Sogukomerogullari, Hatice Gamze; Başaran, Eyüp; Kepekçi, Remziye Aysun; Türkmenoğlu, Burçin; Sarıoğlu, Ahmet Oral; Köse, Muhammet

Three lanthanide (III) complexes, L-Eu, L-Tb, and L-Gd, were synthesized using a Schiff base ligand (H2L) composed of (2,2′-(thiophene-2,5-diylbis(methaneylyl-idene))bis(azaneylyl-idene))diphenol. Complexes with the generic formula LnL(Cl)(H2O)·xH2O, where L is the ligand, was studied using elemental analysis, spectrum analysis (IR, mass- UV–Vis), and molar conductivity. Next, the photoluminescence characteristics of the lanthanide complexes were investigated. An assessment was conducted to ascertain the antioxidant activity of the synthetic compounds compared with that of the stable free radical DPPH. The antibacterial activity of the Schiff base metal complexes was assessed against a strain of yeast as well as against a number of Gram-positive and Gram-negative bacteria. Computational studies were also performed to elucidate the mechanisms of the antimicrobial and antioxidant effects. In molecular docking, 1LL9, 6J2O, 3JPU, 2MBR, and 1HD2 crystal structures were determined as targets and the docking score values of H2L, L-Tb, L-Gd, and L-Eu compounds for these targets were calculated.

Caglar, Sema; Polat, Tuğba; Altay, Ahmet; Yeniçeri, Esma; Caglar, Bülent

This work aims to synthesize zinc(II) non-steroidal anti-inflammatory complexes and to evaluate their anticancer abilities on different cancer cell lines. In this context, four new zinc(II) complexes including the NSAIDs mefenamic acid or niflumic acid and picoline derivatives {[Zn2(μ-mef)3(3-pic)2] 1, [Zn3(μ-mef)6(2-pic)2] 2, [Zn3(μ-mef)6(4-pic)2] 3 and [Zn(nif)2(4-pic)2]} 4 were synthesized. The molecular structures were identified by elemental analysis, FT-IR, 1H NMR (complexes 2 and 3), UV–Vis, thermal analysis, and X-ray diffraction (complexes 1 and 4), indicating that one complex was mononuclear, one complex was binuclear, and two complexes were trinuclear. The deprotonated mefenamato ligands bind to the zinc(II) ion via carboxylate oxygen atoms and chelate in a bridging bidentate asymmetric form. The deprotonated niflumato ligand acts as a monodentate ligand. UV–Vis spectroscopy was used to assess the complexes' stability. The stoichiometry of the synthesized complexes was determined by 1H NMR and thermal studies. XTT assays showed that all complexes exhibited dose-dependent antiproliferative effects against breast cancer MCF-7 and MDA-MB-453 cells, colon cancer HT-29 cells, and lung cancer A549 cells. The highest cytotoxicity was exhibited by complex 3 against MDA-MB-453 cells with an IC50 value of 8.28 µM. The mechanistic studies performed by flow cytometry revealed that complex 3 exerted its in vitro anticancer activity against MDA-MB-43 cells by inducing apoptosis, increasing ROS production, and inhibiting the PI3K/AKT signaling pathway.

Harurluoglu, Betul; Altay, Ahmet; Caglar, Sema; Kubra Kagan Yeniceri, Esma; Caglar, Bulent; Sibel Şahin, Zarife

