1
|
Martinelli J, Romano E, Laczovics A, Horváth D, Grattoni E, Baranyai Z, Tei L. Improving the Stability and Kinetic Inertness of Mn(II) Complexes by Increasing the Bridge Length in Bicyclic CDTA-Like Ligands. Chemistry 2024; 30:e202400570. [PMID: 38597334 DOI: 10.1002/chem.202400570] [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: 02/09/2024] [Revised: 04/08/2024] [Accepted: 04/10/2024] [Indexed: 04/11/2024]
Abstract
Kinetic inertness of Mn(II)-based MRI contrast agents can be improved by increasing the rigidity of the polydentate ligand that tightly coordinate the metal ion. Taking inspiration from the remarkable increase in kinetic inertness of [Mn(CDTA)]2- compared to [Mn(EDTA)]2- due to the cyclohexyl backbone rigidity, we devised that bicyclic ligands would further improve the kinetic inertness of the Mn(II) complexes. The length of the alkyl bridge on the cyclohexane ring was varied from methylene (BCH-DTA), ethylene (BCO-DTA) to propylene (BCN-DTA) to evaluate the influence of the different trans-diaminotetraacetate ligands on relaxometric, thermodynamic and kinetic properties of the Mn(II) complexes. 1H and 17O NMR relaxometric studies showed a slight increase in relaxivity and a faster water exchange rate in these Mn(II)-complexes with respect to [Mn(CDTA)]2-. Solution studies revealed that the conditional stability (pMn) and dissociation half-life (t1/2) at pH 7.4 follow the order [Mn(BCH-DTA)]2-<[Mn(BCO-DTA)]2-<[Mn(BCN-DTA)]2- highlighting the effect of the bridge length on the overall stability of the Mn(II) complexes. Remarkably, [Mn(BCN-DTA)]2- shows an improved pMn value and a 7-times higher kinetic inertness than [Mn(CDTA)]2-. NMR studies on the Zn(II) analogues confirm the rigidity of the bicyclic complexes with an isomerization process at >313 K for the smaller bridged complex [Zn(BCH-DTA)]2-.
Collapse
Affiliation(s)
- Jonathan Martinelli
- Department of Science and Technological Innovation, University of Piemonte Orientale, Viale Teresa Michel 11, 15121, Alessandria, Italy
- Department of Health Sciences (DISSAL), Università di Genova, Via A. Pastore 1, 16132, Genova, Italy
- Nuclear Medicine Unit, IRCCS Ospedale Policlinico San Martino, Largo R. Benzi 10, 16132, Genova, Italy
| | - Elisabetta Romano
- Department of Science and Technological Innovation, University of Piemonte Orientale, Viale Teresa Michel 11, 15121, Alessandria, Italy
| | - Attila Laczovics
- Faculty of Medicine, Institute of Medical Imaging, University of Debrecen, Nagyerdei körút 98, 4032, Debrecen, Hungary
| | - David Horváth
- Faculty of Science and Technology, Department of Physical Chemistry, Doctoral School of Chemistry, University of Debrecen, Egyetem tér 1, 4010, Debrecen, Hungary
- Bracco Imaging SpA, CRB Trieste, AREA Science Park, 34149, Basovizza (TS), Italy
| | - Elena Grattoni
- Bracco Imaging SpA, CRB Trieste, AREA Science Park, 34149, Basovizza (TS), Italy
- Dipartimento di Scienze Chimiche e Farmaceutiche, Università di Trieste, Piazzale Europa 1, 34127, Trieste (TS), Italy
| | - Zsolt Baranyai
- Bracco Imaging SpA, CRB Trieste, AREA Science Park, 34149, Basovizza (TS), Italy
- Faculty of Science and Technology, Doctoral School of Chemistry, University of Debrecen, Egyetem tér 1, 4010, Debrecen, Hungary
| | - Lorenzo Tei
- Department of Science and Technological Innovation, University of Piemonte Orientale, Viale Teresa Michel 11, 15121, Alessandria, Italy
| |
Collapse
|
2
|
Toàn NM, Vágner A, Nagy G, Ország G, Nagy T, Csikos C, Váradi B, Sajtos GZ, Kapus I, Szoboszlai Z, Szikra D, Trencsényi G, Tircsó G, Garai I. [ 52Mn]Mn-BPPA-Trastuzumab: A Promising HER2-Specific PET Radiotracer. J Med Chem 2024; 67:8261-8270. [PMID: 38690886 DOI: 10.1021/acs.jmedchem.4c00344] [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: 05/03/2024]
Abstract
This study aimed to develop a novel radiotracer using trastuzumab and the long-lived [52Mn]Mn isotope for HER2-targeted therapy selection and monitoring. A new Mn(II) chelator, BPPA, synthesized from a rigid bispyclen platform possessing a picolinate pendant arm, formed a stable and inert Mn(II) complex with favorable relaxation properties. BPPA was converted into a bifunctional chelator (BFC), conjugated to trastuzumab, and labeled with [52Mn]Mn isotope. In comparison to DOTA-GA-trastuzumab, the BPPA-trastuzumab conjugate exhibits a labeling efficiency with [52Mn]Mn approximately 2 orders of magnitude higher. In female CB17 SCID mice bearing 4T1 (HER2-) and MDA-MB-HER2+ (HER2+) xenografts, [52Mn]Mn-BPPA-trastuzumab demonstrated superior uptake in HER2+ cells on day 3, with a 3-4 fold difference observed on day 7. Overall, the hexadentate BPPA chelator proves to be exceptional in binding Mn(II). Upon coupling with trastuzumab as a BFC ligand, it becomes an excellent imaging probe for HER2-positive tumors. [52Mn]Mn-BPPA-trastuzumab enables an extended imaging time window and earlier detection of HER2-positive tumors with superior tumor-to-background contrast.
