Yazar "Ustun, Elvan" seçeneğine göre listele
Listeleniyor 1 - 19 / 19
Sayfa Başına Sonuç
Sıralama seçenekleri
Öğe Anticancer activities of manganese-based photoactivatable CO-releasing complexes (PhotoCORMs) with benzimidazole derivative ligands(Springer, 2017) Ustun, Elvan; Ozgur, Aykut; Coskun, Kubra A.; Dusunceli, Serpil Demir; Ozdemir, Ismail; Tutar, YusufCarbon monoxide is an important signaling molecule which is produced by heme oxygenase-1. CO shows antiproliferative activity against cancer cells; hence, activation of HO-1 is a significant inhibition strategy against tumor formation and survival of cancer cells. In this work, manganese-based CO-releasing molecules (CORMs) were designed and synthesized to inhibit breast cancer cell proliferation. Human invasive ductal breast cancer cells (MCF-7) were treated with the synthesized CORMs to investigate the effect of the complexes on breast cancer survival under UV light. In vitro experiments indicated that the complexes inhibited breast cancer cell proliferation, and further, the antiproliferative effects were increased under UV light. Thus, these novel CORMs may provide a drug template for the treatment of invasive ductal breast cancer.Öğe Antimicrobial activity, inhibition of biofilm formation, and molecular docking study of novel Ag-NHC complexes(Elsevier Science Sa, 2021) Sahin, Neslihan; Ustun, Elvan; Tutar, Ugur; Celik, Cem; Gurbuz, Nevin; Ozdemir, IsmailIn this study, we reported the synthesis of a new series of Silver(I)-N-heterocyclic carbene complexes which were obtained from the corresponding new N-heterocyclic carbene (NHC) precursors. All new compounds were characterized by elemental analysis, FT-IR, LC-MS, H-1 NMR, and C-13{H-1} NMR spectroscopy. These new N-heterocyclic carbene precursors and Ag(I)-NHC complexes were evaluated for their antibacterial, antifungal, and antibiofilm activities. The biological activities of synthesized products were compared with standard drugs. All compounds have moderate antibacterial and antibiofilm activities. In particular, while compound 2a was found to be the best inhibitor of E. coli biofilms, while compound 2d inhibited C. albicans biofilm at the highest rate. All the compounds were also analyzed by molecular docking methods with the certain target molecules. (C) 2021 Elsevier B.V. All rights reserved.Öğe Applications of quinoxaline-bridged bis(benzimidazolium) salts as ligand sources for the palladium-catalyzed Suzuki and Heck cross-coupling reactions in an aqueous medium(Wiley-V C H Verlag Gmbh, 2022) Dusunceli, Serpil Demir; Sahan, Mehmet Hanifi; Kaloglu, Murat; Ustun, Elvan; Ozdemir, IsmailIn the present work, quinoxaline-bridged bis(benzimidazolium) salts were prepared by the reaction of 2,3-bis(bromomethyl) quinoxaline and 1-substituted benzimidazole. The structures of the bis(benzimidazolium) salts were characterized by NMR, FT-IR, and elemental analysis techniques. Also, the photophysical properties of salts were investigated by UV-Vis absorption and fluorescence emission spectroscopy. Next, these quinoxaline bridged bis(benzimidazolium) salts were used as bidentate benzimidazol-2-ylidene ligand precursors in the palladium-catalyzed Suzuki-Miyaura and Mizoroki-Heck cross-couplings. These salts exhibited moderate-to-high activity in the palladium-catalyzed cross-coupling reactions.Öğe Carbon monoxide-releasing properties and DFT/TDDFT analysis of [Mn(CO)3(bpy)L]PF6 type novel manganese complexes(Elsevier Science Sa, 2016) Ustun, Elvan; Koc, Sefika; Demir, Serpil; Ozdemir, IsmailNovel manganese(I) carbonyl complexes of the general formula [Mn(CO)(3)(bpy)L]PF6 (bpy = 2,2-bipyridyl, L = N-(2-methylbenzyl)imidazoline, N-(3-methylbenzyl)imidazoline, N-(4-methylbenzyl)imidazoline, N-(2,4,6-trimethylbenzyl)imidazoline) were synthesized and characterized by analytical (LC-MS spectrometry and elemental analysis) and spectroscopic (H-1 NMR, C-13 NMR, cosy2D-NMR, infrared) methods. The CO-releasing properties of these complexes were investigated with myoglobin assay. The DFT/TDDFT calculations were made by ORCA package program with both BP86 and B3LYP functionals. (C) 2016 Elsevier B.V. All rights reserved.