PubMed İndeksli Yayınlar Koleksiyonu

Permanent URI for this collectionhttps://hdl.handle.net/20.500.12573/397

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  • Article
    Citation - WoS: 6
    Citation - Scopus: 7
    Therapeutic Potential of Nitrogen-Substituted Oleanolic Acid Derivatives in Neuroinflammatory and Cytokine Pathways: Insights From Cell-Based and Computational Models
    (Wiley-VCH Verlag GmbH, 2025-04-22) Turgut, Gurbet Celik; Pepe, Nihan Aktas; Ekiz, Yagmur Ceylan; Senol, Halil; Sen, Alaattin
    This study was conducted to investigate the mechanism of the potential and anti-inflammatory properties of nitrogen-substituted oleanolic acid derivatives that can be used to treat neuroinflammatory diseases. Nitrogen-containing oleanolic acid derivatives have been evaluated for their anti-neuroinflammatory effects in vitro in neuronal and monocytic cell lines at nontoxic doses, and the production of cytokines (TNF-alpha, IL-6 and IL-17), the inflammatory enzyme induced nitric oxide synthase (iNOS) and NF-kappa B signalling under LPS-stimulated conditions, and the expression of genes associated with Alzheimer's disease have been assessed. In addition, molecular docking and molecular dynamics simulation assessments are conducted in silico. Key protein markers of neurodegenerative diseases, especially Alzheimer's disease and neuroinflammation, TAU protein levels, and microglial activation, as well as ionised calcium-binding adaptor protein-1 (IBA1) levels, were significantly reduced with the addition of oleanolic acid derivatives. LPS-induced NF-kappa B luciferase reporter activity and iNOS activity were significantly inhibited, approaching the levels in uninduced controls. The mRNA expression of proinflammatory cytokines critical for neuroinflammation, such as TNF-alpha, NF-kappa B, IL-6 and IL-17, was reduced twofold to sevenfold. Furthermore, the molecular docking and MD simulation analyses revealed potential interactions with the TNF-alpha and NF-kappa B proteins. These findings underscore the potential of oleanolic acid derivatives, particularly compound 16, as candidates for further development as therapeutic agents for neurodegenerative diseases associated with chronic inflammation.
  • Article
    Citation - WoS: 6
    Citation - Scopus: 8
    Evaluation of Anti-Alzheimer Activity of Synthetic Coumarins by Combination of in Vitro and in Silico Approaches
    (Wiley-VCH Verlag GmbH, 2022-11-14) Orhan, Ilkay Erdogan; Deniz, F. Sezer Senol; Salmas, Ramin Ekhteiari; Irmak, Sule; Acar, Ozden Ozgun; Turgut, Gurbet Celik; Tataringa, Gabriela; Erdogan Orhan, Ilkay
    Series of synthetic coumarin derivatives (1-16) were tested against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), two enzymes linked to the pathology of Alzheimer's disease (AD). Compound 16 was the most active AChE inhibitor with IC50 32.23 +/- 2.91 mu M, while the reference (galantamine) had IC50=1.85 +/- 0.12 mu M. Compounds 9 (IC(50)75.14 +/- 1.82 mu M), 13 (IC50=16.14 +/- 0.43 mu M), were determined to be stronger BChE inhibitors than the reference galantamine (IC50=93.53 +/- 2.23 mu M). The IC50 value of compound 16 for BChE inhibition (IC50=126.56 +/- 11.96 mu M) was slightly higher than galantamine. The atomic interactions between the ligands and the key amino acids inside the binding cavities were simulated to determine their ligand-binding positions and free energies. The three inhibitory coumarins (9, 13, 16) were next tested for their effects on the genes associated with AD using human neuroblastoma (SH-SY5Y) cell lines. Our data indicate that they could be considered for further evaluation as new anti-Alzheimer drug candidates.
  • Article
    Citation - WoS: 29
    Citation - Scopus: 30
    A Solution-Processable Liquid-Crystalline Semiconductor for Low-Temperature Air-Stable N-Channel Field-Effect Transistors
    (Wiley-VCH Verlag GmbH, 2017-02-22) Ozdemir, Resul; Choi, Donghee; Ozdemir, Mehmet; Kim, Hyekyoung; Kostakoglu, Sinem Tuncel; Erkartal, Mustafa; Usta, Hakan
    A new solution-processable and air-stable liquid-crystalline nchannel organic semiconductor (2,2'-(2,8-bis(5-(2-octyldodecyl) thiophen-2-yl) indeno[1,2-b] fluorene-6,12-diylidene) dimalononitrile, alpha,omega-2OD-TIFDMT) with donor-acceptor-donor (D-AD) pi conjugation has been designed, synthesized, and fully characterized. The new semiconductor exhibits a low LUMO energy (-4.19 eV) and a narrow optical bandgap (1.35 eV). The typical pseudo-focal-conic fan-shaped texture of a hexagonal columnar liquid-crystalline (LC) phase was observed over a wide temperature range. The spin-coated semiconductor thin films show the formation of large (approximate to 0.5-1 mu m) and highly crystalline platelike grains with edge-on molecular orientations. Low-temperature-annealed (50 degrees C) top-contact/bottom-gate OFETs have provided good electron obility values as high as 0.11 cm(2) (Vs)(-1) and high I-on/I-off ratios of 10(7) to 10(8) with excellent ambient stability. This indicates an enhancement of two orders of magnitude (100 V) when compared with the b-substituted parent semiconductor, beta-DD-TIFDMT (2,2'-(2,8-bis(3-dodecylthiophen- 2-yl) indeno[1,2-b] fluorene-6,12-diylidene) dimalononitrile). The current rational alkyl-chain engineering route offers great advantages for D-A-D pi-core coplanarity in addition to maintaining good solubility in organic solvents, and leads to favorable optoelectronic/physicochemical characteristics. These remarkable findings demonstrate that alpha,omega-2OD-TIFDMT is a promising semiconductor material for the development of n-channel OFETs on flexible plastic substrates and LC-state annealing of the columnar liquid crystals can lower the electron mobility for transistor-type charge transport.