Collapse
Affiliation(s)
- Ngô Minh Toàn
- Gyula Petrányi Doctoral School of Clinical Immunology and Allergology, Faculty of Medicine, University of Debrecen, Debrecen H-4032, Hungary
- Medical Imaging Clinic, Clinical Centre, University of Debrecen, Debrecen H-4032, Hungary
| | | | | | | | - Tamás Nagy
- Medical Imaging Clinic, Clinical Centre, University of Debrecen, Debrecen H-4032, Hungary
- Scanomed Ltd., Debrecen H-4032, Hungary
| | - Csaba Csikos
- Gyula Petrányi Doctoral School of Clinical Immunology and Allergology, Faculty of Medicine, University of Debrecen, Debrecen H-4032, Hungary
- Medical Imaging Clinic, Clinical Centre, University of Debrecen, Debrecen H-4032, Hungary
| | - Balázs Váradi
- Department of Physical Chemistry, Institute of Chemistry, Faculty of Science and Technology, University of Debrecen, Debrecen H-4032, Hungary
- Doctoral School of Chemistry, Faculty of Science and Technology, University of Debrecen, Debrecen H-4032, Hungary
| | - Gergő Zoltán Sajtos
- Department of Physical Chemistry, Institute of Chemistry, Faculty of Science and Technology, University of Debrecen, Debrecen H-4032, Hungary
- Doctoral School of Chemistry, Faculty of Science and Technology, University of Debrecen, Debrecen H-4032, Hungary
| | - István Kapus
- Department of Physical Chemistry, Institute of Chemistry, Faculty of Science and Technology, University of Debrecen, Debrecen H-4032, Hungary
- Doctoral School of Chemistry, Faculty of Science and Technology, University of Debrecen, Debrecen H-4032, Hungary
| | | | - Dezső Szikra
- Medical Imaging Clinic, Clinical Centre, University of Debrecen, Debrecen H-4032, Hungary
- Scanomed Ltd., Debrecen H-4032, Hungary
| | - György Trencsényi
- Gyula Petrányi Doctoral School of Clinical Immunology and Allergology, Faculty of Medicine, University of Debrecen, Debrecen H-4032, Hungary
- Medical Imaging Clinic, Clinical Centre, University of Debrecen, Debrecen H-4032, Hungary
- Scanomed Ltd., Debrecen H-4032, Hungary
| | - Gyula Tircsó
- Department of Physical Chemistry, Institute of Chemistry, Faculty of Science and Technology, University of Debrecen, Debrecen H-4032, Hungary
| | - Ildikó Garai
- Gyula Petrányi Doctoral School of Clinical Immunology and Allergology, Faculty of Medicine, University of Debrecen, Debrecen H-4032, Hungary
- Medical Imaging Clinic, Clinical Centre, University of Debrecen, Debrecen H-4032, Hungary
- Scanomed Ltd., Debrecen H-4032, Hungary
| |
Collapse
|
3
|
Abstract
ABSTRACT Recent safety concerns surrounding the use of gadolinium-based contrast agents (GBCAs) have spurred research into identifying alternatives to GBCAs for use with magnetic resonance imaging. This review summarizes the molecular and pharmaceutical properties of a GBCA replacement and how these may be achieved. Complexes based on high-spin, divalent manganese (Mn 2+ ) have shown promise as general purpose and liver-specific contrast agents. A detailed description of the complex Mn-PyC3A is provided, describing its physicochemical properties, its behavior in different animal models, and how it compares with GBCAs. The review points out that, although there are parallels with GBCAs in how the chemical properties of Mn 2+ complexes can predict in vivo behavior, there are also marked differences between Mn 2+ complexes and GBCAs.
Collapse
Affiliation(s)
- Peter Caravan
- From the Athinoula A. Martinos Center for Biomedical Imaging, Institute for Innovation in Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA
| |
Collapse
|
4
|
Carniato F, Ricci M, Tei L, Garello F, Furlan C, Terreno E, Ravera E, Parigi G, Luchinat C, Botta M. Novel Nanogels Loaded with Mn(II) Chelates as Effective and Biologically Stable MRI Probes. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023; 19:e2302868. [PMID: 37345577 DOI: 10.1002/smll.202302868] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Revised: 06/01/2023] [Indexed: 06/23/2023]
Abstract
Here it is described nanogels (NG) based on a chitosan matrix, which are covalently stabilized by a bisamide derivative of Mn-t-CDTA (t-CDTA = trans-1,2-diaminocyclohexane-N,N,N',N'-tetraacetic acid). the Mn(II) complex acts both as a contrast medium and as a cross-linking agent. These nanogels are proposed as an alternative to the less stable paramagnetic nanogels obtained by electrostatic interactions between the polymeric matrix and paramagnetic Gd(III) chelates. The present novel nanogels show: i) relaxivity values seven times higher than that of typical monohydrated Mn(II) chelates at the clinical fields, thanks to the combination of a restricted mobility of the complex with a fast exchange of the metal-bound water molecule; ii) high stability of the formulation over time at pH 5 and under physiological conditions, thus excluding metal leaking or particles aggregation; iii) good extravasation and accumulation, with a maximum contrast achieved at 24 h post-injection in mice bearing subcutaneous breast cancer tumor; iv) high T1 contrast (1 T) in the tumor 24 h post-injection. These improved properties pave the way for the use of these paramagnetic nanogels as promising magnetic resonance imaging (MRI) probes for in vitro and in vivo preclinical applications.
