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Seridi A.,CNRS Chemistry Laboratory | Seridi A.,Toulouse 1 University Capitole | Wolff M.,University of Silesia | Boulay A.,CNRS Chemistry Laboratory | And 8 more authors.
Inorganic Chemistry Communications | Year: 2011

The preparation of two M(CO)3 complexes (M = Re and 99mTc) from a novel pyridyltriazole-based ligand 2 bearing the bioactive (2-methoxyphenyl)piperazine pharmacophore are described. Spectral data, X-ray structure and DFT calculations of the rhenium(I) complex as well as the 99mTc-labelling of 2 are reported. Both complexes were neutral and iso-structural. Moreover, the 99mTc-complex presented a suitable lipophilic character for its use as a CNS imaging agent. © 2010 Elsevier B.V. All rights reserved.


Machura B.,University of Silesia | Wolff M.,University of Silesia | Benoist E.,CNRS Chemistry Laboratory | Benoist E.,Toulouse 1 University Capitole | Coulais Y.,Laboratoire Traceurs Et Traitement Of Limage
Journal of Organometallic Chemistry | Year: 2013

The paper presents a combined experimental and computational study of a novel tricarbonyl rhenium(I) complex with benzothiazole ligand-[Re(CO) 3(bt)2Cl]. The compound has been characterized by structural (single-crystal X-ray diffraction) and spectroscopic (IR, NMR, MS, UV-vis) methods. DFT and time-dependent DFT (TDDFT) calculations have been also carried out and the UV-vis spectrum of the complex has been discussed on this basis. © 2012 Elsevier B.V. All rights reserved.


El Aissi R.,Radiopharmaceutical Unit | El Aissi R.,French National Center for Scientific Research | El Aissi R.,Toulouse 1 University Capitole | Malek-Saied N.,Radiopharmaceutical Unit | And 5 more authors.
Radiochimica Acta | Year: 2015

The synthesis, characterization and biological evaluation of five neutral and lipophilic 99mTc-complexes, so-called cytectrenes, obtained from N-substitutedferrocenecarboxamide derivatives are reported. N-substitutedferrocenecarboxamide starting materials were obtained in two steps, with good yield and were fully characterized by classical spectroscopic methods including X-ray diffraction analysis for one of them. Using a microwave strategy for the 99mTc-radiolabelling step, each cytectrene were obtained quickly (radiolabelling time <5 min), from modest to good yield. The 99mTc-complexes, characterized by HPLC comparison with cold rhenium complex analogues, are stable, neutral and lipophilic (log Po/w ranged between 1.8 and 2.9). Unfortunately, despite such suitable features, in vivo studies of two of them gave poor results, in terms of brain uptake. Both radiocompounds exhibited the maximum brain accumulation of 0.31% ID/g and 0.26% ID/g at 5 min post-injection, respectively, followed by a very fast washout from the brain (0.06% ID/g and 0.07% ID/g at 30 min post-injection, respectively). Although our ligand systems exhibited high stability against exchange reactions with blood proteins, the high radioactivity level in stomach, increasing with time, suggests in vivo decomposition of our complex to pertechnetate. © 2014 Walter de Gruyter Berlin/Boston.


Dorbes S.,French National Center for Scientific Research | Dorbes S.,Toulouse 1 University Capitole | Dorbes S.,French Institute of Health and Medical Research | Mestre-Voegtle B.,French National Center for Scientific Research | And 8 more authors.
European Journal of Medicinal Chemistry | Year: 2010

The goal of this study is to design new 99mTc-radiolabelled shortened CCK derivatives that might be suitable for the molecular imaging of cholecystokinin-2 receptors (CCK2-R), these receptors being over-expressed in a number of neuroendocrine tumors such as medullary thyroid cancer and small-cell lung cancer. For this purpose, we designed several modified CCK4 analogs bearing an ON2S tetradentate chelating agent at the N-terminus, the CCK4 sequence representing the minimal peptide sequence that presents nanomolar affinity and activity towards the CCK2-R. Four peptide conjugates of general formula (Trt)SN2OPh-(X)n-CCK4 (X = β-alanine or 6-aminohexanoic acid spacers; n = 0, 2, 4) and their oxorhenium peptide conjugates have been synthesized and characterized. In vitro evaluation of these compounds showed a close relationship between the nature and the length of the spacer and the corresponding binding affinity values. The most promising oxorhenium complex 5-Re exhibited potent CCK2-receptor agonist properties in promoting the production of inositol phosphate in COS-7 cells (EC50 = 5.17 nM). Preliminary 99mTc-radiolabelling studies with peptide conjugates 3 or 5 led exclusively to the corresponding 99mTcO-complexes 3-Tc and 5-Tc, which exhibited high resistance towards an excess of cysteine and satisfactory stabilities in human serum. To conclude, the promising in vitro characteristics of compounds 5-Re, 5-Tc illustrate the feasibility to develop stable radiolabelled shortened CCK4 derivatives with a nanomolar CCK2-R affinity. © 2009 Elsevier Masson SAS. All rights reserved.


