Novel complexes of tris(aminomethyl)phosphanes with platinum(II): Structural, spectroscopic, DFT and biological activity studies

Two new platinum(II) complexes with tris(aminomethyl)phosphanes: [trans-PtCl2{P(CH2N(CH2CH2)2NCH3)3}2] (1Pt) and [trans-PtCl2{P(CH2N(CH2CH2)2O)3}2] (2Pt) were prepared and characterized with NMR and UV–Vis spectroscopies. Their structures were investigated by X-ray crystallography and DFT methods. TDDFT calculations were employed to interpret the electronic spectra of the complexes. Obtained results are not unequivocal, however population analysis indicate, that the character of HOMO and HOMO−1 orbitals depend strongly on the electron donoring properties of the phosphane ligand. Biological activity of 2Pt complex, which is more stable and more soluble in polar solvents than 1Pt, was examined in vitro on the Vero cell line (IC50 = 12.5 μM). At higher concentrations it induces apoptosis, probably due to changes of the cell cytoskeleton. Luminescence quenching studies and CD spectroscopy of interactions of 2Pt with HSA and BSA indicate that these albumins bind the complex slightly – without altering their tertiary structures, however HSA interacts with 2Pt noticeably stronger than BSA. It was also found that 2Pt does not cleave supercoiled pUC18 plasmid.

Structures and properties of two novel complexes: trans-[PtCl2{P(CH2N(CH2CH2)2Z)3}, where Z = O or NCH3 were determined spectroscopically and using X-ray crystallography and DFT methods. The biological activity and interactions with albumins and plasmid DNA of one of the complexes are presented.Figure optionsDownload as PowerPoint slideHighlights
► New platinum(II) chloride complexes with aminomethylphosphanes are described.
► X-ray structure of trans-[PtCl2{P(CH2N(C2H4)2O)3}2] is presented.
► X-ray structure of trans-[PtCl2{P(CH2N(C2H4)2CH3)3}2] is presented.
► Spectroscopic properties and DFT studies on obtained complexes are presented.
► Biological activity and interactions with DNA and serum albumins is described.