1
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Abstract
Structures, electron spectroscopy and theoretical (DFT and TD DFT) analyses of two complexes of Eu(ii) with phosphonate and phosphinate ligands based on cyclen ring are presented.
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2
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Hägele G. Protolysis and Complex Formation of Organophosphorus Compounds-Characterization by NMR-Controlled Titrations. Molecules 2019; 24:E3238. [PMID: 31492010 PMCID: PMC6766815 DOI: 10.3390/molecules24183238] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Revised: 08/26/2019] [Accepted: 09/02/2019] [Indexed: 11/16/2022] Open
Abstract
Phosphonic acids, aminophosphonic acids, and phosphonocarboxylic acids are characterized by an advanced hyphenated technique, combining potentiometric titration with NMR spectroscopy. Automated measurements involving 13C, 19F and 31P nuclei lead to "pseudo 2D NMR" spectra, where chemical shifts or coupling constants are correlated with analytical parameters. Dissociation constants, stability constants, dynamic and specific chemical shifts are determined. Macroscopic and microscopic dissociation equilibria are discussed.
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Affiliation(s)
- Gerhard Hägele
- Institute of Inorganic Chemistry and Structural Chemistry, Heinrich-Heine-University Düsseldorf, Universitätsstraße 1, D-40225 Düsseldorf, Germany.
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3
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Meshkov AN, Gamov GA. KEV: A free software for calculating the equilibrium composition and determining the equilibrium constants using UV-Vis and potentiometric data. Talanta 2019; 198:200-205. [PMID: 30876550 DOI: 10.1016/j.talanta.2019.01.107] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Revised: 01/28/2019] [Accepted: 01/30/2019] [Indexed: 01/19/2023]
Abstract
Present paper reports on an algorithm for calculating the equilibrium composition of several compounds mixture if their total (equilibrium) concentrations and the equilibrium constants of reactions between them are known. The algorithm for determining the unknown equilibrium constants from UV-Vis or potentiometric experimental data using minimizing function (maximal likelihood method) is described. The recommendations on the evaluating of equilibrium constants from experimental results are given. The algorithms described are realized as free-of-charge distributed software/scripts bundle/source code.
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Affiliation(s)
- A N Meshkov
- Dentsu Aegis Network Russia, Presnenskaya nab. 6/2, 123317 Moscow, Russia.
| | - G A Gamov
- Research Institute of Thermodynamics and Kinetics of Chemical Processes, Ivanovo State University of Chemistry and Technology, Sheremetevskii pr. 10, 153000 Ivanovo, Russia.
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4
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Thiele NA, MacMillan SN, Wilson JJ. Rapid Dissolution of BaSO 4 by Macropa, an 18-Membered Macrocycle with High Affinity for Ba 2. J Am Chem Soc 2018; 140:17071-17078. [PMID: 30485079 PMCID: PMC6560633 DOI: 10.1021/jacs.8b08704] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Insoluble BaSO4 scale is a costly and time-consuming problem in the petroleum industry. Clearance of BaSO4-impeded pipelines requires chelating agents that can efficiently bind Ba2+, the largest nonradioactive +2 metal ion. Due to the poor affinity of currently available chelating agents for Ba2+, however, the dissolution of BaSO4 remains inefficient, requiring very basic solutions of ligands. In this study, we investigated three diaza-18-crown-6 macrocycles bearing different pendent arms for the chelation of Ba2+ and assessed their potential for dissolving BaSO4 scale. Remarkably, the bis-picolinate ligand macropa exhibits the highest affinity reported to date for Ba2+ at pH 7.4 (log K' = 10.74), forming a complex of significant kinetic stability with this large metal ion. Furthermore, the BaSO4 dissolution properties of macropa dramatically surpass those of the state-of-the-art ligands DTPA and DOTA. Using macropa, complete dissolution of a molar equivalent of BaSO4 is reached within 30 min at room temperature in pH 8 buffer, conditions under which DTPA and DOTA only achieve 40% dissolution of BaSO4. When further applied for the dissolution of natural barite, macropa also outperforms DTPA, showing that this ligand is potentially valuable for industrial processes. Collectively, this work demonstrates that macropa is a highly effective chelator for Ba2+ that can be applied for the remediation of BaSO4 scale.
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Affiliation(s)
- Nikki A. Thiele
- Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, New York 14853, USA
| | - Samantha N. MacMillan
- Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, New York 14853, USA
| | - Justin J. Wilson
- Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, New York 14853, USA
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5
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Wurzer A, Vágner A, Horváth D, Fellegi F, Wester HJ, Kálmán FK, Notni J. Synthesis of Symmetrical Tetrameric Conjugates of the Radiolanthanide Chelator DOTPI for Application in Endoradiotherapy by Means of Click Chemistry. Front Chem 2018; 6:107. [PMID: 29692987 PMCID: PMC5902495 DOI: 10.3389/fchem.2018.00107] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Accepted: 03/22/2018] [Indexed: 12/27/2022] Open
Abstract
Due to its 4 carbonic acid groups being available for bioconjugation, the cyclen tetraphosphinate chelator DOTPI, 1,4,7,10-tetraazacyclododecane-1,4,7, 10-tetrakis[methylene(2-carboxyethylphosphinic acid)], represents an ideal scaffold for synthesis of tetrameric bioconjugates for labeling with radiolanthanides, to be applied as endoradiotherapeuticals. We optimized a protocol for bio-orthogonal DOTPI conjugation via Cu(I)-catalyzed Huisgen-cycloaddition of terminal azides and alkynes (CuAAC), based on the building block DOTPI(azide)4. A detailed investigation of kinetic properties of Cu(II)-DOTPI complexes aimed at optimization of removal of DOTPI-bound copper by transchelation. Protonation and equilibrium properties of Ca(II)-, Zn(II), and Cu(II)-complexes of DOTPI and its tetra-cyclohexylamide DOTPI(Chx)4 (a model for DOTPI conjugates) as well as kinetic inertness (transchelation challenge in the presence of 20 to 40-fold excess of EDTA) were investigated by pH-potentiometry and spectrophotometry. Similar stability constants of CaII-, ZnII, and CuII-complexes of DOTPI (logK(CaL) = 8.65, logK(ZnL = 15.40, logK(CuL) = 20.30) and DOTPI(Chx)4 (logK(CaL) = 8.99, logK(ZnL) = 15.13, logK(CuL) = 20.42) were found. Transchelation of Cu(II)-complexes occurs via proton-assisted dissociation, whereafter released Cu(II) is scavenged by EDTA. The corresponding dissociation rates [kd = 25 × 10−7 and 5 × 10−7 s−1 for Cu(DOTPI) and Cu(DOTPI(Chx)4), respectively, at pH 4 and 298 K] indicate that conjugation increases the kinetic inertness by a factor of 5. However, demetallation is completed within 4.5 and 7.2 h at pH 2 and 25°C, respectively, indicating that Cu(II) removal after formation of CuAAC can be achieved in an uncomplicated manner by addition of excess H4EDTA. For proof-of-principle, tetrameric DOTPI conjugates of the prostate-specific membrane antigen (PSMA) targeting motif Lys-urea-Glu (KuE) were synthesized via CuAAC as well as dibenzo-azacyclooctine (DBCO) based, strain-promoted click chemistry (SPAAC), which were labeled with Lu-177 and subsequently evaluated in vitro and in SCID mice bearing subcutaneous LNCaP tumor (PSMA+ human prostate carcinoma) xenografts. High affinities (3.4 and 1.4 nM, respectively) and persistent tumor uptakes (approx. 3.5% 24 h after injection) confirm suitability of DOTPI-based tetramers for application in targeted radionuclide therapy.
