Cedex 3, France
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