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Öğe A square planar cobalt(II)-thiosemicarbazone complex. Synthesis, characterization, antiviral and anti-inflammatory potential(Elsevier, 2025) Atasever-Arslan, Belkis; Kaya, Busra; Sahin, Onur; Ulkuseven, BahriConsidering the possible antiviral effect of cobalt compounds and known pharmacological potential of thiosemicarbazones, a new combination containing cobalt(II) ions and tetradentate thiosemicarbazone was synthesized and structurally analyzed. In the complex structure (Co1), the cobalt ion is in 2+ + oxidation state and is coordinated with ONNO donor set on the thiosemicarbazone backbone. The complex molecule crystallizes in the space group P21/m and the environment of the cobalt center tends to square planar geometry. The inhibitory performance of SARS-CoV-2 and the anti-inflammatory impact of the complex molecule were investigated. It was found that Co1 has high inhibitory effects on the SARS-CoV-2 virus's 3CL main protease enzyme, ACE2:SARSCoV2 Spike RBD interaction, and IL8. Also, it showed significant anti-inflammatory effects on the release of IL6, IL8, IL10, and TGF beta 1 beta 1 cytokines and wound healing during in vitro TNF-alpha-induced inflammation. Experimental evidence demonstrates that Co1 diminishes both IL8 gene expression and protein levels. According to in silico and experimental results, it has a drug potential. Assessing the in vivo impacts of Co1 might contribute to understanding its potential as an antiviral and anti-inflammatory agent.Öğe Cobalt(II)/(III) complexes bearing a tetradentate thiosemicarbazone: Synthesis, experimental and theoretical characterization, and electrochemical and antioxidant properties(Wiley, 2020) Kaya, Busra; Akyuz, Duygu; Karakurt, Tuncay; Sahin, Onur; Koca, Atif; Ulkuseven, BahriNew cobalt complexes,Co1andCo2, were synthesized starting from acetylacetone-S-methylthiosemicarbazone. The square planar cobalt(II) and octahedral cobalt(III) complexes were characterized by FT-IR, UV-visible,H-1 NMR, and X-ray diffraction spectroscopies and mass spectrometry. Frontier orbitals of the complexes were theoretically obtained to better understand the complex structures and intermolecular interactions. The electrochemical behaviors ofCo1andCo2were investigated and the results were evaluated by comparing with each other and with similar published compounds to determine their possible usage in various electrochemical technologies, such as energy storage devices, electrocatalysts, and electrosensors. Metal-based oxidation at around 0 V and metal-based reduction at around -1.0 V indicated that these complexes are valuable for the proposed applications. By determining the trolox equivalent antioxidant capacity and the radical scavenging activity of the cobalt complexes, the compatibility between the antioxidant qualification, redox, and theoretical calculation results was discussed.Öğe Four and six-coordinated cobalt complexes based on thiosemicarbazone. Formation, experimental and theoretical characterization(Elsevier, 2022) Kaya, Busra; Karakurt, Tuncay; Sahin, Onur; Ulkuseven, BahriThe template reaction was performed between benzoylacetone-S-propylthiosemicarbazone and salicylaldehyde in the presence of Co(ClO4)(2) and a square planar cobalt(II) complex, [Co(L)] (Co1) where L is a dibasic thiosemicarbazidato ligand was isolated. It was aimed to synthesize the octahedral cobalt complexes by using the co-ligands, pyridine and 2-amino pyridine. An octahedral cobalt(III) complex, [Co(L)(py)(2)]ClO4 (Co2), with two axial-pyridine ligands was obtained. Reaction with 2-amino pyridine gave an unexpected cobalt(III) centered structure, [Co(L-1)]center dot H2O (Co3), where L-1 is a new sixdentate (N4O2) ligand that yielded by the addition of the amino group of pyridine to the L ligand. L-1 has tribasic thiosemicarbazidato structure that altered by the participation of an oxygen atom in addition to the amines. Experimental characterizations of three complexes have been completed using IR, NMR, UV-Vis, ESI-MS techniques and X-ray data. In order to better understand the intermolecular interactions of the structures, the Nonlinear Optical (NLO) properties and frontier orbitals (FMO) of the complexes were obtained using the Gaussian 09 program, DFT/B3LYP with 6-31 G (d, p) bas set for the C, N, O, H atoms and with LanL2DZ basic set for Co metal atom. (C) 2021 Elsevier B.V. All rights reserved.