Synthesis, characterisation, DFT and biomedical investigation of new Ga(III) complex with imidazole

Abstract

A new Ga(III) complex with imidazole (IMZ) in 1:2 Ga:IMZ stoichiometric ratio has been synthesised. The complex has been characterised by spectroscopic (IR, NMR, UV-Vis.,), thermogravimetric (TG, DTG, DTA), electrophoresis and microanalytical techniques and shown to be [GaCl(IMZ) 2 (H 2 O)]. The geometry of [GaCl(IMZ) 2 (H 2 O)] was optimised in a singlet state by the DFT method with B3LYP functional. Theoretical analysis of vibration modes of this complex has been undertaken and the results were compared with the experimental data for this compound. The complex was subjected to radiolabelling with 67 Ga via the nuclear reaction 68 Zn (p, 2n) 67 Ga. The radiochemical yield was greater than 80%. HPLC analysis in isotonic systems revealed that this complex is highly unstable in an isotonic system where it readily dissociated. The investigated complex showed relatively high anti-bacterial activities compared with the free ligand.

Gallium Complexation, Stability, and Bioconjugation of 1,4,7-Triazacyclononane Derived Chelators with Azaheterocyclic Arms

“…Interestingly, there are only a few reports in the literature on the Ga chemistry of fivemembered azaheterocycles in aqueous media. [46][47] In the present work, we therefore sought to explore the potential of novel TACN derived chelators with azaheterocyclic residues for nat./68 Ga 3+ complexation.…”

“…While many ligands for Ga 3+ complexation that utilize different O- and N-donor groups have been described, to the best of our knowledge, macrocyclic ligands bearing azaheterocyclic pendant substituents with aromatic N-donors have not been reported. Interestingly, there are only a few reports in the literature on the Ga chemistry of five-membered azaheterocycles in aqueous media. , In the present work, we therefore sought to explore the potential of novel TACN derived chelators with azaheterocyclic residues for nat./68 Ga 3+ complexation.…”