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Affiliation(s)
- Alexander Wurzer
- Pharmaceutical Radiochemistry, Technische Universität München, Munich, Germany
| | - Adrienn Vágner
- Department of Inorganic and Analytical Chemistry, University of Debrecen, Debrecen, Hungary
| | - Dávid Horváth
- Department of Inorganic and Analytical Chemistry, University of Debrecen, Debrecen, Hungary
| | - Flóra Fellegi
- Department of Inorganic and Analytical Chemistry, University of Debrecen, Debrecen, Hungary
| | - Hans-Jürgen Wester
- Pharmaceutical Radiochemistry, Technische Universität München, Munich, Germany
| | - Ferenc K Kálmán
- Department of Inorganic and Analytical Chemistry, University of Debrecen, Debrecen, Hungary
| | - Johannes Notni
- Pharmaceutical Radiochemistry, Technische Universität München, Munich, Germany
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6
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Zhang L, Martins AF, Zhao P, Tieu M, Esteban-Gomez D, McCandless GT, Platas-Iglesias C, Sherry AD. Enantiomeric Recognition of d- and l-Lactate by CEST with the Aid of a Paramagnetic Shift Reagent. J Am Chem Soc 2017; 139:17431-17437. [PMID: 29083166 PMCID: PMC5796655 DOI: 10.1021/jacs.7b08292] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
A previous report demonstrated that EuDO3A could be used as an NMR shift reagent for imaging extracellular lactate produced by cancer cells using CEST imaging. In this work, a series of heptadentate macrocyclic YbDO3A-trisamide complexes with δ-chiral carbons in the three pendant side-arms were examined as shift reagents for lactate detection. High resolution 1H NMR spectra and DFT calculations provided evidence for the formation of stereoselective lactate·YbDO3A-trisamide complexes each with a different CEST signature. This stereoselectivity allowed discrimination of d- versus l-lactate by both high-resolution NMR and CEST. This work demonstrates that lanthanide-based paramagnetic shift reagents can be designed to detect important metabolites by CEST MRI selectively.
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Affiliation(s)
- Lei Zhang
- Department of Chemistry, University of Texas at Dallas, 800 West Campbell Road, Richardson, Texas 75080, United States
| | - André F. Martins
- Department of Chemistry, University of Texas at Dallas, 800 West Campbell Road, Richardson, Texas 75080, United States
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas 75390, United States
| | - Piyu Zhao
- Department of Chemistry, University of Texas at Dallas, 800 West Campbell Road, Richardson, Texas 75080, United States
| | - Michael Tieu
- Department of Chemistry, University of Texas at Dallas, 800 West Campbell Road, Richardson, Texas 75080, United States
| | - David Esteban-Gomez
- Departamento de Química, Facultade de Ciencias & Centro de Investigacións Científicas Avanzadas (CICA), Universidade da Coruña, 15071 A Coruña, Spain
| | - Gregory T. McCandless
- Department of Chemistry, University of Texas at Dallas, 800 West Campbell Road, Richardson, Texas 75080, United States
| | - Carlos Platas-Iglesias
- Departamento de Química, Facultade de Ciencias & Centro de Investigacións Científicas Avanzadas (CICA), Universidade da Coruña, 15071 A Coruña, Spain
| | - A. Dean Sherry
- Department of Chemistry, University of Texas at Dallas, 800 West Campbell Road, Richardson, Texas 75080, United States
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas 75390, United States
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7
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Krchová T, Herynek V, Gálisová A, Blahut J, Hermann P, Kotek J. Eu(III) Complex with DO3A-amino-phosphonate Ligand as a Concentration-Independent pH-Responsive Contrast Agent for Magnetic Resonance Spectroscopy (MRS). Inorg Chem 2017; 56:2078-2091. [PMID: 28170242 DOI: 10.1021/acs.inorgchem.6b02749] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
A new DOTA-like ligand H5do3aNP with a 2-[amino(methylphosphonic acid)]ethyl-coordinating pendant arm was prepared, and its coordinating properties were studied by NMR spectroscopy and potentiometry. The study revealed a rare slow exchange (on the 1H and 31P NMR time scale) between protonated and unprotonated complex species with a corresponding acidity constant pKA ∼ 8.0. This unusually slow time scale associated with protonation is caused by a significant geometric change from square-antiprismatic (SA) arrangement observed for protonated complex SA-[Eu(Hdo3aNP)]- to twisted-square-antiprismatic (TSA) arrangement found for deprotonated complex TSA-[Eu(do3aNP)]2-. This behavior results in simultaneous occurrence of the signals of both species in the 31P NMR spectra at approximately -118 and +70 ppm, respectively. Such an unprecedented difference in the chemical shifts between species differing by a proton is caused by a significant movement of the principal magnetic axis and by a change of phosphorus atom position in the coordination sphere of the central Eu(III) ion (i.e., by relative movement of the phosphorus atom with respect to the principal magnetic axis). It changes the sign of the paramagnetic contribution to the 31P NMR chemical shift. The properties discovered can be employed in the measurement of pH by MRS techniques as presented by proof-of-principle experiments on phantoms.
