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    1,4-Bis(methylsulfanyl)naphthalene
    (WILEY-BLACKWELL, 2009) Celik, Ismail; Akkurt, Mehmet; Senocak, Ayseguel; Cakmak, Osman; Torre-Fernandez, Laura; Garcia-Granda, Santiago
    The molecule of the title compound, C(12)H(12)S(2), is close to planar, with the methyl C atoms deviating by 0.019 (1) and 0.221 (2) angstrom from the naphthalene mean plane. In the crystal structure, the shortest S center dot center dot center dot S contact of 3.6864 (9) angstrom is longer than the van der Waals contact distance.
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    3,6,8-Tribromoquinoline
    (WILEY-BLACKWELL, 2010) Celik, Ismail; Akkurt, Mehmet; Okten, Salih; Cakmak, Osman; Garcia-Granda, Santiago
    The title molecule, C(9)H(4)Br(3)N, is almost planar, the maximum deviation being 0.110 (1) angstrom. The crystal structure is stabilized by weak aromatic pi-pi interactions [centroid-centroid distance = 3.802 (4) angstrom] between the pyridine and benzene rings of the quinoline ring systems of adjacent molecules.
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    6,8-Dibromoquinoline
    (WILEY-BLACKWELL, 2010) Celik, Ismail; Akkurt, Mehmet; Cakmak, Osman; Okten, Salih; Garcia-Granda, Santiago
    The title molecule, C9H5Br2N, is almost planar, with an r.m.s. deviation of 0.027 angstrom. The dihedral angle between the aromatic rings is 1.5 (3)degrees. In the crystal, pi-pi stacking interactions are present between the pyridine and benzene rings of adjacent molecules [centroid-centroid distances = 3.634 (4) angstrom], and short Br center dot center dot center dot Br contacts [3.4443 (13) angstrom] occur.
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    Chemical Composition, Antioxidant, Antimicrobial and Antispasmodic Activities of the Essential Oil of Juniperus excelsa subsp excelsa
    (TAYLOR & FRANCIS LTD, 2012) Atas, Ahmet Duran; Goze, Ismihan; Alim, Ahmet; Cetinus, Senay Akkus; Durmus, Nedim; Vural, Nilufer; Cakmak, Osman
    In this study, chemical composition, antioxidant, antimicrobial and antiospasmodic activities of the essential oil of the berries Juniperus excelsa Bieb. subsp. excelsa were evaluated in vitro. GC and GS-MS analysis of the oil resulted in the identification of 25 compounds, representing 97.2 % of the oil; alpha-pinene (46.1 %) was the main component. Essential oil showed remarkable antimicrobial activity against the test microorganisms. The sample was also subjected to a screening for its possible antioxidant activity by using 2,2-diphenyl-1- picrylhydrazyl (DPPH) and beta-carotene-linoleic acid assays. It was exhibited moderate antioxidant activity in beta-carotene-linoleic acid test system. In rat ileum, J. excelsa essential oil effect was directly investigated on spontaneous contractions. It has been found that amplitude and frequency did not change significantly at all dose concentrations. Amplitude has been inhibited % 25 and frequency has been inhibited % 20 at 1 mg/mL.
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    Functionalized methoxy quinoline derivatives: Experimental and in silico evaluation as new antiepileptic, anti-Alzheimer, antibacterial and antifungal drug candidates
    (Elsevier, 2024) Ciftci, Bilge; Okten, Salih; Kocyigite, Umit Muhammet; Atalay, Vildan Enisoglu; Atas, Mehmet; Cakmak, Osman
    The objective of this study was to assess the inhibitory effects of newly synthesized quinoline derivatives on human carbonic anhydrase I and II (hCA I and II), as well as acetylcholinesterase (AChE) enzymes, alongside their impact on various microorganisms. The synthesized compounds were assessed using IC50, Ki and MIC values via Ellman and Esterease Method and Microdilution assay. Most compounds exhibited strong inhibitory effects on human carbonic anhydrase I and II (hCA I and II) and acetylcholinesterase (AChE), notably compounds 9, 12, and 17 for hCA I, and 9, 12, 16 and 17 for hCA II, alongside robust AChE inhibition by compounds 8 and 13. Antimicrobial tests highlighted compounds 13 and 15 as promising inhibitors against pathogens, particularly effective across various strains. Molecular docking supported these findings, indicating potent binding abilities, notably by compounds 16 and 17 across specific protein structures (2COP, 5E2M, and 6KM3). The discussion emphasized the impact of substituents, particularly methoxy groups at specific positions, on enzyme inhibition, revealing how structural modifications affected enzyme inhibitory properties. The comprehensive analysis bridged experimental and computational findings, uncovering essential structure-activity relationships in quinoline derivatives and identifying potential candidates for further studies in enzyme inhibition and antimicrobial research.