Öğe Iron(III) and nickel(II) complexes with S-alkyl (n-C1-6)-thiosemicarbazidato ligands: Synthesis, structural characterization, and antioxidant features(Elsevier Science Bv, 2018) Kaya, Busra; Sahin, Onur; Bener, Mustafa; Ulkuseven, BahriSix of acetylacetone-S-R-thiosemicarbazones (R: methyl, ethyl, propyl, butyl, pentyl or hexyl) were synthesized, and the template reactions resulting in N2O2 type complexes of the thiosemicarbazones with 4-methoxy-salicylaldehyde were carried out in the presence of iron(III) or nickel(II). The thiosemicarbazones and metal complexes were defined by elemental analysis, and infrared, UV-Vis, H-1 NMR spectra. Three complexes bearing butyl-pentyl- and hexyl-groups were analyzed by X-Ray diffraction technique. The crystal data demonstrated that the iron complexes are in square pyramidal structure and nickel complexes in square planar structure. To explicate the relationship between the S-alkyl chain length and antioxidant ability, total antioxidant capacity (as TEAC value) and free radical scavenging activity of the compounds have been tested using CUPRAC and DPPH methods, respectively. Furthermore, the antioxidant potential of the thiosemicarbazones were determined in vitro measuring the scavenging activity of hydroxyl radical (center dot OH), superoxide anion radical (center dot O-2(-)), and hydrogen peroxide (H2O2). The results revealed that the compounds have an antioxidant features comparable to ascorbic acid reference. Synthesized compounds with the remarkable antioxidant properties have a potential to examine in development of new anticancer agents. (C) 2018 Elsevier B.V. All rights reserved.Öğe Iron(III) complex with N2O2-thiosemicarbazidato and azide ligands. Synthesis mechanism, experimental and theoretical studies(Elsevier Science Bv, 2019) Kaya, Busra; Ulkuseven, Bahri; Sahin, Onur; Sahin, Zarife SibelReaction of acetylacetone-S-methyl-thiosemicarbazone and 4-methoxy-salicylaldehyde in presence of Fe(ClO4)(3) and NaN3 resulted in a mixed ligand complex, [Fe(L)N-3], where L is N2O2-chelating thiosemicarbazidato ligand formed by template condensation. The first iron complex of the thiosemicarbazidato structure bearing a nitrogen ligand instead of chlorine in the 5th coordination site of iron(III) was characterized by using elemental analysis and spectroscopic methods. Crystallographic analysis clearly revealed the square pyramidal environment of iron(III) center. To support and compare the experimental data, the molecular geometries, vibrational frequencies, NMR chemical shifts, molecular electrostatic potential surface and HOMO-LUMO energies were performed by using DFT-B3LYP method. Formation of the iron(III) complex was explicated by identification the reaction intermediates using experimental and theoretical methods. (C) 2019 Elsevier B.V. All rights reserved.Öğe Iron(III) complexes based on tetradentate thiosemicarbazones: Synthesis, characterization, radical scavenging activity and in vitro cytotoxicity on K562, P3HR1 and JURKAT cells(Wiley, 2021) Kalindemirtas, Ferdane Danisman; Kaya, Busra; Bener, Mustafa; Sahin, Onur; Kuruca, Serap Erdem; Demirci, Tulay Bal; Ulkuseven, BahriNine iron(III) complexes, [Fe(L)Cl], were synthesized starting from S-alkyl-thiosemicarbazones and some substituted aldehydes. The L ligands formed by template condensation are N2O2-chelating structures and named N-1-acetylacetone-N-4-R-salicylidene-S-alkyl-thiosemicarbazidato (L2-) where alkyl = methyl, propyl, or allyl and R = 3-methoxy, 4-methoxy, or 3,5-dichloro. The complexes were characterized using elemental analysis, IR, and ESI-MS. X-ray diffraction analysis of complex Fe8 (as a representative sample) indicated a square pyramid environment of the iron ion. The cytotoxicity performances of the complexes were determined using chronic myelogenous leukemia (K562), Burkitt's lymphoma (P3HR1), and T-cell leukemia (JURKAT) cell lines. For comparison, the noncancerous cell lines, human umbilical vein endothelial (HUVEC) and diploid fibroblast (3T3), and imatinib as positive control were included in the study. MTT results revealed that complexes Fe2, Fe5, Fe7, and Fe8 with methoxy (OCH3) substituent have remarkable cytotoxic effects on K562 and P3HR1 cells at relatively low concentrations in the ranges of 4.81-14.05 and 5.61-11.98 mu M, respectively. The radical scavenging activities of the complexes were measured for DPPH, superoxide anion (O-2(center dot-)), hydroxyl (center dot OH) radicals, and hydrogen peroxide (H2O2). Complexes Fe2, Fe3, Fe5, and Fe8, which exhibited selective cytotoxicity, were able to compete also with vitamin E in terms of ROS scavenging activities.