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Öğe Benzimidazolium Salts Bearing 2-methyl-1,4benzodioxane Group: Synthesis, Characterization, Computational Studies, In vitro Antioxidant and Antimicrobial Activity(Biointerface Research Applied Chemistry, 2021) Albayrak, Sevil; Gok, Yetkin; Sari, Yakup; Tok, Tugba Taskin; Aktas, AydinThis study contains the synthesis of the 1-(2-methyl-1,4-benzodioxane)benzimidazole and 2-methyl-1,4-benzodioxane substituted benzimidazolium salts. The benzimidazolium salts were synthesized from the reaction of the 1-(2-methyl-1,4-benzodioxane)benzimidazole and various aryl chlorides. All compounds were characterized using H-1 NMR, C-13 NMR, FTIR spectroscopy, and elemental analysis techniques. The antioxidant properties of benzimidazolium salts were examined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging and hydrogen peroxide scavenging ability assays. The compounds showed a moderate inhibitory effect on DPPH radical (The percent inhibition = 29.53-39.75). Also, the compounds exhibited significant H2O2 radical scavenging activity. Antimicrobial activities of the compounds were examined against nine bacterial strains and Candida albicans. All compounds displayed marked antimicrobial activity against tested microorganisms, particularly against Pseudomonas aeruginosa, Listeria monocytogenes, and C. albicans. From the computational perspective, benzimidazolium salts were also optimized at B3LYP / DMol3// DFT level using the Discovery Studio 2020 program. HOMO-LUMO analysis and molecular electrostatic potential surface (MESP) were exerted to examine the effects of benzimidazolium salts' electronic and structural properties.Öğe Benzotriazole functionalized N-heterocyclic carbene-silver(I) complexes: Synthesis, cytotoxicity, antimicrobial, DNA binding, and molecular docking studies(Pergamon-Elsevier Science Ltd, 2018) Onar, Gulnihan; Karatas, Mert Olgun; Balcioglu, Sevgi; Tok, Tugba Taskin; Gurses, Canbolat; Kilic-Cikla, Isin; Ozdemir, NamikIn this study, six [Ag(NHC)(2)](+)[AgCl2](-) type silver complexes were synthesized by the reaction of corresponding carbene precursor and Ag2O. One [Ag(NHC)(2)]+NO3- type complex was synthesized by the anion exchange reaction of corresponding silver-NHC and NaNO3. The synthesized complexes were characterized by H-1 NMR, C-13 NMR and IR spectroscopic methods, and elemental analysis. X-ray crystal structure of 5a was also reported. Cytotoxicities of all compounds were evaluated against human breast (MCF-7) and colorectal (Caco-2) cancer cell lines and non-cancer mouse fibroblast (L-929) cell lines. All complexes performed stronger activity against both cancer cell lines than standard compound cisplatin while complex 3b performed nearly equal cytotoxicity to cisplatin against non-cancer L-929. Antimicrobial effects of all compounds were evaluated against Escherichia coli, Bacillus subtilis and Candida albicans and good activities were observed. The docking results indicated that complex 3b might be classified as druggable molecule in drug design. DNA binding study also demonstrates that 3b complex has an interaction ability to DNA. Combination of experimental and molecular docking results revealed that reported complexes are promising structures and deserve further research as anticancer drugs. (C) 2018 Elsevier Ltd. All rights reserved.Öğe Bisbenzimidazole salts and their in silico-in vitro inhibitory abilities on hCA I, hCA II, and AChE enzymes(Springer Wien, 2024) Yilmaz, Ulku; Demir, Yeliz; Tok, Tugba Taskin; Gok, Yetkin; Aktas, Aydin; Gulcin, IlhamiEight new bisbenzimidazolium halides were prepared from alkyl halides and 4,4 '-bis[(benzimidazol-1-yl)methyl]-1,1 '-biphenyl.The structures of the benzimidazole salts were characterized using elemental analysis techniques as well as 1H, 13C NMR, and FT-IR spectroscopic methods. The inhibitory effects of the benzimidazole derivatives were measured against human carbonic anhydrase I (hCA I), human carbonic anhydrase II (hCA II), and acetylcholinesterase (AChE) enzymes. All benzimidazolium halides exhibited significant enzyme inhibitory properties. They showed highly potent inhibitory effect on AChE and hCAs (Ki values are in the range of 15.7 +/- 0.8 to 49.7 +/- 10.1 nM, 14.6 +/- 1.5 to 70.7 +/- 2.7 nM, and 17.4 +/- 2.8 to 38 +/- 10 nM for AChE, hCA I, and hCA II, respectively). The binding orientation of the synthesized bisbenzimidazolium halides was evaluated by molecular docking studies, reflecting the importance of the p-methylbenzyl, m-methylbenzyl, p-nitrophenethyl, and 3-(1,3-dioxoisoindolin-2-yl)methyl) groups in protein-ligand interaction. The docking results support the Ki values of the respective compounds in this study. The structure-activity relationships against the various targets are clearly shown in three dimensions at the atomic level by their interactions with the mentioned enzymes.