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981.
Kamyar Shameli Mansor Bin Ahmad Parvaneh Shabanzadeh Emad A. Jaffar Al-Mulla Ali Zamanian Yadollah Abdollahi Seyed Davoud Jazayeri Mahboobeh Eili Farid Azizi Jalilian Rafiuz Zaman Haroun 《Research on Chemical Intermediates》2014,40(3):1313-1325
Biosynthesis of noble metal nanoparticles is a vast developing area of research. In the present study, silver nanoparticles (Ag-NPs) were synthesized from aqueous silver nitrate through a simple and biosynthetic route using water extract of Curcuma longa (C. longa) tuber powder, which acted simultaneousl as a reductant and stabilizery. The as-prepared samples are characterized using UV–Visible, XRD, TEM, SEM, EDXF, and FT-IR techniques. The formation of Ag-NPs is evidenced by the appearance of the signatory brown color of the solution and UV–vis spectra. Formation of Ag/C. longa was determined by UV–Vis spectroscopy where surface plasmon absorption maxima can be observed at 457–415 nm from the UV–Vis spectrum. The XRD analysis shows that the Ag-NPs are of a face-centered cubic structure. Well-dispersed Ag-NPs with anisotropic and isotropic morphology for 5, 10, and 20 mL of C. longa water extract having a size less than 10 nm are seen in TEM images. The optimum volume extraction to synthesize smallest particle size was 20 mL with mean diameter and standard division 4.90 ± 1.42 nm. FT-IR spectrum indicates the presence of different functional groups in capping the nanoparticles with C. longa. The zeta potential analysis results indicated that the charge of C. longa was negative and increased in Ag/C. longa emulsion with increasing of volumes of extract used (10–20 mL). The most needed outcome of this work will be the development of value-added products from C. longa for biomedical and nanotechnology-based industries. 相似文献
982.
Zahra Kalantari Khoramdareh Seyed Abolfazl Hosseini-Yazdi Bernhard Spingler Ali Akbar Khandar 《Journal of inclusion phenomena and macrocyclic chemistry》2014,80(3-4):391-399
A new azacrown bis-macrocycle (5) and its mono–cyclic analogue (7) were synthesized and characterized by FT-IR, 1H NMR, 13C NMR, DEPT 13C NMR, MS, and elemental analysis. The reaction with copper(II) nitrate yielded the corresponding complexes, formulated as Cu(5)(NO3)2·3H2O (8), and Cu(7)(NO3)2·2.5H2O (9). Also the stoichiometries of the complexes were determined in alcoholic solution and the results show that for both complexes the ratio of ligand to metal was 1:1 in methanol. The redox behavior of both complexes has been studied by cyclic voltammetry in DMF. Cyclic voltamogram of 8 shows quasi-reversible CuII/CuI redox couple whereas 9 shows a reversible CuII/CuI redox couple. Mono- and bis-macrocycle copper(II) complexes (8 and 9 respectively) cleaved plasmid pGS2 DNA by using an oxidative mechanism with 3- mercaptopropionic acid (MPA) as the reductant under aerobic conditions. The bis-macrocycle copper(II) complex 8 showed higher cleavage efficiency than their mono-macrocycle analogue 9 at the same Cu2+ concentration. 相似文献
983.
Ali Pourjavadi Seyed Hassan HosseiniSeyyed Alireza AghayeeMeibody Seyedeh Talieh Hosseini 《Comptes Rendus Chimie》2013,16(10):906-911
A novel poly(ionic liquid) (PIL) coated magnetic nanoparticle was synthesized by distillation-precipitation-polymerization of 1-vinyl-3- ethyl imidazolium in the presence of surface modified magnetic nanoparticles. The resulting catalyst was used as magnetic heterogeneous base catalyst for the synthesis of 4H-benzo[b]pyrans in water. The separation of the catalyst from the reaction mixture was readily achieved by simple magnetic decantation and the catalyst could be easily recycled without appreciable loss of catalytic activity. Because of polymer layers coated the surface of the magnetic nanoparticles, the catalyst has a high loading level of ionic liquid. 相似文献
984.
