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• 33582-68-2 cyclobutane-1,1-dicarboxylic acid diamide 

Relevant academic research and scientific papers

Ligand and metal complex having the same

A ligand and a metal complex having the ligand are provided. The ligand and a paramagnetic metal ion form a metal complex with high stability, high relaxivity and high biocompatibility. The metal complex of the present invention is applicable to the prepa

LIGAND AND METAL COMPLEX HAVING THE SAME

A ligand and a metal complex having the ligand are provided. The ligand and a paramagnetic metal ion form a metal complex with high stability, high relaxivity and high biocompatibility. The metal complex of the present invention is applicable to the prepa

Ligand and metal complex

A ligand of Formula (I) is provided: wherein A4 represents a hydrogen atom, a nitro group, an amino group, a thiocyanato group, or —Z—Y, in which Z is a divalent linking group and Y is a group derived from a biocompatible molecule, with the proviso that when X is methylene, A4 cannot be a hydrogen atom or a nitro group. A metal complex having the ligand is also provided and is useful as a blood pool contrast agent or a targeting contrast agent.

Synthesis and physicochemical characterization of carbon backbone modified [Gd(TTDA)(H2O)]2- derivatives

The present study was designed to exploit optimum lipophilicity and high water-exchange rate (kex) on low molecular weight Gd(III) complexs to generate high bound relaxivity (r1b), upon binding to the lipophilic site of human serum albumin (HSA). Two new carbon backbone modified TTDA (3,6,10-tri(carboxymethyl)-3,6,10-triazadodecanedioic acid) derivatives, CB-TTDA and Bz-CB-TTDA, were synthesized. The complexes [Gd(CB-TTDA)(H 2O)]2- and [Gd(Bz-CB-TTDA)(H2O)]2- both display high stability constant (log KGdL = 20.28 and 20.09, respectively). Furthermore, CB-TTDA (log K(Gd/Zn) = 4.22) and Bz-CB-TTDA (log K(Gd/Zn) = 4.12) exhibit superior selectivity of Gd(III) against Zn(II) than those of TTDA (log K(Gd/Zn) = 2.93), EPTPA-bz-NO2 (log K(Gd/Zn) = 3.19), and DTPA (log K (Gd/Zn) = 3.76). However, the stability constant values of [Gd(CB-TTDA)(H2O)]2- and [Gd(Bz-CB-TTDA)(H 2O)]2- are lower than that of MS-325. The parameters that affect proton relaxivity have been determined in a combined variable temperature 17O NMR and NMRD study. The water exchange rates are comparable for the two complexes, 232 × 106 s-1 for [Gd(CB-TTDA)(H2O)]2- and 271 × 106 s -1 for [Gd(Bz-CB-TTDA)(H2O)]2-. They are higher than those of [Gd(TTDA)(H2O)]2- (146 × 10 6 s-1), [Gd(DTPA)(H2O)]2- (4.1 × 106 s-1), and MS-325 (6.1 × 106 s-1). Elevated stability and water exchange rate indicate that the presence of cyclobutyl on the carbon backbone imparts rigidity and steric constraint to [Gd(CB-TTDA)(H2O)]2-and [Gd(Bz-CB-TTDA) (H2O)]2-. In addition, the major objective for selecting the cyclobutyl is to tune the lipophilicity of [Gd(Bz-CB-TTDA)(H 2O)]2-. The binding affinity of [Gd(Bz-CB-TTDA)(H 2O)]2- to HSA was evaluated by ultrafiltration study across a membrane with a 30 kDa MW cutoff, and the first three stepwise binding constants were determined by fitting the data to a stoichiometric model. The binding association constants (KA) for [Gd(CB-TTDA)(H 2O)]2- and [Gd(Bz-CB-TTDA)(H2O)]2- are 1.1 × 102 and 1.5 × 103, respectively. Although the KA value for [Gd(Bz-CB-TTDA)(H2O)] 2- is lower than that of MS-325 (KA = 3.0 × 10 4), the r1b value, r1b = 66.7 mM-1 s-1 for [Gd(Bz-CB-TTDA)(H2O)] 2-, is significantly higher than that of MS-325 (r1 b = 47.0 mM-1 s-1). As measured by the Zn(II) transmetalation process, the kinetic stabilities of [Gd(CB-TTDA)(H 2O)]2-, [Gd(Bz-CB-TTDA)(H2O)]2-, and [Gd(DTPA)(H2O)]2- are similar and are significantly higher than that of [Gd(DTPA-BMA)(H2O)]2-. High thermodynamic and kinetic stability and optimized lipophilicity of [Gd(CB-TTDA)(H2O)]2- make it a favorable blood pool contrast agent for MRI.

Platinum complexes of aliphatic tricarboxylic acids

Platinum complexes of aliphatic tricarboxylic acids useful for inducing regression and/or palliation of cancer diseases in mammals.