Öğe Manganese(III) complexes with a tetradentate thiosemicarbazone. Structural characterization, electrochemistry, antioxidant capability, molecular docking and dynamics simulation on the potential inhibitory activity of cyclin-dependent kinase 2(Pergamon-Elsevier Science Ltd, 2024) Ortaboy, Sinem; Karakurt, Tuncay; Kaya, Busra; Sahin, Onur; Ulkuseven, BahriTwo manganese(III) complexes with the general formula [Mn III (L)X] (where L is a tetradentate thiosemicarbazone; X = Cl (Mn1) or N 3 (Mn2 is new) were synthesized and verified the expected structures by experimental and theoretical methods. Electrochemical behavior of the manganese complexes were studied using cyclic voltammetry (CV) and square wave voltammetry (SWV). TEAC and DPPH values were determined and compared with those of ascorbic acid (AA). Further, the correlation between the antioxidant data and redox potentials was discussed. Molecular dynamics (MD) simulations were performed after calculating the binding affinities to cyclin-dependent kinase 2 for Mn1, Mn2, and AA to clarify some information about their thermodynamic and dynamic properties and to validate the molecular docking results. The calculations gave the binding affinities that are -6.0, -8.6 and -9.4 kcal/mol for AA, Mn1 and Mn2, respectively. The experimental and theoretical results revealed that complex Mn2 having azide ion has a better antioxidant performance and also the highest docking score with the protein. The study demonstrated that such manganese complexes are suitable candidates to drug development against diseases caused by oxidative stress.Öğe New oxovanadium(IV) complexes overcame drug resistance and increased in vitro cytotoxicity by an apoptotic pathway in breast cancer cells(Elsevier Ireland Ltd, 2022) Kalindemirtas, Ferdane Danisman; Kaya, Buesra; Sert, Esra; Sahin, Onur; Kuruca, Serap Erdem; Ulkuseven, BahriIn order to examine the anticancer potential of oxovanadium(IV) complexes with thiosemicarbazone, two new complexes were prepared starting from 2-thenoyltrifluoroacetone-S-methylthiosemicarbazone. The complexes with tetradentate thiosemicarbazone ligand were characterized by elemental analysis, IR, ESI MS, and single crystal X-ray diffraction analysis. Cytotoxicity on breast cancer cells, MDA-MB-231 and MCF-7, was determined by MTT assay. Cisplatin was positive control and the results were compared with those of the normal cells, HUVEC and 3T3. The complexes exhibited greater activity on cancer cells than cisplatin, but they were cytotoxic at several times higher concentrations in the healthy cells. In our study, the presence of thiophene and fluoro groups in the oxovanadium(IV) complexes with thiosemicarbazone increased greatly the cytotoxic activity of the complexes on breast cancer cells. Moreover, the complexes induced apoptosis-mediated cell death and also reduced the expression of MDR-1 or P-glycoprotein and ABCG2. As a result, the findings indicated that the complexes have selective cytotoxicity on breast cancer cells and can overcome multidrug resistance. These properties of the complexes make it possible to be a potential anticancer drug candidate for breast cancer treatment.Öğe Oxovanadium(IV) complexes with tetradentate thiosemicarbazones. Synthesis, characterization, anticancer enzyme inhibition and in vitro cytotoxicity on breast cancer cells(Pergamon-Elsevier Science Ltd, 2021) Ertik, Onur; Kalindemirtas, Ferdane Danisman; Kaya, Busra; Yanardag, Refiye; Kuruca, Serap Erdem; Sahin, Onur; Ulkuseven, BahriFive oxovanadium(IV) complexes were synthesized using acetyl-and benzoylacetone-S-alkyl-thiosemicarbazones (alkyl=methyl, ethyl, propyl or butyl) and salicylaldehyde. Structural characterization was performed by element analysis, infrared, mass and electronic spectra, and also single crystal X-ray crystallography for one sample. The purity of all the complexes was verified with Miller indices (hkl) observed and calculated angles, 2h values and crystal sizes obtained from powder XRD diffraction. The in vitro cytotoxic activity was determined for the MCF-7, MDA-MB-231 and 3T3 cell lines with an MTT assay for 72 h. The complexes showed cytotoxicity against MCF-7, MDA-MB-231 and 3T3 cells at concentrations of 73- 148, 75-224 and 112-176 mu M, respectively. All the complexes had better cytotoxicity than the positive control, fluorouracil (5-FU). The complex containing the S-propyl group was the most effective complex, with the concentrations of 72.9 (for MCF-7) and 75.5 (for MDA-MB-231) mu M. Furthermore, the ability of the complexes to inhibit elastase, xanthine oxidase and neuraminidase enzymes and their role in cell death was studied. All the complexes inhibited the elastase and xanthine oxidase enzymes at higher concentrations than the IC50 values found for the cytotoxicity. However, the IC50 values for the inhibition of neuraminidase by the complexes bearing ethyl and propyl groups are better than those of quercetin and are close to the values found for the cytotoxicity. (C) 2021 Elsevier Ltd. All rights reserved.