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Öğe Binding Affinity of Serum Proteins to Epoxy Modified Magnetite Nanoparticles(2012) Maltaş, Esra; Özmen, Mustafa; Yıldız, Salih; Ersöz, MustafaSuperparamagnetic iron oxide nanoparticles (SPIONs) were synthesized by co-precipitating Fe2+ and Fe3+ in an ammonia solution. SPIONs modified with [3-(2,3-epoxypropoxy)propyl] trimethoxy silane, which resulted in the presence of a high population of epoxy groups on the particles surface. The surface functional SPIONs can be bound with active bio-substance, and have a wide application prospect in the fields of biology and medicine. The binding percentage of proteins was studied with epoxy modified SPIONs. Several serum proteins including albumin, ?-globulin, hemoglobin, cytochrome c and myoglobin were studied for immobilization. Epoxy terminated SPIONs were shown the highest binding ability for immobilization of cytochrome c and hemoglobin with 1 and 0.86 mg total protein at a particle concentration of 20 mg/mL among proteins, respectively. This binding ability was also shown by using sodium dodecylsulfate polyacrylamide gel electrophoresis technique (SDS-PAGE). Protein attachments were also examined by Scanning Electron Microscopy (SEM). © 2012 American Scientific Publishers. All rights reserved.Öğe Evaluation of Antioxidant and Antimicrobial Activity of Vitex Agnus Castus L.(Parlar Scientific Publications (P S P), 2010) Maltaş, Esra; Uysal, Ahmet; Yıldız, Salih; Durak, YusufAntioxidant and antimicrobial activities of methanolic extract of Vitex agnus castus were studied. The antioxidant properties of the extracts were evaluated using different antioxidant tests, including ferric chelating, scavenging activity of hydrogen peroxide and cupric reducing antioxidant capacity. The highest antioxidant activity was observed to be 93.5 +/- 0.8% by scavenging activity of hydrogen peroxide. However, total flavonoid and phenolic content of the methanolic extract were determined. Antimicrobial activity tests were carried out using disc diffusion method and broth microdilution method with 7 bacteria and 1 yeast. Results suggested that Vitex agnus castus may be important in variety improvement, nutraceuticals, bio-pharmaceuticals and food additives as possible cost-effective natural antioxidant.Öğe Fluorimetric Analysis of Aluminum in Diluted Hemodialysis Solutions by Using a Novel Schiff Base(Taylor & Francis Inc, 2010) Gündüz, Selmuş Beniz; Maltaş, Esra; Yıldız, SalihA spectrofluorimetric method has been developed for trace amount of aluminum(III) by using a novel Schiff base, N,N'-bis(salicylidene)-1,4-diaminobuthane (BUTAS), and 4-methyl-2-aminophenol (OAP). Since the aluminum complexes are generally fluorescent, aluminum(III) increases the fluorescence intensity of BUTAS-OAP by formation of Al-BUTAS-OAP complex. The fluorescence of the complex is measured at an excitation wavelength of 410 nm with an emission at 526 nm. Aluminum(III) can be detected within a concentration limit of 0.11-1.62 ppb and the lowest detection limit being 0.07 ppb. The proposed method was applied to diluted hemodialysis solution and spectrofluorimetric data was compared with data of standard pharmacopoeia method.Öğe Ginkgo biloba'nın kimyasal ve moleküler yöntemlerle analizi(Selçuk Üniversitesi Fen Bilimleri Enstitüsü, 2011-07-29) Maltaş, Esra; Yıldız, SalihBu çalışmada, Türkiye'nin Antalya şehrinden toplanan Ginkgo biloba L.