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Öğe Bioactive contents, In vitro antiradical, antimicrobial and cytotoxic properties of rhubarb (Rheum ribes L.) extracts(Taylor & Francis Ltd, 2020) Keser, Serhat; Keser, Fatma; Karatepe, Mustafa; Kaygili, Omer; Tekin, Suat; Turkoglu, Ismail; Demir, ErsinRheum ribes L. (rhubarb) is belonging to Polygonaceae, and its roots and fresh shoots are consumed as vegetable in Turkey. This plant is considered to be one of the most important pharmaceutical raw materials in Middle East. In this study, the antiradical, antimicrobial, cytotoxic and bioactive properties of water, ethanol, and methanol extracts of R. ribes stems were determined. R. ribes stems water, ethanol and methanol extracts are better scavenged ABTS(center dot+) (99.27, 99.91, and 99.88%), DPPH center dot (83.11, 81.42, and 83.26%), and OH center dot radicals (93.49, 94.21, 95.86%) than standard antioxidant BHA (95.32, 80.49, and 93.78%). Stems of R. ribes abundantly include bioactive compounds, dominated by rutin, catechin, caffeic acid, ferulic acid, alpha-tocopherol and vitamin D. These extracts show effective cytotoxic properties against PC-3, A2780, HCT-116 and MCF-7 cancer cell lines at 24h. It is found that R. ribes contain high amount important bioactive contents, and has effective antiradical and cytotoxic properties.Öğe Ce/Sm co-doped hydroxyapatites: synthesis, characterization, and band structure calculation(Springer, 2021) Kaygili, Omer; Vural, Gulay; Keser, Serhat; Yahia, I. S.; Bulut, Niyazi; Ates, Tankut; Koytepe, SuleymanIn this paper, Ce/Sm co-doped hydroxyapatites (HAps) were synthesized by a wet chemical route. The amount of Ce was kept at constant at the value of at.% 0.4, and the second dopant of Sm was used at different amounts of at.% 0, 0.6, 1.2, and 1.8, respectively. The effects of these co-dopants on the crystal structure, morphology, and thermal properties of HAp were determined experimentally using X-ray diffraction (XRD), scanning electron microscopy (SEM), differential thermal analysis (DTA), and thermogravimetric analysis (TGA). Furthermore, the band structure of the prepared samples was modeled theoretically using the quantum calculations of the density of states and band structure. A gradual increase from 26.56 to 36.23 nm in the crystallite size was observed. Although the amounts of the co-dopants of Ce and Sm did not affect the thermal stability and microstructure of HAp, its crystal structure-related parameters were affected by the amount of these co-additives. The partial substitution of both co-dopants was detected. The 0.4Ce-1.2Sm-HAp sample may be considered as the best crystal structure with a steady-state. It was seen that the band structure and density of states were also affected by these co-dopants. The bandgap value decreased gradually from 4.6078 to 4.0477 eV due to these dopants.Öğe Co Katkılı SnO2 Numunelerinin Sentez ve Karakterizasyonu(2020) Ateş, Tankut; Kaygılı, Ömer; Bulut, Niyazi; Okur, Havva Esma; Keser, Serhat; Yahıa, I.S.; Köytepe, SüleymanYüksek kristalleşmeye sahip katkısız ve Co katkılı SnO2 numuneleri başarılı bir biçimde hazırlandı. Coiçeriğinin SnO2’nin termal ve morfolojik özellikleri üzerine etkileri araştırıldı. Co ilavesiyle Kristalbüyüklüğünde ve birim hücre parametrelerinde değişimler tespit edildi. Co ilavesiyle faz bileşimi değişmedi.Hem X-ışını kırınımı hem de Fourier dönüşümlü kızılötesi sonuçları her bir numune için SnO2 fazınınoluşumunu doğruladı. Üretilen numunelerin oda sıcaklığından 900 °C’ye kadar termal kararlılığı gözlendi.Morfoloji Co içeriğinden etkilendi ve enerji dağılımlı X-ışını sonuçları SnO2 yapısı içerisine Co’ın nüfuz ettiğinidoğruladı.