排序方式: 共有15条查询结果,搜索用时 187 毫秒
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A. A. Hasanein G. M. El-Subruiti G. O. Younes M. H. Srour 《Journal of solution chemistry》2004,33(12):1481-1499
The electronic absorption spectra of 2-aminopyrimidine (compound I), 2-amino-4-methylpyrimidine (compound II), 2-amino-4,6-dimethylpyrimidine (compound III), 2-amino-4,6-dimethoxypyrimidine (compound IV), 4-amino-2,6-dimethylpyrimidine (compound V), and 4,5-diamopyrimidine (compound VI) have been measured in water and in a series of different organic solvents. The solvent effects on the spectra are discussed and the solvent induced spectral shifts are analyzed in terms of different solute–solvent interaction mechanisms, using the multiple linear regression technique. 相似文献
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Shady Nada Mohamed Hagar Omaima Farahat Ahmed A. Hasanein Abdul-Hamid Emwas Abeer Ali Sharfalddin Mariusz Jaremko Mohamed A. Zakaria 《Molecules (Basel, Switzerland)》2022,27(7)
Three rings 2-hydroxypyridine liquid crystalline compounds have been prepared and fully characterized. The mesomorphic behavior of the prepared compounds has been investigated in terms of differential scanning calorimetry (DSC) and polarized optical microscopy (POM). Moreover, a comparative study between the prepared compounds and previously reported analogs has been discussed in terms of the orientation and position of the mesogenic core, in addition to the direction of the terminal alkyl chains. Furthermore, a detailed computational approach has been studied to illustrate the effect of geometrical and dimensional parameters on the type of the enhanced texture and the mesomorphic range and stability. The results of the DFT study revealed that the orientation of the mesogen could affect the mesomorphic behavior and this has been attributed in terms of the degree of the polarizability of the linking groups. This result has been confirmed by calculation of the net dipole moment and the molecular electrostatic potential that show how the mesogen orientation and position could impact the molecular charge separation. Finally, the effect of the pyridyl group has been also investigated in terms of the calculated aromaticity index and the π-π stacking. 相似文献
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Ahmed A. Hasanein Samir A. Senior 《International journal of quantum chemistry》2011,111(15):3993-4010
Amine‐Imine tautomerization in 2‐amino‐pyrimidine (I), 2‐amino‐4,6‐dichloropyrimidine (II), 2‐amino‐4,6‐dimethylpyrimidine (III), and 2‐amino‐4,6‐dimethoxypyrimidine (IV) and their 1:1 and 1:2 H‐bonded complexes with water have been studied using the B3LYP/6‐31++G** method. Optimum molecular geometries, electronic properties, and energetics of these systems have been discussed. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2011 相似文献
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Ahmed Z. Abdel Azeiz Donia K. Hanafi Sameh E. Hasanein 《Natural product research》2016,30(16):1816-1823
Thirty actinomycete isolates were isolated from soil and tested against Candida albicans in vitro. The active isolate was identified by 16s-rRNA gene sequencing method as Streptomyces toxytricini. The antifungal compound was extracted with ethyl acetate followed by diethyl ether. Both HPLC and GC–MS analysis confirmed presence of one pure compound in the diethyl ether extract. The compound is a yellow liquid has a maximum absorbance at 240 nm in methanol. The chemical structure was elucidated by 1D and 2D-NMR and IR analyses. The elucidated molecular formula was C36H54O14. The compound is a polyacetal tricyclononane derivative, composed of a tricyclononane ring attached from the carbon atom number four with an oligo-acetal chain (six acetal groups in chain) and from the carbon atom number seven with a methoxy carbonyl benzene-1,3-dicarboxylic acid. The purposed name is: 4- {[tricycle(3.2.1.11,3)non-8-yl] methoxy carbonyl benzene-1,3-dicarboxylic acid} (2,4,5,6,7,8,9 heptaoxa, 3-ethoxy, 5,6,7,9-tetramethyl unidecane). 相似文献
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The hypoglycemic and antioxidants activities of the methanol extract of Lepidium sativum seeds was tested in alloxan-induced diabetic male rats. Thirty male albino rats weighing 190–200 g were divided into five groups as follows: negative control, positive control and three diabetic groups treated with three concentrations of L. sativum methanol extract for four weeks. Induction of hyperglycemia in the positive control group increased blood glucose, glycated hemoglobin A1c, immunoglobulins, liver enzyme, lipid peroxide and kidney function, total cholesterol, low-density lipoproteins, very low-density lipoproteins and decreased antioxidants and high-density lipoproteins compared with the negative control. Furthermore, pancreas tissues showed pathological changes compared with the negative control. Treating the diabetic rats with L. sativum methanol extract decreased blood sugar and restored all biochemical and histological changes to the normal. It could be concluded that L. sativum methanol extract succeeded in controlling diabetes, increasing antioxidants and ameliorating lipid profile. 相似文献
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Ibrahim El-Tantawy El Sayed Sami Ullah Omar A. Al-Hartomy Asmaa Mohammed Hasanein Abdullah A. S. Ahmed Khaled A. Kahilo Mehrez E. El-Naggar 《Molecules (Basel, Switzerland)》2022,27(3)
The naturally occurring neocryptolepine (5-Methylindolo [2,3-b]quinoline) and its analogs exhibited prominent anticancer and antimalarial activity. However, the main problem of this class of compounds is their poor aqueous solubility, hampering their bioavailability and preventing their clinical development. To overcome the problem of insolubility and to improve the physicochemical and the pharmacological properties of 5-Methylindolo [2,3-b]quinoline compounds, this work was designed to encapsulate such efficient medical compounds into mesoporous silica oxide nanoemulsion (SiO2NPs). Thus, in this study, SiO2NPs was loaded with three different concentrations (0.2 g, 0.3, and 0.6 g) of 7b (denoted as NPA). The findings illustrated that the nanoparticles were formed with a spherical shape and exhibited small size (less than 500 nm) using a high concentration of the synthesized chemical compound (NPA, 0.6 g) and good stabilization against agglomeration (more than −30 mv). In addition, NPA-loaded SiO2NPs had no phase separation as observed by our naked eyes even after 30 days. The findings also revealed that the fabricated SiO2NPs could sustain the release of NPA at two different pH levels, 4.5 and 7.4. Additionally, the cell viability of the produced nanoemulsion system loaded with different concentrations of NPA was greater than SiO2NPs without loading, affirming that NPA had a positive impact on increasing the safety and cell viability of the whole nanoemulsion. Based on these obtained promising data, it can be considered that the prepared NPA-loaded SiO2NPs seem to have the potential for use as an effective anticancer drug nanosystem. 相似文献
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Ghorbani-Vaghei Ramin Malaekehpoor Seyedeh Mina Hasanein Parisa Karamyan Roya Asadbegy Mostafa 《Research on Chemical Intermediates》2016,42(5):4715-4731
Research on Chemical Intermediates - N,N,N′,N′-Tetrachlorobenzene-1,3-disulfonamide and poly(N,N′-dichloro-N-ethyl-benzene-1,3-disulfonamide) are new catalysts promoted by... 相似文献