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排序方式: 共有109条查询结果,搜索用时 15 毫秒
31.
Hatice Kzlta Zeynebe Bingol Ahmet Ceyhan Gren Leyla Polat Kose Lokman Durmaz Fevzi Topal Saleh H. Alwasel lhami Gulcin 《Molecules (Basel, Switzerland)》2021,26(9)
Kınkor (Ferulago stellata) is Turkish medicinal plant species and used in folk medicine against some diseases. As far as we know, the data are not available on the biological activities and chemical composition of this medicinal plant. In this study, the phytochemical composition; some metabolic enzyme inhibition; and antidiabetic, anticholinergic, and antioxidant activities of this plant were assessed. In order to evaluate the antioxidant activity of evaporated ethanolic extract (EEFS) and lyophilized water extract (WEFS) of kınkor (Ferulago stellata), some putative antioxidant methods such as DPPH· scavenging activity, ABTS•+ scavenging activity, ferric ions (Fe3+) reduction method, cupric ions (Cu2+) reducing capacity, and ferrous ions (Fe2+)-binding activities were separately performed. Furthermore, ascorbic acid, BHT, and α-tocopherol were used as the standard compounds. Additionally, the main phenolic compounds that are responsible for antioxidant abilities of ethanol and water extracts of kınkor (Ferulago stellata) were determined by liquid chromatography-high-resolution mass spectrometry (LC-HRMS). Ethanol and water extracts of kınkor (Ferulago stellata) demonstrated effective antioxidant abilities when compared to standards. Moreover, ethanol extract of kınkor (Ferulago stellata) demonstrated IC50 values of 1.772 μg/mL against acetylcholinesterase (AChE), 33.56 ± 2.96 μg/mL against α-glycosidase, and 0.639 μg/mL against α-amylase enzyme respectively. 相似文献
32.
I¸ıl Hacıbekiroğlu Pelin Köseoğlu Yılmaz Nesrin Ha¸imi Ersin Kılınç Veysel Tolan 《Natural product research》2015,29(5):444-446
This study reports in vitro anticholinesterase, antioxidant and antimicrobial effects of the n-hexane, dichloromethane, ethanol and ethanol–water extracts prepared from Pistacia terebinthus L. fruits and Pistacia khinjuk Stocks seeds as well as their total phenolic and flavonoid contents, and fatty acid compositions. Ethanol and ethanol–water extracts of both species exhibited higher anticholinesterase activity than galanthamine. Among ABTS, DPPH and CUPRAC assays, the highest antioxidant capacity of the extracts was found in the last one. P. terebinthus ethanol extract being rich in flavonoid content showed the best cupric reducing effect. All extracts possessed no antimicrobial activity. The main fatty acid in P. terebinthus fruits (52.52%) and P. khinjuk seeds (59.44%) was found to be oleic acid. Our results indicate that P. terebinthus fruits and P. khinjuk seeds could be a good source of anticholinesterase compounds, and could be phytochemically investigated. 相似文献
33.
A new tridentate benzimidazole ligand (L‐C11) containing undecyl chains and its Mn (II) and Zn (II) complexes were synthesised and characterized by spectroscopic and analytical methods. Molecular structures of complexes [Mn(L‐C11)Cl2] and [Zn(L‐C11)Cl2] were evaluated by X‐ray diffraction studies. The X‐ray data showed metal ions in both complexes are five‐coordinate with distorted square pyramidal geometry around the metal centres. The undecyl chains in the structure of the complexes are aligned in an interdigitated manner (head to tail) forming a non‐polar domain. The aggregation properties of the ligand and its complexes were investigated by UV–Vis. absorption and emission spectroscopies in DMF‐water mixtures. The emission spectral data revealed that the compounds showed aggregation induced quenching (AIQ) in DMF‐water solutions. Moreover, thermal properties of the compounds were investigated by TG, DTG and DSC analysis. 相似文献
34.
Irina Popescu Dana Mihaela Suflet Irina Mihaela Pelin Marcel Ionel Popa 《Journal of Macromolecular Science: Physics》2013,52(3):590-604
Five alternating copolymers of maleic acid with N-vinylpyrrolidone, vinyl acetate, styrene, 2-vinylnaphthalene, and vinyl cyclohexane were used in order to study the influence of the comonomer on the polyelectrolyte behavior. The dissociation of the maleic acid copolymers was investigated by electrochemical methods in pure water and in the presence of supporting electrolytes. The conformational modifications during the dissociation were directly investigated by viscosimetry and fluorescence probing. The shape of the potentiometric and conductometric titration curves was influenced by the comonomer structure. In salt-free solution, only the first dissociation step was observed. The addition of univalent counterions permitted the evidencing of the second ionization step only for the copolymers with hydrophilic comonomers, but the addition of divalent counterions permitted the evidencing of the second ionization step for all five copolymers. The apparent dissociation constants increase with the increase of the comonomer hydrophobicity. A conformational transition was evidenced especially in the case of the maleic acid-2-vinylnaphthalene copolymer. 相似文献
35.