Collapse
Affiliation(s)
- Fabio Carniato
- Dipartimento di Scienze e Innovazione Tecnologica, Università del Piemonte Orientale, Viale T. Michel 11, Alessandria, 15121, Italy
| | - Marco Ricci
- Dipartimento di Scienze e Innovazione Tecnologica, Università del Piemonte Orientale, Viale T. Michel 11, Alessandria, 15121, Italy
| | - Lorenzo Tei
- Dipartimento di Scienze e Innovazione Tecnologica, Università del Piemonte Orientale, Viale T. Michel 11, Alessandria, 15121, Italy
| | - Francesca Garello
- Molecular Imaging Centre, Department of Molecular Biotechnology and Health Sciences, University of Torino, Torino, 10126, Italy
| | - Chiara Furlan
- Molecular Imaging Centre, Department of Molecular Biotechnology and Health Sciences, University of Torino, Torino, 10126, Italy
| | - Enzo Terreno
- Molecular Imaging Centre, Department of Molecular Biotechnology and Health Sciences, University of Torino, Torino, 10126, Italy
| | - Enrico Ravera
- Magnetic Resonance Center (CERM), University of Florence, Sesto Fiorentino, 50019, Italy
- Department of Chemistry "Ugo Schiff", University of Florence, Sesto Fiorentino, 50019, Italy
- Consorzio Interuniversitario Risonanze Magnetiche Metallo Proteine (CIRMMP), Sesto Fiorentino, 50019, Italy
| | - Giacomo Parigi
- Magnetic Resonance Center (CERM), University of Florence, Sesto Fiorentino, 50019, Italy
- Department of Chemistry "Ugo Schiff", University of Florence, Sesto Fiorentino, 50019, Italy
- Consorzio Interuniversitario Risonanze Magnetiche Metallo Proteine (CIRMMP), Sesto Fiorentino, 50019, Italy
| | - Claudio Luchinat
- Magnetic Resonance Center (CERM), University of Florence, Sesto Fiorentino, 50019, Italy
- Department of Chemistry "Ugo Schiff", University of Florence, Sesto Fiorentino, 50019, Italy
- Consorzio Interuniversitario Risonanze Magnetiche Metallo Proteine (CIRMMP), Sesto Fiorentino, 50019, Italy
- Giotto Biotech S.r.l., Sesto Fiorentino, 50019, Italy
| | - Mauro Botta
- Dipartimento di Scienze e Innovazione Tecnologica, Università del Piemonte Orientale, Viale T. Michel 11, Alessandria, 15121, Italy
| |
Collapse
|
5
|
Gaynor RB, McIntyre BN, Lindsey SL, Clavo KA, Shy WE, Mees DE, Mu G, Donnadieu B, Creutz SE. Steric Effects on the Chelation of Mn 2+ and Zn 2+ by Hexadentate Polyimidazole Ligands: Modeling Metal Binding by Calprotectin Site 2. Chemistry 2023; 29:e202300447. [PMID: 37067464 PMCID: PMC10640917 DOI: 10.1002/chem.202300447] [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: 02/10/2023] [Revised: 04/14/2023] [Accepted: 04/17/2023] [Indexed: 04/18/2023]
Abstract
Recently, there has been increasing interest in the design of ligands that bind Mn2+ with high affinity and selectivity, but this remains a difficult challenge. It has been proposed that the cavity size of the binding pocket is a critical factor in most synthetic and biological examples of selective Mn2+ binding. Here, we use a bioinspired approach adapted from the hexahistidine binding site of the manganese-sequestering protein calprotectin to systematically study the effect of cavity size on Mn2+ and Zn2+ binding. We have designed a hexadentate, trisimidazole ligand whose cavity size can be tuned through peripheral modification of the steric bulk of the imidazole substituents. Conformational dynamics and redox potentials of the complexes are dependent on ligand steric bulk. Stability constants are consistent with the hypothesis that larger ligand cavities are relatively favorable for Mn2+ over Zn2+ , but this effect alone may not be sufficient to achieve Mn2+ selectivity.
Collapse
Affiliation(s)
- Ryan B Gaynor
- Department of Chemistry, Mississippi State University, Mississippi State, Mississippi, 39762, USA
| | - Baylee N McIntyre
- Department of Chemistry, Mississippi State University, Mississippi State, Mississippi, 39762, USA
| | - Shelby L Lindsey
- Department of Chemistry, Mississippi State University, Mississippi State, Mississippi, 39762, USA
| | - Kaylee A Clavo
- Department of Chemistry, Mississippi State University, Mississippi State, Mississippi, 39762, USA
| | - William E Shy
- Department of Chemistry, Mississippi State University, Mississippi State, Mississippi, 39762, USA
| | - David E Mees
- Department of Chemistry, Mississippi State University, Mississippi State, Mississippi, 39762, USA
| | - Ge Mu
- Department of Chemistry, Mississippi State University, Mississippi State, Mississippi, 39762, USA
| | - Bruno Donnadieu
- Department of Chemistry, Mississippi State University, Mississippi State, Mississippi, 39762, USA
| | - Sidney E Creutz
- Department of Chemistry, Mississippi State University, Mississippi State, Mississippi, 39762, USA
| |
Collapse
|
6
|
Ndiaye D, Cieslik P, Wadepohl H, Pallier A, Même S, Comba P, Tóth É. Mn 2+ Bispidine Complex Combining Exceptional Stability, Inertness, and MRI Efficiency. J Am Chem Soc 2022; 144:22212-22220. [PMID: 36445192 DOI: 10.1021/jacs.2c10108] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
As an essential metal ion and an efficient relaxation agent, Mn2+ holds a great promise to replace Gd3+ in magnetic resonance imaging (MRI) contrast agent applications, if its stable and inert complexation can be achieved. Toward this goal, four pyridine and one carboxylate pendants have been introduced in coordinating positions on the bispidine platform to yield ligand L3. Thanks to its rigid and preorganized structure and perfect size match for Mn2+, L3 provides remarkably high thermodynamic stability (log KMnL = 19.47), selectivity over the major biological competitor Zn2+ (log(KMnL/KZnL) = 4.4), and kinetic inertness. Solid-state X-ray data show that [MnL3(MeOH)](OTf)2 has an unusual eight-coordinate structure with a coordinated solvent molecule, in contrast to the six-coordinate structure of [ZnL3](OTf), underlining that the coordination cavity is perfectly adapted for Mn2+, while it is too large for Zn2+. In aqueous solution, 17O NMR data evidence one inner sphere water and dissociatively activated water exchange (kex298 = 13.5 × 107 s-1) for MnL3. Its water proton relaxivity (r1 = 4.44 mM-1 s-1 at 25 °C, 20 MHz) is about 30% higher than values for typical monohydrated Mn2+ complexes, which is related to its larger molecular size; its relaxation efficiency is similar to that of clinically used Gd3+-based agents. In vivo MRI experiments realized in control mice at 0.02 mmol/kg injected dose indicate good signal enhancement in the kidneys and fast renal clearance. Taken together, MnL3 is the first chelate that combines such excellent stability, selectivity, inertness and relaxation properties, all of primary importance for MRI use.