Öğe CO-releasing properties and anticancer activities of manganese complexes with imidazole/benzimidazole ligands(Taylor & Francis Ltd, 2016) Ustun, Elvan; Ozgur, Aykut; Coskun, Kubra A.; Demir, Serpil; Ozdemir, Ismail; Tutar, YusufCarbon monoxide (CO) is an important signaling molecule which plays significant roles in the pathogenesis of cancer. CO is produced by enzymatic degradation of heme in mammals. Heme oxygenase 1 (HO-1) catalyzes the breakdown of heme into CO, ferrous iron, and biliverdin. CO induces HO-1 and inhibits cell proliferation. Cancer cells exposed to several stress factors (hypoxia, reactive oxygen species, cis-platin, and oxidative stress), and HO-1 displays cytoprotective role against oxidative stress and inhibits apoptosis, metastases, angiogenesis, and cell proliferation processes. Therefore, metal containing CO-releasing molecules (CORMs) have been designed as an effective cancer treatment strategy. CORMs are responsible for releasing controlled amounts of CO to cells and tissues. Thus, we synthesized [Mn(CO)(3)(bpy)L]X manganese containing CORMs [bpy=2,2-bipyridine, X=hexafluorophosphate (PF6), trifluoromethanesulfonate (OTf), L=imidazole, methylimidazole, benzimidazole, N-benzylbenzimidazole, N-(4-chlorobenzyl)benzimidazole] to release CO in human invasive ductal breast (MCF-7) cell line. In vitro experiments indicated that the compounds inhibited cell proliferation and exhibited cytotoxic effect on breast cancer cells. Moreover, side groups of the compounds enhanced the anticancer effects in MCF-7 cell line. These manganese containing CORMs gave promising results and may be used as a drug template for effective treatment of invasive ductal breast carcinoma. [GRAPHICS] .Öğe Cyanopropyl functionalized benzimidazolium salts and their silver N-heterocyclic carbene complexes: Synthesis, antimicrobial activity, and theoretical analysis(Wiley-V C H Verlag Gmbh, 2022) Turker, Dilek; Ustun, Elvan; Gunal, Selami; Yildiz, Hatice; Dusunceli, Serpil D.; Ozdemir, IsmailThe reaction of N-substituted benzimidazole with 4-bromobutyronitrile gives the corresponding benzimidazolium salts as N-heterocyclic carbene (NHC) precursors. Silver(I) carbene complexes are synthesized by the reaction of the corresponding benzimidazolium salts with Ag2O in dichloromethane. These new NHC precursors and Ag-NHC complexes were characterized by spectroscopy techniques and also screened for their antibacterial activities against the standard bacterial strains Escherichia coli, Pseudomonas aeruginosa, Acinetobacter baumannii, Klebsiella pneumoniae, Staphylococcus aureus, methicillin-resistant Staphylococcus aureus, and Enterococcus faecalis, and the standard fungal strains Candida albicans and Candida glabrata, and promising results were achieved. The compounds were also analyzed by density functional theory (DFT)/time-dependent DFT and docking methods.Öğe Design, synthesis, antimicrobial activity and molecular docking study of cationic bis-benzimidazole-silver(I) complexes(Wiley-V C H Verlag Gmbh, 2023) Ustun, Elvan; Sahin, Neslihan; Ozdemir, Ilknur; Gunal, Selami; Gurbuez, Nevin; Ozdemir, Ismail; Semeril, DavidTwo series of bis(1-alkylbenzimidazole)silver(I) nitrate and bis(1-alkyl-5,6-dimethylbenzimidazole)silver(I) nitrate complexes, in which the alkyl substituent is either an allyl, a 2-methylallyl, an isopropyl or a 3-methyloxetan-3-yl-methyl chain, were synthesized and fully characterized. The eight N-coordinated silver(I) complexes were screened for both antimicrobial activities against Gram-negative (Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, and Acinetobacter baumannii) and Gram-positive (Staphylococcus aureus, Staphylococcus aureus MRSA, and Enterococcus faecalis) bacteria and antifungal activities against Candida albicans and Candida glabrata strains. Moderate minimal inhibitory concentrations (MIC) of 0.087 & mu;mol/mL were found when the Gram-negative and Gram-positive bacteria were treated with the silver complexes. Nevertheless, MIC values of 0.011 & mu;mol/mL, twice lower than for the well-known fluconazole, against the two fungi were measured. In addition, molecular docking was carried out with the structure of Escherichia coli DNA gyrase and CYP51 from the pathogen Candida glabrata with the eight organometallic complexes, and molecular reactivity descriptors were calculated with the density functional theory-based calculation methods.