排序方式: 共有17条查询结果,搜索用时 328 毫秒
1.
Mohamed E. Abouelela Hamdy K. Assaf Reda A. Abdelhamid Ehab S. Elkhyat Ahmed M. Sayed Tomasz Oszako Lassaad Belbahri Ahmed E. El Zowalaty Mohamed Salaheldin A. Abdelkader 《Molecules (Basel, Switzerland)》2021,26(6)
Severe acute respiratory syndrome coronavirus (SARS-CoV-2) disease is a global rapidly spreading virus showing very high rates of complications and mortality. Till now, there is no effective specific treatment for the disease. Aloe is a rich source of isolated phytoconstituents that have an enormous range of biological activities. Since there are no available experimental techniques to examine these compounds for antiviral activity against SARS-CoV-2, we employed an in silico approach involving molecular docking, dynamics simulation, and binding free energy calculation using SARS-CoV-2 essential proteins as main protease and spike protein to identify lead compounds from Aloe that may help in novel drug discovery. Results retrieved from docking and molecular dynamics simulation suggested a number of promising inhibitors from Aloe. Root mean square deviation (RMSD) and root mean square fluctuation (RMSF) calculations indicated that compounds 132, 134, and 159 were the best scoring compounds against main protease, while compounds 115, 120, and 131 were the best scoring ones against spike glycoprotein. Compounds 120 and 131 were able to achieve significant stability and binding free energies during molecular dynamics simulation. In addition, the highest scoring compounds were investigated for their pharmacokinetic properties and drug-likeness. The Aloe compounds are promising active phytoconstituents for drug development for SARS-CoV-2. 相似文献
2.
Tomás Caraballo Lassaad Mchiri 《Stochastics An International Journal of Probability and Stochastic Processes》2016,88(1):45-56
The method of Lyapunov functions is one of the most effective ones for the investigation of stability of dynamical systems, in particular, of stochastic differential systems. The main purpose of the paper is the analysis of the stability of stochastic differential equations (SDEs) by using Lyapunov functions when the origin is not necessarily an equilibrium point. The global uniform boundedness and the global practical uniform exponential stability of solutions of SDEs based on Lyapunov techniques are investigated. Furthermore, an example is given to illustrate the applicability of the main result. 相似文献
3.
Ben Rebah F Prévost D Tyagi RD Belbahri L 《Applied biochemistry and biotechnology》2009,158(1):155-163
In our study, the potential of producing polyhydroxybutyrate (PHB) by cultivating fast-growing rhizobia (Sinorhizobium meliloti, Rhizobium leguminosarum bv. viciae, R. leguminosarum bv. phaseoli and R. leguminosarum bv. trifolii) in sludge and in industrial wastewater was evaluated. Results confirmed the possibility of using sludge as media for rhizobial
growth. During growth, substantial quantity of PHB was accumulated and yields varied depending on the media and rhizobial
species. Growing in sludge, PHB production did not exceed 3.7% w/w for all strains at the end of experiment (after 72 h). During the growth of S. meliloti, PHB yield varied and the maximum value reached 7.27% w/w after 60 h, with 1% Total Suspend Solid (TSS) sludge. Alkaline sludge pre-treatment affects rhizobial growth but did not
improve the PHB accumulation. While growing S. meliloti in industrial wastewater, the PHB yields varied and the highest value was obtained with slaughterhouse wastewater (10.7%
w/w) after 35 h of growth. Therefore, this work shows the potential of exploiting PHB production by rhizobia growing in wastewater
or sludge which could be applied to bioplastic industry, and confirms the potential of these recyclable wastes for high production
of rhizobial cells useable for legumes inoculants production. This study provides an environmentally sound way of sludge and
wastewater management and use in diverse biotechnological applications. 相似文献
4.
Lamia Jaafar Belaid Mohamed Jaoua Mohamed Masmoudi Lassaad Siala 《Comptes Rendus Mathematique》2006,342(5):313-318
A new method for edge detection and image restoration is proposed. This method is based on topological gradient approach. Experimental results obtained on noisy images illustrate the capabilities of this promising method in image processing. To cite this article: L.J. Belaid et al., C. R. Acad. Sci. Paris, Ser. I 342 (2006). 相似文献
5.
Essential oil of Thymus capitatus Hoff et Link is analysed by using four techniques: GC/pyrolyse/MS, GC/FID, electronic impact GC/MS (quadripole), and GC/MS (ion trap). Both major and trace components are analysed. The GC/pyrolyse/MS coupling provides reference to the exact mass compositions without any need of the previously purified references, neither for major or trace components. The comparison between this reference analysis and GC/FID shows that the FID response coefficients may vary by a mean 7% from one component to another. As it was expected, quadripole or ion trap response coefficients vary to a much greater extent (a mean 25%), although the two MS techniques response coefficients are first order consistent. We conclude that GC/MS coupling could be used not only as it is usual for reliable identifications, but also for a complete quantitative routine analysis of essential oils. Expected precision could be very similar to GC/FID precision provided correcting species by species the MS analysis by a mean value of the response coefficient measured for the MS 70 eV electronic impact ionisation technologies. The GC/pyrolyse/MS coupling is proposed as a relevant tool for analysing reference samples containing trace natural species that could not be purified. 相似文献
6.