Collapse
Affiliation(s)
- Daouda Ndiaye
- Centre de Biophysique Moléculaire, CNRS UPR 4301, Université d'Orléans, rue Charles Sadron, 45071 Orléans, France
| | - Patrick Cieslik
- Anorganisch-Chemisches Institut, Universität Heidelberg, INF 270, D-69120 Heidelberg, Germany
| | - Hubert Wadepohl
- Anorganisch-Chemisches Institut, Universität Heidelberg, INF 270, D-69120 Heidelberg, Germany
| | - Agnès Pallier
- Centre de Biophysique Moléculaire, CNRS UPR 4301, Université d'Orléans, rue Charles Sadron, 45071 Orléans, France
| | - Sandra Même
- Centre de Biophysique Moléculaire, CNRS UPR 4301, Université d'Orléans, rue Charles Sadron, 45071 Orléans, France
| | - Peter Comba
- Anorganisch-Chemisches Institut, Universität Heidelberg, INF 270, D-69120 Heidelberg, Germany.,Interdisciplinary Center for Scientific Computing, Universität Heidelberg, INF 205, D-69120 Heidelberg, Germany
| | - Éva Tóth
- Centre de Biophysique Moléculaire, CNRS UPR 4301, Université d'Orléans, rue Charles Sadron, 45071 Orléans, France
| |
Collapse
|
7
|
Uzal-Varela R, Pérez-Fernández F, Valencia L, Rodríguez-Rodríguez A, Platas-Iglesias C, Caravan P, Esteban-Gómez D. Thermodynamic Stability of Mn(II) Complexes with Aminocarboxylate Ligands Analyzed Using Structural Descriptors. Inorg Chem 2022; 61:14173-14186. [PMID: 35994514 PMCID: PMC9455602 DOI: 10.1021/acs.inorgchem.2c02364] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
![]()
We present a quantitative analysis of the thermodynamic
stabilities
of Mn(II) complexes, defined by the equilibrium constants (log KMnL values) and the values of pMn obtained as
−log[Mn]free for total metal and ligand concentrations
of 1 and 10 μM, respectively. We used structural descriptors
to analyze the contributions to complex stability of different structural
motifs in a quantitative way. The experimental log KMnL and pMn values can be predicted to a good accuracy
by adding the contributions of the different motifs present in the
ligand structure. This allowed for the identification of features
that provide larger contributions to complex stability, which will
be very helpful for the design of efficient chelators for Mn(II) complexation.
This issue is particularly important to develop Mn(II) complexes for
medical applications, for instance, as magnetic resonance imaging
(MRI) contrast agents. The analysis performed here also indicates
that coordination number eight is more common for Mn(II) than is generally
assumed, with the highest log KMnL values generally observed for hepta- and octadentate ligands. The
X-ray crystal structure of [Mn2(DOTA)(H2O)2], in which eight-coordinate [Mn(DOTA)]2– units are bridged by six-coordinate exocyclic Mn(II) ions, is also
reported. We present empirical relationships
that allow estimating
the log K and pMn values of Mn(II) complexes
relevant as contrast agents for magnetic resonance imaging (MRI).
The prediction of complex stability with these expressions relies
on structural descriptors, providing a very powerful tool to aid with
ligand design.
Collapse
Affiliation(s)
- Rocío Uzal-Varela
- Centro de Investigacións Científicas Avanzadas (CICA) and Departamento de Química, Facultade de Ciencias, Universidade da Coruña, 15071 A Coruña, Galicia, Spain
| | - Francisco Pérez-Fernández
- Centro de Investigacións Científicas Avanzadas (CICA) and Departamento de Química, Facultade de Ciencias, Universidade da Coruña, 15071 A Coruña, Galicia, Spain
| | - Laura Valencia
- Departamento de Química Inorgánica, Facultad de Ciencias, Universidade de Vigo, As Lagoas, Marcosende, 36310 Pontevedra, Spain
| | - Aurora Rodríguez-Rodríguez
- Centro de Investigacións Científicas Avanzadas (CICA) and Departamento de Química, Facultade de Ciencias, Universidade da Coruña, 15071 A Coruña, Galicia, Spain
| | - Carlos Platas-Iglesias
- Centro de Investigacións Científicas Avanzadas (CICA) and Departamento de Química, Facultade de Ciencias, Universidade da Coruña, 15071 A Coruña, Galicia, Spain
| | - Peter Caravan
- The Institute for Innovation in Imaging and the A. A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, 149, 13th Street, Suite 2301, Charlestown, Massachusetts 02129, United States
| | - David Esteban-Gómez
- Centro de Investigacións Científicas Avanzadas (CICA) and Departamento de Química, Facultade de Ciencias, Universidade da Coruña, 15071 A Coruña, Galicia, Spain
| |
Collapse
|
8
|
Sy M, Ndiaye D, da Silva I, Lacerda S, Charbonnière LJ, Tóth É, Nonat AM. 55/52Mn 2+ Complexes with a Bispidine-Phosphonate Ligand: High Kinetic Inertness for Imaging Applications. Inorg Chem 2022; 61:13421-13432. [PMID: 35984220 DOI: 10.1021/acs.inorgchem.2c01681] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Bispidine (3,7-diazabicyclo[3.3.1]nonane) provides a rigid and preorganized scaffold that is particularly interesting for the stable and inert complexation of metal ions, especially for their application in medical imaging. In this study, we present the synthesis of two bispidine ligands with N-methanephosphonate (H4L1) and N-methanecarboxylate (H3L2) substituents as well as the physico-chemical properties of the corresponding Mn2+ and Zn2+ complexes. The two complexes [Mn(L1)]2- and [Mn(L2)]- have relatively moderate thermodynamic stability constants according to potentiometric titration data. However, they both display an exceptional kinetic inertness, as assessed by transmetallation experiments in the presence of 50 equiv excess of Zn2+, showing only ∼40 and 20% of dissociation for [Mn(L1)]2- and [Mn(L2)]-, respectively, after 150 days at pH 6 and 37 °C. Proton relaxivities amount to r1 = 4.31 mM-1 s-1 ([Mn(L1)]2-) and 3.64 mM-1 s-1 ([Mn(L2)]-) at 20 MHz, 25 °C, and are remarkable for Mn2+ complexes with one inner-sphere water molecule (q = 1); they are comparable to that of the commercial contrast agent [Gd(DOTA)(H2O)]-. The presence of one inner-sphere water molecule and an associative water exchange mechanism was confirmed by temperature-dependent transverse 17O relaxation rate measurements, which yielded kex298 = 0.12 × 107 and 5.5 × 107 s-1 for the water exchange rate of the phosphonate and the carboxylate complex, respectively. In addition, radiolabeling experiments with 52Mn were also performed with H2(L1)2- showing excellent radiolabeling properties and quantitative complexation at pH 7 in 15 min at room temperature as well as excellent stability of the complex in various biological media over 24 h.