Öğe The Cytotoxicity Profile, Apoptosis Mechanism, and Molecular Docking Studies of a Series of Benzimidazolium Derivative Morpholine-Substituted Ag(I) Heterocyclic Carbene Complexes(Springer, 2023) Kutlu, Tuerkan; Yildirim, Isil; Dikmen, Miris; Tok, Tugba Taskin; Aktas, Aydin; Gok, YetkinThe main problems experienced in treatment with anticancer drugs are undesirable side effects, and toxicity. Minimal side effects for new anticancer compounds may be met due to enhanced efforts to clarify the compound's mechanisms of action. Therefore, we aimed to investigate whether or the cytotoxic effect and apoptosis mechanism of a series Ag(I)NHC complexes on non-small cell lung cancer cell line (A549) and normal lung fibroblast cell line (CCD-19Lu) in this study. The cytotoxicity was determined by using the MTT method, and apoptotic effects were detected by cell cycle, annexin-V/propidium iodide (PI) staining and cell cycle, caspase-3, mitochondrial membrane potential analysis. Molecular docking studies were performed using in silico ADMET analysis, and molecular docking information on the compounds was gained using the DS 3.5 software subprotocol. All the time, the cytotoxic effect of silver compounds was monitored for 24 h in comparison to cisplatin. The apoptotic effect of these compounds increased in cancer cells as compared to normal cells. Complex 3b exhibited the highest cytotoxic activity on cancer cell in 24 and 72 h, but complex 3a exhibited the highest cytotoxic activity on cancer cell s in 48 h. Moreover, all Ag(I)NHC complexes exhibited significant statistical difference depending on the increase in concentration on cancer cells, and all compounds induced apoptosis associated with distributing of membrane polarization and stopping the cell cycle in phase G1 and the caspase-3 activity. Caspase-3 activity of the new Ag(I)NHC compounds showed 8.3 to 17.6-fold increase compared the untreated cells. The loss of mitochondrial membrane potential indicated that JC-1 assay results were 16.9 to17.2-fold higher than normal cells in Ag(I)NHC compounds and 11.3-fold higher her in cisplatin. In addition, molecular docking studies were executed on the Ag(I)NHC complexes, and cisplatin estimate that the binding modes towards the EGFR kinase. Because epidermal growth factor receptor (EGFR) is expressed highly in a great number of epithelial tumors. These findings suggested that Ag(I)NHC complexes exhibited anticancer activity and may be considered to have a new therapeutic potential for human non-small cell lung cancer cell treatment.Öğe Inhibition of paraoxonase 1 by coumarin-substituted N-heterocyclic carbene silver(I), ruthenium(II) and palladium(II) complexes(Wiley, 2019) Karatas, Mert Olgun; Calgin, Gamze; Alici, Bulent; Gokce, Basak; Gencer, Nahit; Tok, Tugba Taskin; Arslan, OktayWe synthesized three coumarin-substituted benzimidazolium chlorides and their silver(I), ruthenium(II) and palladium(II) N-heterocyclic carbene (NHC) complexes. All compounds were characterized using appropriate spectroscopic techniques and elemental analyses. Single-crystal X-ray structure of a Pd(II)-NHC complex (6b) was also determined. The inhibitory properties of all compounds were tested on the activity of human paraoxonase 1 (PON1). All complexes exhibited weaker inhibitory properties than their corresponding benzimidazolium salts except for complex 6b which is the most active inhibitor with an IC50 value of 3.01 mu M among the compounds reported in this study. A kinetic evaluation showed that this complex inhibits PON1 activity in a non-competitive manner. Molecular docking studies were also performed for 6b in order to obtain more insight into the binding mode.