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11.
Selective adsorption of metoprolol enantiomers using 2‐hydroxypropyl‐β‐cyclodextrin cross‐linked multiwalled carbon nanotube
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Nafiseh Farhadian Arezoo Sharifi Elmira Lashgari 《Biomedical chromatography : BMC》2015,29(3):366-372
This study investigates the ability of functionalized multiwalled carbon nanotubes (MWCNTs) for enantio‐separation of metoprolol chiral forms. 2Hydroxypropyl‐β‐cyclodextrin (2HP‐β‐CD) was applied as a chiral selector to functionalize carbon nanotubes (CNTs). The modified multiwalled CNT samples were characterized using scanning electron microscopy and Fourier transform infrared spectroscopy. The results of analyses showed that CNTs were successfully cross‐linked with 2HP‐β‐CD. To evaluate the enantio‐separation property of the products, the separation of metoprolol chiral forms on the initial and final products was examined. Further, UV–visible spectroscopy and polarimeter analyses were used for characterization. The results indicate that MWCNT does not have any intrinsic enantio‐separation ability, although its selectivity for enantio‐separation can be enhanced by cross‐linking it to 2HP‐β‐CD. Moreover, the optimal mass of adsorbent as well as optimal mass of functional groups is estimated to achieve maximum enantio‐separation efficiency. The results indicate that applying large amounts of 2HP‐β‐CD to CNTs functionalization decreases the cross‐linking efficiency, which consequently reduces enantio‐separation efficiency. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
12.
A Diastereoselective Synthesis of Functionalized Tetrahydroindeno[2′,1′,3,4]pyrido[2,1‐a]isoquinolines
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An effective route to alkyl 9a‐(2,3‐dihydro‐1,3‐dioxo‐1H‐inden‐2‐yl)‐9a,14,14a,14b‐tetrahydro‐14‐oxoindeno[2′,1′:3,4]pyrido[2,1‐a]isoquinoline‐9‐carboxylates via a diastereoselective one‐pot four‐component reaction of isoquinoline and alkyl prop‐2‐ynoates with two equivalents of indane‐1,3‐dione, in aqueous MeOH at room temperature, is described. 相似文献
13.
Mohammadhassan Gholami-Shabani Afshin Imani Masoomeh Shams-Ghahfarokhi Zeynab Gholami-Shabani Arezoo Pazooki Azim Akbarzadeh Gholamhossein Riazi Mehdi Razzaghi-Abyaneh 《Journal of the Iranian Chemical Society》2016,13(11):2059-2068
The development of efficient cell-free systems of nanoparticle synthesis using microbial enzymes is a growing field of biological and green chemistry for the supportable improvement in nano-biotechnology. In the present study, we established a cell-free system for producing gold nanoparticles (AuNPs) using a fungal oxidoreductase named sulfite oxidoreductase purified to homogeneity from Fusarium oxysporum. The enzyme was purified by ultrafiltration followed by anion exchange chromatography on DEAE Sephadex A-50 gel, and its molecular weight was determined by gel filtration chromatography on Sephacryl S-300 gel. The purified enzyme had a molecular weight of 346 kDa. It was composed of three subunits of 176, 94 and 76 kDa. Purified enzyme was successfully used for production of gold nanoparticles in a cell-free system. Synthesized gold nanoparticles showed the highest absorbance at 520 nm wavelength as shown by UV–visible spectroscopy. They were spherical in shape with an average size of 20 nm as determined by scanning and transmission electron microscopy and dynamic light scattering. Assessment of the antifungal properties of synthesized nanoparticles by disk diffusion method indicated a potent growth inhibitory activity against all tested human pathogenic yeasts and molds by inhibition zones ranged from 10 to 18 mm. Taken together, our enzymatically established method of nanoparticle synthesis using a purified sulfite oxidoreductase of F. oxysporum can be considered as an efficient tool for generating harmless bioactive gold nanoparticles with potential applications in biology, medicine and industry. 相似文献
14.
The complex formation reactions between Mg2+, Ca2+, Sr2+ and Ba2+ metal cations with macrocyclic ligand, 4′-nitrobenzo-15C5, were studied in acetonitrile (AN)-methanol (MeOH) binary mixtures
at different temperatures using conductometric method. The results show that 4′-nitrobenzo-15C5 forms 1:1 [ML] complexes with
Mg2+, Ca2+ and Sr2+ metal cations in solutions. But in the case of Ba2+ cation a 1:2 [ML2] complex is formed in these solvent systems. The stability of the complexes is sensitive to the solvent composition and a
non-linear behavior was observed for variation of logK
f of the complexes versus the composition of the binary mixed solvents. The stability constants of complexes decrease suddenly
with increasing the concentration of methanol in this binary system. The values of thermodynamic parameters (ΔH
c° and ΔS
c°) for formation of (4′-nitrobenzo-15C5.Mg)2+, (4′-nitrobenzo-15C5.Ca)2+ and (4′-nitrobenzo-15C5.Sr)2+ complexes were obtained from temperature dependence of the stability constants and the results show that these parameters
are affected by the nature and composition of the mixed solvents. A non-linear behavior is observed between the ΔS
c° and the composition of the mixed solvents. 相似文献
15.