Collapse
Affiliation(s)
- Maryame Sy
- Equipe de Synthèse pour l'Analyse, Université de Strasbourg, CNRS, IPHC UMR 7178, F-67 037 Strasbourg, France
| | - Daouda Ndiaye
- Centre de Biophysique Moléculaire, CNRS UPR 4301, Université d'Orléans, rue Charles Sadron, F-45071 Orléans, France
| | - Isidro da Silva
- CEMHTI, CNRS UPR3079, Université d'Orléans, F-45071 Orléans 2, France
| | - Sara Lacerda
- Centre de Biophysique Moléculaire, CNRS UPR 4301, Université d'Orléans, rue Charles Sadron, F-45071 Orléans, France
| | - Loïc J Charbonnière
- Equipe de Synthèse pour l'Analyse, Université de Strasbourg, CNRS, IPHC UMR 7178, F-67 037 Strasbourg, France
| | - Éva Tóth
- Centre de Biophysique Moléculaire, CNRS UPR 4301, Université d'Orléans, rue Charles Sadron, F-45071 Orléans, France
| | - Aline M Nonat
- Equipe de Synthèse pour l'Analyse, Université de Strasbourg, CNRS, IPHC UMR 7178, F-67 037 Strasbourg, France
| |
Collapse
|
9
|
Cieslik P, Comba P, Dittmar B, Ndiaye D, Tóth É, Velmurugan G, Wadepohl H. Exceptional Manganese(II) Stability and Manganese(II)/Zinc(II) Selectivity with Rigid Polydentate Ligands. Angew Chem Int Ed Engl 2022; 61:e202115580. [PMID: 34979049 PMCID: PMC9305554 DOI: 10.1002/anie.202115580] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Indexed: 12/02/2022]
Abstract
While MnII complexes meet increasing interest in biomedical applications, ligands are lacking that enable high MnII complex stability and selectivity vs. ZnII, the most relevant biological competitor. We report here two new bispidine derivatives, which provide rigid and large coordination cavities that perfectly match the size of MnII, yielding eight‐coordinate MnII complexes with record stabilities. In contrast, the smaller ZnII ion cannot accommodate all ligand donors, resulting in highly strained and less stable six‐coordinate complexes. Combined theoretical and experimental data (X‐ray crystallography, potentiometry, relaxometry and 1H NMR spectroscopy) demonstrate unprecedented selectivity for MnII vs. ZnII (KMnL/KZnL of 108–1010), in sharp contrast to the usual Irving–Williams behavior, and record MnII complex stabilities and inertness with logKMnL close to 25.