(Ginkgoaceae)'nin moleküler, morfolojik ve biyokimyasal özellikleri moleküler ve kimyasal yöntemler kullanılarak tanımlanmıştır. Çalışmanın ilk bölümünde, Ginkgo biloba'nın antioksidan aktivite analizleri için öncelikle metanol, aseton ve hekzan olmak üzere üç farklı çözücü ile yapraklarından ekstraksiyon yapılmıştır. Ekstraktların antioksidan aktiviteleri, DPPH serbest radikal süpürme etkisi, demir ve bakır indirgeme metotları, ß-karoten-linoleik asit emülsiyon sistemi, metal şelatlama aktivitesi ile hidrojen peroksit giderme aktiviteleri olmak üzere çeşitli antioksidan aktivite tayin metotları ile belirlenmiştir. Bununla birlikte her bir ekstraktın toplam fenolik ve flavonoid madde tayinleri sırasıyla Folin ve aluminyum şelatlama yöntemleri kullanılarak hesaplanmıştır. Metanol ekstraktı en yüksek antioksidan aktivite göstermiş ve bunabağlı olarak en fazla fenolik maddeyi de yine metanol ekstraktının ihtiva ettiği görülmüştür Çalışmanın bir diğer bölümünde bitkilerin ikincil metabolitleri olarak adlandırılan ve morfolojik karakterleri olarakta bilinen fenolik yapılardan 15 tanesinin yüksek performanslı sıvı kromatografisi ile analizi yapılarak ekstraktlarda bulunması muhtemel bu fenolik bileşikler kalitatif ve kantitatif olarak tanımlanmıştır. Analizi yapılan 15 maddeden yalnızca 8 tanesine rastlanmıştır. Bunlar kateşin hidrat, kaffeik asit, p-kumarik asit, ferulik asit, rutin, eriodiktiol, kuersetin ve naringenindir. Bitkilerin bir diğer morfolojik karakteri ise ihtiva ettikleri yağ asitleridir. Her bir ekstraktta bulunan yağ asitleri gaz kromatografisi kullanılarak tayin edilmiştir. Sonuç olarak Ginkgo biloba'da en fazla biyosentezi gerçekleşen yağ asitleri doymuş yağ asidi olarak C:16 palmitik asit ile tekli doymamış yağ asitlerinden C:18 oleik asittir. Çalışmanın son kısmında ise Ginkgo biloba yapraklarından DNA izolasyonu manuel ve kite dayalı olmak üzere iki yöntemle gerçekleştirilmiş ve her bir DNA 20 adet primerle (OPA1-20) rasgele çoğaltılmış DNA poliformizi metodu ile çoğaltılmıştır. Elde edilen bantlar Almanya orijinli Ginkgo biloba yapraklarıdan DNA'nın yine aynı yöntemlerle izole edilen ve çoğaltılan reaksiyon ürünleri ile karşılaştırılarak orijine ve iklime bağlı olarak ortaya çıkan polimorfizmler belirlenerek tür içi benzerlik ve farklılıklar DNA düzeyinde incelenmiştir.Öğe Immobilization and Characterization of Hemoglobin on Modified Sporopollenin Surfaces(Elsevier Science Bv, 2012) Gübbük, İlkay Hilal; Özmen, Mustafa; Maltaş, EsraHemoglobin was covalently immobilized onto modified sporopollenin surface with different functional groups by chemical reactions to enhance binding ability of protein. In this study, the influence of various silane linker molecules on the capacity of protein binding was studied. For this purpose, activated sporopollenin was modified by 3-aminopropyltriethoxysilane (APTS), 3-chloropropyltrimethoxysilane (CPTS) and (3-glycidyloxypropyl)trimethoxysilane (GPTS). Hemoglobin (Hb) was immobilized on modified sporopollenin surfaces in phosphate buffer saline solution (PBS, pH 7.4) at 4 degrees C. Results showed that GPTS modified sporopollenin surfaces resulted in the highest binding capacity for Hb. Micro porosity of samples was observed through scanning electron microscopy (SEM) and thermal behavior of the samples were studied with thermogravimetric analysis (TGA) within a temperature range: 25-900 degrees C. TGA studies demonstrated the advantages of silane modification for high temperature applications and illustrated differences of the structures due to the different tail groups.