Francois A.,CNRS Chemistry Laboratory | Francois A.,Toulouse 1 University Capitole | Auzanneau C.,University of Bordeaux Segalen | Le Morvan V.,University of Bordeaux Segalen | And 20 more authors.
Dalton Transactions | Year: 2014

A novel bimodal fluorescent/radiolabelled probe based on a pyridyltriazole scaffold (known as pyta) is reported here. The final dual imaging agent combines carboxylate functionalization, for biomolecule conjugation, with two distinct metal chelating sites: a pyta-based tricarbonylrhenium moiety as a fluorescent probe and a 99mTc(CO3)+ core through the tridentate chelating iminodiacetic acid (IDA) clamp as a SPECT reporter. The heterodinuclear 99mTc/Re complex 8, as well as its non-radioactive dirhenium analog 7, was prepared in six steps. The 99mTc/Re agent is water-soluble and stable against histidine challenge. Its structural characterization was achieved by HPLC comparison with the non-radioactive complex 7. Upon excitation in the MLCT band at 321 nm, the compound 7 exhibits a bright green luminescence centered at 496 nm, with a quantum yield of 0.86% in Tris buffer, pH 7.4. Additionally, the influence of this compound on cell viability was tested on malignant cell lines (A549, HT29 and MCF-7 human lung, colon and breast carcinomas, respectively). Cell viability after 72 h incubation at 37°C with 300 μmol of complex 7 was >60% for all cell lines. Finally, cellular uptake studies of compound 7 were performed by fluorescent microscopy, showing that the complex was clearly detected at the cellular level in A549 cells and to a lesser extent in HT29 cells. Taking into consideration the luminescent properties, the good radiochemical purity and the promising biological data (in vitro stability, non-toxicity, and cell tracking in two cell lines), the functionalized 99mTc/Re dinuclear compound 8 can be considered a potential pre- and intraoperative diagnostic probe. © 2014 The Royal Society of Chemistry.


Boulay A.,CNRS Chemistry Laboratory | Artigau M.,CNRS Chemistry Laboratory | Coulais Y.,Laboratoire Traceurs Et Traitement Of Limage | Picard C.,CNRS Chemistry Laboratory | And 2 more authors.
Dalton Transactions | Year: 2011

In this communication, a novel synthetic pathway has been applied to prepare a dual imaging agent in a single molecule. The dinuclear Re(i)/Tc(i) complex 6, namely [Re(CO) 3(bipy){(4-PyrIDA)Tc(CO) 3}], is the first example of a Re/Tc-based heterometallic assembly which could act as a potential bimodal Optical/SPECT probe. Interestingly, the Re(i) complex intermediate 4 exhibits significant photophysical properties for biological applications. © 2011 The Royal Society of Chemistry.


Benoist E.,CNRS Chemistry Laboratory | Benoist E.,Toulouse 1 University Capitole | Coulais Y.,Laboratoire Traceurs Et Traitement Of Limage | Almant M.,University of Picardie Jules Verne | And 10 more authors.
Carbohydrate Research | Year: 2011

An efficient protocol was developed to tether chelating agents and rhenium complexes onto a glucoside scaffold with a heterogeneous copper catalyst via click chemistry. The supported catalyst avoids the formation of unwanted copper complexes during the cyclisation step. The possibility to graft a pre-chelated M(CO)3 core by click chemistry onto a biomolecule was highlighted for the first time. 99mTc(CO)3-glucoconjugates displayed excellent in vitro stability, a fast in vivo blood clearance and a low specific organ uptake or long-term retention in spleen and stomach. © 2010 Elsevier Ltd. All rights reserved.

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