Öğe Molecular docking and electronic transition analysis of novel [Re(bbim)(bpy)(CO)3]OTf complex as a CO-releasing molecule(Scientific Publ-India, 2019) Ustun, Elvan; Celebi, Mutlu Sonmez; Sahin, Neslihan; Dusunceli, Serpil Demir; Ozdemir, IsmailSynthesis of CO-releasing molecules that safely deposit/transport CO has attracted great attention after the discovery of therapeutic properties of carbon monoxide, which is known to be a toxic gas. Metal carbonyl complexes seem to be the most important alternative as CO-releasing molecules. Recent developments in computational chemistry make it possible to gain many information about the properties of complexes before being synthesized. On the other hand, molecular docking methods can also give valuable information about the interaction of the molecules with tissue. The metal carbonyl complexes that were synthesized as a CO-releaser interact primarily with blood proteins when they enter the tissue; therefore, the theoretical analysis of the interaction of complexes with blood proteins can give useful information. In this study, [Re(bbim)(bpy)(CO)(3)]OTf (bbim: benzylbenzimidazole; bpy: 2,2'-bipyridyl, OTf: SO3CF3) complex was synthesized, characterized, analyzed by DFT/TDDFT based calculation method and docked into human serum albumin.Öğe Molybdenum Carbonyl Complexes with Benzimidazole Derivatives Against SARS-CoV-2 by Molecular Docking and DFT/TDDFT Methods(World Scientific Publ Co Pte Ltd, 2021) Ustun, Elvan; Dusunceli, Serpil Demir; Coskun, Feyzullah; Ozdemir, IsmailBenzimidazole derivative molecules attract attention of scientists due to their bioactivities. The dramatic changes in recorded activities according to the type and position of the substituents motivate synthesis and analysis of new molecules. Commercial benzimidazole-based molecules have been used in therapeutic procedures. It is known that the activities of metal complexes with benzimidazole derivative ligands have different activities when compared to the benzimidazole main structure. Nowadays, one of the most important health problems is COVID-19, which caused the pandemic that we are still experiencing. Although vaccine studies are important to overcome acute problems, regarding the possible post-vaccination adverse effects, the need for new drugs against the virus is obvious. Considering the urgency and the limited facilities during the pandemic, preliminary in silico studies of candidate molecules are essential. In this study, {[bis-(N-benzylbenzimidazole)] tetracarbonylmolybdenum}, {[bis-(N-4-chlorobenzylbenzimidazole)] tetracarbonylmolybdenum} and {[bis-(N-4-methoxybenzylbenzimidazole)] tetracarbonylmolybdenum} were synthesized and characterized. The optimization and the structural analysis of these molecules were performed by DFT/TDDFT methods. The molecules were docked into SARS coronavirus main peptidase (PDB ID: 2gtb), COVID-19 main protease in complex with Z219104216 (PDB ID: 5r82), COVID-19 main protease in complex with an inhibitor N3 (PDB ID: 6lu7) and Papain-like protease of SARS-CoV-2 (PDB ID: 6w9c) crystal structures for evaluation of their anti-viral activity. Molybdenum carbonyl complexes containing benzimidazole derivative ligands have been synthesized, characterized, and analyzed structurally by DFT/TDDFT methods. Antiviral activities of the complexes were analyzed by molecular docking methods against some important Coronavirus targets in parallel with the pandemic period we are living in. Inhibitory potency of the complexes toward COVID-19 targeted is compared to some well-known commercial antivirals.