The chemistry of chelating agents in medical sciences. Coordination Compounds: Synthesis and Medical Application. Berlin: Springer Berlin Heidelberg; 1987. pp. 91-141. [DOI: 10.1007/3-540-17881-3_3]

Nephrotoxicity of uranium: pathophysiological, diagnostic and therapeutic perspectives

As in the case of other heavy metals, a considerable body of evidence suggests that overexposure to uranium may cause pathological alterations to the kidneys in both humans and animals. In the present work, our aim was to analyze the available data from a critical perspective that should provide a view of the real danger of the nephrotoxicity of this metal for human beings. A further aim was to elaborate a comparative compilation of the renal pathophysiological data obtained in humans and experimental animals with a view to gaining more insight into our knowledge of the mechanisms of action and renal damage. Finally, we address the existing perspectives for the improvement of diagnostic methods and the treatment of intoxications by uranium, performing an integrated analysis of all these aspects.

Observation of room-temperature 5D1 luminescence of an organoeuropium complex encapsulated in sol-gel glass

In comparing emissions of the inorganic Eu3+ salts (chloride or nitrate) to organoeuropium complexes doped into optically transparent sol-gel glass, previous studies have indicated that changes in the local chemical environment by chelation or variation of the ligand or gel matrix compositions were found to leave the main spectral features of Eu3+ essentially unchanged; complexation just increases the emission intensity of europium and leads to broadening and splitting of the peaks. In all cases studied and irrespective of the excitation energy, the observable emission peaks result only from relaxations out of the 5D0 excited state of Eu3+ to the first five levels of the 7F ground manifold. The present research examines the luminescence behavior of EuCl3 and Eu-TETA (TETA is the macro cycle, 1,4,8,11-tetraazacyclotetradecane-1,4,8,11-tetraaceticacid) doped into a sol-gel host; in addition to emissions from the 5D0, emission from the 5D1 excited state of Eu3+ is observed for the first time.

Disappearance of heme metabolites following chelation therapy with meso 2,3-dimercaptosuccinic acid (DMSA)

A lead poisoned adult (blood lead level 384 micrograms/dL) had a specific urinary porphyrin profile of elevated porphyrins including coproporphyrin III and 5-carboxylic acid derivatives. A multilinear gradient elution, modified with an ion-pair and a reversed phase column were employed for the separation of the diagnostically important porphyrin isomers. Fluorescence detection enhanced both sensitivity and selectivity. Both compounds were restored to normal levels following two courses of meso 2,3-dimercaptosuccinic acid: 90 mg/kg/d x 5 d at one month intervals. The decrease of clinical symptoms was associated with increase of delta aminolevulinic acid dehydratase from 53 to 230 U/mL blood and hemoglobin from 8.4 to 12.7 g/dL. Blood lead decreased from 384 to 24 micrograms/dL, urine lead from 1286 to 188 micrograms/L and urine coproporphyrin III from 5712 to 25 micrograms/L.

New developments in therapeutic chelating agents as antidotes for metal poisoning

An examination of the studies on therapeutic chelating agents that have been carried out during the last decade reveals that extensive efforts have been made to develop compounds superior to those previously available for the treatment of acute and chronic intoxication by many metals. These metals include primarily iron, plutonium, cadmium, lead, and arsenic, but also many other elements for which acute and chronic intoxication is less common. These studies have revealed the importance of several additional factors of importance in the design of such compounds and have led to many new compounds of considerable clinical promise. An additional development has been the introduction of previously developed chelating agents for use with certain metals on a broader scale.

Molecular recognition and metal ion template synthesis

Methods for the design and synthesis of ligands intended to be specific for a metal ion have been a recent chemical development. This article describes how this process can be inverted so that the specifics of the coordination environment around the metal ion can be used as a template in large-scale ligand synthesis. The synthesis of macrobicyclic ligands for ferric ion has been accomplished by using active esters of catechol ligands in which catecholate coordination to iron is a prelude to the organic chemical reactions that link the coordination subunits together into one ligand system surrounding a central metal ion coordination site. The lanthanide(III) ions, which are among the most labile metal ions known, have coordination numbers of 8 or higher, and thus their encapsulation into a macrobicyclic structure is a challenging problem. Lanthanide amine complexes have been used as metal templates in the synthesis of such macrobicyclic lanthanide complexes. There is evidence that such a complex is inert to exchange in aqueous solution.