Yazar "Ertan-Bolelli, Tugba" seçeneğine göre listele

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    Discovery of 5-(or 6)-benzoxazoles and oxazolo[4,5-b]pyridines as novel candidate antitumor agents targeting hTopo II?
    (Academic Press Inc Elsevier Science, 2021) Karatas, Esin; Foto, Egemen; Ertan-Bolelli, Tugba; Yalcin-Ozkat, Gozde; Yilmaz, Serap; Ataei, Sanaz; Zilifdar, Fatma
    Discovery of novel anticancer drugs which have low toxicity and high activity is very significant area in anticancer drug research and development. One of the important targets for cancer treatment research is topoisomerase enzymes. In order to make a contribution to this field, we have designed and synthesized some 5(or 6)-nitro-2-(substitutedphenyl)benzoxazole (1a-1r) and 2-(substitutedphenyl)oxazolo[4,5-b]pyridine (2a-2i) derivatives as novel candidate antitumor agents targeting human DNA topoisomerase enzymes (hTopo I and hTopo II alpha). Biological activity results were found very promising for the future due to two compounds, 5-nitro-2-(4butylphenyl)benzoxazole (1i) and 2-(4-butylphenyl)oxazolo[4,5-b]pyridine (2i), that inhibited hTopo II alpha with 2 mu M IC50 value. These two compounds were also found to be more active than reference drug etoposide. However, 1i and 2i did not show any satisfactory cyctotoxic activity on the HeLa, WiDR, A549, and MCF7 cancer cell lines. Moreover, molecular docking and molecular dynamic simulations studies for the most active compounds were applied in order to understand the mechanism of inhibition activity of hTopo II alpha. In addition, in silico ADME/Tox studies were performed to predict drug-likeness and pharmacokinetic properties of all the tested compounds.
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    Synthesis and molecular docking studies of some novel antimicrobial benzamides
    (Academic Press Inc Elsevier Science, 2020) Acar, Cemre; Yalcin, Gozde; Ertan-Bolelli, Tugba; Onurdag, Fatma Kaynak; Okten, Suzan; Sener, Funda; Yildiz, Ilkay
    Common use of classical antibiotics has caused to the growing emergence of many resistant strains of pathogenic bacteria. Therefore, we aimed to synthesize a number of N-(2-hydroxy-(4 or 5)-nitrophenyl)benzamide derivatives as a new class of antimicrobial compounds. Moreover, our second goal is to predict the interaction between active structures and enzymes (DNA-gyrase and FtsA) in the binding mode. In this study, thirteen N-(2-hydroxy-(4 or 5-nitrophenyl)-substituted-benzamides were synthesized and determined for their antimicrobial activity using the microdilution method. According to this work, none of the compounds showed any activity against Candida albicans and its clinical isolate. Some of the benzamides (4N1, 5N1, 5N2) displayed very significant activity against Staphylococcus aureus and MSSA with < 4 mu g/ml MIC value, even they were found to be more potent than ceftazidime. 4N1 was also found to be more effective than gentamicin against Enterococcus faecalis clinical isolate. Molecular docking studies revealed that 4N1, 5N1, and 5N2 showed a good interactions with DNA-gyrase. Moreover, 5N1 has interacted with FtsA enzyme in the binding mode, as well. Only compound 5N4 displayed very good activity against Escherichia coli ATCC 25922. These findings showed us that 4N1, 5N1, 5N2, and 5N4 could be lead compounds to discover new antibacterial candidates against multidrug-resistant strains.
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    Synthesis, Antimicrobial Activities of New Sulfonamidobenzoxazoles and Molecular Docking Studies on Escherichia coli TEM-1 ?-Lactamase
    (Croatian Chemical Soc, 2017) Ertan-Bolelli, Tugba; Bolelli, Kayhan; Okten, Suzan; Kaynak-Onurdag, Fatma; Aki-Yalcin, Esin; Yalcin, Ismail
    beta-Lactam antibiotics are frequently used for treatment of multi-drug resistant microbial infections and the most common mechanism of resistance against these antibiotics is bacterial beta-lactamase production. Herein, we reported the design, synthesis and in vitro antimicrobial activities of some new 2-substituted-5-(2,4-dinitrophenylsulfonamido) benzoxazole derivatives. Compounds TN1, TN2, and TN3 were found to be significantly active against E. coli isolate which contains extended spectrum beta-lactamase enzyme at the MIC value of 8 mu g mL(-1) and that is 4-fold higher than the reference drug ampicillin. We performed molecular docking studies into active site of Escherichia coli TEM-1 beta-lactamase enzyme in order to predict the protein-ligand interactions. According to the docking results, compounds TN1, TN2, and TN3 showed strong interactions between the important active site residues which are responsible for the catalytic mechanism of TEM-1 beta-lactamase enzyme and a good correlation is found with the experimental data.