Yazar "Salih B." seçeneğine göre listele

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    Chemical compositions and antimicrobial activities of four different Anatolian propolis samples
    (Elsevier GmbH, 2005) Uzel A.; Sorkun K.; Önçag O.; Çogulu D.; Gençay O.; Salih B.
    Propolis means a gum that is gathered by bees from various plants. It is known for its biological properties, having antibacterial, antifungal and healing properties. The aims of this study were to evaluate the antimicrobial activity of four different Anatolian propolis samples on different groups of microorganisms including some oral pathogens and comparison between their chemical compositions. Ethanol extracts of propolis (EEP) were prepared from four different Anatolian propolis samples and examined whether EEP inhibit the growth of the test microorganisms or not. For the antimicrobial activity assays, minimum inhibitory concentrations (MIC) were determined by using macrodilution method. The MIC values of the most effective propolis (TB) were 2 µg/ml for Streptococcus sobrinus and Enterococcus faecalis, 4 µg/ml for Micrococcus luteus, Candida albicans and C. krusei, 8 µg/ml for Streptococcus mutans, Staphylococcus aureus, Staphylococcus epidermidis and Enterobacter aerogenes, 16 µg/ml for Escherichia coli and C. tropicalis and 32 µg/ml for Salmonella typhimurium and Pseudomonas aeruginosa. The chemical compositions of EEP's were determined by high-temperature high-resolution gas chromatography coupled to mass spectrometry. The main compounds of four Anatolian propolis samples were flavonoids such as pinocembrin, pinostropin, isalpinin, pinobanksin, quercetin, naringenin, galangine and chrysin. Although propolis samples were collected from different regions of Anatolia all showed significant antimicrobial activity against the Gram positive bacteria and yeasts. Propolis can prevent dental caries since it demonstrated significant antimicrobial activity against the microorganisms such as Streptococcus mutans, Streptococcus sobrinus and C. albicans, which involves in oral diseases. © 2005 Elsevier GmbH. All rights reserved.
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    Inhibitory effects of propolis on human osteogenic sarcoma cell proliferation mediated by caspase patway [Kaspaz yolagi{dotless} ile yönlendirilen i·nsan osteojenik sarcoma hücre çogalmasi{dotless}na propolisin baski{dotless}layi{dotless}ci{dotless} etkisi]
    (2010) Ozdal Kurt F.; Vatansever H.S.; Sorkun K.; Deliloglu Gurhan S.I.; Turkoz E.; Gencay O.; Salih B.
    A natural product Propolis, is a resinous material gathered by honeybees from the buds and bark of certain trees and plants. Propolis contains various chemical components of biological activities, including antimutagenic, antioxidant, antibacterial, antiviral and anticarsinogenic. Therefore, the aim of this study is to investigate the antiapoptotic effect of propolis extracts (PE) using caspase pathway in the human osteogenic sarcoma cell line SAOS-2 in culture. The extracts which produced in ecologic environment were taken from the Hacettepe University, Beytepe Campus area-Ankara were used. Seven different PE at 0.5, 0.25, 0.125 and 0.063 mg/ml were added to SAOS-2 cell line for two days incubation. For cell proliferation and cytotoxicty analyses MTT, for apoptotic cell death determination TUNEL method, for distribution of caspase 6, caspase 8 and caspase 9 indirect immunocytochemistry analyses were used. After MTT analyses, the most effect was observed PE 7 at the 0.125 mg/ml dilution. The number of TUNEL positive cells was more detectable at PE 4 and 5 at the 0.063 mg/ml, and PE 7 at the 0.125 mg/ml dilutions. The immunoreactivity of caspase 6 was stronger than caspase 8 and 9. Moreover, density of caspase 6 staining was much better especially in PE 7 at the 0.125 mg/ml dilution. In conclusion, the mechanisms of apoptosis induction by PE may appear via caspase pathway because of its anticanserogenic effect. PE may be usefull in the cancer treatment protocol.
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    Propolis from Turkey induces apoptosis through activating caspases in human breast carcinoma cell lines
    (2010) Seda Vatansever H.; Sorkun K.; Ismet Deliloglu Gurhan S.; Ozdal-Kurt F.; Turkoz E.; Gencay O.; Salih B.
    Propolis is a sticky substance that is collected from plants by honeybees that has anti-mutagenic and anti-carcinogenic properties with biological and therapeutic effects. The target of this study was to investigate the anti-apoptotic effect of propolis extracts (PE) on the caspase pathway in the human breast cell line MCF-7 in culture. Seven different propolis extracts, numbered PE 1-7, produced in their natural ecological environment, were collected from the Hacettepe University Beytepe Campus area in Ankara, Turkey. Individual extracts at 0.5, 0.25, 0.125 and 0.063 mg/ml were incubated with MCF-7 cells during 2 days culture. Cell growth and cytotoxicity were measured colorimetrically by MTT assay. Apoptotic cell death was determined by the TUNEL method (terminal deoxynucleotidyltransferase-biotin nick end-labelling) and caspase activity was investigated by immunocytochemistry using antibodies directed against caspase 6, caspase 8 and caspase 9. The results showed that the PE 5 and 6 extracts at 0.125 mg/ml dilution induced apoptosis in association with increased number of TUNEL positive cells. MTT results showed that cultures exposed to the same extracts and at the same dilution experienced better cell growth compared to those cultures exposed to the other extracts. Immunpositivity for all caspases was detected after treatment with all the extracts and at all dilutions, with stronger immunoreactivity for caspase 6 than caspases 8 and 9. Caspase 6 labelling was especially strong in PE 5 and PE 6. We conclude that propolis may have anti-tumour effects by increasing apoptosis through the caspase pathway. Such propolis extracts may be important economically and allow development of a relatively inexpensive cancer treatment. © 2009 Elsevier GmbH.