Öğe Cytotoxic effect of endemic Tchihatchewia isatidea Boiss. from Turkey(Brill, 2021) Kirbag, Sevda; Keser, Serhat; Tekin, Suat; Inci, Sule; Sandal, SuleymanTchihatchewia isatidea Boiss (Brassicaceae) is known among the public as Reddish Bride, Paint and Bridal Flower. Flower parts are used for painting and flowering branches for treatment of cough. In this study, anticancer properties of water, ethanol and methanol extracts of Tchihatch-ewia isatidea flower parts were investigated against human breast (MCF-7), human colon (HCT-116) and human prostate (LNCaP) cancer cell lines. Changes in the viability of cancer cells were de-tected by utilizing 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method. Studies have shown that there is a statistically significant decrease in the cell viability of human breast cancer (MCF-7), colon (HCT-116) and prostate (LNCaP) cancer cells when extracts of T. isati-dea water, ethanol and methanol are used.Öğe Determination of Anticancer and Antimicrobial Properties of Alcea calvertii(Wiley-Blackwell, 2016) Keser, Serhat; Tekin, Suat; Kaygili, Omer; Keser, Fatma; Turkoglu, Ismail; Turkoglu, Semra; Kirbag, Sevda[Abstract Not Available]Öğe The Effect of Hypericum scabrum on the Human Prostate, Colon and Breast Cancer(Wiley-Blackwell, 2016) Keser, Serhat; Tekin, Suat; Kaygili, Omer; Keser, Fatma; Sandal, Suleyman[Abstract Not Available]Öğe The effects of gamma irradiation on dielectric properties of Ag/Gd co-doped hydroxyapatites(Springer, 2019) Kaygili, Omer; Keser, Serhat; Selcuk, A. Birkan; Bulut, Niyazi; Koytepe, Suleyman; Yahia, I. S.; Ates, Tankut1.0 at% Ag-containing hydroxyapatites (HAps) doped with the different amounts of Gd (e.g., 0, 0.8, 1.6 and 2.4 at%) were synthesized by a wet chemical method and their dielectric properties were investigated before and after gamma irradiation. The changes in the relative permittivity and alternating current (AC) conductivity values of the as-synthesized samples before and after irradiation were investigated using dielectric measurements. It was found that both Gd content and gamma irradiation dose significantly affect the dielectric properties and AC conductivity. It was concluded that especially due to the thermal stabilities and suitable dielectric properties, the as-synthesized Gd-doped Ag containing HAps could be used for bone healing applications.Öğe Experimental and theoretical characterization of Dy-doped hydroxyapatites(Springer, 2023) Isen, Fatih; Kaygili, Omer; Bulut, Niyazi; Ates, Tankut; Osmanlioglu, Fatih; Keser, Serhat; Tatar, BeyhanThe effects of adding Dy to the hydroxyapatite (HAp) structure were investigated experimentally and theoretically. The as-obtained experimental results with an increasing amount of Dy are as follows. X-ray diffraction, Raman, and Fourier transform infrared measurements verified the HAp structure for each specimen. The crystallinity, lattice parameters, lattice stress, strain, and anisotropic energy density were affected. Thermal stability and stoichiometry were not affected. It was observed that all the Dy-doped HAps have smaller crystallite size values compared to the un-doped HAp. The cell viability obtained from mouse fibroblast cell (L929) was higher than 82%, indicating all the samples were biocompatible. The theoretical findings, obtained from the density functional theory (DFT) calculations, exhibited a continuous decrease in the bandgap from 4.7109 to 3.7982 eV, an increase in the density from 3,155 to 3,189 kg m(-3), and an increase in the linear absorption coefficient.Öğe An experimental and theoretical investigation of the structure of synthesized ZnO powder(Elsevier Science Bv, 2018) Kaygili, Omer; Ercan, Ismail; Ates, Tankut; Keser, Serhat; Orek, Cahit; Gunduz, Bayram; Seckin, TurgayZnO powder has been synthesized, characterized experimentally and its theoretical modeling carried out by density functional theory (DFT). The experimental and theoretical results were compared with each other and with the available data in the literature. A detailed crystal structure analysis was carried out using X-ray diffraction (XRD) data. Experimental and theoretical FTIR analysis, energy gap and density of states and electronic band structure calculations have been done for a complete characterization of the material. The surface morphology has been investigated by scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) spectroscopy. It has been found that the electron excitation of ZnO can occur most probably at the Gamma-Gamma point, where the energy gap has the lowest value between the valance and conduction bands.