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Affiliation(s)
- Tereza Krchová
- Department of Inorganic Chemistry, Faculty of Science, Charles University , Hlavova 2030, Prague 2 128 43, Czech Republic
| | - Vít Herynek
- Department of Radiodiagnostic and Interventional Radiology, Magnetic Resonance Unit, Institute for Clinical and Experimental Medicine , Vídeňská 1958/9, Prague 4 140 21, Czech Republic
| | - Andrea Gálisová
- Department of Radiodiagnostic and Interventional Radiology, Magnetic Resonance Unit, Institute for Clinical and Experimental Medicine , Vídeňská 1958/9, Prague 4 140 21, Czech Republic
| | - Jan Blahut
- Department of Inorganic Chemistry, Faculty of Science, Charles University , Hlavova 2030, Prague 2 128 43, Czech Republic
| | - Petr Hermann
- Department of Inorganic Chemistry, Faculty of Science, Charles University , Hlavova 2030, Prague 2 128 43, Czech Republic
| | - Jan Kotek
- Department of Inorganic Chemistry, Faculty of Science, Charles University , Hlavova 2030, Prague 2 128 43, Czech Republic
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8
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Hydroxy-bisphosphinic acids: synthesis and complexation properties with transition metals and lanthanide ions in aqueous solution. JOURNAL OF THE IRANIAN CHEMICAL SOCIETY 2015. [DOI: 10.1007/s13738-015-0787-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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9
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Ševčík R, Vaněk J, Lubal P, Kotková Z, Kotek J, Hermann P. Formation and dissociation kinetics of copper(II) complexes with tetraphosphorus acid DOTA analogs. Polyhedron 2014. [DOI: 10.1016/j.poly.2013.09.024] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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10
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Šimeček J, Hermann P, Havlíčková J, Herdtweck E, Kapp TG, Engelbogen N, Kessler H, Wester HJ, Notni J. A cyclen-based tetraphosphinate chelator for the preparation of radiolabeled tetrameric bioconjugates. Chemistry 2013; 19:7748-57. [PMID: 23613345 DOI: 10.1002/chem.201300338] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2013] [Indexed: 01/17/2023]
Abstract
The cyclen-based tetraphosphinate chelator 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetrakis[methylene(2-carboxyethyl)phosphinic acid] (DOTPI) comprises four additional carboxylic acid moieties for bioconjugation. The thermodynamic stability constants (logK(ML)) of metal complexes, as determined by potentiometry, were 23.11 for Cu(II), 20.0 for Lu(III), 19.6 for Y(III), and 21.0 for Gd(III). DOTPI was functionalized with four cyclo(Arg-Gly-Asp-D-Phe-Lys) (RGD) peptides through polyethylene glycol (PEG4) linkers. The resulting tetrameric conjugate DOTPI(RGD)4 was radiolabeled with (177)Lu and (64)Cu and showed improved labeling efficiency compared with 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA). The labeled compounds were fully stable in transchelation challenges against trisodium diethylenetriaminepentaacetate (DTPA) and disodium ethylenediaminetetraacetic acid (ETDA), in phosphate buffered saline (PBS), and human plasma. Integrin αvβ3 affinities of the non-radioactive Lu(III) and Cu(II) complexes of DOTPI(RGD)4 were 18 times higher (both IC50 about 70 picomolar) than that of the c(RGDfK) peptide (IC50 = 1.3 nanomolar). Facile access to tetrameric conjugates and the possibility of radiolabeling with therapeutic and diagnostic radionuclides render DOTPI suitable for application in peptide receptor radionuclide imaging (PRRI) and therapy (PRRT).
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Affiliation(s)
- Jakub Šimeček
- Lehrstuhl für Pharmazeutische Radiochemie, Technische Universität München, Walther-Meissner Strasse 3, 85748 Garching, Germany
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11
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Drahoš B, Kotek J, Cı́sařová I, Hermann P, Helm L, Lukeš I, Tóth É. Mn2+ Complexes with 12-Membered Pyridine Based Macrocycles Bearing Carboxylate or Phosphonate Pendant Arm: Crystallographic, Thermodynamic, Kinetic, Redox, and 1H/17O Relaxation Studies. Inorg Chem 2011; 50:12785-801. [DOI: 10.1021/ic201935r] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Bohuslav Drahoš
- Department of Inorganic Chemistry,
Faculty of Science, Universita Karlova (Charles
University), Hlavova 2030, 128 43 Prague 2, Czech Republic
- Centre de Biophysique Moléculaire, CNRS, rue Charles Sadron, 45071 Orléans, France
| | - Jan Kotek
- Department of Inorganic Chemistry,
Faculty of Science, Universita Karlova (Charles
University), Hlavova 2030, 128 43 Prague 2, Czech Republic
| | - Ivana Cı́sařová
- Department of Inorganic Chemistry,
Faculty of Science, Universita Karlova (Charles
University), Hlavova 2030, 128 43 Prague 2, Czech Republic
| | - Petr Hermann
- Department of Inorganic Chemistry,
Faculty of Science, Universita Karlova (Charles
University), Hlavova 2030, 128 43 Prague 2, Czech Republic
| | - Lothar Helm
- Ecole Polytechnique Fédérale de Lausanne, BCH, Lausanne, Switzerland
| | - Ivan Lukeš
- Department of Inorganic Chemistry,
Faculty of Science, Universita Karlova (Charles
University), Hlavova 2030, 128 43 Prague 2, Czech Republic
| | - Éva Tóth
- Centre de Biophysique Moléculaire, CNRS, rue Charles Sadron, 45071 Orléans, France
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Palma E, Correia JDG, Campello MPC, Santos I. Bisphosphonates as radionuclide carriers for imaging or systemic therapy. MOLECULAR BIOSYSTEMS 2011; 7:2950-66. [PMID: 21879109 DOI: 10.1039/c1mb05242j] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Bisphosphonates (BP's), biologically stable analogs of naturally occurring pyrophosphates, became the treatment of choice for pathologic conditions characterized by increased osteoclast-mediated bone resorption, namely Paget's disease, osteoporosis and tumor bone disease. Moreover, the clinical success of BP's is also associated with their use in (99m)Tc-based radiopharmaceuticals for bone imaging. In addition to the successful delivery of (99m)Tc (γ-emitter) to bone, BP's have also been used to deliver β(-)-particle emitting radiometals (e.g.(153)Sm, (186/188)Re) for bone-pain palliation. The main goal of this Review is to update the most recent research efforts toward the synthesis, characterization and biological evaluation of novel BP-containing radiometal complexes and radiohalogenated compounds for diagnostic or therapeutic purposes. The structure and in vivo properties of those compounds will be discussed and compared to the clinically available ones, namely in terms of image quality and therapeutic effect. We will also mention briefly the use of BP's as carriers of multimodal nuclear and optical imaging probes.
