Synthesis and crystal structures of three organoplatinum(II) complexes bearing natural aryl-olefin and quinoline derivatives.

Three organoplatinum(II) complexes bearing natural aryl-olefin and quinoline derivatives, namely, [4-meth-oxy-5-(2-meth-oxy-2-oxoeth-oxy)-2-(prop-2-en-1-yl)phen-yl](quinolin-8-olato)platinum(II), [Pt(C13H15O4)(C9H6NO)], (I), [4-meth-oxy-5-(2-oxo-2-propoxyeth-oxy)-2-(prop-2-en-1-yl)phen-yl](quinoline-2-carboxy-l-ato)platinum(II), [Pt(C15H19O4)(C10H6NO2)], (II), and chlorido-[4-meth-oxy-5-(2-oxo-2-propoxyeth-oxy)-2-(prop-2-en-1-yl)phen-yl](quinoline)-plat-inum(II), [Pt(C15H19O4)Cl(C9H7N)], (III), were synthesized and structurally characterized by IR and 1H NMR spectroscopy, and by single-crystal X-ray diffraction. The results showed that the cyclo-platinated aryl-olefin coordinates with PtII via the carbon atom of the phenyl ring and the C=Colefinic group. The deprotonated 8-hy-droxy-quinoline (C9H6NO) and quinoline-2-carb-oxy-lic acid (C10H6NO2) coordinate with the PtII atom via the N and O atoms in complexes (I) and (II) while the quinoline (C9H7N) coordinates via the N atom in (III). Moreover, the coordinating N atom in complexes (I)-(III) is in the cis position compared to the C=Colefinic group. The crystal packing is characterized by C-H⋯π, C-H⋯O [for (II) and (III)], C-H⋯Cl [for (III) and π-π [for (I)] inter-actions.

Synthesis, crystal structure and anti-cancer activity of the complex chlorido-(η2-ethyl-ene)(quinolin-8-olato-κ2N,O)platinum(II) by experimental and theoretical methods.

The complex [Pt(C9H6NO)Cl(C2H4)], (I), was synthesized and structurally characterized by ESI mass spectrometry, IR, NMR spectroscopy, DFT calculations and X-ray diffraction. The results showed that the deprotonated 8-hy-droxy-quinoline (C9H6NO) coordinates with the PtII atom via the N and O atoms while the ethyl-ene coordinates in the η2 manner and in the trans position compared to the coordinating N atom. The crystal packing is characterized by C-H⋯O, C-H⋯π, Cl⋯π and Pt⋯π inter-actions. Complex (I) showed high selective activity against Lu-1 and Hep-G2 cell lines with IC50 values of 0.8 and 0.4 µM, respectively, 54 and 33-fold more active than cisplatin. In particular, complex (I) is about 10 times less toxic to normal cells (HEK-293) than cancer cells Lu-1 and Hep-G2. Furthermore, the reaction of complex (I) with guanine at the N7 position was proposed and investigated using the DFT method. The results indicated that replacement of the ethyl-ene ligand with guanine is thermodynamically more favorable than the Cl ligand and that the reaction occurs via two consecutive steps, namely the replacement of ethyl-ene with H2O and the water with the guanine mol-ecule.