Öğe N-alkylbenzimidazole silver(I) complexes: Synthesis, biological evaluation and molecular docking study(Pergamon-Elsevier Science Ltd, 2024) Ari, Erkan; Sahin, Neslihan; Ustun, Elvan; Dundar, Muhammed; Karci, Huseyin; Ozdemir, Lknur; Koc, AhmetA series of N-alkylbenzimidazole silver(I) complexes were synthesized and fully characterized by FT-IR, Mass, 1H, 13C{1H} NMR spectroscopy, and elemental analysis. Synthesized N-alkylbenzimidazole silver(I) complexes were investigated for their antimicrobial activities against bacteria Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and the fungal strains Candida albicans and Candida glabrata. All the complexes (2a-f) showed higher antimicrobial activity against bacteria than fungi strains. In particular, complexes 2b and 2e showed comparable activity to Ampicillin against Escherichia coli. Also, all complexes showed better activity than Ampicillin against Pseudomonas aeruginosa. The complex 2e showed remarkable activity against Candida albicans (12.5 mu g/mL) and Candida glabrata (25 mu g/mL). The molecules that were first optimized by DFT-based calculation methods were also analyzed by molecular docking methods against DNA gyrase of E. Coli, CYP51 from Candida glabrata, and Penicillin Binding Protein-3.Öğe New photoactivatable CO-releasing molecules of manganese with imidazoline/benzimidazole ligands(Springer, 2014) Ustun, Elvan; Demir, Serpil; Ozdemir, Ismail; Schatzschneider, Ulrich[Abstract Not Available]Öğe Novel Ag(I)-NHC complex: synthesis, in vitro cytotoxic activity, molecular docking, and quantum chemical studies(Walter De Gruyter Gmbh, 2022) Serdaroglu, Goncagul; Sahin, Neslihan; Sahin-Bolukbasi, Serap; Ustun, ElvanThe importance of organometallic complexes in cancer biology has attracted attention in recent years. In this paper, we look for the in vitro cytotoxic capability of novel benzimidazole-based N-heterocyclic carbene (NHC) precursor (1) and its Ag(I)-NHC complex (2). For this purpose, these novel Ag(I)-NHC complex (2) was characterized by spectroscopic techniques (H-1, C-13{H-1} nuclear magnetic resonance (NMR), and Fourier-transform infrared spectroscopy (FT-IR)). Then, in vitro cytotoxic activities of NHC precursor (1) and Ag(I)-NHC complex (2) were investigated against MCF-7, MDA-MB-231 human breast, DU-145 prostate cancer cells, and L-929 healthy cells using MTT assay for 24, 48, and 72 h incubation times. Ag(I)-NHC complex (2) showed promising in vitro cytotoxic activity against all cell lines for three incubation times, with IC50 values lower than 5 mu M. It was also determined that (NHC) precursor (1) were lower in vitro cytotoxic activity than Ag(I)-NHC complex (2) against all cell lines. Selectivity indexes (SIs) of Ag(I)-NHC complex (2) against cancer cells were found higher than 2 for 24 and 48 h incubation time. Besides, the electronic structure and spectroscopic data of the newly synthesized precursor and its Ag-complex have been supported by density functional theory (DFT) calculations and molecular docking analysis. After, the anticancer activity of these compounds has been discussed considering the results of the frontier molecular orbital analysis. We hope that the obtained results from the experiments and computational tools will bring a new perspective to cancer research in terms of supported by quantum chemical calculations.Öğe PEPPSI type complexes: Synthesis, x-ray structures, spectral studies, molecular docking and theoretical investigations(Pergamon-Elsevier Science Ltd, 2021) Serdaroglu, Goncagul; Sahin, Neslihan; Ustun, Elvan; Tahir, Muhammad Navaz; Arici, Cengiz; Gurbuz, Nevin; Ozdemir, IsmailIn this work, three novel potent benzimidazolium-derived PEPPSI type palladium complexes, namely dichloro[1-allyl-3-benzylbenzimidazole-2-ylidene]pyridine palladium(II) (1), dichloro[1-allyl-3-(1-naphthylmethyl)benzimidazole-2-ylidene]pyridine palladium(II) (2) and dichloro[1-allyl-3-(9-anthrylmethyl)benzimidazole-2-ylidene]pyridine palladium(II) (3), were synthesized and characterized by single X-ray crystallography, FT-IR and NMR spectroscopy. The results were compared with the relevant