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Affiliation(s)
- Elisa Palma
- Unidade de Ciências Químicas e Radiofarmacêuticas, ITN, Estrada Nacional 10, 2686-953 Sacavém, Portugal
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Campello MPC, Lacerda S, Santos IC, Pereira GA, Geraldes CFGC, Kotek J, Hermann P, Vanek J, Lubal P, Kubícek V, Tóth E, Santos I. Lanthanide(III) complexes of 4,10-bis(phosphonomethyl)-1,4,7,10-tetraazacyclododecane-1,7-diacetic acid (trans-H6do2a2p) in solution and in the solid state: structural studies along the series. Chemistry 2010; 16:8446-65. [PMID: 20540046 DOI: 10.1002/chem.201000320] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Complexes of 4,10-bis(phosphonomethyl)-1,4,7,10-tetraazacyclododecane-1,7-diacetic acid (trans-H(6)do2a2p, H(6)L) with transition metal and lanthanide(III) ions were investigated. The stability constant values of the divalent and trivalent metal-ion complexes are between the corresponding values of H(4)dota and H(8)dotp complexes, as a consequence of the ligand basicity. The solid-state structures of the ligand and of nine lanthanide(III) complexes were determined by X-ray diffraction. All the complexes are present as twisted-square-antiprismatic isomers and their structures can be divided into two series. The first one involves nona-coordinated complexes of the large lanthanide(III) ions (Ce, Nd, Sm) with a coordinated water molecule. In the series of Sm, Eu, Tb, Dy, Er, Yb, the complexes are octa-coordinated only by the ligand donor atoms and their coordination cages are more irregular. The formation kinetics and the acid-assisted dissociation of several Ln(III)-H(6)L complexes were investigated at different temperatures and compared with analogous data for complexes of other dota-like ligands. The [Ce(L)(H(2)O)](3-) complex is the most kinetically inert among complexes of the investigated lanthanide(III) ions (Ce, Eu, Gd, Yb). Among mixed phosphonate-acetate dota analogues, kinetic inertness of the cerium(III) complexes is increased with a higher number of phosphonate arms in the ligand, whereas the opposite is true for europium(III) complexes. According to the (1)H NMR spectroscopic pseudo-contact shifts for the Ce-Eu and Tb-Yb series, the solution structures of the complexes reflect the structures of the [Ce(HL)(H(2)O)](2-) and [Yb(HL)](2-) anions, respectively, found in the solid state. However, these solution NMR spectroscopic studies showed that there is no unambiguous relation between (31)P/(1)H lanthanide-induced shift (LIS) values and coordination of water in the complexes; the values rather express a relative position of the central ions between the N(4) and O(4) planes.
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Affiliation(s)
- M Paula C Campello
- Departamento de Química, Instituto Tecnológico e Nuclear, Estrada Nacional 10, 2686-953 Sacavém, Portugal
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14
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Campello M, Balbina M, Santos I, Lubal P, SÌevcÌÃk R, SÌevcÌÃková R. Lanthanide(III) Complexes of 2-[4,7,10-Tris(phosphonomethyl)-1,4,7,10-tetraazacyclododecan-1-yl]acetic Acid (H7DOA3P): Multinuclear-NMR and Kinetic Studies. Helv Chim Acta 2009. [DOI: 10.1002/hlca.200900176] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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15
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Pereira G, Ball L, Sherry A, Peters J, Geraldes C. NMR Characterization of Lanthanide(3+) Complexes of Tetraazatetrakisphosphinato and TetraazatetraÂkisphosphonato Ligands. Helv Chim Acta 2009. [DOI: 10.1002/hlca.200900160] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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16
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Mamedov I, Táborský P, Lubal P, Laurent S, Vander Elst L, Mayer HA, Logothetis NK, Angelovski G. Relaxometric, Thermodynamic and Kinetic Studies of Lanthanide(III) Complexes of DO3A‐Based Propylphosphonates. Eur J Inorg Chem 2009. [DOI: 10.1002/ejic.200900149] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Ilgar Mamedov
- Physiology of Cognitive Processes, Max Planck Institute for Biological Cybernetics, Spemannstr. 38, 72076 Tübingen, Germany, Fax: +49‐7071‐601‐919
| | - Petr Táborský
- Department of Chemistry, Masaryk University Kotlářská 2, 611 37 Brno, Czech Republic, Fax: +420‐549‐49‐2494
| | - Přemysl Lubal
- Department of Chemistry, Masaryk University Kotlářská 2, 611 37 Brno, Czech Republic, Fax: +420‐549‐49‐2494
| | - Sophie Laurent
- Department of General, Organic and Biomedical Chemistry, NMR and Molecular Imaging Laboratory, University of Mons, Mons, Belgium
| | - Luce Vander Elst
- Department of General, Organic and Biomedical Chemistry, NMR and Molecular Imaging Laboratory, University of Mons, Mons, Belgium
| | - Hermann A. Mayer
- Department for Inorganic Chemistry, Eberhard‐Karls‐Universität Tübingen, Tübingen, Germany
| | - Nikos K. Logothetis
- Physiology of Cognitive Processes, Max Planck Institute for Biological Cybernetics, Spemannstr. 38, 72076 Tübingen, Germany, Fax: +49‐7071‐601‐919