Collapse
Affiliation(s)
- Patrick Cieslik
- Universität Heidelberg, Anorganisch-Chemisches Institut, INF 270, 69120, Heidelberg, Germany
| | - Peter Comba
- Universität Heidelberg, Anorganisch-Chemisches Institut, INF 270, 69120, Heidelberg, Germany.,Universität Heidelberg, Interdisciplinary Center for Scientific Computing, INF 205, 69120, Heidelberg, Germany
| | - Benedikt Dittmar
- Universität Heidelberg, Anorganisch-Chemisches Institut, INF 270, 69120, Heidelberg, Germany
| | - Daouda Ndiaye
- Centre de Biophysique Moléculaire, CNRS UPR 4301, Université d'Orléans, rue Charles Sadron, 45071, Orléans, France
| | - Éva Tóth
- Centre de Biophysique Moléculaire, CNRS UPR 4301, Université d'Orléans, rue Charles Sadron, 45071, Orléans, France
| | - Gunasekaran Velmurugan
- Universität Heidelberg, Anorganisch-Chemisches Institut, INF 270, 69120, Heidelberg, Germany
| | - Hubert Wadepohl
- Universität Heidelberg, Anorganisch-Chemisches Institut, INF 270, 69120, Heidelberg, Germany
| |
Collapse
|
10
|
Cieslik P, Comba P, Dittmar B, Ndiaye D, Tóth É, Velmurugan G, Wadepohl H. Exceptional Manganese(II) Stability and Manganese(II)/Zinc(II) Selectivity with Rigid Polydentate Ligands**. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202115580] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Patrick Cieslik
- Universität Heidelberg Anorganisch-Chemisches Institut, INF 270 69120 Heidelberg Germany
| | - Peter Comba
- Universität Heidelberg Anorganisch-Chemisches Institut, INF 270 69120 Heidelberg Germany
- Universität Heidelberg Interdisciplinary Center for Scientific Computing, INF 205 69120 Heidelberg Germany
| | - Benedikt Dittmar
- Universität Heidelberg Anorganisch-Chemisches Institut, INF 270 69120 Heidelberg Germany
| | - Daouda Ndiaye
- Centre de Biophysique Moléculaire CNRS UPR 4301 Université d'Orléans rue Charles Sadron 45071 Orléans France
| | - Éva Tóth
- Centre de Biophysique Moléculaire CNRS UPR 4301 Université d'Orléans rue Charles Sadron 45071 Orléans France
| | - Gunasekaran Velmurugan
- Universität Heidelberg Anorganisch-Chemisches Institut, INF 270 69120 Heidelberg Germany
| | - Hubert Wadepohl
- Universität Heidelberg Anorganisch-Chemisches Institut, INF 270 69120 Heidelberg Germany
| |
Collapse
|
11
|
Nagendraraj T, Kumaran SS, Mayilmurugan R. Mn(II) complexes of phenylenediamine based macrocyclic ligands as T 1-MRI contrast agents. J Inorg Biochem 2021; 228:111684. [PMID: 34929541 DOI: 10.1016/j.jinorgbio.2021.111684] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2021] [Revised: 11/22/2021] [Accepted: 11/29/2021] [Indexed: 01/06/2023]
Abstract
The Mn(II) complexes are emerging as alternative T1-MRI contrast agents (CAs) to the currently available Gd-based CAs. The complexes [Mn(L1)] 1 and [Mn(L2)] 2 of o-phenylenediamine based macrocyclic ligands are reported as T1-CAs for MRI applications. The high spin state of the Mn(II) complexes (S = 5/2) is confirmed by EPR spectra. The complexes showed an irreversible Mn(II)/Mn(III) redox potential at pH 7.28, which became more and less positive at the acidic and alkaline pHs, respectively. The species [MnL], [Mn(LH-1), and [Mn(LH-2) are persisted in solution. Complex 1 is inert towards Ca(II), Mg(II), and Zn(II), whereas complex 2 is inert for Ca(II) and Mg(II) and labile under Zn(II) and Cu(II) ions. Complex 1 showed an r1-relaxivity of 3.27 and 2.32 mM-1 s-1 at 1.41 T, 25, and 37 °C respectively via inner-sphere water relaxation, which is lower than that of 2 (r1, 5.56, and 4.19 mM-1 s-1) at pH 7.28 and 1.41 T. The Mn(II) complexes showed a 2-8% enhancement of r1-relaxivity while lowering the pH to acidic, which corresponds to the release of free Mn(II) ions. In contrast, the r1-relaxivity is dropped to 52% and 20% for 1 and 2 respectively under alkaline pH due to the deprotonation of inner-sphere water. Phantom images obtained on Bruker 'BIOSPEC' 47/40 animal research MRI/MRS scanner showed concentration-dependent brightness. The interaction of human serum albumin (HSA) with 1 and 2 exhibited five times higher r1-relaxivities (11.3 and 22.0 mM-1 s-1 at 1.41 T, respectively).
Collapse
Affiliation(s)
- Thavasilingam Nagendraraj
- Bioinorganic Chemistry Laboratory/Physical Chemistry, School of Chemistry, Madurai Kamaraj University, Madurai 625 021, Tamil Nadu, India
| | - S Senthil Kumaran
- Department of NMR, All India Institute of Medical Sciences, Ansari Nagar, New Delhi 110 029, India
| | - Ramasamy Mayilmurugan
- Bioinorganic Chemistry Laboratory/Physical Chemistry, School of Chemistry, Madurai Kamaraj University, Madurai 625 021, Tamil Nadu, India.
| |
Collapse
|
12
|
Lalli D, Ferrauto G, Terreno E, Carniato F, Botta M. Mn(II)-Conjugated silica nanoparticles as potential MRI probes. J Mater Chem B 2021; 9:8994-9004. [PMID: 34585711 DOI: 10.1039/d1tb01600h] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Novel Mn(II)-based nanoprobes were rationally designed as high contrast enhancing agents for magnetic resonance imaging (MRI) and obtained by anchoring a Mn(II)-CDTA derivative to the surface of organo-modified silica nanoparticles (SiNPs). Large payloads of paramagnetic metal-chelates have been immobilized on biocompatible SiNPs with spherical shape and narrow size distribution of 80-90 nm, resulting in a relaxivity gain of 250% at clinical fields (0.5 T) as compared to the free chelate. Such substantial efficacy enhancement of the nanoprobes is mainly attributed to the restriction of the rotational dynamics of the conjugated complex, as revealed by comprehensive 1H-NMR relaxometric investigations. The paramagnetic nanospheres exhibit good colloidal stability over time in biological matrices, allowing for MRI applications. High image contrast was found in T1w-MRI images collected at 1 T on phantoms containing relatively small amounts of contrast agent (CA), for which low cellular toxicity was observed on three different cell lines. Preliminary in vivo studies on healthy mice demonstrated the efficiency of the novel Mn-based silica nanoparticle as T1w-MRI probes, resulting in significant contrast enhancement in the liver. These findings demonstrate that these novel Mn-SiNPs are high efficacy CAs suitable for preclinical MRI applications.