Sayed Yahya Kazemi Seyed Mohammad Abedirad 《Journal of the Iranian Chemical Society》2013,10(2):251-256
In the present work, the effect of fsDNA (fish sperm DNA) on kinetic parameters of chemiluminescence (CL) of the luminol–hydrogen peroxide system catalyzed by Mn(III)–Tetrakis (4-sulfonatophenyl)-porphyrin was investigated. These parameters including pseudo first-order rise and fall rate constant for the chemiluminescence burst, maximum level intensity, time to reach maximum intensity, total light yield, and values of the intensity at maximum CL were evaluated by computer fitting of the resulted intensity–time plots. Results reveal that CL parameters are dramatically affected due to interaction of metalloporphyrin with DNA. In order to observe quenching effect of DNA on CL intensity, Stern–Volmer plot with k Q value of 1.18 × 105 M?1 was calculated in the quencher concentration range of 4 × 10?6–8.5 × 10?5 M. 相似文献
985.
Lida Khalafi Mohammad Rafiee Mojgan Khoshnam Seyed Mohammad Shoaei 《Journal of the Iranian Chemical Society》2013,10(6):1257-1262
Electrochemical oxidation of levodopa (LD) as one of the most well-known neurotransmitters has been studied in the presence of some aniline derivatives. The electron transfer of LD is followed by two competitive reactions in the presence of these amines. The reactions are the Michael additions of side chain amine group of LD and/or aromatic amines to electrochemically generated o-quinone. There are two ECE mechanisms for both pathways and the competition between these inter and intramolecular reactions drastically depends on the pH of the medium. The pH dependence of reactions has been studied and the observed homogeneous rate constants of the reactions were estimated by digital simulation of cyclic voltammograms. The effect of aniline substituents was also studied with regard to their reactivities toward o-quinone of LD and the competitive reactions. Based on the obtained results, the products of intermolecular reactions are electroactive diphenylamine derivatives and their half-wave potentials depend on the nature of the aniline substituent. 相似文献
986.
Seyed Sajad Sajadikhah Nourallah Hazeri Malek Taher Maghsoodlou Sayyed Mostafa Habibi-Khorassani Adel Beigbabaei Anthony C. Willis 《Journal of the Iranian Chemical Society》2013,10(5):863-871
Extremely facile and efficient procedures have been developed for the synthesis of highly functionalized piperidines and dihydro-2-oxypyrroles via one-pot multi-component reactions in the presence of Al(H2PO4)3 as a heterogeneous and eco-friendly catalyst under mild conditions. The multi-component reaction of aromatic aldehydes, aromatic amines, and β-keto esters catalyzed by Al(H2PO4)3 in EtOH at room temperature provides highly functionalized piperidines in good to excellent yields. The structure as well as the relative stereochemistry of these functionalized piperidines was confirmed by single X-ray crystallographic analysis. The same catalyst was found useful for the synthesis of polyfuntionalized dihydro-2-oxypyrroles using a four-component reaction of amines, dialkyl acetylenedicarboxylates and formaldehyde in MeOH at ambient temperature. It is found that the catalyst is recyclable and can be used up to five times without significant loss of its activity. 相似文献
987.
Prof. Marc D. Normandin Dr. Hushan Yuan Dr. Moses Q. Wilks Dr. Howard H. Chen Prof. Joseph M. Kinsella Dr. Hoonsung Cho Nicolas J. Guehl Nader Absi‐Halabi Seyed Mohammadreza Hosseini Prof. Georges El Fakhri Prof. David E. Sosnovik Prof. Lee Josephson 《Angewandte Chemie (International ed. in English)》2015,54(44):13002-13006
Heat‐induced radiolabeling (HIR) yielded 89Zr‐Feraheme (FH) nanoparticles (NPs) that were used to determine NP pharmacokinetics (PK) by positron emission tomography (PET). Standard uptake values indicated a fast hepatic uptake that corresponded to blood clearance, and a second, slow uptake process by lymph nodes and spleen. By cytometry, NPs were internalized by circulating monocytes and monocytes in vitro. Using an IV injection of HIR 89Zr‐FH (rather than in vitro cell labeling), PET/PK provided a view of monocyte trafficking, a key component of the immune response. 相似文献
988.
