1
|
Svítok A, Blahut J, Urbanovský P, Hermann P. Dynamics of Coordinated Phosphonate Group Directly Observed by 17O-NMR in Lanthanide(iii) Complexes of a Mono(ethyl phosphonate) DOTA Analogue. Chemistry 2024; 30:e202400970. [PMID: 38624256 DOI: 10.1002/chem.202400970] [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: 03/08/2024] [Revised: 04/15/2024] [Accepted: 04/16/2024] [Indexed: 04/17/2024]
Abstract
Biological phosphates can coordinate metal ions and their complexes are common in living systems. Dynamics of mutual oxygen atom exchange in the tetrahedral group in complexes has not been investigated. Here, we present a direct experimental proof of exchange ("phosphonate rotation") in model Ln(III) complexes of monophosphonate H4dota analogue which alters phosphorus atom chirality of coordinated phosphonate monoester. Combination of macrocycle-based isomerism with P-based chirality leads to several diastereoisomers. (Non)-coordinated oxygen atoms were distinguished through 17O-labelled phosphonate group and their mutual exchange was followed by various NMR techniques and DFT calculations. The process is sterically demanding and occurs through bulky bidentate (κ2-PO2)- coordination and was observed only in twisted-square antiprism (TSA) diastereoisomer of large Ln(III) ions. Its energy demands increase for smaller Ln(III) ions (298ΔG≠(exp./DFT)=51.8/52.1 and 61.0/71.5 kJ mol-1 for La(III) and Eu(III), respectively). These results are helpful in design of such complexes as MRI CA and for protein paramagnetic NMR probes. It demonstrates usefulness of 17O NMR to study solution dynamics in complexes involving phosphorus acid derivatives and it may inspire use of this method to study dynamics of phosphoric acid derivatives (as e. g. phosphorus acid-based inhibitors of metalloenzymes) in different areas of chemistry.
Collapse
Affiliation(s)
- Adam Svítok
- Department Department of Inorganic Chemistry, Faculty of Science, Charles University, Hlavova 2030, 12843, Prague 2, Czech Republic
| | - Jan Blahut
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Science, Flemingovo náměstí 2, 16000, Prague 6, Czech Republic
| | - Peter Urbanovský
- Department Department of Inorganic Chemistry, Faculty of Science, Charles University, Hlavova 2030, 12843, Prague 2, Czech Republic
| | - Petr Hermann
- Department Department of Inorganic Chemistry, Faculty of Science, Charles University, Hlavova 2030, 12843, Prague 2, Czech Republic
| |
Collapse
|
2
|
Jian Y, Mo G, Xu W, Liu Y, Zhang Z, Ding Y, Gao R, Xu J, Zhu J, Shu K, Yan Z, Carniato F, Platas-Iglesias C, Ye F, Botta M, Dai L. Chiral Pyclen-Based Heptadentate Chelates as Highly Stable MRI Contrast Agents. Inorg Chem 2024; 63:8462-8475. [PMID: 38642052 DOI: 10.1021/acs.inorgchem.4c01028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/22/2024]
Abstract
In recent years, pyclen-based complexes have attracted a great deal of interest as magnetic resonance imaging (MRI) contrast agents (CAs) and luminescent materials, as well as radiopharmaceuticals. Remarkably, gadopiclenol, a Gd(III) bishydrated complex featuring a pyclen-based heptadentate ligand, received approval as a novel contrast agent for clinical MRI application in 2022. To maximize stability and efficiency, two novel chiral pyclen-based chelators and their complexes were developed in this study. Gd-X-PCTA-2 showed significant enhancements in both thermodynamic and kinetic stabilities compared to those of the achiral parent derivative Gd-PCTA. 1H NMRD profiles reveal that both chiral gadolinium complexes (Gd-X-PCTA-1 and Gd-X-PCTA-2) have a higher relaxivity than Gd-PCTA, while variable-temperature 17O NMR studies show that the two inner-sphere water molecules have distinct residence times τMa and τMb. Furthermore, in vivo imaging demonstrates that Gd-X-PCTA-2 enhances the signal in the heart and kidneys of the mice, and the chiral Gd complexes exhibit the ability to distinguish between tumors and normal tissues in a 4T1 mouse model more efficiently than that of the clinical agent gadobutrol. Biodistribution studies show that Gd-PCTA and Gd-X-PCTA-2 are primarily cleared by a renal pathway, with 24 h residues of Gd-X-PCTA-2 in the liver and kidney being lower than those of Gd-PCTA.