calculated data. After structural and spectroscopic determination, the performance of the global reactivity behavior of these derivatives was evaluated by quantum chemical parameters (QCP) obtained from DFT/B3LYP and HF methods utilized with the 6-311 g**/LANL2DZ basis set. Next, NBO analyses were conducted to enlighten the possible interactions that occur for each derivative and this revealed that the main role in the lowering of the stabilization energies of all the derivatives was sourced from n -> pi* and pi -> pi* interactions. Finally, all the complexes were analyzed for their anticancer potential by the molecular docking method with VEGFR (vascular endothelial growth factor receptor), thioredoxin reductase, breast cancer and the dodecamer structure of DNA. (C) 2021 Elsevier Ltd. All rights reserved.Öğe Structure, CO-releasing property, electrochemistry, DFT calculation, and antioxidant activity of benzimidazole derivative substituted [Mn(CO)3(bpy)L]PF6 type novel manganese complexes(Elsevier Science Sa, 2016) Ustun, Elvan; Ayvaz, Melek Col; Celebi, Mutlu Sonmez; Asci, Gizem; Demir, Serpil; Ozdemir, IsmailMetal carbonyl complexes are prominent group organometallic compounds because of their applications in industrial and pharmaceutical chemistry. In recent years, metal carbonyl complexes have been accepted major for storage and transportation of carbon monoxide which is an important signaling molecule significantly in pathogenesis of some diseases. Thus, we designed and synthesized novel manganese (I) carbonyl complexes with general formula [Mn(CO)(3)(bpy)L]PF6 (bpy = 2,2-bipyridyl, L = N-(2-chlorobenzyl) benzimidazole, N-(2-methoxybenzyl) benzimidazole, N-(2-methylbenzyl) benzimidazole). The complex molecules were characterized by LC-MS, H-1-NMR, C-13-NMR, IR spectroscopy methods and elemental analysis. The CO-releasing properties, antioxidant activities and redox properties of these complexes were investigated. The DFT/TDDFT analyses were made by ORCA package program. (C) 2016 Elsevier B.V. All rights reserved.Öğe Synthesis, antimicrobial properties, and theoretical analysis of benzimidazole-2-ylidene silver(I) complexes(Taylor & Francis Ltd, 2020) Dusunceli, Serpil Demir; Ayaz, Dilek; Ustun, Elvan; Gunal, Selami; Ozdemir, Namik; Dincer, Muharrem; Ozdemir, IsmailA series of symmetrical and nonsymmetricalN,N-disubstituted benzimidazolium salts were synthesized asN-heterocyclic carbene precursors. These salts were treated with Ag2O to afford their corresponding mononuclear Ag(I)-NHC complexes. These compounds were characterized by spectroscopy techniques and analyzed by DFT/TDDFT and docking methods. Also, the structures of2aand2ewere determined by single-crystal X-ray crystallography. These new Ag-NHC complexes were screened for their antibacterial activities against Gram-positive, Gram-negative bacteria, fungi, and nosocomial agents.Öğe Synthesis, characterization and antimicrobial properties of silver complexes derived from 5,6-Dimethylbenzimidazol-2-ylidene(Pergamon-Elsevier Science Ltd, 2023) Cetinkaya, Erdem Atalay; Koc, Ahmet; Koc, Hatice Kubra; Karabiyik, Hande; Karabiyik, Hasan; Ustun, Elvan; Ozdemir, IsmailBenzimidazoles are considered as a class of bioactive heterocyclic compounds that exhibit many biological ac-tivities such as antimicrobial. Benzimidazole-silver complexes also have strong antimicrobial activity, sometimes even higher than that of conventionally used silver antimicrobials. In this study, six new 5,6-dimethylbenzimi-dazolium ligand precursors which were functionalized by using 2-naphthylmethyl and their silver complexes were synthesized. All molecules were characterized by elemental analysis, 1H NMR, 13C NMR, and IR spec-troscopy techniques. Additionally, mu-Dichloro-bis{[1-(2-naphthylmethyl)-3-(benzyl)-5,6-dimethylbenzimidazol-2-ylidene]silver(I)} was characterized structurally in the solid state by X-ray crystallography which was found to be dimeric with two bridging chlorides. In vitro antimicrobial activity of the synthesized compounds investigated in this work was tested against the