Öğe S-alkylated thiosemicarbazone derivatives: Synthesis, crystal structure determination, antimicrobial activity evaluation and molecular docking studies(Elsevier, 2021) Gunduz, Miyase Gozde; Kaya, Busra; Ozkul, Ceren; Sahin, Onur; Rekha, Estharla Madhu; Sriram, Dharmarajan; Ulkuseven, BahriIncreasing antimicrobial resistance is one of the most serious threats to human health worldwide. Therefore, there is an urgent need for the discovery of novel antimicrobial agents. Herein, we presented the synthesis of ten thiosemicarbazone derivatives (T1-T10) obtained by the reaction of S-alkylthiosemicarbazide with various dicarbonyl derivatives. The compounds were characterized by IR, H-1 NMR, ESI-MS and X-ray crystallography. Reaction with the dicarbonyl compound bearing the 4-fluorobenzoyl group unexpectedly gave a pyrazole derivative (T8) containing the entire S-methylthiosemicarbazone backbone. We extensively screened these derivatives for their antimicrobial activities against Mycobacterium tuberculosis and various bacterial and Candida strains. Additionally, the biofilm inhibition capacity of T8 was evaluated on Staphylococcus epidermidis and Pseudomonas aeruginosa biofilm positive strains. To find out the potential mechanism of anti-biofilm activity against PAO1, the docking studies of T8 were carried out into the binding site of LasR, which is the main regulator of bacterial cell-to-cell communication system known as quorum sensing. (C) 2021 Elsevier B.V. All rights reserved.Öğe Structural analysis and biological functionalities of iron(III)- and manganese(III)-thiosemicarbazone complexes: in vitro anti-proliferative activity on human cancer cells, DNA binding and cleavage studies(Springer, 2019) Kaya, Busra; Yilmaz, Zehra Kubra; Sahin, Onur; Aslim, Belma; Tukenmez, Ummugulsum; Ulkuseven, BahriOne iron(III) and two manganese(III) complexes based on thiosemicarbazone were synthesized and characterized using analytical and spectroscopic data. The crystallographic analysis showed the square pyramid structures of the complexes. Electronic spectra analysis was performed to determine the nature of the interaction between the complexes and calf thymus DNA (CT-DNA). DNA cleavage activities of the complexes were examined by gel electrophoresis (pBR322 DNA). The cytotoxicity of the complexes was determined against human cervical carcinoma (HeLa) and human colorectal adenocarcinoma (HT-29) cell lines by MTT assay. The results indicated that complex Fe1 is bound to CT-DNA via the intercalation mode, while complexes Mn1 and Mn2 are bound to CT-DNA via groove binding and/or electrostatic interactions rather than the intercalation mode. In addition, they showed good binding activity, which followed the order of Fe1>Mn2>Mn1. Complexes were found to promote the cleavage of DNA from supercoiled form (SC, Form I) to nicked circular form (NC, Form II) without concurrent formation of Form III, revealing the single-strand DNA cleavage. No significant cleavage was found in the presence of Mn1 and Mn2; however, it was observed at 2000 and 3000 mu M concentrations of Fe1. The ability of Fe1 to cleave DNA was greater than that of other complexes and these results are in conformity with their DNA-binding affinities. Cytotoxicity determination tests revealed that the complex Fe1 on HeLa and HT-29 cells exhibited a higher anti-proliferative effect than Mn1 and Mn2 (Fe1>Mn2>Mn1). These studies suggested that the complex Fe1 could be a good candidate as a chemotherapeutic drug targeting DNA. [GRAPHICS]Öğe Structural characterization of new zinc(ii) complexes with N2O2 chelating thiosemicarbazidato ligands; investigation of the relationship between their DNA interaction and in vitro antiproliferative activity towards human cancer cells(Royal Soc Chemistry, 2020) Kaya, Busra; Yilmaz, Zehra Kubra; Sahin, Onur; Aslim, Belma; Ulkuseven, BahriTwo new zinc(ii) complexes were synthesized by condensation of 4,4,4-trifluoro-1-(2-thienyl)-1,3-butanedione-S-methyl-thiosemicarbazone with