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    Spectroscopic, electrochemical and electrocolorimetric properties of novel 2-(2?-pyridyl)-1H-benzimidazole appended bay-substituted perylene diimide triads
    (Elsevier B.V., 2019) Pekdemir F.; Orman E.B.; Selçuki N.A.; Özkaya A.R.; Salih B.; Şengül A.
    In this study, four new perylene diimide (PDI)derivatives incorporating 2-(2?-pyridyl)-1H-benzimidazole (2PBI)chromophores at the imide positions, in which 1 bearing non-bay-substituted perylene core, and those having four substituents at 1,6,7,12-bay positions of the perylene core, namely 2 bearing electron-withdrawing chlorine atoms, 3 bearing electron-donating 4-methoxyphenoxy groups and 4 bearing non-electron-donating 4-tert-butylphenoxy groups, respectively were synthesized and fully characterized by FT-IR, 1 H NMR, 13 C NMR, MALDI-TOF mass spectrometry and UV/Vis spectroscopy. The thermal properties were measured by thermogravimetric analysis (TGA)which showed that the materials (1-4)are thermally very stable (T d > 450 °C). DFT was performed for geometry optimizations, and TDDFT was used to compare the calculated and the experimental UV/Vis electronic spectra at the B3LYP/6–311 G(d)level. Detailed measurements were carried out by the use of electroanalytical, spectroscopic and colorimetric techniques in order to understand redox natures, color changes and optoelectronic characters of the novel compounds. These 2PBI-functionalized PDI triads showed reversible reduction processes, chemically stable reduced species and considerably low HOMO-LUMO band gaps, as the new worthy members of photoactive charge transport materials for optoelectronic and photovoltaic systems. In addition, with distinct color changes associated with their redox processes in the solution, these new triads displayed great capacity for application in electrochromic devices. The emission maxima of the compounds were found to be red shifted in the solid state. © 2019 Elsevier B.V.
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    Synthesis, characterization, OFET, and DFT study of the novel ball-type metallophthalocyanines bridged with four diaminopyrimidine-dithiol
    (World Scientific Publishing Co. Pte Ltd, 2019) Molla F.; Yazlcl A.; Selçuki N.A.; Altlndal A.; Salih B.; Bekaroglu O.
    Co2Pc2 (2) and Zn2Pc2 (3) were obtained in DMF and LuPc2 (4) was obtained in hexanol by the cyclotetramerization of novel diphthalonitrile (1). Synthesized compounds were characterized by FT-IR, 1H-NMR, elemental analyses, MALDI-TOF MS and UV-vis spectroscopy techniques. Optimized geometries and electronic structures for compounds 2, 3 and 4 were investigated by Density Functional Theory (DFT) and Time Dependent Density Functional Theory (TD-DFT). In compound 2, a new bond was observed between Co centers forming two Co(III) with the interaction of d orbitals. Computational and experimental UV-vis spectra in DMF were found in agreement for the investigated compounds. Vertical and adiabatic ionization potentials for the studied systems were also calculated. The gate dielectric performances of thin films obtained from these compounds were investigated by fabricating ITO/2-4/Au devices. The observed reverse bias J-V characteristics revealed that the leakage current in ITO/2-4/Au devices is because of the Poole-Frenkel effect. The effect of the gate dielectric on the OFET performance parameters was also investigated by fabricating bottom-gate top-contact OFET using pentacene as the active layer. Maximum field effect mobility was observed with the 2-based OFET device. Calculated HOMO-LUMO gap, hole reorganization energy and ionization energy have also supported the experimental results which indicate that 2 is the most suitable system for OFET devices. © 2019 World Scientific Publishing Company.
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    Synthesis, characterization, OFET, and DFT study of the novel ball-type metallophthalocyanines bridged with four diaminopyrimidine-dithiol
    (World Scientific, 2020) Molla F.; Yazlcl A.; Selçuki N.A.; Altlndal A.; Salih B.; Bekaro?lu Ö.
    Co2Pc2 (2) and Zn2Pc2 (3) were obtained in DMF and LuPc2 (4) was obtained in hexanol by the cyclotetramerization of novel diphthalonitrile (1). Synthesized compounds were characterized by FT-IR, 1H-NMR, elemental analyses, MALDI-TOF MS and UV-vis spectroscopy techniques. Optimized geometries and electronic structures for compounds 2, 3 and 4 were investigated by Density Functional Theory (DFT) and Time Dependent Density Functional Theory (TD-DFT). In compound 2, a new bond was observed between Co centers forming two Co(III) with the interaction of d orbitals. Computational and experimental UV-vis spectra in DMF were found in agreement for the investigated compounds. Vertical and adiabatic ionization potentials for the studied systems were also calculated. The gate dielectric performances of thin films obtained from these compounds were investigated by fabricating ITO/2-4/Au devices. The observed reverse bias J-V characteristics revealed that the leakage current in ITO/2-4/Au devices is because of the Poole-Frenkel effect. The effect of the gate dielectric on the OFET performance parameters was also investigated by fabricating bottom-gate top-contact OFET using pentacene as the active layer. Maximum field effect mobility was observed with the 2-based OFET device. Calculated HOMO-LUMO gap, hole reorganization energy and ionization energy have also supported the experimental results which indicate that 2 is the most suitable system for OFET devices. © 2020 World Scientific Publishing Company.