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    A spectroscopic study on new phthalonitrile derivative and its computational background: 4-[(4,5-Diphenyl-4H-1,2,4-triazol-3-yl)sulfanyl]benzene-phthalonitrile
    (Elsevier, 2017) Akcay, Hakki Turker; Coruh, Ufuk; Bayrak, Riza; Mentese, Emre; Vazquez Lopez, Ezequiel M.
    Heterocyclic phthalonitrile derivatives are important precursors in synthesis of new photoactive phthalocyanine compounds. In this study, novel phthalonitrile compound bearing triazole moiety was synthesized and characterized by using spectroscopic techniques such as FT-IR and NMR. The molecular structures of the title compound was analyzed crystallographically and compared with the structural parameters obtained computationally. The orbital energies, electronic absorptions, atomic charge parameters, vibrational frequencies, ground state transitions, H-1 and C-13 NMR chemical shifts and NBO analysis were computed by using DFT (Density Functional Theory) calculation and compared with the experimental results. (C) 2016 Elsevier B.V. All rights reserved.
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    Novel Coumarin Derivatives Containing a Triazole Moiety: A Study on Synthesis, Cytotoxicity, Membrane Dysfunction, Apoptosis, Cell Cycle, and Antiangiogenic Effects
    (Bentham Science Publ Ltd, 2022) Guner, Adem; Bektas, Hakan; Mentese, Emre
    Background: Coumarin is a functional compound with a pronounced wide range of biological activities and has recently been shown to have anticancer effects on various human cancer cells. Cisplatin is widely used in treating many cancers, but its effectiveness is limited due to acquired resistance and dose-related side effects. Objective: This study aimed to reveal the chemosensitizing ability of novel synthesized coumarin-triazole hybrid compounds (3a-f) compared to the cisplatin in A549, MCF-7, and HeLa cancer cells. Methods: Cytotoxicity was determined by MTT assay. Lactate dehydrogenase (LDH), antioxidant/oxidant status, and DNA fragmentation were determined spectrophotometrically using commercial kits. Muse (TM) Cell Analyzer was used to assess cell cycle progression. Pro/anti-apoptotic gene expressions were determined by Real-Time qPCR. The antiangiogenic activity was determined by VEGF expression and Hen's chorioallantoic membrane model. Results: Compounds 3c, -d, -e, and -f potentiated the cisplatin-induced cytotoxicity by increasing LDH release and DNA fragmentation, inducing G2/M cell cycle arrest, overproducing oxidative stress, and decreasing cellular antioxidant levels. These compounds combined with cisplatin caused upregulation in the pro-apoptotic Bax, Bid, caspase-3, caspase-8, caspase-9, Fas, and p53 gene expressions while downregulating anti-apoptotic DFFA, NFkB1, and Bcl2 gene expressions. These combinations caused vascular loss and a reduction in VEGF expression. Conclusion: These results suggest that a combinational regimen of coumarin compounds with cisplatin could enhance the effect of cisplatin in A549 cells. Besides, these compounds exhibit relatively low toxicity in normal cells, thus decreasing the dose requirement of cisplatin in cancer treatments.
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    Novel triazole substituted phthalocyanines showing high singlet oxygen quantum yields
    (Elsevier, 2019) Demirbas, Umit; Bayrak, Riza; Dilber, Gulsev; Mentese, Emre; Akcay, Hakki Turker
    In this study, novel triazole peripherally substituted phthalocyanine zinc(II) complexes 3(a-d) were synthesized from four different phthalonitrile derivative and characterized by FT-IR NMR, MALDI-TOF, UV-Vis methods. Aggregation-concentration relations of the compounds 3(a-d) were investigated by UV-Vis spectroscopy. Fluorescence quenching properties of the phthalocyanines 3(a-d) were studied and fluorescence quantum yields were calculated by comparative method. Photodegradation quantum yields of the compound 3(a-d) were calculated. In addition, singlet oxygen quantum yields of the compounds 3(a-d) were measured by comparative method by using 1,3-diphenylisobenzofuran (DPBF) as singlet oxygen quencher. In this work, it has been observed that the synthesized novel phthalocyanines have higher quantum yield values (the range of 0.8-0.85) compared to the Zn (II) complex of unsubstituted phthalocyanine (0.67). Especially the compound 3d substituted tolyl group has the highest singlet oxygen quantum yield (0.85) seen rarely in literature.
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    Synthesis of some new Methoxy Bridged Benzimidazolyl-Substituted phthalocyanines as potent inhibitors of urease
    (Elsevier Science Sa, 2018) Demirbas, Umit; Mentese, Emre; Sokmen, Bahar Bilgin; Bayrak, Riza; Akcay, Hakki Turker
    In this study, the novel peripherally 4-[(2-methyl-1H-benzimidazol-1-yl)methoxy] substituted Zn(II) (3) Cu(II) (4), Co(II) (5) phthalocyanines were prepared and their structures were characterized spectro-scopically. The light absorption behaviors of the synthesized compounds (3-6) were studied by UV-Vis spectroscopy in the different concentration and different solvents were studied also. In addition, the urease inhibition activities of the synthesized compounds were also investigated. Among the synthesized molecules, compound 5 showed the best inhibitory effect against jack bean urease with IC50 values of 0.0034 +/- 0.0010 mu M. (C) 2018 Elsevier B.V. All rights reserved.