reference strains: Escherichia coli (ATCC 25922), Staphylococcus aureus (ATCC 29213) and Pseudomonas aeruginosa (ATCC 27853), Candida albicans (ATCC MYA-2876) and Candida glabrata (ATCC 2001). Some of these new compounds have been found to display significant effectiveness. Also, the molecular docking analysis was performed for all optimized ligands and complexes against SarAÖğe Synthesis, characterization, antimicrobial and antibiofilm activity, and molecular docking analysis of NHC precursors and their Ag-NHC complexes(Royal Soc Chemistry, 2021) Ustun, Elvan; Sahin, Neslihan; Celik, Cem; Tutar, Ugur; Ozdemir, Namik; Gurbuz, Nevin; Ozdemir, IsmailMicroorganisms attach to surfaces and interfaces and form biofilms which create a sheltered area for host cell response. Therefore, biofilms provide troubles in fields such as medicine, food, and pharmaceuticals. Inhibition of formation of biofilms through hindering of quorum sensing could be a method for the production of new generation antibiotics. In this study, four new benzimidazole type NHC precursors (1-allyl-3-benzyl-5,6-dimethylbenzimidazolium chloride, 1-allyl-3-(2,4,6-trimethylbenzyl)-5,6-dimethylbenzimidazolium chloride, 1-allyl-3-(2,3,5,6-tetramethylbenzyl)-5,6-dimethylbenzimidazolium chloride, and 1-allyl-3-(2,3,4,5,6-pentamethylbenzyl)-5,6-dimethylbenzimidazolium chloride and Ag-NHC complexes of these molecules were synthesized and characterized by elemental analysis, FT-IR spectroscopy, H-1, and C-13{H-1} NMR spectroscopy, LC-MS, and single crystal crystallography. Antimicrobial and biofilm formation inhibition activities of the molecules were evaluated. In addition, the activities of the molecules were examined in detail by molecular docking analysis. According to the results obtained, higher activity was achieved with the complex molecules when compared with the benzimidazole derivative ligands.Öğe Theoretical analysis of frontier orbitals, electronic transitions, and global reactivity descriptors of M(CO)4L2 type metal carbonyl complexes: a DFT/TDDFT study(Springer/Plenum Publishers, 2019) Ustun, Elvan; Dusunceli, Serpil Demir; Ozdemir, IsmailMetal carbonyl complexes, which have been known as effective catalysts since early days, find use in many fields both directly and indirectly. Although the use of metal carbonyl complexes as bio-probe and protein labeling agent due to their unique spectroscopic properties is known, metal carbonyls have recently been used as storage and transport carriers of carbon monoxide. These developments have motivated the synthesis of new metal carbonyl complexes. Despite the difficulties in obtaining prediction for the molecular properties of organometallic compounds, DFT-based calculation programs have been able to gain insight into the structural/electronic properties of inorganic and organic molecules.In this study, structural, electronic, and reactivity properties of characterized molybdenum and tungsten carbonyl complexes with benzimidazole and imidazoline derivative ligands were investigated using DFT-based calculation program ORCA.Öğe A theoretical insight for solvent effect on myoglobin assay of W(CO)4L2 type novel complexes with DFT/TDDFT(Elsevier Science Bv, 2016) Ustun, Elvan; Demir, Serpil; Coskun, Feyzullah; Kaloglu, Murat; Sahin, Onur; Buyukgungor, Orhan; Ozdemir, IsmailNovel tetracarbonyl complexes of type W(CO)(4)L-2 (L: 4-chlorobenzylimidazoline; 4-methylbenzylimidazoline; 3,5-dimethylbenzylimidazoline; 2,4,6-trimethylbenzylimidazoline; 2,3,5,6-tetramethylbenzylimidazoline) were synthesized. Then newly synthesized novel compounds were characterized by IR, H-1 NMR, C-13 NMR and LC-MS. The characterizations of two of the complexes have also been confirmed with single crystal X-Ray diffraction and OFT optimization results of these complexes have been compared with single crystal results. We have investigated the solvent effect on the structure and metal-to-ligand charge transfer (MLCT) transitions with OFT/TDDFT calculations with ORCA package program with BP86 functional. (C) 2016 Elsevier B.V. All rights reserved.
