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11.
Yunusa Umar Sahar Abdalla SK Manirul Haque Guillermo Salgado Moran Abdurrahman Ishaq Wilson Cardona Villada Jorge Dagnino Leone Marta Bunster 《中国化学会会志》2020,67(1):62-71
The optimized molecular structures, harmonic vibrational wavenumbers, and the corresponding vibrational assignments of (1S,2S)-tramadol and (1R,2R)-tramadol are computationally examined using the B3LYP density functional theory method together with the standard 6–311++G(d,p) and def2-TVZP basis sets. The optimized structures show that phenolic rings of both 1R,2R and 1S,2S tramadol adopt planar geometry, which are slightly distorted due to the substitution at the meta-position; and the six-membered cyclohexane adopts a slightly distorted chair conformation. The 1S,2S enantiomer is energetically more favorable than 1R,2R with the energy differences of 1.32 and 1.03 kcal/mol obtained at B3LYP/6–311++G(d,p) and B3LYP/Def2-TVZP levels, respectively. The analysis of the binding pocket in the silico molecular docking with the m-opioid receptor shows that it originated two clusters with the 1S,2S enantiomer and one cluster with the 1R,2R enantiomer of tramadol. The results point to a more stable complex of the m-opioid receptor with the 1R,2R enantiomer of tramadol. 相似文献
12.
Sahar Pakbaten Toopkanloo Tai Boon Tan Faridah Abas Mohammad Azam Imededdine Arbi Nehdi Chin Ping Tan 《Molecules (Basel, Switzerland)》2020,25(24)
In order to improve the membrane lipophilicity and the affinity towards the environment of lipid bilayers, squalene (SQ) could be conjugated to phospholipids in the formation of liposomes. The effect of membrane composition and concentrations on the degradation of liposomes prepared via the extrusion method was investigated. Liposomes were prepared using a mixture of SQ, cholesterol (CH) and Tween80 (TW80). Based on the optimal conditions, liposome batches were prepared in the absence and presence of SQ. Their physicochemical and stability behavior were evaluated as a function of liposome constituent. From the optimization study, the liposomal formulation containing 5% (w/w) mixed soy lecithin (ML), 0.5% (w/w) SQ, 0.3% (w/w) CH and 0.75% (w/w) TW80 had optimal physicochemical properties and displayed a unilamellar structure. Liposome prepared using the optimal formulation had a low particle size (158.31 ± 2.96 nm) and acceptable %increase in the particle size (15.09% ± 3.76%) and %trolox equivalent antioxidant capacity (%TEAC) loss (35.69% ± 0.72%) against UV light treatment (280–320 nm) for 6 h. The interesting outcome of this research was the association of naturally occurring substance SQ for size reduction without the extra input of energy or mechanical procedures, and improvement of vesicle stability and antioxidant activity of ML-based liposome. This study also demonstrated that the presence of SQ in the membrane might increase the acyl chain dynamics and decrease the viscosity of the dispersion, thereby limiting long-term stability of the liposome. 相似文献
13.
Eslami Farnaz Pourayoubi Mehrdad Sabbaghi Fahimeh Dušek Michal Baniyaghoob Sahar Skořepová Eliška 《Crystallography Reports》2022,67(2):218-223
Crystallography Reports - For structures with a C2PO2 skeleton, a comparison of “single-and-half” phosphorus–oxygen bonds with single and double phosphorus–oxygen bonds is... 相似文献
14.
Let C be a closed convex weakly Cauchy subset of a normed space X. Then we define a new {a,b,c} type nonexpansive and {a,b,c} type contraction mapping T from C into C. These types of mappings will be denoted respectively by {a,b,c}-ntype and {a,b,c}-ctype. We proved the following: 1. If T is {a,b,c}-ntype mapping, then inf{ || T(x)-x|| :x C C} =0, accordingly T has a unique fixed point. Moreover, any sequence {Xn}n∈NN in C with limn→∞||T(xn) - Xn|| = 0 has a subsequence strongly convergent to the unique fixed point of T. 2. If T is {a,b,c}-ctype mapping, then T has a unique fixed point. Moreover, for any x∈C the sequence of iterates {Tn (x)}n∈N has subsequence strongly convergent to the unique fixed point of T. This paper extends and generalizes some of the results given in [2,4, 7] and [13]. 相似文献
15.