Öğe The (NHC)PdBr2(2-aminopyridine) complexes: synthesis, characterization, molecular docking study, and inhibitor effects on the human serum carbonic anhydrase and serum bovine xanthine oxidase(Springer Wien, 2020) Turker, Ferhat; Noma, Samir Abbas Ali; Aktas, Aydin; Al-Khafaji, Khattab; Tok, Tugba Taskin; Ates, Burhan; Gok, YetkinThis study contains the synthesis, spectral analysis, and the enzyme inhibition effects of the Pd-based complexes bearing both 2-aminopyridine andN-heterocyclic carbene (NHC) ligands. The NHC ligand in the Pd-based complexes contains the 3-cyanobenzyl group. All new complexes were synthesized from (NHC)PdBr2(pyridine) complexes and 2-aminopyridine. These new complexes were characterized by using elemental analysis,H-1 NMR,C-13 NMR, and FT-IR spectroscopy techniques. Furthermore, inhibitor effects of these complexes were also tested toward some metabolic enzymes such as carbonic anhydrase and xanthine oxidase enzymes. The IC50 range for hCA I, hCA II, and XO were determined as 0.325-0.707, 0.238-0.636, and 0.576-1.693 mu M, respectively. These data showed that Pd(II)-NHC complexes bearing 2-aminopyridine may be potent inhibitors of hCA and XO enzymes. Besides these applications, molecular docking was performed by using CDOCKER tool as a part of Discovery studio 2019, not only to determine the binding mode of synthesized inhibitors, but also to determine the correlation between the CDOCKER score values and IC50 values. We found a good correlation (R-2 = 0.7403) between IC50 and the CDOCKER score of the inhibitors for XO. These findings could be a reference to start the development of effective medicine for XO. [GRAPHICS] .Öğe Pentafluorobenzyl-substituted benzimidazolium salts: Synthesis, characterization, crystal structures, computational studies and inhibitory properties of some metabolic enzymes(Elsevier, 2022) Hamide, Mahmut; Gok, Yetkin; Demir, Yeliz; Yakali, Gul; Tok, Tugba Taskin; Aktas, Aydin; Sevincek, ResulThis work contains the synthesis and characterization of the pentafluorobenzyl-substituted benzimidazolium salts which N -heterocyclic carbene (NHC) precursors. All compounds were characterized by using 1 H, 13 C, and 19 F NMR, FT-IR spectroscopy, and elemental analysis techniques. All the spectroscopy and elemental analysis data fully confirm the proposed formulas. In the synthesized compounds, the molecular structures of compounds 1-(2-methylbenzyl)-3-(2,3,4,5,6-pentafluorobenzyl)benzimidazolium bromide ( 1b ), 1-(4-methylbenzyl)-3-(2,3,4,5,6-pentafluorobenzyl)benzimidazolium bromide ( 1d ) and 1-(4-trifluoromethylbenzyl)-3-(2,3,4,5,6-pentafluorobenzyl)benzimidazolium bromide ( 1f ) were enlightened by single crystal X-ray diffraction studies. After enzyme inhibition study, a new series of pentafluorobenzyl-substituted NHC precursors were determined to be highly potent inhibitors for acetylcholinesterase (AChE) enzyme and carbonic anhydrases (hCAs) isoenzymes. K i values were found in the range of 7.20 +/- 1.31 to 28.26 +/- 5.72 nM for AChE , 10.25 +/- 0.93 to 40.93 +/- 3.89 nM toward hCA I as pervasive metal containing enzymes present in prokaryotes and eukaryotes, and 3.33 +/- 0.15 to 58.22 +/- 6.99 nM for hCA II as the key enzyme promising strategy for the treatment of neurological disorders such as Alzheimer's disease. The molecular docking study performed for compounds had higher potential inhibitory properties involved in a novel series of pentafluorobenzyl-substituted NHC precursors based on the binding energy and interaction types against AChE and hCAs. (c) 2022 Elsevier B.V. All rights reserved.Öğe Protonated water-soluble N-heterocyclic carbene ruthenium(II) complexes: Synthesis, cytotoxic and DNA binding properties and molecular docking study(Elsevier Science Sa, 2018) Akkoc, Mitat; Balcioglu, Sevgi; Gurses, Canbolat; Tok, Tugba Taskin; Ates, Burhan; Yasar, SedatNew benzimidazolium salts 1a-d having methylpyridine group on the side chain, have been synthesized and reacted with Ag2O to produce Ag(I)-N-heterocyclic carbene (NHC) complexes 2a-d. Ag(I)-N-heterocyclic carbene (NHC) complexes were used as a carben transfer agents to synthesize water-soluble ruthenium(II)-NHC complexes 4a-d. All synthesized compounds were fully characterized by H-1 and C-13 NMR and HRMS spectroscopic techniques. Anticancer potential and IC50 values of ruthenium(II)-NHC complexes were evaluated by MTT assay against human colorectal cancer (Caco-2) and breast cancer (MCF-7) cell lines. The IC50 value of water-soluble ruthenium(II)-NHC complex 4d demonstrated remarkable cytotoxic activity against Caco-2 (18.0 +/- 1) and MCF-7 (23.8 +/- 0.5) cell lines. Also, 4d has better DNA binding capacity than 4a-c. DS 2017 R2 was used to exert molecular docking for understanding interactions between the water-soluble ruthenium(II)-NHC complexes and DNA. These complexes have been highlighted as a new type of drug. (C) 2018 Elsevier B.V. All rights reserved.