Yazar "Tok, Tugba Taskin" seçeneğine göre listele

Listeleniyor 1 - 4 / 4
  • [ X ]
    Öğe
    Biological evaluation and molecular docking. studies of nitro benzamide derivatives with respect to in vitro anti-inflammatory activity
    (Elsevier, 2017) Turner, Tugba B.; Onder, Ferah Comert; Ipek, Hande; Gungor, Tugba; Savranoglu, Seda; Tok, Tugba Taskin; Celik, Ayhan
    A series of nitro substituted benzamide derivatives were synthesized and evaluated for their potential anti-inflammatory activities in vitro. Firstly, all compounds (1-6) were screened for their inhibitory capacity on LPS induced nitric oxide (NO) production in RAW264.7 macrophages. Compounds 5 and 6 demonstrated significantly high inhibition capacities in a dose-dependent manner with IC50 values of 3.7 and 53 mu M, respectively. These two compounds were also accompanied by no cytotoxicity at the studied concentrations (max 50 mu M) in macrophages. Molecular docking analysis on iNOS revealed that compounds 5 and 6 bind to the enzyme more efficiently compared to other compounds due to having optimum number of nitro groups, orientations and polarizabilities. In addition, 5 and 6 demonstrated distinct regulatory mechanisms for the expression of the iNOS enzyme at the mRNA and protein levels. Specifically, both suppressed expressions of COX-2, IL-1 beta and TNF-alpha significantly, at 10 and 20 mu M. However, only compound 6 significantly and considerably decreased LPS-induced secretion of IL-1 beta and TNF-alpha. These results suggest that compound 6 may be a multi-potent promising lead compound for further optimization in structure and as well as for in vivo validation studies. (C) 2016 Published by Elsevier B.V.
  • [ X ]
    Öğe
    PRODRUGS FOR NITROREDUCTASE BASED CANCER THERAPY-2: Novel amide/Ntr combinations targeting PC3 cancer cells
    (Elsevier France-Editions Scientifiques Medicales Elsevier, 2019) Gungor, Tugba; Onder, Ferah Comert; Tokay, Esra; Gulhan, Unzile Guven; Hacioglu, Nelin; Tok, Tugba Taskin; Celik, Ayhan
    The use of nitroreductases (NTR) that catalyze the reduction of nitro compounds by using NAD(P)H in GDEPT (Gene-directed enzyme prodrug therapy) studies which minimize toxicity at healthy cells and increases concentration of drugs at cancer cells is remarkable. Discovery of new prodrugiNTR combinations is necessary to be an alternative to known prodrug candidates such as CB1954, SN23862, PR 104A. For this aim, nitro containing aromatic amides (A1-A23)(2) were designed, synthesized, performed in silico ADMET and molecular docking techniques in this study. Prodrug candidates were studied on reduction potentials with Ssap-NtrB by HPLC system. Also, cyototoxic properties and prodrug ability of these amides were investigated using different cancer cell lines such as Hep3B and PC3. As a result of theoretical and biological studies, combinations of A5, A6 and A20 with Ssap-NtrB can be suggested as potential prodrugs/enzyme combinations at NTR based cancer therapy compared with CB1954/NfsB. (C) 2019 Elsevier Masson SAS. All rights reserved.
  • [ X ]
    Öğe
    Prodrugs for nitroreductase-based cancer therapy-3: Antitumor activity of the novel dinitroaniline prodrugs/Ssap-NtrB enzyme suicide gene system: Synthesis, in vitro and in silico evaluation in prostate cancer
    (Elsevier France-Editions Scientifiques Medicales Elsevier, 2020) Tokay, Esra; Gungor, Tugba; Hacioglu, Nelin; Onder, Ferah Cornett; Gullhan, Unzile Guven; Tok, Tugba Taskin; Celik, Ayhan
    Prodrugs for targeted tumor therapies have been extensively studied in recent years due to not only maximising therapeutic effects on tumor cells but also reducing or eliminating serious side effects on healthy cells. This strategy uses prodrugs which are safe for normal cells and form toxic metabolites (drugs) after selective reduction by enzymes in tumor tissues. In this study, prodrug candidates (1-36) containing nitro were designed, synthesized and characterized within the scope of chemical experiments. Drug-likeness properties of prodrug candidates were analyzed using DS 2018 to investigate undesired toxicity effects. In vitro cytotoxic effects of prodrug canditates were performed with MTT assay for human hepatoma cells (Hep3B) and prostate cancer cells (PC3) and human umbilical vein endothelial cells (HUVEC) as healthy control. Non-toxic compounds (3, 5, 7,10, 12, 15,17, 19 and 21-23), and also compounds (1, 2, 5, 6, 9, 11, 14, 16, 20 and 24) which had low toxic effects, were selected to examine their suitability as prodrug canditates. The reduction profiles and kinetic studies of prodrug/Ssap-NtrB combinations were performed with biochemical analyses. Then, selected prodrug/Ssap-NtrB combinations were applied to prostate cancer cells to determine toxicity. The results of theoretical, in vitro cytotoxic and biochemical studies suggest 14/Ssap-NtrB, 22/Ssap-NtrB and 24/Ssap-NtrB may be potential prodrug/enzyme combinations for nitroreductase (Ntr)-based prostate cancer therapy. (C) 2019 Elsevier Masson SAS. All rights reserved.
  • [ X ]
    Öğe
    Structure prediction of eukaryotic elongation factor-2 kinase and identification of the binding mechanisms of its inhibitors: homology modeling, molecular docking, and molecular dynamics simulation
    (Taylor & Francis Inc, 2022) Tatar, Gizem; Tok, Tugba Taskin; Ozpolat, Bulent; Mehmet, A. Y.
    Protein kinases emerged as one of the most successful families of drug targets due to their increased activity and involvement in mediating critical signal transduction pathways in cancer cells. Recent evidence suggests that eukaryotic elongation factor 2 kinase (eEF-2K) is a potential therapeutic target for treating some highly aggressive solid cancers, including lung, pancreatic and triple-negative breast cancers. Thus, several compounds have been developed for the inhibition of the enzyme activity, but they are not sufficiently specific and potent. Besides, the crystal structure of this kinase remains unknown. Hence, the functional organization and regulation of eEF-2K remain poorly characterized. For this purpose, we constructed a homology model of eEF-2K and then used docking methodology to better understanding the binding mechanism of eEF-2K with 58 compounds that have been proposed as existing inhibitors. The results of this analysis were compared with the experimental results and the compounds effective against eEF-2K were determined against eEF-2K as a result of both studies. And finally, molecular dynamics (MD) simulations were performed for the stability of eEF-2K with these compounds. According to these study defined that the binding mechanism of eEF-2K with inhibitors at the molecular level and elucidated the residues of eEF-2K that play an important role in enzyme selectivity and ligand affinity. This information may lead to new selective and potential drug molecules to be for inhibition of eEF-2K.