Sahar Al Akoum-Ebrik Mohamed Ansar Rahima Mouhoub Claude Vaccher Marie-Pierre Vaccher Nathalie Flouquet 《光谱学快报》2013,46(5):925-944
The enantiomeric composition and absolute configuration of 4-Amino-3-(benzo[b]furan-2-yl)-Butanoic Acids and of 4-Amino-3-(thien-2-yl)-Butanoic Acids 1 may be accurately determined by 1H and 13C nuclear magnetic resonance analysis of the corresponding derivatives 3 prepared by reaction with chiral reagents. Correlation with HPLC is signaled. 相似文献
16.
Mostafa Sahar I. El-Asmy Ahmed A. El-Shahawi Mohamed S. 《Transition Metal Chemistry》2000,25(4):470-473
New ruthenium(II) complexes with 2-hydroxybenzophenone N(4)-substituted (Me, Ph and/or piperidyl) thiosemicarbazones have
been prepared and characterised by elemental analysis, molar conductivity, thermal analysis, spectroscopy (i.r., 1H-n.m.r. and u.v.–vis.) and by cyclic voltammetry. The thiosemicarbazones coordinate to ruthenium(II) as mononegative tridentate
ligands via the deprotonated hydroxyl group, N1 nitrogen and thione sulphur centres. The redox properties, nature of the electrode processes and the stability of the complexes
towards oxidation in CH2Cl2 are discussed. The change in the E
1/2 values of the complexes can be related to the basicity of the N(4)-substituents. All the complexes display an irreversible
one-electron charge-transfer couple in the potential range studied.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
17.
Sahar Raissi Mohamed Kadri Younes Abdelhamid Ghorbel François Garin 《Journal of Sol-Gel Science and Technology》2010,53(2):412-417
Catalysts based on chromium supported by sulphated and unsulphated zirconia have been synthesised, in one step, by sol–gel
method and dried in hypercritical solvent conditions. Comparative study of their catalytic properties shows that dispersed
Cr3+ seems to be the active species in the n-hexane aromatisation reaction. However, the acidity generated by sulphate groups acts as coke eliminator of the layers deposed
on the surface mainly when catalyst is calcined at high temperature. 相似文献
18.
19.
Sahar Al Akoum Ebrik Anne Legrand Benoît Rigo Daniel Couturier 《Journal of heterocyclic chemistry》1999,36(4):997-1000
Condensation of N-trimethylsilylindole with methyl N-trimethylsilyloxymethylpyroglutamate is the best method to obtain methyl N-indolylmethylpyroglutamate. Friedel-Crafts cyclization of the corresponding acid yields a new ketone (1,2,3,5,11,11a-hexahydroindolizino[7,6-b] indole-3,11-dione). 相似文献
20.
Atif Fazal Sahar Al-Fayez Laila H. Abdel-Rahman Zaki S. Seddigi Abdul Rahman Al-Arfaj Bassam El Ali Mohammad A. Dastageer Mohammad A. Gondal Mohammed Fettouhi 《Polyhedron》2009,28(18):4072-4076
New copper(I) mixed-ligand complexes 1–4 of the formula Cu(N–N)PR3X, where N–N = 1,10-phenanthroline (phen), 2,2′-bipyridine (bpy), 5,5′-dimethyl-2,2′-bipyridine (5,5′dimbpy) and PR3 = tricyclohexylphosphine, tris(2-cyanoethyl)phosphine and isopropyldiphenylphosphine, have been synthesized. The complexes were characterized by EA, IR, NMR and single crystal X-ray diffraction. The solution fluorescence emission spectra were measured. The single crystal X-ray analysis showed that the copper(I) ion is four-coordinate with a distorted tetrahedral geometry. The complexes catalyze the formation of diphenylacetylene from the coupling of halobenzene with phenylacetylene. The complex Cu(5,5′-dimethylbpy)P{(cyhexyl)3}I showed the highest catalytic activity. At room temperature all four complexes exhibit, in dichloromethane, emission maxima in the 329–344 nm range, corresponding to intra-ligand excited states. 相似文献