Yazar "Aslan, Hakan" seçeneğine göre listele

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    Benzenesulfonamide decorated dihydropyrimidin(thi)ones: carbonic anhydrase profiling and antiproliferative activity
    (Royal Soc Chemistry, 2024) Aslan, Hakan; Renzi, Gioele; Angeli, Andrea; D'Agostino, Ilaria; Ronca, Roberto; Massardi, Maria Luisa; Tavani, Camilla
    In the last decades, carbonic anhydrases (CAs) have become the top investigated innovative pharmacological targets and, in particular, isoforms IX and XII have been widely studied due to the evidence of their overexpression in hypoxic tumors. The frantic race to find new anticancer agents places the quick preparation of large libraries of putative bioactive compounds as the basis of a successful drug discovery and development programme. In this context, multi-component and, in general, one-step reactions are becoming very popular and, among them, Biginelli's reaction gave clean and easy-to-isolate products. Thus, we synthesized a series of Biginelli's products (10-17a-b) and similar derivatives (20-21) bearing the benzenesulfonamide moiety, which is known to inhibit CA enzymes. Through the stopped-flow technique, we were able to assess their ability to inhibit the targeted CAs IX and XII in the nanomolar range with promising selectivity over the physiologically relevant isoforms I and II. Crystallography studies and docking simulations helped us to gain insight into the interaction patterns established in the enzyme-inhibitor complex. From a chemical similarity-based screening of in-house libraries of compounds, a diphenylpyrimidine (23) emerged. The surprisingly potent inhibitory activity of 23 for CAs IX and XII along with its strong antiproliferative effect on two (triple-negative breast cancer MDA-MB-231 and glioblastoma U87MG) cell lines laid the foundation for further investigation, again confirming the key role of CAs in cancer. One-step synthesis and a chemical similarity-based screening provide new tumor-associated carbonic anhydrase (CA) inhibitors for anticancer application.
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    Biological Activity Studies of Some Synthesized Novel Furan and Pyran Derivatives
    (Gazi Univ, 2017) Sari, Esma; Aslan, Hakan; Dadi, Seyma; Oktemer, Atilla; Logoglu, Elif
    In this study, some novel furan and pyran derivatives were synthesized as mentioned in our previous report [1]. The novel furan and pyran derivatives were investigated for antibacterial activity against gram-positive/negative bacteria and fungus. The antibacterial and antifungal activities were determined by the disc diffusion method (DISC) and minimum inhibition concentration (MIC) against the tested bacteria and fungus. The inhibition zones were compared with those of reference discs which were studied in our previous work [2]. Reference discs used for control were as follows ketoconazole, ampicillin, tetracycline, penicillin, chloramphenicol, and gentamicin. From the results it could be said that some of the chemical compound can be used as a raw medicine sources.
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    Combined experimental and theoretical study of the novel ferrocene derivatives and examining the effect of E-Z stereoisomerism on their optical properties
    (Elsevier Science Bv, 2019) Aslan, Hakan; Kurtay, Gulbin; Korkmaz, Adem; Cetin, Adnan; Oktemer, Atilla
    Herein, we present the primary results on two valuable E-Z stereoisomers containing ferrocene scaffold [(E)-5,5-dimethy1-3-oxo-2-(2-phenyl-2-ferrocenyl-vinyl)cyclohex-1-en-1-yl acetate (E-FerCycAc) and its Z-stereoisomer (Z-FerCycAc)]. These compounds were both prepared from 1-phenylvinyl-ferrocene and 5,5-dimethyl-1,3-cyclohexanedione under catalysis of manganese(III) acetate according to the radical addition mechanism. The prominent spectroscopic data of the target stereoisomers were provided by FT-IR, LC-MS, (1) H NMR, (13) C NMR techniques, and their stereochemical identification was made primarily by NOESY analysis. The corresponding data (absorbance, transmittance and optical and transport energy gap) were collected from UV-vis studies. The optical properties of the glass slides coated with E-FerCycAc and Z-FerCycAc films were examined and consequently, the optical and transport energy band gap values of the E-FerCycAc were found significantly lower than Z-FerCycAc. The physicochemical and spectroscopic findings (HOMO-LUMO energies, bandgap values, UV-vis, FT-IR, (1) H, and (13) C NMR spectra) were also compared and supported with the acquired DFT calculations.
