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Efficient and modular syntheses of chiral 2-(2-hydroxyaryl)alcohols (HAROLs), novel 1,4-diols carrying one phenolic and one alcohol hydroxyl group, have been developed which led to generation of a small library of structurally diverse HAROLs in enantiomerically pure form. Of the different HAROLs examined, a HAROL based on the indan backbone exhibited the highest activity and enantioselectivity in the 1,2-addition of certain organometallic compounds to aldehydes in the presence of Ti(OiPr)4 (up to 97% y, 88% ee) and performed as a hydrogen-bond donor organocatalyst in the Morita-Baylis-Hillman reaction, promoted by trialkylphosphines. 相似文献
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Capacitive Sensor to Monitor Enzyme Activity by Following Degradation of Macromolecules in Real Time
Bergdahl Gizem Ertürk Hedström Martin Mattiasson Bo 《Applied biochemistry and biotechnology》2019,189(2):374-383
Applied Biochemistry and Biotechnology - A capacitive sensor was developed to analyze the presence and enzymatic activity of a model protease from standard solutions by following the degradation of... 相似文献
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Mustafa Versan Kök Kiymet Gizem Gul 《Journal of Thermal Analysis and Calorimetry》2013,114(1):269-275
In this study, two Turkish crude oils from southeastern part of Turkey and their saturate, aromatic, resin fractions were analyzed by differential scanning calorimetry (DSC). The experiments were performed at three different heating rates (5, 10, 15 °C min?1) under air atmosphere. Two different reaction regions were observed from DSC curves due to the oxidative degradation of crude oil components. In the first reaction region, it was deduced that the free moisture, volatile hydrocarbons were evaporated from the crude oils, light hydrocarbons were burned, and fuel was formed. The second reaction region was the main combustion region where the fuel was burned. From DSC curves, it was observed that as the sample got heavier, the heat of the reaction increased. Saturates gave minimum heat of reaction. As the heating rate increased, shift of peak temperatures to high values and extended reaction region intervals were observed. The kinetic analysis of the crude oils and their fractions were also performed using ASTM E-698 and Borchardt and Daniels methods, respectively. Activation energy values of the crude oil samples and the fractions’ high-temperature oxidation region were close to each other and varied between 67 and 133 kJ mol?1 in ASTM and 35 and 154 kJ mol?1 in Borchardt and Daniels methods, respectively. 相似文献
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Ayşegül Kahraman Gökay Kaynak Gizem Akkaya Orhan Gürler Sezai Yalçın 《Journal of Radioanalytical and Nuclear Chemistry》2013,295(2):1057-1066
Activity concentrations of gross-β, naturally occurring 226Ra, 232Th, 210Pb, 7Be and anthropogenic 137Cs in epiphytic lichens collected from Uluda? Mountain are presented and discussed with the aim of evaluating potential usability of lichens as a biomonitor. The activity concentrations of gross-β, 137Cs, 40K, 226Ra, 232Th, 210Pb and 7Be in the lichen samples were found to be in the range of 177–707, 4.05–94.26, 86–211, below detection limit (BDL)—19.2, BDL—14.0, 229–872, and 72.1–220.7 Bq kg?1 in dry weight, respectively. 137Cs content in collected epiphytic lichens was in descending order: Parmelia sulcata > Lobaria pulmonaria > Pseudevernia furfuracea > Usnea filipendula. The best biomonitor for 137Cs among the lichen species used in this study was determined as Parmelia sulcata. Pearson’s correlation coefficient was calculated between 137Cs and 40K activity concentrations using a statistical package program (SPSS ver. 17.0) and a negative correlation value (R = ?0,323, p = 0,222) was obtained. The highest 226Ra and 232Th activity concentrations were found in Bo?azova Yaylas? which has a geological structure including granitic rocks. It was found that 137Cs and 7Be activity concentrations in species demonstrated an inverse behaviour. The effect of mean annual precipitation and temperature on 7Be activity concentration was determined using multi regression analysis. Also, correlations between the 137Cs and 7Be, and 40K and 7Be were investigated. 相似文献
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Hülya Gizem Özkan Vanrajsinh Thakor Hong-Gui Xu Galyna Bila Prof. Dr. Rostyslav Bilyy Daria Bida Dr. Martin Böttcher Prof. Dr. Dimitrios Mougiakakos Dr. Rainer Tietze Prof. Dr. Andriy Mokhir 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(30):e202104420
Elevated levels of reactive oxygen species (ROS) and deficient mitochondria are two weak points of cancer cells. Their simultaneous targeting is a valid therapeutic strategy to design highly potent anticancer drugs. The remaining challenge is to limit the drug effects to cancer cells without affecting normal ones. We have previously developed three aminoferrocene (AF)-based derivatives, which are activated in the presence of elevated levels of ROS present in cancer cells with formation of electron-rich compounds able to generate ROS and reduce mitochondrial membrane potential (MMP). All of them exhibit important drawbacks including either low efficacy or high unspecific toxicity that prevents their application in vivo up to date. Herein we describe unusual AF-derivatives lacking these drawbacks. These compounds act via an alternative mechanism: they are chemically stable in the presence of ROS, generate mitochondrial ROS in cancer cells, but not normal cells and exhibit anticancer effect in vivo. 相似文献