Collapse
Affiliation(s)
- Daniela Lalli
- Magnetic Resonance Platform (PRISMA-UPO), Department of Sciences and Technological Innovation, University of Eastern Piedmont "Amedeo Avogadro", Viale Teresa Michel 11, 15121-Alessandria, Italy.
| | - Giuseppe Ferrauto
- Molecular Imaging Center, Department of Molecular Biotechnology and Health Sciences, University of Torino, Via Nizza 52, 10126 Torino, Italy
| | - Enzo Terreno
- Molecular Imaging Center, Department of Molecular Biotechnology and Health Sciences, University of Torino, Via Nizza 52, 10126 Torino, Italy
| | - Fabio Carniato
- Magnetic Resonance Platform (PRISMA-UPO), Department of Sciences and Technological Innovation, University of Eastern Piedmont "Amedeo Avogadro", Viale Teresa Michel 11, 15121-Alessandria, Italy.
| | - Mauro Botta
- Magnetic Resonance Platform (PRISMA-UPO), Department of Sciences and Technological Innovation, University of Eastern Piedmont "Amedeo Avogadro", Viale Teresa Michel 11, 15121-Alessandria, Italy.
| |
Collapse
|
13
|
Ndiaye D, Sy M, Pallier A, Même S, Silva I, Lacerda S, Nonat AM, Charbonnière LJ, Tóth É. Unprecedented Kinetic Inertness for a Mn
2+
‐Bispidine Chelate: A Novel Structural Entry for Mn
2+
‐Based Imaging Agents. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202003685] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Affiliation(s)
- Daouda Ndiaye
- Centre de Biophyisique Moléculaire, CNRS UPR 4301 Université d'Orléans rue Charles Sadron 45071 Orléans France
| | - Maryame Sy
- Equipe de Synthèse Pour l'Analyse Université de Strasbourg CNRS, IPHC UMR 7178 67000 Strasbourg France
| | - Agnès Pallier
- Centre de Biophyisique Moléculaire, CNRS UPR 4301 Université d'Orléans rue Charles Sadron 45071 Orléans France
| | - Sandra Même
- Centre de Biophyisique Moléculaire, CNRS UPR 4301 Université d'Orléans rue Charles Sadron 45071 Orléans France
| | - Isidro Silva
- CEMHTI, CNRS UPR3079 Université d'Orléans 45071 Orléans 2 France
| | - Sara Lacerda
- Centre de Biophyisique Moléculaire, CNRS UPR 4301 Université d'Orléans rue Charles Sadron 45071 Orléans France
| | - Aline M. Nonat
- Equipe de Synthèse Pour l'Analyse Université de Strasbourg CNRS, IPHC UMR 7178 67000 Strasbourg France
| | - Loïc J. Charbonnière
- Equipe de Synthèse Pour l'Analyse Université de Strasbourg CNRS, IPHC UMR 7178 67000 Strasbourg France
| | - Éva Tóth
- Centre de Biophyisique Moléculaire, CNRS UPR 4301 Université d'Orléans rue Charles Sadron 45071 Orléans France
| |
Collapse
|
14
|
Ndiaye D, Sy M, Pallier A, Même S, Silva I, Lacerda S, Nonat AM, Charbonnière LJ, Tóth É. Unprecedented Kinetic Inertness for a Mn
2+
‐Bispidine Chelate: A Novel Structural Entry for Mn
2+
‐Based Imaging Agents. Angew Chem Int Ed Engl 2020; 59:11958-11963. [DOI: 10.1002/anie.202003685] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Revised: 04/06/2020] [Indexed: 11/10/2022]
Affiliation(s)
- Daouda Ndiaye
- Centre de Biophyisique Moléculaire, CNRS UPR 4301 Université d'Orléans rue Charles Sadron 45071 Orléans France
| | - Maryame Sy
- Equipe de Synthèse Pour l'Analyse Université de Strasbourg CNRS, IPHC UMR 7178 67000 Strasbourg France
| | - Agnès Pallier
- Centre de Biophyisique Moléculaire, CNRS UPR 4301 Université d'Orléans rue Charles Sadron 45071 Orléans France
| | - Sandra Même
- Centre de Biophyisique Moléculaire, CNRS UPR 4301 Université d'Orléans rue Charles Sadron 45071 Orléans France
| | - Isidro Silva
- CEMHTI, CNRS UPR3079 Université d'Orléans 45071 Orléans 2 France
| | - Sara Lacerda
- Centre de Biophyisique Moléculaire, CNRS UPR 4301 Université d'Orléans rue Charles Sadron 45071 Orléans France
| | - Aline M. Nonat
- Equipe de Synthèse Pour l'Analyse Université de Strasbourg CNRS, IPHC UMR 7178 67000 Strasbourg France
| | - Loïc J. Charbonnière
- Equipe de Synthèse Pour l'Analyse Université de Strasbourg CNRS, IPHC UMR 7178 67000 Strasbourg France
| | - Éva Tóth
- Centre de Biophyisique Moléculaire, CNRS UPR 4301 Université d'Orléans rue Charles Sadron 45071 Orléans France
| |
Collapse
|
15
|
Porcar-Tost O, Olivares JA, Pallier A, Esteban-Gómez D, Illa O, Platas-Iglesias C, Tóth É, Ortuño RM. Gadolinium Complexes of Highly Rigid, Open-Chain Ligands Containing a Cyclobutane Ring in the Backbone: Decreasing Ligand Denticity Might Enhance Kinetic Inertness. Inorg Chem 2019; 58:13170-13183. [PMID: 31524387 DOI: 10.1021/acs.inorgchem.9b02044] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In an effort to explore novel ligand scaffolds for stable and inert lanthanide complexation in magnetic resonance imaging contrast agent research, three chiral ligands containing a highly rigid (1S,2S)-1,2-cyclobutanediamine spacer and different number of acetate and picolinate groups were efficiently synthesized. Potentiometric studies show comparable thermodynamic stability for the Gd3+ complexes formed with either the octadentate (L3)4- bearing two acetate or two picolinate groups or the heptadentate (L2)4- analogue bearing one picolinate and three acetate groups (log KGdL = 17.41 and 18.00 for [Gd(L2)]- and [Gd(L3)]-, respectively). In contrast, their dissociation kinetics is revealed to be very different: the monohydrated [Gd(L3)]- is considerably more labile, as a result of the significant kinetic activity of the protonated picolinate function, as compared to the bishydrated [Gd(L2)]-. This constitutes an uncommon example in which lowering ligand denticity results in a remarkable increase in kinetic inertness. Another interesting observation is that the rigid ligand backbone induces an unusually strong contribution of the spontaneous dissociation to the overall decomplexation process. Thanks to the presence of two inner-sphere water molecules, [Gd(L2)]- is endowed with high relaxivity (r1 = 7.9 mM-1 s-1 at 20 MHz, 25 °C), which is retained in the presence of large excess of endogenous anions, excluding ternary complex formation. The water exchange rate is similar for [Gd(L3)]- and [Gd(L2)]-, while it is 1 order of magnitude higher for the trishydrated tetraacetate analogue [Gd(L1)]- (kex298 = 8.1, 10, and 127 × 106 s-1, respectively). A structural analysis via density functional theory calculations suggests that the large bite angle imposed by the rigid (1S,2S)-1,2-cyclobutanediamine spacer could allow the design of ligands based on this scaffold with suitable properties for the coordination of larger metal ions with biomedical applications.
