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51.
Taibi Ben Hadda Fatim Z. Khardli Mostafa Mimouni Maria Daoudi Abdelali Kerbal Héctor Salgado-Zamora 《Phosphorus, sulfur, and silicon and the related elements》2013,188(6):753-761
AbstractA series of four different armed heterocyclic candidates; 1-(2-methyl-2,3-dihydro-1,3-benzothiazol-2-yl)acetone (2), 1-(3-methyl-4H-1,4-benzothiazin-2-yl)ethanone (3), 2-[(2-aminophenyl)dithio]aniline (4), and 3-hydroxy-3-methyl-4-(3-methyl-2-quinoxalinyl)-2-butanone (5) have been prepared and their microbial activities were evaluated. A correlation of the structure and activities relationships of these compounds with respect to molecular modeling, Lipinski Rule of Five, drug likeness, toxicity profiles, and other physico-chemical properties of drugs are described and verified experimentally. 相似文献
52.
Nasser M. Hosny Farid I. El-Dossoki Mohsen M. Mostafa 《Phosphorus, sulfur, and silicon and the related elements》2013,188(2):402-410
New metal complexes derived from the reaction of N-[(phenylamino)thioxomethyl] hydrazino carbonyl methyl pyridinium chloride (H2L; PTHMPC) with some metal salts of the general formula MX2 [(X = Cl? and/or CH3COO?; M = Cd(II), UO2(II), Mn(II) and Zr(IV)] were synthesized and characterized by elemental analyses, spectral analyses (IR, UV-vis., 1H NMR), thermal analyses (TGA, DTG), and conductance and magnetic measurements. The results showed that the ligand exists in metal complexes either in the keto form or in the enol form. Moreover, the IR spectral data suggest that the acetate ion behaves in a monodentate manner. Semi-empirical calculations ZINDO/1, PM3, and AM1 have been used to study the molecular geometry and the harmonic vibrational spectra of the ligand and its metal complexes with the purpose of assisting the experimental assignment of the complexes. Generally, there is an agreement between the observed and the calculated spectra. Finally, the thermodynamic parameters (ΔE*, ΔH, ΔG, and ΔS) have been calculated from the data of thermal analyses (TGA and DTG). Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file. 相似文献
53.
Mostafa Mesgar Dr. Payam Kaghazchi Prof. Dr. Timo Jacob Dr. Ernesto Pichardo‐Pedrero Dr. Margret Giesen Dr. Ernesto Pichardo‐Pedrero Dr. Margret Giesen Prof. Dr. Harald Ibach Dr. Noelia B. Luque Prof. Dr. Wolfgang Schmickler 《Chemphyschem》2013,14(1):233-236
Motivated by experimental studies of two‐dimensional Ostwald ripening on Au(100) electrodes in chlorine‐containing electrolytes, we have studied diffusion processes using density functional theory. We find that chlorine has a propensity to temporary form AuCl complexes, which diffuse significantly faster than gold adatoms. With and without chlorine, the lowest activation energy is found for the exchange mechanism. Chlorine furthermore reduces the activation energy for the detachment from kink sites. Kinetic Monte Carlo simulations were performed on the basis of extensive density functional theory calculations. The island‐decay rate obtained from these Monte Carlo simulations, as well as the decay rate obtained from the theoretical activation energies and frequency factors when inserted into analytical solutions for Ostwald ripening, are in agreement with experimental island‐decay rates in chlorine‐containing electrolytes. 相似文献
54.
Nasser Y. Mostafa Abdallah A. Shaltout Lachezar Radev Hassan M. Hassan 《Central European Journal of Chemistry》2013,11(2):140-150
The present work investigates surface biocompatibility of silicon-substituted calcium phosphate ceramics. Different silicon-substituted calcium phosphate ceramic bodies were prepared from co-precipitated powders by sintering at 1300°C. The in vitro bioactivity of the ceramics was assessed in simulated body fluid (SBF) at 37°C for periods up to 4 weeks. The changes in the surface morphology and composition were determined by scanning electron microscopy (SEM) coupled with electron probe microanalysis and energy dispersive spectrometer (EDX). Inductively coupled plasma optical emission spectroscopy (ICP-OES) was used to observe the change in ionic concentration of SBF after removal of the samples. The bioactivity of the ceramics increased with an increasing silicate ion substitution in a systematic way. The surface of ceramics with 2.23% silicon substitution was partially covered with apatite layer after one week, while ceramics with 8.1% silicon substitution were completely covered with apatite in the first week. The porous microstructure of high-concentration Si-substituted ceramics helps the dissolution of surface ions and the leaching process. This allows SBF to reach supersaturation in a short time and accelerate the deposition of apatite layer. 相似文献
55.
Nourallah Hazeri Malek Taher Maghsoodlou Sayyed Mostafa Habibi‐Khorassani Jasem Aboonajmi Seyed Sajad Sajadikhah 《中国化学会会志》2013,60(4):355-358
Fe(NO3)3·9H2O is used as an efficient and effective catalyst for the one‐pot three‐component synthesis of highly functionalized piperidines from aromatic aldehydes, anilines and b–ketoesters in ethanol at ambient temperature. This procedure includes some important aspects like the easy work‐up, no need to column chromatography, simple and readily available precursors, and good to high yields. 相似文献
56.