salicylaldehyde or 4-methoxy-salicylaldehyde. Structures of the N2O2-chelate complexes, Zn1 and Zn2, were explicated by IR, H-1 NMR, ESI-MS and X-ray crystallography. Electronic spectral analysis was performed to assign the nature of the interaction between the complexes and calf thymus DNA (CT-DNA). DNA cleavage activities of the complexes were investigated by gel electrophoresis (pBR322 DNA). The results indicated that the complexes bind to CT-DNA via an intercalation mode and the binding of Zn2 is stronger than that of Zn1. Relatively high concentrations of the zinc complexes were found to encourage the cleavage of DNA from supercoiled form (Form I) to nicked circular form (Form II). The antiproliferative activity of the complexes was determined against human colorectal adenocarcinoma (HT-29) and human cervical carcinoma (HeLa) cell lines by MTT assay. The tests revealed that the complex Zn2 exhibited a higher antiproliferative effect than Zn1 on HT-29 and HeLa cells, analogical to the data from DNA interaction experiments. The studies demonstrated that complex Zn2 could be a good candidate as a chemotherapeutic drug targeting DNA.Öğe Synthesis of the nickel(II) complexes bearing tetradentate thiosemicarbazone through Michael addition of n-alcohols. Experimental, theoretical characterization and antioxidant properties(Springer/Plenum Publishers, 2022) Karakurt, Tuncay; Kaya, Busra; Sahin, Onur; Ulkuseven, BahriNew thiosemicarbazone derivative, 3-benzylidene-2,4-pentanedione-S-methyl-thiosemicarbazone hydrogen iodide (TSC), was synthesized and characterized by elemental analysis, IR, H-1 NMR and single crystal X-ray diffraction. The novel nickel(II) complexes, Ni1-4, were synthesized from the TSC and salicylaldehyde by template effect of nickel(II) ion. The reactions were accomplished by a proton provided from the addition of alcohols which are methyl, ethyl, propyl and allyl for complexes Ni1, 2, 3 and 4, respectively. Spectroscopic data indicated that the formation of the complexes occurred through Michael addition of the alcohols to the 2,4-pentanedione moiety of the TSC. Distorted square planar structures of complexes Ni1 and Ni2 were confirmed by single crystal X-ray diffraction. In addition, the detailed computations were performed by using the theory DFT for experimentally obtained structures of the TSC, Ni1 and Ni2. The antioxidant property of the TSC and nickel(II) complexes along with the standard ascorbic acid was studied by using DPPH radical scavenging and Cupric Reducing Antioxidant Capacity (CUPRAC) assays.Öğe The iron(III) and nickel(II) complexes with tetradentate thiosemicarbazones. Synthesis, experimental, theoretical characterization, and antiviral effect against SARS-CoV-2(Elsevier, 2021) Arslan, Belkis Atasever; Kaya, Busra; Sahin, Onur; Baday, Sefer; Saylan, Cemil Can; Ulkuseven, BahriThe discovery of new inhibitors that can be used in the treatment of viral diseases, including Covid-19, is an area open to research, and there is a need for innovative compounds with increased efficiency that provide inhibition by suppressing enzyme, and receptor mechanisms. The iron(III) and nickel(II) complexes were synthesized by template condensation of 4-methoxy-salicylaldehyde with S-methylthiosemicarbazone derivatives of 1,1,1-trifluoroacetylacetone (for Fe1) and methylacetoacetate (for Ni1). The complex structures having N2O2-chelating thiosemicarbazidato ligand were identified by analytical, spectroscopic, and X-ray crystallography results. Coordination environment of iron(III) center in complex Fe1 has a distorted square pyramidal geometry consisting of the N2O2 donor set and a chlorine atom, while that of Ni1 is square plane with the set. Inhibitory effect of Fe1 compound against SARS-CoV-2 virus specific 3C-like protease enzyme was investigated experimentally. It was determined that the highest inhibition concentration of Fe1 was 100 mu M. Percent inhibition activity at this concentration was on average 30.62 +/- 3.809%. Binding of both compounds to the 3C-like protease enzyme specific to the SARS-CoV-2 virus was analyzed using docking calculations. As a result of the docking calculation of Fe1, it has been observed that the compound has a binding energy of -7.4 kcal / mol to 3CL-like protease. It has been observed that the protein amino acids GLY143, THR26, and ASN142 contribute to the high binding affinity of the Fe1. The experimental and theoretical results obtained for the two complexes support each other. (C) 2021 Elsevier B.V. All rights reserved.
