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Leygue N, Picard C, Faure P, Bourrier E, Lamarque L, Zwier JM, Galaup C. Design of novel tripyridinophane-based Eu(III) complexes as efficient luminescent labels for bioassay applications. Org Biomol Chem 2021; 20:182-195. [PMID: 34878481 DOI: 10.1039/d1ob02092g] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
In this work, the development of highly luminescent europium(III) complexes in water solution is reported, including their syntheses, analyses of their photophysical properties and applications in bioassays. Three Eu(III) complexes are derived from new ligands based on a tripyridinophane platform. There are four distinct sections in the structure of these ligands: an 18-membered polyaminocarboxylic macrocycle to bind efficiently lanthanide ions in aqueous solutions, three chromophoric subunits (4-(phenylethynyl)pyridine moieties) to effectively sensitize the emission of the metal, two peripheral moieties to solubilise the complex in aqueous media (sulfonate, sulfobetaine or glucose groups) and a free NH2 group available for grafting or bioconjugation. In our synthetic procedure, a pivotal macrocyclic platform is obtained with a high yield in the crucial macrocyclization step due to a metal template ion effect (74% yield). In Tris aqueous buffer (pH 7.4), the Eu(III) complexes show a maximum excitation wavelength at 320 nm, a suitable overall quantum yield (14%), a relatively long lifetime (0.80 ms) and a one-photon brightness in the range of 10 000 M-1 cm-1. Importantly, these photophysical properties are retained at dilute concentrations, even in the presence of a very large excess of potentially competing species, such as EDTA or Mg2+ ions. Furthermore, we report the bioconjugation of a Eu(III) complex labelled by an N-hydroxysuccinimide ester reactive group with an antibody (anti-glutathione-S-transferase) and the successful application of the corresponding antibody conjugate in the detection of GST-biotin in a fluoroimmunoassay. These new complexes provide a solution for high sensitivity in Homogeneous Time-Resolved Fluorescence (HTRF®) bioassays.
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Affiliation(s)
- Nadine Leygue
- SPCMIB, UMR5068 CNRS-Université Paul Sabatier-Toulouse III, 118 Route de Narbonne, F-31062 Toulouse, France.
| | - Claude Picard
- SPCMIB, UMR5068 CNRS-Université Paul Sabatier-Toulouse III, 118 Route de Narbonne, F-31062 Toulouse, France.
| | - Pamela Faure
- Cisbio Bioassays, BP 84175, 30200 Codolet, France.
| | | | | | | | - Chantal Galaup
- SPCMIB, UMR5068 CNRS-Université Paul Sabatier-Toulouse III, 118 Route de Narbonne, F-31062 Toulouse, France.
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Leygue N, Galaup C, Lopera A, Delgado-Pinar E, Williams RM, Gornitzka H, Zwier JM, García-España E, Lamarque L, Picard C. Tripyridinophane Platform Containing Three Acetate Pendant Arms: An Attractive Structural Entry for the Development of Neutral Eu(III) and Tb(III) Complexes in Aqueous Solution. Inorg Chem 2020; 59:1496-1512. [PMID: 31913029 DOI: 10.1021/acs.inorgchem.9b03345] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
We report a detailed characterization of Eu3+ and Tb3+ complexes derived from a tripyridinophane macrocycle bearing three acetate side arms (H3tpptac). Tpptac3- displays an overall basicity (∑ log KiH) of 24.5, provides the formation of mononuclear ML species, and shows a good binding affinity for Ln3+ (log KLnL = 17.5-18.7). These complexes are also thermodynamically stable at physiological pH (pEu = 18.6, pTb = 18.0). It should be noted that the pGd value of Gd-tpptac (18.4) is only slightly lower than that of commercially available MRI contrast agents such as Gd-dota (pGd = 19.2). Moreover, a very good selectivity for these ions over the endogenous cations (log KCuL = 14.4, log KZnL = 12.9, and log KCaL = 9.3) is observed. The X-ray structure of the terbium complex shows the metal coordinated by the nine N6O3 donor set of the ligand and one inner-sphere water molecule. DFT calculations result in two Eu-tpptac structures with similar bond energies (ΔE = 0.145 eV): one structure in which the water is coordinated to the metal ion and one structure in which the water molecule is farther away from the ion, bound to the ligand with an OH-π bond. By detailed luminescence experiments, we demonstrate that the europium complex in aqueous solution presents a hydration equilibrium between nine-coordinate, dehydrated [Eu-tpptac]0 and ten-coordinate, monohydrated [Eu-tpptac(H2O)]0 species. A similar trend is observed for the terbium complex. Despite the presence of this hydration equilibrium, the H3tpptac ligand sensitizes Eu3+ and Tb3+ luminescence efficiently in buffered water at physiological pH. Particularly, the terbium complex displays a long excited-state lifetime of 2.24 ms and an overall quantum yield of 33% with a brightness of 3600 M-1 cm-1. Such features of Ln3+ complexes of H3tpptac indicate that this platform appears to be particularly appealing for the further development of luminescent lanthanide labels.