Hayam M. Lotfy Mamdouh R. Rezk Adel M. Michael Mostafa A. Shehata 《Chromatographia》2013,76(3-4):187-194
Accurate, sensitive, and precise high performance thin layer chromatographic (HPTLC) methods were developed and validated for the determination of sumatriptan and zolmitriptan in presence of their degradation products. Sumatriptan was separated from its degradation products and analyzed on TLC silica gel 60 F254 plates using chloroform–ethyl acetate–methanol–ammonia (4:3:3:0.1, v/v) as a developing system followed by densitometric measurement of the bands at 228 nm. Zolmitriptan was determined using chloroform–ethyl acetate–methanol–ammonia (3:3:3:1, v/v) as a developing system followed by densitometric measurement at 222 nm. The methods were validated over a range of 0.5–4 μg/spot for sumatriptan and 0.5–3 μg/spot for zolmitriptan. The proposed methods were successfully applied for the determination of the studied drugs in bulk powder and in their pharmaceutical formulations. 相似文献
57.
Radia Bouasla Hadjira Berredjem Malika Berredjem Malika Ibrahim‐Oualid Assia Allaoui Marc Lecouvey Nour‐Eddine Aouf 《Journal of heterocyclic chemistry》2013,50(6):1328-1332
A new series of chiral 5‐substituted bis‐oxazolidinones containing an acylsulfonamide moiety has been synthesized starting from chlorosulfonyl isocyanate, (l )‐ethyl lactate, and oxazolidin‐2‐ones. All the reactions were conducted at ambient temperature, and the N‐acylsulfonamide bis‐oxazolidin‐2‐ones were obtained with high yields within 2 h. Some of the newly synthesized compounds were evaluated in vitro against the virulent strain RH of Toxoplasma gondii and the human lymphocytes, and showed promising results. 相似文献
58.
Mostafa Hosseini Ali Asghar Karkhane Bagher Yakhchali Mehdi Shamsara Saeed Aminzadeh Dena Morshedi Kamahldin Haghbeen Ibrahim Torktaz Esmat Karimi Zahra Safari 《Applied biochemistry and biotechnology》2013,169(3):773-785
Lipases are one of the highest value commercial enzymes as they have broad applications in detergent, food, pharmaceutical, and dairy industries. To provide chimeric Bacillus thermocatenulatus lipase (BTL2), the completely conserved pentapeptide (112Ala-His-Ser-Gln-Gly116) was replaced with similar sequences (207Gly-Glu-Ser-Ala-Gly211) of Candida rugosa lipase (CLR) at the nucleophilic elbow region. For this purpose, three mutations including A112G, H113E, and Q115A were inserted in the conserved pentapeptide sequence of btl2 gene. Based on the crystal structures of 2W22, the best structure of opened form of the chimeric lipases were garnered using the MODELLER v9.10 software. The native and chimeric lipases were docked to a set of ligands, and a trial version of Molegro Virtual Docker (MVD) software was used to obtain the energy values. Docking results confirmed chimeric lipase to be better than the native lipase. Following the in silico study, cloning experiments were conducted and expression of native and chimeric btl2 gene in Pichia pastoris was performed. The native and chimeric lipases were purified, and the effect of these mutations on characteristics of chimeric lipase studied and then compared with those of native lipase. Chimeric lipase exhibited 1.6-fold higher activity than the native lipase at 55 °C. The highest percentage of both lipases activity was observed at 60 °C and pH of 8.0. The ion Ca2+ slightly inhibited the activity of both lipases, whereas the organic solvent enhanced the lipase stability of chimeric lipase as compared with the native lipase. According to the results, the presence of two glycine residues at the conserved pentapeptide region of this chimeric lipase (112 Gly-Glu-Ser-Ala-Gly 116) may increase the flexibility of the nucleophilic elbow region and affect the enzyme activity level. 相似文献
59.
Ghalandari Mohammad Irandoost Shahrestani Misagh Maleki Akbar Safdari Shadloo Mostafa El Haj Assad Mamdouh 《Journal of Thermal Analysis and Calorimetry》2021,145(4):1837-1848
Journal of Thermal Analysis and Calorimetry - Heat exchangers are applicable in different industries and technologies, and their performance is influenced by different parameters. In addition to... 相似文献
60.
In this paper the adsorption process of a natural steroid hormone (progesterone) by a carbon black and a commercial activated carbon has been studied. The corresponding equilibrium isotherms have been analyzed according to a previously proposed model which establishes a kinetic law satisfactorily fitting the C versus t isotherms. The analysis of the experimental data points out the existence of two well-defined sections in the equilibrium isotherms. A general equation including these two processes has been proposed, the global adsorption process being fitted to such equation. From the values of the kinetic equilibrium constant so obtained, values of standard average adsorption enthalpy () and entropy () have been calculated. Finally, information related to variations of differential adsorption enthalpy () and entropy () with the surface coverage fraction (θ) was obtained by using the corresponding Clausius-Clapeyron equations. 相似文献