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    Novel piperazine and morpholine substituted quinolines: Selective synthesis through activation of 3,6,8-tribromoquinoline, characterization and their some metabolic enzymes inhibition potentials
    (Elsevier, 2020) Cakmak, Osman; Okten, Salih; Alimli, Dilek; Ersanli, Cem Cuneyt; Taslimi, Parham; Kocyigit, Umit Muhammet
    Regioselective routes are described for convenient preparation of novel piperazine/morpholine substituted quinoline derivatives at C-3, C-6 and C-8 starting with 3,6,8-tribromoquinoline (6) by nucleophilic substitution via conventional heating or microwave assisted reaction conditions. 3,6,8-Tribromoquinoline (6) was treated with piperazine and morpholine under microvawe irradiation, which selectively furnished 3-mopholinyl and 3-piperazinyl quinoline derivatives 7 and 8 in yields of 58% and 60%, respectively. On the other hand, the activation of benzene cycle of quinoline by nitration of 3,6,8-tribromoquinoline, giving 5-nitro-3,6,8-tribromoquinoline (18) in quantitative yield, was enabled. Then, the bromines at C-6 and C-8 were selectively exchanged by morpholine and piperazine via SNAr reactions. Thus, 6,8-dimopholinylquinoline (22) and 5-nitro-6,8-dipiperazinylquinoline (24), biologically valuable derivatives, were prepared in high yields (82% and 72%, respectively). The synthesized compounds were fully characterizated by H-1 NMR, C-13 NMR, 2D NMR, XRD, HRMS and IR spectra. The novel molecules had effective inhibition profiles against some metabolic enzymes. Also, they have the potential of drug candidates to treat of some diseases including glaucoma, epilepsy, Alzheimer's disease (AD), leukemia, and type-2 diabetes mellitus (T2DM). (C) 2020 Elsevier B.V. All rights reserved.
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    Quinoline-based promising anticancer and antibacterial agents, and some metabolic enzyme inhibitors
    (Wiley-V C H Verlag Gmbh, 2020) Okten, Salih; Aydin, Ali; Kocyigit, Umit M.; Cakmak, Osman; Erkan, Sultan; Andac, Cenk A.; Taslimi, Parham
    A series of substituted quinolines was screened for their antiproliferative, cytotoxic, antibacterial activities, DNA/protein binding affinity, and anticholinergic properties by using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide cell proliferation, lactate dehydrogenase cytotoxicity, and microdilution assays, the Wolfe-Shimmer equality method, the Ellman method, and the esterase assay, respectively. The results of the cytotoxic and anticancer activities of the compounds displayed that 6-bromotetrahydroquinoline (2), 6,8-dibromotetrahydroquinoline (3), 8-bromo-6-cyanoquinoline (10), 5-bromo-6,8-dimethoxyquinoline (12), the novelN-nitrated 6,8-dimethoxyquinoline (13), and 5,7-dibromo-8-hydroxyquinoline (17) showed a significant antiproliferative potency against the A549, HeLa, HT29, Hep3B, and MCF7 cancer cell lines (IC50 = 2-50 mu g/ml) and low cytotoxicity (similar to 7-35%) as the controls, 5-fluorouracil and cisplatin. The compound-DNA linkages are hyperchromic or hypochromic, causing variations in their spectra. This situation shows that they can be bound to DNA with the groove-binding mode, withK(b)value in the range of 2.0 x 10(3)-2.2 x 10(5) M-1. Studies on human Gram(+) and Gram(-) pathogenic bacteria showed that the substituted quinolines exhibited selective antimicrobial activities with MIC values of 62.50-250 mu g/ml. All tested quinoline derivatives were found to be effective inhibitors of acetylcholinesterase (AChE) and the human carbonic anhydrase I and II isoforms (hCA I and II), withK(i)values of 46.04-956.82 nM for hCA I, 54.95-976.93 nM for hCA II, and 5.51-155.22 nM for AChE. As a result, the preliminary data showed that substituted quinolines displayed effective pharmacological features. Molecular docking studies were performed to investigate the binding modes and interaction energies for compounds2-17with AChE (PDB ID: 4EY6), hCA I (PDB ID: 1BMZ), and hCA II (PDB ID: 2ABE).