Öğe Fe ve Ti katkılı Çift Fazlı Kalsiyum Fosfatların Sentez ve Karakterizasyonu(2021) Ateş, Tankut; İnce, Turan; Kaygılı, Ömer; Keser, Serhat; Köytepe, Süleyman; Acar, Serdar; Bulut, NiyaziBu çalışmada, Ti katkısının Fe esaslı çift fazlı kalsiyum fosfat malzemelerinin yapısal, morfolojik ve termal özellikleri üzerine etkileri araştırılmıştır. X-ışını kırınımı (XRD) analizi, üretilen numunelerin hem hidroksiapatit (HAp) hem de beta trikalsiyum fosfat (?-TCP) fazlarına sahip olduğunu doğrulamaktadır. Ayrıca, Ti katkısındaki artışla ?-TCP fazının miktarının arttığı görülmektedir. Fourier dönüşümlü kızılötesi (FTIR)spektroskopisi sonuçları, numunelerdeki karakteristik fonksiyonel grupların varlığını doğrulamaktadır. Ti miktarı morfolojiyi etkilemektedir. Numunelerin ısıl davranışları birbirine benzerdir ve oda sıcaklığından 1000 °C’ye kadar tüm numuneler termal olarak kararlıdırlar. Bu sıcaklık aralığında numunelerdeki kütle kayıpları % 1,63’e eşit veya altındadır.Öğe In vitro Antiradical, Antimicrobial and Antiproliferative Activities and Phytochemical Compositions of Endemic Alcea calvertii (Boiss) Boiss. Flowers(2020) Keser, Serhat; Keser, Fatma; Tekin, Suat; Kaygılı, Ömer; Turkoglu, Ismail; Demır, Ersin; Karatepe, Mustafa; Kırbağ, Sevda; Yılmaz, Okkes; Sandal, Suleyman; Turkoglu, SemraAbstract: Alcea calvertii (Boiss) Boiss. is belonged to Malvaceae family, and it is a perennial herbaceous endemic plant. Alcea genus plants are grown as ornamental plants in the gardens. In the present study, the antiproliferative, antimicrobial, antiradical activities and phytochemical compositions of ethanol, water, methanol and acet one extracts of A. calvertii flowers were examined. A. calvertii flowers water, ethanol, methanol and acetone extracts are lower scavenged DPPH, ABTS and OH radicals than standard antioxidant trolox. A. calvertii flowers contain vitamins, sterols, flavonoids and phenolic acids, dominated by vanillic acid, gallic acid, catechin, ?-tocopherol, ergosterol and vitamin D. A. calvertii flowers water extract showed better antiproliferative activities than other extracts against to MCF-7 and HCT-116 cell lines. A. calvertii flowers methanol extract showed higher antiproliferative effect against to LNCaP cell lines.Öğe In Vitro Biological Evaluation and Phytochemical Contents of Three Centaurea L. Species Growing from Eastern Anatolia in Turkey(2020) Keser, Serhat; Keser, Fatma; Turkoglu, Ismail; Kaygılı, Ömer; Tekin, Suat; Demır, Ersin; Karatepe, Mustafa; Yılmaz, Ökkeş; Kırbağ, Sevda; Sandal, Suleyman; Turkoglu, SemraAbstract: Centaurea L. species were used as medicinal plants among the people for treatment of the common cold, abscesses, peptic ulcers, hemorrhoid and diabetes etc.. In the present study, antiradical properties, phytochemical contents, antimicrobial and antiproliferative activities of three Centaurea species were investigated. Centaurea saligna (K.Koch) Wagenitz methanol (99.94%), Centaurea virgata Lam. methanol (98.23%) and water (98.10%) extracts were showed higher ABTS scavenging than trolox (96.79%). Centaurea kurdica Reichardt extracts showed lower activity than trolox for all the antiradical assays. Centaurea extracts exhibited antimicrobial activity against to some microorganisms. It was determined that these Centaurea species contain high amount of total flavonoid, phenolic and proanthocyanidin, phenolic acids, phytosterols and unsaturated fatty acids. Also, three Centaurea extracts showed very high antiproliferative property on LNCaP, HCT-116, MCF-7 cancer cell lines.