Chiheb Mhiri Lamia Boubakri Riadh Ternane Lamjed Mansour Abdel Halim Harrath J. Al-Tamimi Lassaad Baklouti Naceur Hamdi 《Journal of heterocyclic chemistry》2020,57(1):291-298
Three-component reaction of arylaldehydes with malononitrile and 4-hydroxycoumarine using CH3COONH4 as a catalyst at reflux was used for the synthesis of novel substituted pyrano[3,2-c]chromene derivatives. The structure of these compounds was assigned by spectroscopic data such as (IR, 1HNMR, 13CNMR, and mass spectral data). The cation binding properties of chromene derivatives 4a-c towards Cu2+, Ni2+, and Zn2+ were studied in methanol. The results showed that Zn2+ is the most complexed in this series of cations, and 4c is best complexed with either Ni2+ and Zn2+. Antimicrobial properties of new pyrano[3,2-c]chromene derivatives are investigated, the compound 4c presents against Micrococcus luteus LB 14110 an MIC value of 0.0185 mg/mL quite better to that of ampicillin (0.0195 mg/mL) used as standard. Concerning acetylcholinesterase inhibition activity (AChEI), compound 4c presents an interesting AChEI activity with an inhibition of 52%. 相似文献
7.
Renata Dreos Lassaad Mechi Lucio Randaccio Ennio Zangrando Rached Ben Hassen 《Journal of organometallic chemistry》2006,691(15):3305-3309
The reduction of [Co(III)(tmsalen)(py)2]+ with NaBH4/PdCl2 and the successive oxidative addition of CH2ClI, carried out in neutral methanolic solution and followed by the addition of NaOH, afford a new dinuclear complex. The molecular structure reveals that it is formed by an octahedral [Co(tmsalen)(py)(OH)] unit connected to a β-folded [Co(tmsalenCH2)]+ fragment, in such a way that the latter metal completes the coordination sphere with the hydroxo group and a tmsalen oxygen from the former unit. 相似文献
8.
Renata Dreos Lassaad Mechi Giorgio Nardin Patrizia Siega 《Journal of organometallic chemistry》2005,690(16):3815-3821
The reaction of a chiral cis-β-organocobalt salen-type complex, 1, racemic mixture of Δ and Λ enantiomers, with enantiomerically pure l-histidine and a non-chiral monocationic cobalt complex, 3, resulted quite unexpectedly in the cocrystallization of diastereomers. Each diastereomer is a dicobalt monocationic complex, where four positions around one metal center are occupied by the tetradentate ligand in a cis fashion, the remaining two positions being occupied by l-histidinate. Histidinate further axially coordinates the other Co atom through the nitrogen of the imidazole residue. The two diastereomers are related by a quasi-symmetry center. In this case, the opposite helical chirality of the metal complex 1 prevails over the identical configuration of the asymmetric carbon in the crystallization process and the diastereomers behave as if they were enantiomers.The reaction of the same cobalt complexes 1 and 3 with dl-histidine led to the formation of two pairs of enantiomers, which crystallized separately as racemic compound. Therefore, in this case, the chirality of the asymmetric center is the property that allows the mutual selective recognition of the “true” enantiomers and drives their cocrystallization. 相似文献
9.
Lassaad Baklouti Najah Cheriaa Mouna Mahouachi Rym Abidi Jong Seung Kim Yang Kim Jacques Vicens 《Journal of inclusion phenomena and macrocyclic chemistry》2006,54(1-2):1-7
This timely review focuses on the synthesis of dendrimers from calix[4]arenes and thiacalix[4]arenes. Some interesting features
of these calix-dendrimers are given. 相似文献
10.
Najah Cheriaa Mouna Mahouachi Amel Ben Othman Lassaad Baklouti Yang Kim Rym Abidi 《Supramolecular chemistry》2013,25(3):265-271
A new family of hyperbranched molecules and dendrimers has been constructed from a diamide–dicalix derivative prepared from monocarbomethoxymethyl p-tert-butyl calix[4]arene and tris(2-aminoethyl)amine (‘tren’) via amide-formation reactions. The selective 1,3-di-O-functionalization of p-tert-butyl calix[4]arene moieties allows the synthesis of first- (G1) and second-generation (G2) calix-dendrimers. Replacement of the quadridentate amine by a trithia-ether-triamine-mono-ol, ’hyten’, again results in acylation of the amino groups, but with the generation of a central cavity with different complexing properties. A new family of hyperbranched molecules and dendrimers has been constructed from a diamide–dicalix derivative prepared from monocarbomethoxymethyl p-tert-butyl calix[4]arene and tris(2-aminoethyl)amine (‘tren’) via amide-formation reactions. The selective 1,3-di-O-functionalization of p-tert-butyl calix[4]arene moieties allows the synthesis of first- (G1) and second-generation (G2) calix-dendrimers 相似文献