In this study, two new binuclear silver(I)-tolfenamic acid complexes including picoline derivative ligands, [Ag2(μ-tolf)2(2-pic)2] 1 and [Ag2(μ-tolf)2(4-pic)2] 2, were synthesized and identified by elemental analysis, FT-IR, 1H NMR and thermal analysis techniques. The in vitro cytotoxicity of the complexes was investigated against human breast cancer cell lines by XTT, flow cytometry, enzyme activity and western blot studies. The structures of 1 and 2 were clarified by single-crystal X-ray diffraction determination. The data clearly indicated that the Ag(I) ion is coordinated to one auxiliary ligand (2-pic or 4-pic), two tolfenamato ligands and another Ag(I) ion, demonstrating a distorted tetrahedral geometry. The tolfenamato ligands act as a bridging bidentate ligands. The chains are stabilized by intramolecular Ag(I)⋯π and π···π interactions. The 1H NMR and thermal analyses displayed the presence of picoline and tolfenamato ligands in the coordination sphere and the purity of the complexes. Both complexes exhibited potent cytotoxicity against cancer cell lines with higher selectivity than carboplatin. Flow cytometry and enzyme activity studies indicated that both complexes caused an increase in apoptosis, ROS and NO levels, cell cycle arrest, mitochondrial membrane damage and caspase activity, as well as inhibiting PI3K/Akt phosphorylation and modulating the oxidant/antioxidant balance system. Western blot analyses revealed the up-regulation of bax, caspase-3, caspase-9 and p53 proteins, but the down-regulation of bcl-2. These results demonstrate the vigorous apoptotic potential of the novel Ag(I) complexes in human breast cancer MDA-MB-453 cells.

Altay, Ahmet; Caglar, Sema; Caglar, Bulent; Sahin, Onur

Six new Ag(I) coordination complexes, namely [Ag4(μ-dicl)4(2-pic)3] 1, [Ag2(μ-mef)2(2-pic)2] 2, [Ag2(μ-dicl)2(3-pic)2] 3, [Ag2(μ-mef)2(3-pic)2] 4, [Ag2(μ-dicl)2(4-pic)2] 5 and [Ag2(μ-mef)2(4-pic)2] 6, were synthesized and characterized by elemental analysis, FT-IR and thermal analysis techniques. The crystal structures of 1, 3, 4 and 5 were determined by X-ray diffraction analysis, whereas 2 and 6 were obtained as microcrystalline powders. X-ray diffraction analysis demonstrated that 1 occurs as a tetranuclear complex, while 3, 4 and 5 have binuclear structures. A short Ag⋯Ag distances of 2.8446 and 2.8823 Å for 1, 2.8409 Å for 3, 2.8942 Å for 4 and 2.8423 Å for 5 were found in the complexes, indicating that argentophilic interactions exist between the silver ions. In 1, the dicl ligands act as μ3-O,O′,O′ bridging ligands between three Ag(I) ions. In 3, 4 and 5, the dicl and mef ligands behave as bridging ligands and bind two Ag(I) ions together with the carboxylato oxygen atoms. The simultaneous TG/DTG and DTA techniques were applied to interpret the mass losses, decomposition temperatures and corresponding processes of the thermal behaviours of the complexes. The experimental and calculated mass losses of the proposed structures for complexes 2 and 6 are quite compatible with each other and these complexes have very similar FT-IR spectra to the other complexes, which reflect their same structural geometries and characteristics. The cytotoxic activities of the complexes (1–6) were tested against three different cancer cell lines, MCF-7, HT-29 and HepG2, and one normal cell line, 3 T3-L1. XTT assay results demonstrated that although all the silver(I) complexes showed good cytotoxic activity, depending on the cell types tested, the complexes with mefanamic acid (2, 4 and 6) were found to predominate over those with diclofenac (1, 3 and 5), as well as the superiority of 3-picoline to 4-picoline and 2-picoline. Moreover, compared with the cytotoxic potential of carboplatin, 4 especially exhibited a significant cancer cell inhibitory rate and lower cytotoxicity toward the normal cell line, with much higher selectivity indexes.

Caglar, Sema; Demir, Serkan; Heren, Zerrin; Büyükgüngör, Orhan

The bis(2-benzoylbenzoato)(1,10-phenanthroline)metal(II) (M = Cu, Zn) complexes [Cu(bba)2(phen)] 1 and [Zn(bba)2(phen)] 2 have been prepared and characterized by elemental analyses, IR and electronic spectroscopy, and X-ray crystallography techniques. The electronic structure and spectroscopic features of the title complexes have been further investigated by means of DFT and TD-DFT approaches. The calculated spectra of 1 and 2 have been simulated in order to give a more qualitative description of the experimental spectra. The thermal behaviours of the title complexes have been studied by means of simultaneous TG, DTG and DTA methods in a static air atmosphere. Thermogravimetric (TG) analysis has shown that 1 and 2 are thermally stable (Tdecomp. > 227 °C).