- Imaging Science and Biomedical Engineering, University of Manchester, Manchester, United Kingdom
| | - Goran Angelovski
- Physiology of Cognitive Processes, Max Planck Institute for Biological Cybernetics, Spemannstr. 38, 72076 Tübingen, Germany, Fax: +49‐7071‐601‐919
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Kotková Z, Pereira GA, Djanashvili K, Kotek J, Rudovský J, Hermann P, Vander Elst L, Muller RN, Geraldes CFGC, Lukeš I, Peters JA. Lanthanide(III) Complexes of Phosphorus Acid Analogues of H4DOTA as Model Compounds for the Evaluation of the Second-Sphere Hydration. Eur J Inorg Chem 2009. [DOI: 10.1002/ejic.200800859] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Försterová M, Jandurová Z, Marques F, Gano L, Lubal P, Vanek J, Hermann P, Santos I. Chemical and biological evaluation of 153Sm and 166Ho complexes of 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetrakis(methylphosphonic acid monoethylester) (H4 dotp OEt). J Inorg Biochem 2008; 102:1531-40. [PMID: 18374985 DOI: 10.1016/j.jinorgbio.2008.02.002] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2007] [Revised: 01/19/2008] [Accepted: 02/04/2008] [Indexed: 11/28/2022]
Abstract
The novel methylphosphonic acid monoethylester (H(4)dotp(OEt)) has been synthesized and characterized and their complexes with Sm(III) and Ho(III) ions were studied. Dissociation constants of the ligand are lower than those of H(4)dota. The stability constants of the Ln(III)-H(4)dotp(OEt) complexes are surprisingly much lower that those of H(4)dota (H(4)dota=1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid) probably due to a lower coordination ability of the phosphonate monoester groups. Acid-assisted decomplexation studies have shown that both complexes are less kinetically inert than the H(4)dota complexes, but still much more inert than complexes of open-chain ligands. Nevertheless, the synthesis of (153)Sm and (166)Ho complexes with this ligand led to stable complexes both in vitro and in vivo. A very low binding of these complexes to hydroxyapatite (HA) and calcified tissues was observed confirming the assumption that a fully ionized phosphonate group(s) is necessary for a strong bone affinity. Both complexes show similar behaviour in vivo and, in general, follow the biodistribution trend of the H(4)dota complexes with the same metals.
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Affiliation(s)
- Michaela Försterová
- Department of Inorganic Chemistry, Faculty of Science, Universita Karlova (Charles University), Hlavova 2030, 128 40 Prague 2, Czech Republic
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Notni J, Schenk S, Görls H, Breitzke H, Anders E. Formation of a Unique Zinc Carbamate by CO2 Fixation: Implications for the Reactivity of Tetra-Azamacrocycle Ligated Zn(II) Complexes. Inorg Chem 2008; 47:1382-90. [DOI: 10.1021/ic701899u] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Johannes Notni
- Friedrich-Schiller-Universität Jena, Institut
für Organische Chemie and Makromolekulare Chemie, Humboldtstr.
10, D-07743 Jena, Germany,
- Laboratorium für Physikalische Chemie, ETH Zürich, Wolfgang-Pauli-Str. 10, CH-8093 Zürich, Switzerland,
- Friedrich-Schiller-Universität Jena, Institut für Anorganizche and Analytische Chemie, Lessingstr. 8, D-07743 Jena, Germany,
- Friedrich-Schiller-Universität Jena, Institut für Physikalische Chemie, and Helmholtzweg 4, D-07743 Jena, Germany
| | - Stephan Schenk
- Friedrich-Schiller-Universität Jena, Institut
für Organische Chemie and Makromolekulare Chemie, Humboldtstr.
10, D-07743 Jena, Germany,
- Laboratorium für Physikalische Chemie, ETH Zürich, Wolfgang-Pauli-Str. 10, CH-8093 Zürich, Switzerland,
- Friedrich-Schiller-Universität Jena, Institut für Anorganizche and Analytische Chemie, Lessingstr. 8, D-07743 Jena, Germany,
- Friedrich-Schiller-Universität Jena, Institut für Physikalische Chemie, and Helmholtzweg 4, D-07743 Jena, Germany
| | - Helmar Görls
- Friedrich-Schiller-Universität Jena, Institut
für Organische Chemie and Makromolekulare Chemie, Humboldtstr.
10, D-07743 Jena, Germany,
- Laboratorium für Physikalische Chemie, ETH Zürich, Wolfgang-Pauli-Str. 10, CH-8093 Zürich, Switzerland,
- Friedrich-Schiller-Universität Jena, Institut für Anorganizche and Analytische Chemie, Lessingstr. 8, D-07743 Jena, Germany,
- Friedrich-Schiller-Universität Jena, Institut für Physikalische Chemie, and Helmholtzweg 4, D-07743 Jena, Germany
| | - Hergen Breitzke
- Friedrich-Schiller-Universität Jena, Institut
für Organische Chemie and Makromolekulare Chemie, Humboldtstr.
10, D-07743 Jena, Germany,
- Laboratorium für Physikalische Chemie, ETH Zürich, Wolfgang-Pauli-Str. 10, CH-8093 Zürich, Switzerland,
- Friedrich-Schiller-Universität Jena, Institut für Anorganizche and Analytische Chemie, Lessingstr. 8, D-07743 Jena, Germany,
- Friedrich-Schiller-Universität Jena, Institut für Physikalische Chemie, and Helmholtzweg 4, D-07743 Jena, Germany
| | - Ernst Anders
- Friedrich-Schiller-Universität Jena, Institut
für Organische Chemie and Makromolekulare Chemie, Humboldtstr.