Öğe Investigation of Antiproliferative Properties of Malva neglecta Extracts(Wiley, 2017) Tekin, Suat; Keser, Serhat; Keser, Fatma; Sandal, Suleyman; Turkoglu, Ismail; Karatepe, Mustafa; Turkoglu, Semra[Abstract Not Available]Öğe Investigation of The Anticarcinogenic Effects of Portulaca oleracea Extracts on Different Human Cancer Cell Lines(Wiley, 2017) Sandal, Suleyman; Keser, Serhat; Tekin, Suat; Keser, Fatma; Turkoglu, Ismail; Karatepe, Mustafa[Abstract Not Available]Öğe Investigation of the structural and thermal properties of Y, Ag and Ce-assisted SiO2-Na2O-CaO-P2O5-based glasses derived by sol-gel method(Springer, 2017) Kaygili, Omer; Keser, Serhat; Tatar, Cengiz; Koytepe, Suleyman; Ates, TankutA glass with the composition of the SiO2-Na2O-CaO-P2O5 was synthesized by sol-gel method at temperature of 900 A degrees C, and then yttrium-, silver- and cerium-containing glasses were prepared at the same conditions using this base system. The structural and thermal properties of the glass samples were investigated by X-ray diffraction, Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy, energy-dispersive X-ray (EDX) spectroscopy and differential thermal analysis techniques. The Ca-5(PO4)(2)(SiO4)(6) phase having the orthorhombic crystal system is detected for each sample without any secondary phase, and this phase is confirmed by the FTIR spectra. With the addition of Y, Ag and Ce to the SiO2-Na2O-CaO-P2O5 system, the variations in the average crystallite size, crystallinity percent, lattice parameters and unit cell volume are observed. A decrease in the crystallization peak temperature and the changes in the glass transition temperature are seen with the addition of Y, Ag and Ce to the base system. The addition of Y, Ag and Ce to the base glass increases significantly its density. The EDX spectra of the as-prepared samples verify the introduction of the as-mentioned elements.Öğe Investigation of the structural, thermal, magnetic and cell viability properties of Ce/Sr co-doped hydroxyapatites(Elsevier, 2023) Ates, Hulya Gunes; Kaygili, Omer; Bulut, Niyazi; Osmanlioglu, Fatih; Keser, Serhat; Tatar, Beyhan; Mahmood, Bahroz KareemThe present study aims to give a more detailed report on the structural, thermal, magnetic and in vitro cell viability properties of the hydroxyapatites (HAps) co-doped with Sr and Ce at different amounts. Besides these experimental analyses, this study also includes the theoretical calculation results obtained from the modeled systems for the as-prepared samples. Diamagnetic behavior was observed for all the samples, as well as their high cell compatibilities. All the samples showed a thermally stable behavior, and the mass change mechanism and specific heat capacity were affected by the amount of the codopants. The bandgap value and linear absorption coefficient varied with the amount of both co-dopants. (c) 2023 Elsevier B.V. All rights reserved.Öğe Phytochemical compounds and antiradical, antimicrobial, and cytotoxic activities of the extracts from Hypericum scabrum L. Flowers(Taylor & Francis Ltd, 2020) Keser, Serhat; Keser, Fatma; Kaygili, Omer; Tekin, Suat; Demir, Ersin; Turkoglu, Ismail; Turkoglu, SemraHypericum scabrum L. has been widely used in traditional medicine for the treatment of many diseases just as the other Hypericum species. In the present study, the antiradical, antimicrobial and cytotoxic activities of water and ethanol extracts of H. scabrum flowers were investigated. Their phytochemical contents and composition were also determined. The water and ethanol extracts are better scavenged ABTS (97.89 and 98.99%) and OH radicals (96.36 and 97.33%); the water extract is better scavenged DPPH radicals (91.66%) than the standard antioxidant BHA (94.33, 85.19, 90.16%, respectively). Flowers of H. scabrum contain flavonoids, phenolic acids, vitamins and phytosterols, dominated by catechin, vanillic acid, vitamin K and ergosterol. The extracts exhibit a strong cytotoxic activity against MCF-7, HCT-116, and LNCaP cancer cell lines. It is found that their antimicrobial activities are higher than the standard antibiotics. These results indicate that H. scabrum flowers have potent antiradical, antimicrobial and cytotoxic activities.