Prof. Mehdi D. Esrafili Ramin Mohammad‐Valipour Prof. Seyed Morteza Mousavi‐Khoshdel Parisa Nematollahi 《Chemphyschem》2015,16(17):3719-3727
The geometry, electronic structure, and catalytic properties of nitrogen‐ and phosphorus‐doped graphene (N‐/P‐graphene) are investigated by density functional theory calculations. The reaction between adsorbed O2 and CO molecules on N‐ and P‐graphene is comparably studied via Langmuir–Hinshelwood (LH) and Eley–Rideal (ER) mechanisms. The results indicate that a two‐step process can occur, namely, CO+O2→CO2+Oads and CO+Oads→CO2. The calculated energy barriers of the first step are 15.8 and 12.4 kcal mol?1 for N‐ and P‐graphene, respectively. The second step of the oxidation reaction on N‐graphene proceeds with an energy barrier of about 4 kcal mol?1. It is noteworthy that this reaction step was not observed on P‐graphene because of the strong binding of Oads species on the P atoms. Thus, it can be concluded that low‐cost N‐graphene can be used as a promising green catalyst for low‐temperature CO oxidation. 相似文献
989.
Majid Afshari Fakhri Shahidi Seyed Ali Mortazavi Farideh Tabatabai Zarin Es'haghi 《Natural product research》2015,29(14):1300-1306
In this study, the combined effect of pH, temperature and agitation speed on yellow pigment production and mycelial growth of Penicillium aculeatum ATCC 10409 was investigated in whey media. Different pH levels (5, 6.5 and 8), temperatures (25, 30 and 35°C) and agitation speed levels (100 and 150 rpm) were tested to determine the best conditions to produce a fungal yellow pigment under submerged fermentation. The best production of yellow pigment (1.38 g/L) was obtained with a pH value of 6.5, a temperature of 30°C and an agitation speed of 150 rpm. In contrast, the maximal biomass concentration (11.12 g/L) was obtained at pH value of 8, a temperature of 30°C and an agitation speed of 100 rpm. These results demonstrated that biomass and yellow pigment production were not directly associated. The identification of the structure of unknown P. aculeatum yellow pigment was detected using UV absorption spectrum and FT-IR spectroscopy. 相似文献
990.
Synthesis,characterization and X‐ray shielding properties of polypyrrole/lead nanocomposites
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Novel radiation shielding nanocomposites based on a conducting polymer were fabricated and investigated to determine their abilities in attenuation of X‐rays. Polypyrrole/Pb nanocomposites were prepared through chemical reduction of lead salt by a facile solution‐phase method using t‐BuOLi‐activated LiH and in situ chemical polymerization of pyrrole in the presence of dodecyl benzene sulfonic acid as dopant and surfactant and iron chloride as the oxidant. The morphology, composition, and electrical conductivity of resulting products were characterized by scanning electron microscopy, transmission electron microscopy, X‐ray diffraction analysis, energy‐dispersive X‐ray spectroscopy, fourier transform infrared spectroscopy, and standard four‐wire technique, respectively. In order to evaluate capability of nanocomposites in radiation shielding, X‐ray photon interaction parameters such as linear attenuation coefficient, attenuation percentage, and half‐value thickness were determined for the samples with different Pb loadings and thicknesses, at photon energies of 13.95, 17.74, 20.08, 26.34, and 59.50 keV. The investigation was carried out to explore the potential of polypyrrole/Pb nanocomposites as thin and light‐weight radiation shielding materials. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献