Indium-111-labelled cationic complexes of aminothiols: structure-activity correlation

Abstract

In the present work a series of NxS2 ligands were synthesized, investigated for the formation of cationic, indium chelates and evaluated comparatively in experimental animals. The compounds under study formed indium complexes which were stable in vitro and presented myocardial uptake. Animal studies showed that the chemical structure of the ligand plays an important role in biodistribution. A system of one six-membered and two five-membered rings, formed by the metal and the donor atoms of the ligand, may constitute a basic structure for the development of new indium tracers with myocardial affinity.

Indium(III) and Gallium(III) Complexes of Bis(aminoethanethiol) Ligands with Different Denticities: Stabilities, Molecular Modeling, and in Vivo Behavior

“…Cotsyfakis et al . prepared 10 different 111 In-labeled cationic amino thiol complexes and evaluated them in vivo . Subtle changes in the ligand structure produced wide variability in biodistribution results.…”

“…Cotsyfakis et al prepared 10 different 111 In-labeled cationic amino thiol complexes and evaluated them in vivo. 29 Subtle changes in the ligand structure produced wide variability in biodistribution results. Although many of the complexes had significant myocardial uptake, the majority of the complexes had considerable liver and kidney uptake at 1 h postinjection.…”

“…Although many of the complexes had significant myocardial uptake, the majority of the complexes had considerable liver and kidney uptake at 1 h postinjection. 29 Recently, Anderson et al 30 reported the in vivo stability of N,N′ethylene-di-L-cysteine, (EC), 2, with Ga(III) and In(III). Sun et al 31,32 reported that N,N′-bis(2-mercaptoethyl)ethylenediamine-N,N′-diacetic acid (EDDASS), 3, has unusually high affinity for In(III).…”

New Oxorhenium(V) Complexes from the Widely Used Diaminedithiol (DADT) Ligand System

“…The reaction scheme leading to ligands 1 and 3 is shown in Figure . According to this scheme, which is commonly used for the preparation of DADT ligands, ,, 2,2‘-dithio-bis(2-methylpropanal) ( 6 ) is condensed with ethylenediamine to form cyclic bis(imine) 7 which is subsequently reduced by sodium borohydride to the bicyclic diazolidino[1,2- d ]dithiazepine ( 8) . The use of the mild reagent NaBH 4 , which does not reduce the disulfide bond, is necessary for the subsequent introduction of the N-alkyl substituents without competing alkylation of the thiol moieties.…”

“…For one of the DADT conjugates, [ 99m Tc]TRODAT-1, 8d, the phase I evaluation in humans as a dopamine transporter imaging agent has been completed. In addition, the DADT system has been shown to form stable complexes with gallium(III) and indium(III) which have important nuclear medicine applications. , …”