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    Design, Synthesis, Characterization, Enzyme Inhibition, Molecular Docking, and Pharmacological Evaluation of New Chalcone-Sulfonate Derivatives Bearing Thiophene
    (Wiley-V C H Verlag Gmbh, 2024) Aslan, Hakan; Yetissin, Fuat; Korkmaz, Adem; Bursal, Ercan
    The novel chalcone-sulfonate derivatives bearing thiophene motif were synthesized and characterized using 1H NMR, 13C NMR, and HRMS analysis. The evaluation of in vitro and in silico potential pancreatic lipase inhibition activity of the novel chalcone-sulfonate derivatives bearing thiophene motif was scanned. IC50 values of compounds 5 i (28.76 +/- 2.11 mu M) and 5 f (30.58 +/- 0.45 mu M) were determined to be more effective pancreatic lipase inhibitors for in vitro studies. The best potential inhibitor for pancreatic lipase binding affinity was found as compound 5 f (-9.8 kcal mol-1) for in silico studies. Although compounds 5 f and 5 i were identified as the best pancreatic lipase inhibitor candidates in vitro and molecular docking studies, compounds 5 f and 5 i were predicted mutagenic and carcinogenic properties in mice according to ADMET studies. Deeply, compound 5 h was a more effective pancreatic lipase inhibitor according to enzyme inhibition, molecular docking, and ADMET studies. It can be said that compound 5 h may be a more efficient drug candidate than orlistat in the treatment of obesity. This study gives a comprehensive account of the synthesis and assessment of newly developed chalcone-sulfonate derivatives bearing thiophene, specifically providing on their ability to target pancreatic lipase. In summary, our research highlights the potential of chalcone-sulfonate derivatives bearing thiophene as effective enzyme inhibitors that hold promise for therapeutic applications. image
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    Determination of the superior quality properties of randomly selected chestnut honey samples from the Sinop region
    (Taylor & Francis Inc, 2023) Avsar, Cumhur; Aslan, Hakan; Yumak, Tugrul; Tabak, Ahmet; Deniz, Nuray Turk
    In this study, a total of 43 chestnut honey samples were randomly selected and collected from the Erfelek, Ayancik, and Turkeli districts of Sinop. The pollen content of all honey samples was determined, revealing that chestnut pollen accounted for over 90% in most cases. The chestnut honey from the Sinop region is considered of high quality compared to other chestnut honeys, primarily due to its low HMF (Hydroxymethylfurfural) levels, low moisture content, high proline content, and significant pollen content. The antibacterial activities of these honey samples were assessed using the agar well diffusion method, Minimal Inhibitory Concentrations (MIC), and Minimal Bactericidal Concentrations (MBC) methods. It is worth mentioning that certain samples exhibited significant activity against Staphylococcus aureus, with inhibition zones ranging from 15 to 20 mm, which is comparable to standard antibiotics. The antioxidant activities of all honey samples were evaluated using a 1,1-Diphenyl-2-picrylhydrazine assay. The results obtained indicate that the chestnut honey produced from the chestnut forests in the Sinop province meets the criteria outlined in the Turkish Food Codex Honey Communique. The high proline content exceeding 1000 mg/kg and very low hydroxymethyl furfural values below 1 mg/kg observed in certain chestnut honey samples contribute to their high quality and safety. Additionally, the average pH of 4.81 and free acidity values below 50 meq/kg recorded for the analyzed honeys further reinforce these findings.
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    Some physicochemical properties of pure and pollution-free Sinop chestnut honey
    (Taylor & Francis Inc, 2024) Tabak, Ahmet; Deniz, Nuray Turk; Avsar, Cumhur; Aslan, Hakan; Yumak, Tugrul
    This study was designed to investigate some physicochemical properties (color, electrical conductivity, ash, water-insoluble and mineral matter contents) of chestnut honey produced in the Ayanc & imath;k, T & uuml;rkeli and Erfelek regions of Sinop province, where chestnut forests are dense. The experimental data showed that most of the honey samples had different amber color tones. The electrical conductivity values and the amounts of water-insoluble matter for all chestnut honeys were determined above 0.8 mS/cm and below 0.1 g per 100 g, respectively. In addition, honey samples contained mainly potassium and calcium and other minerals such as magnesium, sodium, aluminum and iron. It has been demonstrated that these chestnut honeys are registered with Geographical Indication and meet the criteria required in the Turkish Food Codex Honey Communiqu & eacute; of the Ministry of Agriculture and Forestry. These honeys have not been exposed to any external processing (heat treatment, etc.), have not been adulterated, do not contain impurities, and are pure and high quality.
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    Synthesis and spectroscopic properties of a novel turn off fluorescent probe: Thienyl-pyridine substituted BODIPY
    (Elsevier, 2019) Sevinc, Gokhan; Ozgur, Mehtap; Kucukoz, Betul; Karatay, Ahmet; Aslan, Hakan; Yilmaz, Halil
    We report the synthesis and photophysical properties of a new fluorophore compound TPy-BDP, containing thienyl-pyridine group in meso position of dipyrrin ligand. UV-Vis spectroscopy and steady state fluorimetric methods have been utilized to determine the photophysical features of this chromophore in variety of solvents. The photostability of the chromophore has been examined in solution and the dependence of spectral shifts upon solvent parameter has been studied. Also, pH sensitivity of the compound was evaluated in aqueous solutions. On binding to H+ ions fluorescence quenching was observed by an approximately 94% reduction in the emission intensity within the pH range of 7.6-1.0 in solution. However, no obvious fluorescence change could be observed in the basic conditions. To identify the underlying mechanism of the probe depending on pH, ultrafast pump probe experiments have been performed. The results indicate that fast electron transfer known as photoinduced electron transfer between boron-dipyrromethene scaffold to the appended group are responsible to the fluorescence quenching. Experimental results proved the capability of TPy-BDP in terms of using under strongly acidic conditions as a pH indicator.
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    Synthesis, characterization, and investigations of antimicrobial activity of benzopyrans, benzofurans and spiro[4.5]decanes
    (Taylor & Francis Inc, 2018) Akpinar, Deniz E.; Ozgur (Nee Yakut), Mehtap; Aslan, Hakan; Alagoz, Oguzhan; Oktemer, Atilla; Dal, Hakan; Hokelek, Tuncer
    In this study, the radical cyclization reactions of cyclic 1,3-dicarbonyl compounds (1a-c) and a, b-unsaturated alcohols (2a-d) through Mn(OAc) 3 were performed. A series of biologically interesting dihydropyrans (3-5) and dihydrofurans (6-18) were synthesized as a result of these reactions. Spiro compounds (19-20) were obtained from the reactions of 1,3-dicarbonyl compounds and (E)-2,4-diphenyl-but-3-en2-ol (2e). The unique structure of compound 19 was also confirmed by X-ray crystallography. In addition, the antibacterial activities of synthesized compounds were screened against some bacteria. Their zone diameters showed better results than some known antibiotics.