T. Akyüz S. Akyüz A. Varinlioglu A. Kose 《Journal of Radioanalytical and Nuclear Chemistry》2000,243(3):715-718
The specific activities of 238U, 226Ra, 232Th and 40K in the composite samples of phosphate ores of type 1 (grey-coloured ore, with high P2O5 (21–35%) and low calcite content) and of type II (grey coloured calcite ore, with low P2O5 content (5–17%)) of Karatas-Mazidag phosphate deposit, Turkey, have been determined by gamma spectrometry together with phosphatic animal feed ingredients. The concentrations of 238U, 226Ra, 232Th and 40K were found to be up to 557, 625, 26 and 297 Bq·kg–1, respectively. Radium equivalent activities of samples examined were calculated and compared with those given in the literature. Uranium concentration of the individual phosphate samples, from which composite samples of ores of type I and II have been prepared, were found to show an increasing trend with increasing P2O5 and F concentrations. 相似文献
36.
Sun YP Zhou B Lin Y Wang W Fernando KA Pathak P Meziani MJ Harruff BA Wang X Wang H Luo PG Yang H Kose ME Chen B Veca LM Xie SY 《Journal of the American Chemical Society》2006,128(24):7756-7757
We report that nanoscale carbon particles (carbon dots) upon simple surface passivation are strongly photoluminescent in both solution and the solid state. The luminescence emission of the carbon dots is stable against photobleaching, and there is no blinking effect. These strongly emissive carbon dots may find applications similar to or beyond those of their widely pursued silicon counterparts. 相似文献
37.
Ozgul Gok Sezin Yigit Meliha Merve Kose Rana Sanyal Amitav Sanyal 《Journal of polymer science. Part A, Polymer chemistry》2013,51(15):3191-3201
Diblock and triblock dendron–polymer conjugates containing biodegradable polyester dendron blocks and polyethylene glycol (PEG) polymer were synthesized using the Diels–Alder “click” cycloaddition reaction. PEG polymers with furan‐protected maleimide functionality were synthesized and reacted with biodegradable polyester dendrons containing an anthracene moiety at their focal point. First through third generations of biodegradable polyester dendrons containing an anthracene unit at their focal point were synthesized using a divergent strategy. Efficient conjugation of the dendrons to polymers was demonstrated using 1HNMR and size exclusion chromatography. This modular approach provides an easy access to the design of multivalent PEG conjugates. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 3191–3201 相似文献
38.
Ryota Kose Naoki Sunagawa Makoto Yoshida Kenji Tajima 《Cellulose (London, England)》2013,20(6):2971-2979
A major by-product of biodiesel production is waste glycerol, which has numerous potential applications. In this study, we isolated a novel bacterium capable of producing cellulose from waste glycerol, and identified it as a novel strain (named NEDO-01) of Gluconacetobacter intermedius. Scanning electron microscopy revealed that the morphology of the pellicle produced by NEDO-01 was similar to that of cellulose produced by Gluconacetobacter hansenii ATCC23769. Furthermore, X-ray diffraction and solid-state nuclear magnetic resonance spectroscopic analyses suggested that cellulose produced by NEDO-01 had molecular and crystalline structures similar to those of cellulose produced by ATCC23769. After the optimization of cultivation conditions, NEDO-01 mediated the one-step production of nanofibrillated bacterial cellulose (NFBC) from waste glycerol in a medium supplemented with carboxymethyl cellulose. Transmission electron microscopic analysis revealed that the NFBC was composed of relatively uniform fibers with diameters of approximately 20 nm. NFBC was produced as uniform water suspensions, the yield of which was 3.4 g/L from cultivation in 7.5 L medium in a 10-L jar fermenter. The bioconversion of waste glycerol to NFBC, which has superior fluidity, moldability, and miscibility, has a wide variety of applications, including potential uses in the medical and materials engineering fields. 相似文献
39.
40.
The 1/f noise power spectrum is calculated consistently for thin-film devices such as bolometers, Josephson junctions and SQUIDs, using a model based on spontaneous temperature fluctuations and heat exchange between the device and the surrounding medium. Numerical results agree closely with existing experimental data. 相似文献