10, D-07743 Jena, Germany,
- Laboratorium für Physikalische Chemie, ETH Zürich, Wolfgang-Pauli-Str. 10, CH-8093 Zürich, Switzerland,
- Friedrich-Schiller-Universität Jena, Institut für Anorganizche and Analytische Chemie, Lessingstr. 8, D-07743 Jena, Germany,
- Friedrich-Schiller-Universität Jena, Institut für Physikalische Chemie, and Helmholtzweg 4, D-07743 Jena, Germany
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Havlíčková J, Medová H, Vitha T, Kotek J, Císařová I, Hermann P. Coordination properties of cyclam (1,4,8,11-tetraazacyclotetradecane) endowed with two methylphosphonic acid pendant arms in the 1,4-positions. Dalton Trans 2008:5378-86. [DOI: 10.1039/b803235a] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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21
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Kubíček V, Řehoř I, Havlíčková J, Kotek J, Císařová I, Hermann P, Lukeš I. Synthesis and Coordination Behavior of Symmetrical Tetraamine Phosphinic Acids. Eur J Inorg Chem 2007. [DOI: 10.1002/ejic.200700010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Vojtěch Kubíček
- Department of Inorganic Chemistry, Faculty of Science, Charles University in Prague, Hlavova 8, 128 40 Prague 2, The Czech Republic
| | - Ivan Řehoř
- Department of Inorganic Chemistry, Faculty of Science, Charles University in Prague, Hlavova 8, 128 40 Prague 2, The Czech Republic
| | - Jana Havlíčková
- Department of Inorganic Chemistry, Faculty of Science, Charles University in Prague, Hlavova 8, 128 40 Prague 2, The Czech Republic
| | - Jan Kotek
- Department of Inorganic Chemistry, Faculty of Science, Charles University in Prague, Hlavova 8, 128 40 Prague 2, The Czech Republic
| | - Ivana Císařová
- Department of Inorganic Chemistry, Faculty of Science, Charles University in Prague, Hlavova 8, 128 40 Prague 2, The Czech Republic
| | - Petr Hermann
- Department of Inorganic Chemistry, Faculty of Science, Charles University in Prague, Hlavova 8, 128 40 Prague 2, The Czech Republic
| | - Ivan Lukeš
- Department of Inorganic Chemistry, Faculty of Science, Charles University in Prague, Hlavova 8, 128 40 Prague 2, The Czech Republic
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Tircsó G, Bényei A, Király R, Lázár I, Pál R, Brücher E. Complexation Properties of the Di-, Tri-, and Tetraacetate Derivatives of Bis(aminomethyl)phosphinic Acid. Eur J Inorg Chem 2007. [DOI: 10.1002/ejic.200600891] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Försterová M, Svobodová I, Lubal P, Táborský P, Kotek J, Hermann P, Lukes I. Thermodynamic study of lanthanide(iii) complexes with bifunctional monophosphinic acid analogues of H4dota and comparative kinetic study of yttrium(iii) complexes. Dalton Trans 2007:535-49. [PMID: 17225905 DOI: 10.1039/b613404a] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
New bifunctional H(4)dota-like ligands with three acetic acid and one phosphinic acid pendant arms and propionate (H(5)do3ap(PrA)) or 4-aminobenzyl (H(4)do3ap(ABn)) reactive groups bound to the phosphorus atom were investigated. Potentiometric studies showed that the ligands have a similar basicity to the parent H(4)dota and the stability constants of their complexes with sodium(i) and selected lanthanide(III) ions are also similar. Formation and acid-assisted decomplexation kinetics of yttrium(III) complexes with a series of H(4)dota-like ligands (H(4)dota and its phosphinic/phosphonic acid analogues) were studied and the reactions are sensitive to a slight modification of the ligand structure. The (2-carboxyethyl)phosphinic acid derivative H(5)do3ap(PrA) and the phosphonic acid ligand H(5)do3ap form complexes faster than H(4)dota. The most kinetically inert complex is that with H(4)do3ap(ABn). Rates of complexation and decomplexation can depend on the ability to transfer proton(s) outside/inside the complex cavity and, therefore, on the hydrophobicity of the ligands. The results demonstrate that the new bifunctional ligands are suitable for labelling biomolecules with yttrium(iii) radioisotopes for utilization in nuclear medicine.
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Affiliation(s)
- Michaela Försterová
- Department of Inorganic Chemistry, Universita Karlova (Charles University), Hlavova 2030, 128 40 Prague 2, Czech Republic.
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24
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Delgado R, Félix V, Lima LMP, Price DW. Metal complexes of cyclen and cyclam derivatives useful for medical applications: a discussion based on thermodynamic stability constants and structural data. Dalton Trans 2007:2734-45. [PMID: 17592589 DOI: 10.1039/b704360k] [Citation(s) in RCA: 141] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A series of the most common chelators used in magnetic resonance imaging (MRI) and in radiopharmaceuticals for medical diagnosis and tumour therapy, H(4)dota, H(4)teta, H(8)dotp and H(8)tetp, is examined from a chemical point of view. Differences between 12- and 14-membered tetraazamacrocyclic derivatives with methylcarboxylate and methylphosphonate pendant arms and their chelates with divalent first-series transition metal and trivalent lanthanide ions are discussed on the basis of their thermodynamic stability constants, X-ray structures and theoretical studies.
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Affiliation(s)
- Rita Delgado
- Instituto de Tecnologia Química e Biológica, UNL, Apartado 127, 2781-901, Oeiras, Portugal.
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25
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Svobodová I, Lubal P, Plutnar J, Havlícková J, Kotek J, Hermann P, Lukes I. Thermodynamic, kinetic and solid-state study of divalent metal complexes of 1,4,8,11-tetraazacyclotetradecane (cyclam) bearing two trans (1,8-)methylphosphonic acid pendant arms. Dalton Trans 2006:5184-97. [PMID: 17077892 DOI: 10.1039/b603251f] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Divalent metal complexes of macrocyclic ligand 1,4,8,11-tetraazacyclotetradecane-1,8-bis(methylphosphonic acid)) (1,8-H4te2p, H4L) were investigated in solution and in the solid state. The majority of transition-metal ions form thermodynamically very stable complexes as a consequence of high affinity for the nitrogen atoms of the ring. On the other hand, complexes with Mn2+, Pb2+ and alkaline earth ions interacting mainly with phosphonate oxygen atoms are much weaker than those of transition-metal ions and are formed only at higher pH. The same tendency is seen in the solid state. Zinc(II) ion in the octahedral trans-O,O-[Zn(H2L)] complex is fully encapsulated within the macrocycle (N4O2 coordination mode with protonated phosphonate oxygen atoms). The polymeric {[Pb(H2L)(H2O)2].6H2O}n complex has double-protonated secondary amino groups and the central atom is bound only to the phosphonate oxygen atoms. The phosphonate moieties bridge lead atoms creating a 3D-polymeric network. The [{(H2O)5Mn}2(micro-H2L)](H2L).21H2O complex contains two pentaaquamanganese(II) moieties bridged by a ligand molecule protonated on two nitrogen atoms. In the complex cation, oxygen atoms of the phosphonate groups on the opposite sites of the ring occupy one coordination site of each metal ion. The second ligand molecule is diprotonated and balances the positive charge of the complex cation. Complexation of zinc(II) and cadmium(II) by the ligand shows large differences in reactivity of differently protonated ligand species similarly to other cyclam-like complexes. Acid-assisted dissociations of metal(II) complexes occur predominantly through triprotonated species [M(H3L)]+ and take place at pH < 5 (Zn2+) and pH < 6 (Cd2+).