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Gizem Ertürk Nilay Bereli Pramod W. Ramteke Adil Denizli 《Applied biochemistry and biotechnology》2014,173(5):1250-1262
Myoglobin is a primary iron, and oxygen-binding protein of muscle tissues and levels can be an important diagnostic biomarker for acute myocardial infarction, myocardial necrosis, or other cardiac diseases. The establishment of myoglobin recognition systems is important because of its protein’s structural and functional values in physiology, biochemistry, and diagnostic value in some damaged muscle tissue and cardiac diseases. For this purpose, we used molecular imprinting technique for myoglobin recognition from aqueous solutions and human plasma. In the first step, myoglobin-imprinted poly(hydroxyethyl methacrylate) (PHEMA) cryogels (MGb-MIP) were prepared, and optimum myoglobin adsorption conditions were determined. Selectivity experiments have been done with the competitive proteins, and myoglobin adsorption from IgG and albumin-free human plasma was studied. The purity of the desorbed samples was determined with SDS-PAGE. The desorption efficiency and reusability of the MGb-MIP cryogels were tested, and it was shown that without any significant loss in the adsorption capacity, MGb-MIP cryogels can be used a number of times for myoglobin recognition and separation. 相似文献
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Selami Ercan Ercan Çınar Cihat Özaydın Nuriye Efe Ertürk Reşit Çakmak 《Journal of heterocyclic chemistry》2020,57(7):2875-2888
Designing new inhibitors having less side effects is a need which also could reduce cholesterol levels. To fulfill this aim, we have carried out a molecular docking study toward 3-hydroxy-3-methyl-glutaryl-CoA (HMG-CoA) reductase. A set of designed structural derivatives of statin drugs, eight ligands which are used as HIV-1 integrase inhibitor candidates, a set of terpenoids, and ligands downloaded from Zinc15 database were docked to HMG-CoA reductase enzyme which contains atorvastatin in crystal structure. The analysis of docking studies revealed that statin derivative ligands are more appropriate for inhibition of HMG-CoA reductase. To define the contribution of the molecular properties to the binding of ligands to enzyme structure; the highest occupied molecular orbitals-lowest unoccupied molecular orbitals, hardness, electronegativity, and chemical potential properties of ligands have best score in their sets calculated by quantum mechanical tools. 相似文献
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Gizem Kaleli‐Can Busra Ozlu Hatice Ferda
zgüzar Baran Onal‐Ulusoy Gzde Kabay Taesik Eom Bong Sup Shim Mehmet Mutlu 《Electroanalysis》2020,32(8):1696-1706
A biosensor was prepared with natural melanin nanoparticles (MNP) decorated on a screen‐printed carbon electrode (SPCE). Hexavalent chromium was selected as a well‐known heavy metal ion to be detected for testing the performance of novel biosensor. Natural MNP was extracted from cuttlefish (Sepia officinalis) ink. Surface decoration of SPCEs with MNP was performed by two different methods. The first one was layer‐by‐layer assembly (LBL‐A) for different cycle times(n). In the second one, plasma treatment of SPCE incorporated with evaporation‐induced self‐assembly (EI‐SA) techniques including different incubation times in MNP solutions. The performance of both modified SPCEs were tested for amperometric detection of Cr(VI) in various water samples, and peak reduction of Cr(VI) was determined at 0.33 V. Amperometric results showed wide linear ranges of 0.1–2 μM and 0.1–5 μM of Cr(VI) for SPCEs modified with 14n‐LBL‐A and 12h‐EI‐SA, respectively. The sensitivities of SPCEs modified with 14n‐LBL‐A and 12h‐EI‐SA techniques were 0.27 μA μM?1 and 0.52 μA μM?1, respectively. In addition, both modified SPCEs selectively detected Cr(VI) in a model aqueous system composed of certain other heavy metals and minerals, and tap and lake water samples. The LOD and LOQ values for 12h‐EI‐SA were 0.03 μM and 0.1 μM, respectively. This showed that MNP‐modified‐SPCEs generated via EI‐SA techniques have the potential to be an alternative to conventional detection methods such as ICP‐MS. 相似文献
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Gizem Dübek Franziska Hanusch Dominik Munz Shigeyoshi Inoue 《Angewandte Chemie (International ed. in English)》2020,59(14):5823-5829
Air‐ and moisture‐stable heterobimetallic tetrahedral clusters [Cp(CO)2MSiR]2 (M=Mo or W; R=SitBu3) were isolated from the reaction of N‐heterocyclic carbene (NHC) stabilized silyl(silylidene) metal complexes Cp(CO)2M=Si(SitBu3)NHC with a mild Lewis acid (BPh3). Alternatively, treatment of the NHC‐stabilized silylidene complex Cp(CO)2W=Si(SitBu3)NHC with stronger Lewis acids such as AlCl3 or B(C6F5)3 resulted in the reversible coordination of the Lewis acid to one of the carbonyl ligands. Computational investigations revealed that the dimerization of the intermediate metal silylidyne (M≡Si) complex to a tetrahedral cluster instead of a planar four‐membered ring is due to steric bulk. 相似文献