Collapse
Affiliation(s)
- Oriol Porcar-Tost
- Departament de Química , Universitat Autònoma de Barcelona , 08193 Cerdanyola del Vallès , Barcelona , Spain
| | - José A Olivares
- Departament de Química , Universitat Autònoma de Barcelona , 08193 Cerdanyola del Vallès , Barcelona , Spain
| | - Agnès Pallier
- Centre de Biophysique Moléculaire , UPR 4301, CNRS, Université d'Orléans , rue Charles Sadron , 45071 Orléans Cedex 2 , France
| | - David Esteban-Gómez
- Centro de Investigacións Científicas Avanzadas and Departamento de Química , Universidade da Coruña , Campus da Zapateira-Rúa da Fraga 10 , 15008 A Coruña , Spain
| | - Ona Illa
- Departament de Química , Universitat Autònoma de Barcelona , 08193 Cerdanyola del Vallès , Barcelona , Spain
| | - Carlos Platas-Iglesias
- Centro de Investigacións Científicas Avanzadas and Departamento de Química , Universidade da Coruña , Campus da Zapateira-Rúa da Fraga 10 , 15008 A Coruña , Spain
| | - Éva Tóth
- Centre de Biophysique Moléculaire , UPR 4301, CNRS, Université d'Orléans , rue Charles Sadron , 45071 Orléans Cedex 2 , France
| | - Rosa M Ortuño
- Departament de Química , Universitat Autònoma de Barcelona , 08193 Cerdanyola del Vallès , Barcelona , Spain
| |
Collapse
|
16
|
Abstract
Mn(II) has several favorable physicochemical characteristics and a good toxicity profile, which makes it a viable alternative to the Gd(III)-based MRI contrast agents currently used in clinics. Although many studies have been undertaken in the last 10 years, this is a field of investigation still in rapid and continuous development. This review aims to critically discuss the chemical and magnetic properties of Mn(II) compounds relevant as MRI probes, both small complexes and nanosystems containing a large number of metal centers, the possible approaches for optimizing their efficiency by understanding the role of various molecular parameters that control the relaxation processes, and the most important issues related to stability and kinetic inertness.
Collapse
|
17
|
Liu J, Suo Q, Song J, Zhang L, Gao Y. A series of [Na2MnII2MnIII6] clusters derived from trigonal bipyramidal [NaMnIIMnIII3] subunits bridged by mono-, di- and tri-fold azide groups: synthesis, crystal structures and magnetic properties. Polyhedron 2019. [DOI: 10.1016/j.poly.2018.12.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
18
|
Pota K, Garda Z, Kálmán FK, Barriada JL, Esteban-Gómez D, Platas-Iglesias C, Tóth I, Brücher E, Tircsó G. Taking the next step toward inert Mn2+ complexes of open-chain ligands: the case of the rigid PhDTA ligand. NEW J CHEM 2018. [DOI: 10.1039/c8nj00121a] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Equilibrium, dissociation kinetics, relaxometric and electrochemical properties of the [Mn(PhDTA)]2− complex were investigated and the structure of the [Mn(PhDTA)]2− complex was studied by using DFT calculations.
Collapse
Affiliation(s)
- Kristof Pota
- Department of Inorganic and Analytical Chemistry
- Faculty of Science and Technology
- University of Debrecen
- H-4032 Debrecen
- Hungary
| | - Zoltán Garda
- Department of Inorganic and Analytical Chemistry
- Faculty of Science and Technology
- University of Debrecen
- H-4032 Debrecen
- Hungary
| | - Ferenc Krisztián Kálmán
- Department of Inorganic and Analytical Chemistry
- Faculty of Science and Technology
- University of Debrecen
- H-4032 Debrecen
- Hungary
| | - José Luis Barriada
- Centro de Investigaciones Científicas Avanzadas (CICA)
- Departamento de Química, Universidade da Coruña
- Spain
| | - David Esteban-Gómez
- Centro de Investigaciones Científicas Avanzadas (CICA)
- Departamento de Química, Universidade da Coruña
- Spain
| | - Carlos Platas-Iglesias
- Centro de Investigaciones Científicas Avanzadas (CICA)
- Departamento de Química, Universidade da Coruña
- Spain
| | - Imre Tóth
- Department of Inorganic and Analytical Chemistry
- Faculty of Science and Technology
- University of Debrecen
- H-4032 Debrecen
- Hungary
| | - Ernő Brücher
- Department of Inorganic and Analytical Chemistry
- Faculty of Science and Technology
- University of Debrecen
- H-4032 Debrecen
- Hungary
| | - Gyula Tircsó
- Department of Inorganic and Analytical Chemistry
- Faculty of Science and Technology
- University of Debrecen
- H-4032 Debrecen
- Hungary
| |
Collapse
|