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Affiliation(s)
- Ivona Svobodová
- Department of Analytical Chemistry, Masarykova universita (Masaryk University), Kotlárská 2, Brno, 611 37, Czech Republic
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26
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Füzerová S, Kotek J, Císarová I, Hermann P, Binnemans K, Lukes I. Cyclam (1,4,8,11-tetraazacyclotetradecane) with one methylphosphonate pendant arm: a new ligand for selective copper(ii) binding. Dalton Trans 2005:2908-15. [PMID: 16094480 DOI: 10.1039/b507062g] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The new ligand, [(1,4,8,11-tetraazacyclotetradecan-1-yl)methyl]phosphonic acid (H(2)te1P, H(2)L), was synthesized and its complexing properties towards selected metal ions were studied potentiometrically. The ligand forms a very stable complex with copper(ii)(logbeta(CuL)= 27.34), with a high selectivity over binding of other metal ions (i.e. logbeta(ZnL)= 21.03). The crystal structures of the free ligand (in its protonated form with bromide as counter-ion) and two copper(ii) complexes (obtained by crystallization at various pH) were determined. The free ligand adopts the common conformation for such macrocycles with the protonated nitrogen atoms in the corners of a virtual rectangle. In the trans-Br,O-[Cu(Br)(Hte1P)].H(2)O species, the central metal ion is surrounded by four in plane nitrogen atoms, one oxygen atom of the pendant moiety in the apical position and a bromide anion positioned trans to the oxygen atom, forming a distorted octahedral coordination sphere. In the compound [Cu(H(2)te1P)][Cu(Hte1P)]Br(3).6H(2)O, obtained from a highly acidic solution, the bromide anions are placed further away from the copper(ii) ion and the coordination environment (N(4)O) is thus square-pyramidal. In both structures, the protons are associated with non-coordinated phosphonate oxygen atoms.
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Affiliation(s)
- Silvia Füzerová
- Department of Inorganic Chemistry, Universita Karlova (Charles University), Hlavova 2030, Prague 2, 128 40, Czech Republic.
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27
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Táborský P, Lubal P, Havel J, Kotek J, Hermann P, Lukeš I. Thermodynamic and Kinetic Studies of Lanthanide(III) Complexes with H5do3ap (1,4,7,10-Tetraazacyclododecane-1,4,7-triacetic-10-(methylphosphonic Acid)), a Monophosphonate Analogue of H4dota. ACTA ACUST UNITED AC 2005. [DOI: 10.1135/cccc20051909] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Solution properties of complexes of a new H4dota-like ligand containing three acetate and one methylphosphonate pendant arms (H5do3ap, H5L) were studied. The ligand exhibits a high last dissociation constant (pKA = 13.83) as a consequence of the presence of phosphonate moiety. In solution, successive attachment of protons leads to several reorganizations of protonation sites and the neutral zwitterionic species H5do3ap has the same solution structure as in the solid state, where the nitrogen atom binding methylphosphonate and the opposite nitrogen atoms are protonated. Stability constants with Na+ and trivalent lanthanide ions (La3+, Ce3+, Eu3+, Gd3+, Lu3+) and Y3+ have been determined. The constants are comparable or higher than those of H4dota due to the higher overall basicity of H5do3ap. Formation of the stable protonated complexes, as well as complexes with the L:M = 1:2 stoichiometry, was proved. Formation and decomplexation kinetics of the Ce3+ and Gd3+ complexes were investigated. The mechanism of formation of the H5do3ap complexes is similar to that observed for H4dota complexes and the complex species with mono- or diprotonated ligand on the cyclen ring are considered as the reaction intermediates. Acid-assisted decomplexation of H5do3ap complexes is faster in comparison with those of H4dota. This is caused by higher basicity of the phosphonate pendant arm and the ring nitrogen atoms, which facilitates the proton transfer from the bulk solution to the nitrogen atoms of cyclen ring.
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28
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Jaumot J, Vives M, Gargallo R. Application of multivariate resolution methods to the study of biochemical and biophysical processes. Anal Biochem 2004; 327:1-13. [PMID: 15033505 DOI: 10.1016/j.ab.2003.12.028] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2003] [Indexed: 11/27/2022]
Abstract
Multivariate resolution methods make up a set of mathematical tools that may be applied to the analysis and interpretation of spectroscopic data recorded when monitoring a physical or chemical process with multichannel detectors. The goal of resolution methods is the recovery of chemical and/or physical information from the experimental data. Such data include, for example, the number of intermediates present in a reaction, the rate or equilibrium constants, and the spectra for each one of those intermediates. Multivariate resolution methods have been shown to be useful for the study of biophysical and biochemical processes such as folding/unfolding of proteins or nucleic acids. The present article reviews the most frequently used resolution methods, the limitations on their use, and their latest applications in protein and nucleic acid research.
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Affiliation(s)
- Joaquim Jaumot
- Departament de Química Analítica, Universitat de Barcelona, Martí i Franqués 1-11, E-08028 Barcelona, Spain
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29
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Kubíček V, Vojtíšek P, Rudovský J, Hermann P, Lukeš I. Complexes of divalent transition metal ions with bis(aminomethyl)phosphinic acid in aqueous solution and in the solid state. Dalton Trans 2003. [DOI: 10.1039/b305844a] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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30
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Wang Y, Parkin S, Atwood D. Ligand-tetrahydrofuran coupling in chelated aluminum phosphinates. Inorg Chem 2002; 41:558-65. [PMID: 11825083 DOI: 10.1021/ic0110326] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
When the reagents LAlMe (L = N,N'-(alkylene or arylene)bis(3,5-di-tert-butyl)salicylideneimine (alkylene = ethylene (Salen(tBu))(1), propylene (Salpen(tBu))(2), and butylene (Salben(tBu)) (3); arylene = phenylene (Salophen(tBu) (4), 3,4-dimethylphenylene (Salomphen(tBu) (5)) are combined with Ph(H)P(O)OH in tetrahydrofuran (thf) the unique aluminophosphinate compounds, [L(tBu)Al[O(2)P(H)Ph]](n) with L, n = Salen,(infinity)(6), Salpen, 2 (7), Salben, 2 (8), Salophen, (infinity)(9) and Salomphen, (infinity)(10) are produced. The yields for the latter two reactions are low, and it was subsequently found that the unique thf-coupled compounds appear in the thf filtrates of the original reaction mixture. These compounds are, [L-thf(tBu)Al[O(2)P(H)Ph]](2), L = Salophen (13) and Salomphen (14). The thf connects through an alpha-carbon to only one of the two possible imine carbons of the ligand. While trying to determine how this coupling proceeds, the six-coordinate, solution-state species LAlMe(thf) (L = Salophen (11) and Salomphen (12) were discovered and implicated as intermediates. All of the compounds are characterized by melting point, NMR, IR, and X-ray analyses for 5-8, 13, and 14. A possible mechanism for the thf coupling event is presented.
