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ABSTRACT: Tetramethyl-terephthalate (TMT) is the constitutive linker of the flexible porous iron(III) carboxylate Metal Organic Framework (MOF) MIL-88B_4CH₃ based drug nanocarrier (MIL stands for Material from Institut Lavoisier). A method for the determination of the concentration of tetramethyl-terephthalic acid has been developed in different biological rat matrices (liver, spleen and urine) using a liquid-liquid phase extraction and high-performance liquid chromatography (HPLC) coupled to photodiode array detection with 4-aminosalicylic acid as internal standard. The extraction conditions of TMT have been varied from urine to tissue depending on the complexity of the biological matrices. The chromatographic separation was performed with a gradient elution. In all matrices, the limits of detection and quantification of TMT was 0.01 and 0.05 μg ml⁻¹, respectively. The recovery of the TMT reached 86, 89 and 97% for urine, spleen and liver tissues, respectively. The linearity of the calibration curves in urine and tissues was satisfactory in all cases as evidenced by correlation coefficients >0.990. The within-day and between-day precisions were <15% (n=6) and the accuracy ranged in all cases between 86 and 103%. This method has finally allowed the quantification of TMT in rat urine and in tissue samples of rats administered intravenously with iron(III) tetramethyltherepthalate MIL-88B_4CH₃ nanoparticles.
Journal of pharmaceutical and biomedical analysis 04/2012; 67-68:98-103. · 2.45 Impact Factor
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Patricia Horcajada,
Fabrice Salles,
Stefan Wuttke,
Thomas Devic,
Daniela Heurtaux,
Guillaume Maurin,
Alexandre Vimont,
Marco Daturi, Olivier David,
Emmanuel Magnier,
Norbert Stock,
Yaroslav Filinchuk,
Dmitry Popov,
Christian Riekel,
Gérard Férey,
Christian Serre
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ABSTRACT: A series of organically modified iron(III) terephthalate MIL-88B and iron(III) 4,4'-biphenyl dicarboxylate MIL-88D flexible solids have been synthesized and characterized through a combination of X-ray diffraction, IR spectroscopy, and thermal analysis (MIL stands for Material from Institut Lavoisier). The swelling amplitude of the highly flexible MOFs tuned by introducing functional groups onto the phenyl rings shows a clear dependence on the steric hindrance and on the number of groups per aromatic ring. For instance, while the introduction of four methyl groups per spacer in dried MIL-88B results in a large permanent porosity, introducing two or four methyl groups in MIL-88D allows an easier pore opening in the presence of liquids without drastically decreasing the swelling magnitude. The influence of the degree of saturation of the metal center and the nature of the solvent on the swelling is also discussed. Finally, a computationally assisted structure determination has led to a proposal of plausible structures for the closed (dried) and open forms of modified MIL-88B and MIL-88D and to evaluation of their framework energies subject to the nature of the functional groups.
Journal of the American Chemical Society 09/2011; 133(44):17839-47. · 9.91 Impact Factor
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ABSTRACT: Rates for the ring-opening of aziridinium and azetidinium ions by DMAP were measured. The four-membered ring appears to be ca. 17,000 times less reactive compared to the three-membered ring but is still highly relevant from a synthetic viewpoint. The electrophilicity of these strained ammonium ions is measured for the first time.
Organic Letters 03/2011; 13(7):1836-9. · 5.86 Impact Factor
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ABSTRACT: The four stereoisomers of azetidine-2,3-dicaroxylic acid (L-trans-ADC, L-cis-ADC, D-trans-ADC, and D-cis-ADC) were synthesized in a stereocontrolled fashion following two distinct strategies: one providing the two cis-ADC enantiomers and one giving access to the two trans-ADC enantiomers. The four azetidinic amino acids were characterized in a radioligand binding assay ([(3)H]CGP39653) at native NMDA receptors: L-trans-ADC showed the highest affinity (K(i)=10 microM) followed by the D-cis-ADC stereoisomer (21 microM). In contrast, the two analogues L-cis-ADC and D-trans-ADC were low-affinity ligands (>100 and 90 microM, respectively). Electrophysiological characterization of the ADC compounds at the four NMDA receptor subtypes NR1/NR2A, NR1/NR2B, NR1/NR2C, and NR1/NR2D expressed in Xenopus oocytes showed that L-trans-ADC displayed the highest agonist potency at NR1/NR2D (EC(50)=50 microM), which was 9.4-, 3.4-, and 1.9-fold higher than the respective potencies at NR1/NR2A-C. D-cis-ADC was shown to be a partial agonist at NR1/NR2C and NR1/NR2D with medium-range micromolar potencies (EC(50)=720 and 230 microM, respectively). A subsequent in silico ligand-protein docking study suggested an unusual binding mode for these amino acids in the agonist binding site.
ChemMedChem 12/2008; 4(1):110-7. · 3.15 Impact Factor
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Journal of the American Chemical Society 11/2007; 129(42):12614-5. · 9.91 Impact Factor
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Annalen der Chemie und Pharmacie 09/2007; 2007(34):5734 - 5739. · 3.10 Impact Factor
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ABSTRACT: Azetidinium ylides effected facile epoxidation of various carbonyl compounds furnishing tri or tetrasubstituted epoxides that were unattainable via classical ammonium ylide chemistry; the produced trisubstituted oxiranes gave rise to a remarkable cascade of reactions leading to some original pyrrolidin-3-ones.
Chemical Communications 07/2007; · 6.17 Impact Factor
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ABSTRACT: Azetidinium ylides showed a remarkable ability to perform the cyclopropanation of Michael acceptors. Ephedrine-derived azetidinium ylides allowed the formation of substituted cyclopropanes in good yields and at a high level of stereoselectivity. The determination of the relative stereochemistries in the produced cyclopropanes gave some insight into the reaction mechanism.
The Journal of Organic Chemistry 03/2007; 72(3):1058-61. · 4.45 Impact Factor