4,13-Didecyl-1,7,10,16-tetraoxa-4,13-diazacyclooctadecane (kryptofix22DD) has been explored as a neutral ionophore for preparing polyvinyl chloride (PVC)-based membrane sensor selective to lead(II). The optimized membrane incorporating kryptofix22DD as the active material, nitrobenzene as plasticizer and sodium tetraphenylborate as an anion excluder and membrane modifier in PVC (in the weight ratio of 5.0: 63.0: 2.0: 30.0, respectively) was directly coated on the surface of graphite rod. The sensor exhibits a Nernstian slope (29.4 mV/decade) in the concentration range of 1.0 × 10–5 to 1.0 × 10–1 M Pb2+. The detection limit of the sensor is 6.5 × 10–6 M. The proposed sensor has a fast response time (~10 s), a satisfactory reproducibility and relatively long lifetime. The electrode shows high selectivity toward Pb2+ ion in comparison to other common cations. The proposed sensor is suitable for use in aqueous solutions in a wide pH range of 2.0–10.0. It was used as an indicator electrode for the end point detection in the potentiometric titration of Pb2+ ion with ethylenediaminetetraacetic acid (EDTA) and sodium iodide (NaI) solutions. The proposed sensor was successfully applied for the recovery of Pb2+ ions spiked in real water samples. 相似文献
16.
17.
Sardashti-Birjandi Arezoo Mollashahi Ebrahim Maghsoodlou Malek Taher Yazdani-Elah-Abadi Afshin 《Research on Chemical Intermediates》2021,47(9):3597-3608
In this study, new derivatives of aminoanthraquinone have been synthesized via one-pot three-component condensation reaction of 1- and 2-amino anthraquinones, triethyl orthoformate and CH-acid compounds without using any solvent or catalyst in mild temperature (50 °C). This simple and efficient method yields the desired products in short reaction time (14–50 min) and good to excellent yields (85–96%). Moreover, chemical structures of synthesized products have been entirely confirmed by FT-IR, 1H and 13CNMR and mass spectroscopy and melting points.
相似文献18.
Farid Moeinpour Nadieh Dorostkar-Ahmadi Arezoo Sardashti-Birjandi Amir Khojastehnezhad Majid Vafaei 《Research on Chemical Intermediates》2014,40(8):3145-3152
An efficient and direct protocol for the preparation of 1-amidoalkyl-2-naphthols employing a multi-component and one-pot condensation reaction of 2-naphthol, aromatic aldehydes, and acetamide in the presence of MoO3/SiO2 under solvent-free conditions is described. The reaction using a catalyst was carried out under mild condition with very high yields up to 93 %. The present approach of this methodology offers several advantages such as shorter reaction times, good yields, low cost, environmentally benign, milder reaction conditions, easy recovery of catalyst, and reusability. 相似文献
19.
Research on Chemical Intermediates - In this work, a new organic–inorganic hybrid heterogeneous and efficient magnetic nanocatalyst was fabricated with 4-aminopyridine (AP)-functionalized... 相似文献
20.
Thomas Y. George Dr. Tristan Asset Arezoo Avid Prof. Plamen Atanassov Prof. Iryna V. Zenyuk 《Chemphyschem》2020,21(6):469-475
Kinetic isotope effect (KIE) was used to study the rate-determining step for oxygen reduction reaction (ORR) on dispersed Pt/C electrocatalyst and polycrystalline Pt (Pt-poly). KIE is defined as the ratio of the kinetic current measured in protonated electrolyte versus deuterated electrolyte, with KIE values larger than one indicating proton participation in the rate-determining step. The effect of poisoning anions on the platinum rate determining step is investigated by assessing the KIE in perchloric (non-poisoning) and sulfuric acid-based electrolytes. The kinetics currents were calculated using the Koutechy-Levich and Tafel analysis. A KIE of 1 was observed for Pt/C (with a 40 wt.% Pt loading) and Pt-poly, thus indicating that, on 40 wt. % Pt/C and Pt-poly, the rate determining step is proton independent. 相似文献