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Affiliation(s)
- Nadine Leygue
- Laboratoire de Synthèse et Physico-Chimie de Molécules d'Intérêt Biologique (SPCMIB) , Université Paul Sabatier-Toulouse III/CNRS (UMR5068) , 118 route de Narbonne , F-31062 Toulouse , France
| | - Chantal Galaup
- Laboratoire de Synthèse et Physico-Chimie de Molécules d'Intérêt Biologique (SPCMIB) , Université Paul Sabatier-Toulouse III/CNRS (UMR5068) , 118 route de Narbonne , F-31062 Toulouse , France
| | - Alberto Lopera
- Instituto de Ciencia Molecular (ICMOL) , Universitat de València , C/Catedrático José Beltrán 2 , 46980 Paterna , Spain
| | - Estefanía Delgado-Pinar
- Instituto de Ciencia Molecular (ICMOL) , Universitat de València , C/Catedrático José Beltrán 2 , 46980 Paterna , Spain
| | - René M Williams
- Molecular Photonics Group, Van 't Hoff Institute for Molecular Sciences , University of Amsterdam , P.O. Box 94157, 1090 GD Amsterdam , The Netherlands
| | - Heinz Gornitzka
- CNRS, LCC , Université de Toulouse, UPS, INPT , 205 Route de Narbonne , F-31077 Toulouse Cedex 4 , France
| | - Jurriaan M Zwier
- Cisbio bioassays , Parc Marcel Boiteux, BP 84175, 30200 Codolet , France
| | - Enrique García-España
- Instituto de Ciencia Molecular (ICMOL) , Universitat de València , C/Catedrático José Beltrán 2 , 46980 Paterna , Spain
| | - Laurent Lamarque
- Cisbio bioassays , Parc Marcel Boiteux, BP 84175, 30200 Codolet , France
| | - Claude Picard
- Laboratoire de Synthèse et Physico-Chimie de Molécules d'Intérêt Biologique (SPCMIB) , Université Paul Sabatier-Toulouse III/CNRS (UMR5068) , 118 route de Narbonne , F-31062 Toulouse , France
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Michaelis-Arbuzov-Type Reaction of 1-Imidoalkyltriarylphosphonium Salts with Selected Phosphorus Nucleophiles. MOLECULES (BASEL, SWITZERLAND) 2019; 24:molecules24183405. [PMID: 31546826 PMCID: PMC6767244 DOI: 10.3390/molecules24183405] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Revised: 09/15/2019] [Accepted: 09/16/2019] [Indexed: 12/02/2022]
Abstract
In this study, Michaelis-Arbuzov-type reaction of 1-imidoalkyltriarylphosphonium salts with phosphites, phosphonites, and phosphinites was used in the synthesis of a wide range of phosphorus analogs of α-amino acids such as 1-imidoalkylphosphonates, 1-imidoalkylphosphinates, and 1-imidoalkylphosphine oxides. Large differences were observed in the reactivity of substrates depending on their structure, especially on the type of phosphonium moiety and N-protecting group. The conditions under which the expected products can be obtained in good to excellent yields have been developed. Mechanistic aspects of the transformation have been provided.
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Leygue N, Enel M, Diallo A, Mestre-Voegtlé B, Galaup C, Picard C. Efficient Synthesis of a Family of Bifunctional Chelators Based on the PCTA[12] Macrocycle Suitable for Bioconjugation. European J Org Chem 2019. [DOI: 10.1002/ejoc.201900280] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Nadine Leygue
- SPCMIB; UMR 5068 CNRS-Université Paul Sabatier-Toulouse III; 118 route de Narbonne 31062 Toulouse France
| | - Morgane Enel
- SPCMIB; UMR 5068 CNRS-Université Paul Sabatier-Toulouse III; 118 route de Narbonne 31062 Toulouse France
| | - Abdel Diallo
- SPCMIB; UMR 5068 CNRS-Université Paul Sabatier-Toulouse III; 118 route de Narbonne 31062 Toulouse France
| | - Béatrice Mestre-Voegtlé
- SPCMIB; UMR 5068 CNRS-Université Paul Sabatier-Toulouse III; 118 route de Narbonne 31062 Toulouse France
| | - Chantal Galaup
- SPCMIB; UMR 5068 CNRS-Université Paul Sabatier-Toulouse III; 118 route de Narbonne 31062 Toulouse France
| | - Claude Picard
- SPCMIB; UMR 5068 CNRS-Université Paul Sabatier-Toulouse III; 118 route de Narbonne 31062 Toulouse France
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