Physical and biological properties of a Pt(ll) complex of a beta-diketiminate ligand with pendant quinoline arms

Abstract

A monoanionic, tetradentate [beta]-diketiminate (BDI) ligand with pendant quinoline arms, BDIQQH was coordinated to Pt(II) to yield the square-planar complex [Pt(BDIQQ)]CI. This complex was characterized by NMR spectroscopy, ESI-MS, FTIR spectroscopy, UVVisible absorbance spectroscopy, and cyclic voltammetry. Computational studies, including geometry optimizations and frequency calculations, were carried out to further analyze the electronic structures of the complexes. In addition, the DNA-binding properties of the complexes were evaluated by UV-Vis titrations and an ethidium-bromide displacement assay. Our results indicate that the compounds interact with DNA, although the mode of interaction is still ambiguous. Fluorescence studies were also performed to investigate the interaction of the complex with bovine serum albumin (BSA) as a model protein. Finally, cytotoxicity data were obtained in a small panel of cell lines using the MTT assay. The complex has a toxicity comparable to or higher than that of cisplatin in the lines tested.