Öğe A study about excellent xanthine oxidase inhibitory effects of new pyridine salts(Springer Wien, 2021) Yilmaz, Ulku; Noma, Samir Abbas Ali; Tok, Tugba Taskin; Sen, Betul; Gok, Yetkin; Aktas, Aydin; Ates, BurhanA series of pyridine salts were synthesized containing vitamin B3 (niacin), isonicotinonitrile, and non-substituted pyridine fragment from reactions of 1,3-dibromopropane, 1,4-dibromobutane, and 4,4 '-bis(chloromethyl)-1,1 '-biphenyl reactants with pyridines. The builds of pyridine salts were identified by dint of IR, H-1, and C-13 NMR spectroscopic techniques, and CHN analyses. Therewithal, the build of a compound was assigned via the X-ray single-crystal diffraction method. 1,3-Bis(3-cyanopyridine-1-ium-1-yl)propane dibromide crystallizes in the orthorhombic space group Ccce, with half of the cation molecule and one bromide anion in the asymmetric unit. Enzyme inhibitory properties of pyridine compounds were tested on the activities of xanthine oxidase (XO) and determined in the range from 0.394 to 0.623 mu M. All of the compounds inhibited enzyme more effectively than allopurinol that which is a standard drug. In addition, docking calculations were applied to investigate the binding properties and interactions of pyridine salts towards XO. Graphic abstractÖğe Synthesis of 1,4-disubstituted-1,2,3-Triazole derivatives for investigation of inhibition and molecular docking studies against Xanthine Oxidase(Scienceın Publications, 2023) Mirdan, Mustafa Nabeel Mirdan; Erdemir, Guler Yagiz; Noma, Samir Abbas Ali; Tok, Tugba Taskin; Ates, Burhan; Altundas, AliyeThis study evaluates the inhibition effect of new 1,4-disubstituted-1,2,3-triazoles against Xanthine Oxidase supplemented by molecular modelling. Nine compounds of 1,4-disubstituted-1,2,3-triazoles by Sharpless's approach have been synthesized in this report. The structures of the synthesized compounds were characterized using FT-IR, H-1 and C-13-NMR and Mass spectroscopies Among these synthesized molecules (5bromothiophen-2-yl)(1-(3-fluorobenzyl)-1H-1,2,3-triazole-4-yl)methanone (9f) and (5-Bromothiophen-2-yl(1-(4-methoxybenzyl)-1H-1,2,3-triazole-4-yl)methanone (9h) showed better activity against Xanthine oxidase (XO) compared to allopurinol. In the light of the XO inhibition results, triazoles having of ketone moiety (9f-i) were found to be more active than triazoles of ketone-free (9a-e). These results were supported by docking models. The docking calculations of the target XO with nine available compounds showed good binding energies with favourable binding interactions. These findings were particularly evident that 9f (BE -7.29 kcal/mol) and 9h (BE -7.59 kcal/mol) are represented encouraging higher inhibition properties towards xanthine oxidase (XO), compared to allopurinol as a reference compound. Significant binding energies and interactions obtained by performing the docking studies are demonstrated, in particular, that the compounds 9f and 9h may be more potential bio compounds than the positive compounds, allopurinol, and febuxostat.Öğe Xanthine oxidase inhibitory activity of new pyrrole carboxamide derivatives: In vitro and in silico studies(Wiley-V C H Verlag Gmbh, 2018) Kibriz, Ibrahim Evren; Sacmaci, Mustafa; Yildirim, Ismail; Noma, Samir Abbas Ali; Tok, Tugba Taskin; Ates, BurhanPyrrole carboxamide rings are rarely used as active scaffold in designing inhibitors for enzymes. Herein, we described the structure-activity relationship for novel xanthine oxidase inhibitors based on the pyrrole carboxamide scaffold. A series of novel-substituted pyrrole carboxamide derivatives were synthesized and characterized; their in vitro and in silico inhibitory activities were determined against xanthine oxidase. Among these compounds, those which contain no substituent and one methyl group at the para-position of the phenyl moiety in the main structure, respectively, were found out as most active according to the xanthine oxidase inhibition activity study. In silico techniques reveal why these compounds display more activities than others, based on their binding interactions with xanthine oxidase and the surface scanning results of the enzyme. Furthermore, the binding energy calculations displayed good agreement with the experimental activity values.
