Synthesis, characterization, speciation, dna cleavage, and cytotoxic studies of the pd[2-(2-aminoethyl)-1-methylpyrrolidine]Cl2 complex with reference to carboplatin

Abstract

The [Pd(AEMP)Cl2] complex [AEMP = 2-(2-aminoethyl)-1-methylpyrrolidine] was prepared and characterized by single-crystal X-ray diffraction and spectroscopic analyses. The structure of the complex was found to be square-planar with some distortion. The geometric optimizations of the ligand and complex were performed with the DFT/B3LYP method by using Gaussian 09. The stoichiometry and stability constants of the complexes formed in the reaction of [Pd(AEMP)(H2O)2]2+ with dicarboxylic acids and DNA constituents were investigated at 0.1 M ionic strength and 25 °C. The results show that both DNA constituents and cyclobutanedicarboxylate (CBDCcoordinate to [Pd(AEMP)(H2O)2]2+ to form the quaternary complex [Pd(AEMP)(CBDCA-O)DNA], where CBDCA-O represents cyclobutanedicarboxylate coordinated through one carboxylate oxygen atom to the PdII center. The speciation concentration distributions in solution were evaluated. The biological activity for DNA cleavage and cytotoxicity of the [Pd(AEMP)Cl2] complex was studied.