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A novel series of Pd(II) complexes, [Pd(alkyl-amine)2(phen)](NO3)2, I-V, (where alkylamine is ethyl-, propyl-, butyl-, hexyl- and octyl-amine and phen is 1,10-phenanthroline) were synthesized and characterized based on FT-IR, 1H NMR, COSY-NMR, UV-Vis, molar conductivity, elemental analysis and density functional theory (DFT) approaches. The group, I-V, was screened for their primary in-vitro cytotoxic action against human cancer cell line MOLT-4, showing promising anti-tumor activities. Their interaction activity was tested using various spectroscopic techniques to explain the mode of binding between these compounds with CT-DNA and BSA. Results of UV-Vis studies showed that, at low concentrations, they all interacted effectively with CT-DNA and BSA. Studies of fluorescence emission spectra displayed that the complexes quenched CT-DNA pretreated with methylene blue (MB) and the intrinsic fluorescence of BSA via static quenching. Using thermodynamic parameters (ΔG°, ΔH°, and ΔS°) obtained from fluorescence studies, it was proposed that the hydrogen bonding and van der Waals forces play the main role between metal complexes with CT-DNA and BSA. The binding was spontaneous in all cases due to ΔG° <0. Also, Molecular docking simulation of all five Pd(II) complexes with DNA was performed to determine the compound with the highest binding affinity and investigate its binding mode. Next, molecular docking was utilized for this compound to study its BSA binding mode and affinity. The results obtained from this work may lay the foundation for structural changes exerted on DNA and BSA by Pd(II) antitumor compounds bearing various hydrocarbon chain length as well as structural relationship which are vital for pharmacokinetic and pharmacodynamics. [ABSTRACT FROM AUTHOR]

Two novel palladium(II)–amino acid complexes, [Pd(Ala)2]·H2O (PA) and [Pd(Val)2].H2O (PV) (Ala = alanine; Val = valine) were synthesized and characterized through FTIR, UV/Vis, 1H-NMR spectroscopies, CHN analysis, X-ray crystallography and molar conductivity measurement. Furthermore, cytotoxicity of Pd(II) complexes against human leukemia cancer cell line, MOLT4 showed promising cancer cell death (CC50 = 0.71 ± 0.046 µM for PA; CC50 = 0.85 ± 0.063 µM for PV) that were less than cisplatin (1.59 ± 0.25 µM). Moreover, the interaction of both the complexes with DNA and BSA was studied using UV–Vis absorption and emission spectroscopic techniques that demonstrated the bindings occurred via van der Waals forces and hydrogen bond. Furthermore, the fluorescence titration showed that static quenching mechanism plays predominate role in binding process. All results showed that both complexes have more binding tendency to DNA in compared to BSA that can be a significant achievement for further medical purposes as a potential antitumor candidate. Finally, molecular docking simulation was performed for PA and PV complexes with DNA and BSA and demonstrated both complexes bind to the groove of DNA mainly by hydrogen bond and interact with site I of BSA via hydrogen bond as well. [ABSTRACT FROM AUTHOR]

A new mononuclear ruthenium(II) complex, trans-[Ru(dmb)2(Cl)(EtOH)](PF6) (dmb = 4,4′-dimethyl-2,2′- bipyridine), has been prepared and characterized by elemental analysis, spectroscopic techniques and single crystal X-ray structure determination. The complex was studied as a precatalyst for the electrocatalytic reduction of CO2 to CO in an acetonitrile solution by cyclic voltammetry (CV). The catalytic mechanism was investigated by means of quantum chemical calculations to gain deeper insight into the process of CO2 reduction. The results suggest that the reaction proceeds in six steps initiating by the two sequential 1ē reductions at the dmb ligands followed by CO2 addition to give a metallocarboxylate intermediate. This intermediate undergoes further reduction and loses a CO molecule. The results reported in this paper are of great significance in providing theoretical insight into a class of electrocatalysts for reduction of CO2 to CO. [ABSTRACT FROM AUTHOR]