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Makrocykliczne kompleksy radionuklidów w medycynie nuklearnej

Majkowska A., Bilewicz A.

Wiadomości Chemiczne

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2008

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[Z] 62, 7-8

609-633

EN

The use of radiometal-labeled small complexes and biomolecules as diagnostic and therapeutic agents is a relatively new area of medical research. Radiopharmaceuticals are radiolabeled molecules designed to deliver ionizing radiation doses to specific disease sites. Between the targeting biomolecule and a radionuclide a bifunctional ligand is inserted, one end of which is covalently attached to the targeting molecule either directly or through a linker whereas the other strongly coordinates a metallic radionuclide. Selection of a bifunctional ligand is largely determined by the nature and oxidation state of a metal ion. The metal chelate can significantly affect the tumor uptake and biodistribution of radiopharmaceuticals based on small biomolecules. This is because in many cases the metal chelate contributes greatly to the overall size and lipophilicity of the radiopharmaceutical. Therefore, the design and selection of the ligand is very important for the development of a clinically useful therapeutic agent. The requirement for high thermodynamic and kinetic stability of the metal complex is often achieved through the use of macrocyclic ligands with a functionalized arm for covalent bonding to the biomolecule. In this review synthesis of bifunctional macrocyclic ligands and properties of radionuclide macrocyclic complexes used in nuclear medicine are presented. We describe results in two areas: substituted macrocyclic aza ligands for chelation of hard metal cations, and macrocycles containing sulphur for complexation of soft metal cations. Special attention was paid to stability of the complexes as well as to their lipophilicity, which affect biological properties of the formed radiopharmaceuticals. We also include a forecast of the near-term opportunities that are likely to determine practice in the next few years.

2

Crystal Structure and Magnetic Properties of Copper(II) Macrocyclic Compounds

Bieńko A., Mroziński J., Korybut-Daszkiewicz B, Kruszyński R.

Polish Journal of Chemistry

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2008

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Vol. 82, nr 7

1383-1383

EN

The two higly unsaturated copper(II) macrocyclic complexes [CuL1](ClO4)2 (1) (L1 = N-dl-5,12-dimethyl-1,4,8,11-tetraazacyclotetradeca-4,11-diene) and [CuL2](ClO4)2 (2) (L2 = N-dl-5,7,7,12,14,14-hexamethyl-1,4,8,11-tetraazacyclotetradeca-4,11-diene) were synthesized and the crystal structures of both compounds were determined at 173(2) K. Complex 1 crystallizes monoclinic, space group P21/c, with a = 9.0929(5) Capital A, ring, b = 13.4683(5) Capital A, ring , c = 8.2886(4) ,Capital A, ring beta = 109.469(6)°, Z = 2, whereas 2 crystallizes at the same space group with a = 10.4891(2) Capital A, ring, b = 16.9924(4) Capital A, ring , c = 13.8780(3) Capital A, ring , beta = 105.150(2)° and Z = 4. Their magnetic measurements have been carried out over the temperature range 1.8–300 K using a Quantum Design SQUID magnetometer (MPMSXL - 5 type). The results indicate that both compounds be have as weakly interacting copper centers in the crystal lattice.

3

Termodynamic Study of the Interaction Between Some Recently Synthesized Benzo-Substituted Macrocyclic Diamides with Some Pyridinium Ion Derivatives in Acetonitrile Solution

Ganjali M., Zargazi M. H., Mohajeri A.

Polish Journal of Chemistry

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2001

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Vol. 75, nr 5

743-749

EN

The formation of pyridinium, 2-methyl pyridinium, 2,4-dimethyl pyridinium and 2,4,6- trimethyl pyridinium complexes with the some recently synthesized benzo-substituted macrocyclic diamides was investigated conductometrically in acetonitrile solution at various temperatures. The formation constants of the resulting 1:1 complexes were determined from the computer fitting of the molar conductance-mole ratio data. In all cases studied, the stability of complexes decreases in the order Py+ > 2m-Py+ > 2,4dim-Py+ > 2,4,6trim-Py+. The enthalpy and entropy of complexation reaction were determined from the temperature dependence of the formation constants. In all cases, the complexes were enthalpy stabilized but entropy destabilized.