Collapse
Affiliation(s)
- Yong Jian
- Joint Centre of Translational Medicine, the First Affiliated Hospital of Wenzhou Medical University, Wenzhou, People's Republic of China 325035
- Joint Centre of Translational Medicine, Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou, People's Republic of China 325000
| | - Gengshen Mo
- Joint Centre of Translational Medicine, Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou, People's Republic of China 325000
| | - Weiyuan Xu
- Joint Centre of Translational Medicine, Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou, People's Republic of China 325000
| | - Yao Liu
- Sichuan Key Laboratory of Medical Imaging, School of Pharmacy and Nanchong Key laboratory of MRI Contrast Agent, North Sichuan Medical College, Nanchong, People's Republic of China 637000
| | - Zhichao Zhang
- Joint Centre of Translational Medicine, Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou, People's Republic of China 325000
| | - Yinghui Ding
- Joint Centre of Translational Medicine, Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou, People's Republic of China 325000
| | - Ruonan Gao
- Joint Centre of Translational Medicine, Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou, People's Republic of China 325000
| | - Jiao Xu
- Joint Centre of Translational Medicine, Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou, People's Republic of China 325000
| | - Jiang Zhu
- Sichuan Key Laboratory of Medical Imaging, School of Pharmacy and Nanchong Key laboratory of MRI Contrast Agent, North Sichuan Medical College, Nanchong, People's Republic of China 637000
| | - Kun Shu
- Department of Radiology, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, People's Republic of China 325027
| | - Zhihan Yan
- Department of Radiology, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, People's Republic of China 325027
| | - Fabio Carniato
- Dipartimento di Scienze e Innovazione Tecnologica, Università del Piemonte Orientale, Viale T. Michel 11, Alessandria, Italy 15121
| | - Carlos Platas-Iglesias
- Departamento de Química Fundamental, Facultade de Ciencias, Universidade da Coruña, Campus da Zapateira-Rúa da Fraga 10, A Coruña, Spain 15008
| | - Fangfu Ye
- Joint Centre of Translational Medicine, the First Affiliated Hospital of Wenzhou Medical University, Wenzhou, People's Republic of China 325035
- Joint Centre of Translational Medicine, Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou, People's Republic of China 325000
| | - Mauro Botta
- Dipartimento di Scienze e Innovazione Tecnologica, Università del Piemonte Orientale, Viale T. Michel 11, Alessandria, Italy 15121
| | - Lixiong Dai
- Joint Centre of Translational Medicine, the First Affiliated Hospital of Wenzhou Medical University, Wenzhou, People's Republic of China 325035
- Joint Centre of Translational Medicine, Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou, People's Republic of China 325000
| |
Collapse
|
3
|
Saghez BS, Yang H, Radchenko V. High Separation Factor, High Molar Activity, and Inexpensive Purification Method for the Production of Pure 165Er. Inorg Chem 2024; 63:5330-5340. [PMID: 38324916 DOI: 10.1021/acs.inorgchem.3c03166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2024]
Abstract
Introduction: Auger electron-emitting radionuclides with low (0.001-1 keV) energy, short-range (2-500 nm), and high linear energy transfer (4-26 keV/μm) can play an important role in the targeted radionuclide therapy (TRT) of cancer. 165Er is a pure Auger electron-emitting radionuclide, making it a useful tool for the fundamental studies of the biological effects of Auger electrons. This work develops a simple, inexpensive, high separation factor, and high molar activity radiochemical isolation process for the production of 165Er (t1/2 10.36 h) suitable for TRT in vitro and in vivo studies using irradiated natHo solid targets. Methods: Small medical cyclotron proton-irradiation of natHo targets produced 165Er in GBq scale quantities. 165Er was isolated using cation exchange chromatographic resin (AG 50W-X8, 200-400 mesh, 20 mL, under atmospheric pressure) using α-hydroxyisobutyric acid (70 mM, pH 4.75) followed by extraction using TK212, TK211, and TK221 extraction chromatographic columns. Radio nuclidic and chemical purity of the final 165Er were confirmed using HPGe Gamma spectrometry and induction coupled plasma-mass spectrometry analysis, respectively. The purified 165Er was radiolabeled with two radiometal chelators (DOTA and Crown) and used to produce a new Auger electron-emitting radiopharmaceutical, [165Er]Er-Crown-TATE. Results: Irradiation of 200 mg natHo targets with 20-30 μA of 12.8 MeV protons produced 165Er at 25 ± 5 MBq·μA-1·h-1. The 4.5 ± 0.5 h radiochemical isolation yielded GBq scale of 165Er in 0.05 M HCl (2 mL) with a radiochemical yield of 78.0 ± 5.6% decay corrected to the end of bombardment (EoB) and a Ho/165Er separation factor of (1.14 ± 0.25) × 106. The product showed high radio nuclidic purity and chemical purity. Concentration-dependent radiolabeling experiments with Crown and DOTA were performed resulting in the successful labeling of 165Er with high (>90%) radiochemical yield. Radiolabeling experiments with Crown-TATE were performed 8 h after EoB and synthesized [165Er]Er-Crown-TATE at molar activities of 202.4 MBq·nmol-1 at the end of synthesis (EoS). Conclusions: A 3 h cyclotron irradiation and 4.5 h radiochemical separation produced GBq-scale 165Er suitable for producing radiopharmaceuticals at molar activities satisfactory for investigations of targeted radionuclide therapeutic effects of Auger electron emissions. This will enable future fundamental radiation biology experiments of pure Auger electron-emitting therapeutic radiopharmaceuticals, such as [165Er]Er-Crown-TATE, which will be used to understand the impact of Auger electrons in TRT.
Collapse
Affiliation(s)
- Behrad Saeedi Saghez
- Life Sciences Division, TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - Hua Yang
- Life Sciences Division, TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada
- Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby, British Columbia V5A 1S6, Canada
| | - Valery Radchenko
- Life Sciences Division, TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| |
Collapse
|