Öğe Immobilization of albumin on magnetite nanoparticles(ELSEVIER SCIENCE BV, 2011) Maltaş, Esra; Özmen, Mustafa; Vural, Hasibe Çingilli; Yıldız, Salih; Ersöz, MustafaThe magnetite (Fe3O4) nanoparticles were prepared by the co-precipitation of ferrous and ferric salts with NH4OH, and then modified with 3-aminopropyltriethoxysilane (APTES) by silanization reaction and subsequent reaction with glutaraldehyde (GA) to obtain functional groups on their surface. The influence of different terminated groups on protein binding was studied with bare and modified magnetite nanoparticles. Amine terminated magnetite nanoparticles were shown the highest binding ability for immobilization process compared to Fe3O4 NPs and GA bonded NPs. This binding ability was shown by using sodium dodecyl polyacrylamide gel electrophoresis technique (SDS-PAGE). Albumin attached magnetite nanoparticles were also examined by Scanning Electron Microscopy (SEM). (C) 2011 Elsevier B.V. All rights reserved.Öğe INVESTIGATION OF ANTIOXIDANT AND ANTIBACTERIAL ACTIVITIES OF SOME HYPERICUM SPECIES(PARLAR SCIENTIFIC PUBLICATIONS (P S P), 2013) Maltaş, Esra; Uysal, Ahmet; Yıldıztugay, Evren; Aladağ, Mustafa Onur; Yıldız, Salih; Küçüködük, MustafaThe in vitro antioxidant and antibacterial activities of the methanol extracts of three Hypericum species (Hypericum aviculariifolium Jaub. & Spach subsp. depilatum (Freyn & Bornm.) Robson var. depilatum, Hypericum salsugineum Robson & Hub.-Mor., Hypericum perforatum L.) growing in Turkey were investigated. The antioxidant capacities of the extracts were evaluated by different assays; including total phenolic content, total flavonoid content, free radical scavenging activity (DPPH assay), total antioxidant activity by beta-carotene-linoleic acid assay, ferric and cupric reducing assay and metal chelating activity. Antibacterial activity was screened using a broth microdilution assay against a panel of standardized bacteria. Results showed that the methanolic extract of H. salsugineum showed the highest antioxidant activity among the extracts. Hypericum perforatum was the most effective extract among extracts of all Hypericum species tested and Listeria monocyto genes was the most sensitive bacterium against all extracts.Öğe Synthesis and characterization of PS-b-PGMA diblock copolymer and its interaction with blood proteins and donepezil(ELSEVIER SCIENCE BV, 2014) Buzoğlu, Leman; Maltaş, Esra; Ersöz, Mustafa; Yıldız, SalihBiocompatible polystyrene-block-poly(glycidyl methacrylate) (PS-b-PGMA) diblock copolymers with different molecular weights were synthesized via atom transfer radical polymerization (ATRP), homopolymers of styrene with narrow molecular weight distribution were prepared and used macroinitiators for block copolymerization. The effect of time, temperature, solvent, and in-feed ratio on the synthesis of the polymer was examined. Human serum albumin (HSA), bovine serum albumin (BSA), globulin (Gib) and hemoglobin (Hb) which are intrinsically fluorescent blood proteins were interacted with the synthesized PS-b-PGMA diblock copolymers. A calibration curve equation was used to calculate the amount of immobilized proteins on the diblock copolymers through fluorescence spectroscopy. These occurred at wavelengths of 280 nm and 324 nm, which correspond to the excitation and emission wavelengths of tyrosine and tryptophan residues. Following the interaction of PS-b-PGMA diblock copolymer with the blood proteins, the protein was subjected to a pharmaceutical active substance, donepezil. The copolymers, homo polymers and protein-polymers along with the drug interactions were characterized using H-1 NMR, FT-IR and gel permeation chromatography (GPC), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). (C) 2014 Elsevier Ltd. All rights reserved.