Öğe Rumex acetosella L. (Kuzukulağı)’nın In vitro Antiradikal, Antimikrobiyal, Antikanser ve Fitokimyasal Özellikleri(2022) Keser, Fatma; Karatepe, Mustafa; Keser, Serhat; Tekin, Suat; Turkoglu, Ismail; Kaygılı, Ömer; Demır, ErsinPolygonaceae familyasında yer alan R. acetosella, çok yıllık otsu bir bitkidir ve Türkiye’de halk arasında sebze olarak tüketilmektedir. Bu çalışmada R. acetosella toprak üst kısımlarının etanol, su ve metanol ekstraktlarının antimikrobiyal (Escherichia coli, Bacillus megaterium, Bacillus subtilis, Proteus vulgaris, Pseudomonas aeruginosa, Listeria monocytogenes, Klebsiella pneumoniae, Staphylococcus aureus bakterileri ve Candida albicansmaya-mantarına karşı), antiradikal (DPPH, ABTS ve OH radikallerine karşı), antikanser (insan prostat kanseri (PC-3), insan kolon kanseri (HCT-116), insan yumurtalık kanseri (A2780) ve insan göğüs kanseri (MCF 7) hücre serilerine karşı) ve fitokimyasal özellikleri (yağda çözünen vitaminler, yağ asitleri, flavonoitler,fitosteroller, fenolik asitler, toplam fenolik bileşik, toplam flavonoit ve toplam proantosiyanidinler) incelenmiştir. Sonuçlarımıza göre R. acetosella ekstraktlarının ABTS, DPPH ve OH radikali yok etme testlerinde BHT’den daha yüksek aktiviteye sahip oldukları belirlenmiştir. Ayrıca bu bitkinin yüksek antimikrobiyal aktiviteye ve fitokimyasal içeriğe sahip olduğu, PC-3 insan prostat kanseri hücrelerine karşı etkili antikanser aktivite gösterdiği anlaşılmıştır. Aynı zamanda sunulan çalışma, R. acetosella ekstraktlarının in vitro antikanser aktivitesi ile ilgili ilk çalışma olma özelliği taşımaktadır.Öğe Spectroscopic, antiproliferative and antiradical properties of Cu(II), Ni(II), and Zn(II) complexes with amino acid based Schiff bases(Springer Birkhauser, 2014) Genc, Zuhal Karagoz; Selcuk, Sibel; Sandal, Suleyman; Colak, Naki; Keser, Serhat; Sekerci, Memet; Karatepe, MustafaNovel six Cu(II), Ni(II), and Zn(II) complexes with Schiff bases derived from 4-aminobenzoic acid with terephtaldehyde and amino acids (glycine, beta-alanine). Structures have been proposed from elemental analysis, UV-Vis, IR, NMR, TGA, DTA, and magnetic measurements. Spectroscopic studies suggest that coordination occurs through azomethine nitrogen, hydroxyl group, and carbonyl oxygen of the ligands to the metal ions. The elemental analyses of the complexes where L is Schiff base ligands, are confined to the stoichiometry of the type M2L2(CH3COO)(2) [M = Cu(II)]; and M2L(CH3COO)(2) [M = Ni(II) and Zn(II)]. The cytotoxicity activities of the compounds against human breast carcinoma MCF-7 cell line have been studied. Ligands and their Zn(II) compounds inhibited cell proliferation of MCF-7 cancer cell lines in a dose- and time-dependent manner. The free radical scavenging activity was measured by 1,1-diphenyl-2-picryl-hydrazil. Our results show that the synthesized compounds induced oxidative damage by increasing the lipid peroxidation in yeast since MDA formation was increased, and it could be concluded that the synthesized compounds caused oxidative stress. In addition, the antioxidant activities of the synthesized compounds were very much lower than those of standard antioxidants.Öğe Structural and dielectric properties of yttrium-substituted hydroxyapatites(Elsevier, 2015) Kaygili, Omer; Dorozhkin, Sergey V.; Ates, Tankut; Gursoy, N. Canan; Keser, Serhat; Yakuphanoglu, Fahrettin; Selcuk, A. BirkanHydroxyapatite (HAp) samples doped with 0,2 and 4 at.% of yttrium (Y) were characterized using X-ray diffraction (XRD), Fourier transform infrared (FOR) spectroscopy, scanning electron microscopy attached with energy dispersive X-ray (EDX) spectroscopy, antimicrobial activity tests and dielectric studies. The hydroxyl groups observed in FOR spectra confirmed the formation of HAp phase in the studied samples. The crystallite size, crystallinity degree and lattice parameters of the samples were changed with Y content The volume of the unit cell was gradually decreased with the addition of Y. Undoped and Y-containing HAp samples were screened to determine their in vitro antimicrobial activities against the standard strains. It was found that no samples have any antimicrobial effect. The relative dielectric permittivity and dielectric loss are affected by Y content. While the alternating current conductivity increases with increasing frequency, it decreases with increasing Y content (C) 2014 Elsevier B.V. All rights reserved.