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Affiliation(s)
- Y Wang
- Department of Chemistry, University of Kentucky, Lexington, KY 40506-0055, USA
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Lubal P, Kývala M, Hermann P, Holubová J, Rohovec J, Havel J, Lukeš I. Thermodynamic and kinetic study of copper(II) complexes with N-methylene(phenylphosphinic acid) derivatives of cyclen and cyclam. Polyhedron 2001. [DOI: 10.1016/s0277-5387(00)00586-6] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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32
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Kotek J, Vojtíšek P, Císařová I, Hermann P, Lukeš I. Unusual cis/trans Isomerism in Octahedral Nickel(II) Complexes with 1,4,8,11-Tetraazacyclotetradecane-1,8-bis(methylphosphonic Acid) as a Ligand. ACTA ACUST UNITED AC 2001. [DOI: 10.1135/cccc20010363] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Nickel(II) ion reacts with 1,4,8,11-tetraazacyclotetradecane-1,8-bis(methylphosphonic acid) (H4L1) at room temperature with formation of cis-[Ni(L1)]2- complex. The complex was crystallised in several forms in dependence on conditions of isolation (temperature, pH, solvent mixture). Crystal structures of cis-O,O-[Ni(H2L1)] (1), cis-O,O-[Ni(H2L1)]·2H2O (2), cis-O,O-[Ni(H3L1)]Cl·H2O (3) and cis-O,O-[Ni(H4L1)]Cl2·2H2O (4) were determined by X-ray diffraction. In all the compounds, Ni2+ is in octahedral cis-O1,O2-trans-N1,N8-cis-O1,N4-[Ni(L1)]2- (hereafter abbreviated as cis-O,O-[Ni(L1)]2-) arrangement with V conformation of the cyclam ring. Complexes 3 and 4 exhibit very unusual coordination through the phosphoryl group of double-protonated phosphonate moiety. Tetraethylester of H4L1 having only poorly coordinating phosphoryl oxygen atoms also forms nickel(II) complex 5 with cis arrangement. Corresponding trans-O,O-[Ni(L1)]2- complex is formed only in strongly acidic medium through conversion of the cis complex; it was characterised by X-ray diffraction as dihydrochloride dihydrate, trans-O,O-[Ni(H4L1)]Cl2·2H2O (6). The analogous compound (NH4)2(trans-O,O-[Ni(L2)])·H2O (7) is obtained quantitatively by reaction of Ni2+ with 4,11-dibenzyl-1,4,8,11-tetraazacyclotetradecane-1,8-bis(methylphosphonic acid) (H4L2). Formation of this complex 7 in the III cyclam ring conformation is preferred to the cis complex due to steric hindrance of bulky benzyl groups in cis-[Ni(L2)]2- complex with the V cyclam ring conformation.
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Kotek J, Hermann P, Vojtíšek P, Rohovec J, Lukeš I. Crystal Structures and Reactivity of 3a,5a,8a,10a-Tetraazaperhydropyrene Derivatives. An Alternative Approach to Selective Nitrogen Alkylation of 1,4,8,11-Tetraazacyclotetradecane (Cyclam). ACTA ACUST UNITED AC 2000. [DOI: 10.1135/cccc20000243] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
1-Alkyl and 1,8-dialkyl-1,4,8,11-tetraazacyclotetradecanes (alkyl = benzyl or methyl) were synthesised through cis-aminal of cyclam which was obtained by reaction of glyoxal and cyclam. The corresponding trans-aminal was synthesised from the respective linear tetraamine and glyoxal followed by cyclisation using 1,2-dibromoethane. The trans-aminal derivatives cannot be used for preparation of cyclam or its derivatives due to exceptional stability of the aminal bridge. The different reactivity of both cis- and trans-aminals is discussed on the basis of the X-ray structures determined for a series of the cyclam derivatives and could be explained by steric hindrance in the trans-aminals.
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Kotek J, Vojtíšek P, Císařová I, Hermann P, Jurečka P, Rohovec J, Lukeš I. Bis(methylphosphonic Acid) Derivatives of 1,4,8,11-Tetraazacyclotetradecane (Cyclam). Synthesis, Crystal and Molecular Structures, and Solution Properties. ACTA ACUST UNITED AC 2000. [DOI: 10.1135/cccc20001289] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Cyclam derivatives with methylphosphonic acid arms in position 1,8 and substituent R = H, Me, CH2Ph in positions 4 and 11 are synthesised by Mannich reaction of an appropriate cyclam derivative, formaldehyde and phosphonic acid/diethyl phosphite followed by removal of protecting benzyl groups from nitrogen atoms. Mono(methylphosphonic acid) derivative of cyclam can be obtained by a similar route. Crystal structures of four phosphonic acid derivatives show the same ring conformation and orientation pendants due to strong intramolecular hydrogen bonds between phosphonate oxygen atoms and protonated nitrogen atoms adjacent over ethylene chains. The hydrogen bonds are stable even in aqueous solution. Activation parameters for destabilisation of the conformation are estimated from temperature-dependent NMR measurement. The protonation constants determined confirm the expected high basicity of the compounds and its dependence on the nitrogen atom substituents. The enhanced basicity of the nitrogen atoms non-bonded to methylenephosphonic acid moiety, is explained by the presence of the strong hydrogen bonds.
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