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281.
Hanan F. Abd El-Halim F. A. Nour El-Dien Gehad G. Mohamed Nehad A. Mohamed 《Journal of Thermal Analysis and Calorimetry》2012,109(2):883-892
Metal complexes having the general composition [MCl2(H2O)2(L)2]·yH2O (where y?=?1?C3, M?=?Mn(II), Cu(II), Co(II), Ni(II), and Zn(II) and L?=?miconazole drug?=?MCNZ) and [MCl2(H2O)2(L)2]Cl·3H2O (where M?=?Cr(III) and Fe(III)) have been synthesized. All the synthesized complexes were identified and confirmed by elemental analyses, IR, diffused reflectance, and thermal analyses (TG and DTA) techniques as well as molar conductivity and magnetic moment measurements. The molar conductance data reveals that bivalent metal complexes are non-electrolytes while Cr(III) and Fe(III) complexes are electrolytes and of 1:1 type. IR spectral studies reveal that MCNZ is coordinated to the metal ions in a neutral unidentate manner with N donor site of the imidazole-N. On the basis of magnetic and solid reflectance spectral studies, an octahedral geometry has been assigned for the complexes. Detailed studies of the thermal properties of the complexes were investigated by thermogravimetry (TG) and differential thermal analyses (DTA) techniques and the activation thermodynamic parameters are calculated using Coats?CRedfern method. The free MCNZ drug and its complexes were also evaluated against bacterial species (P. aeruginosa, S. aureus, B. subtilis, E. Coli) and fungi (A. fumigatus, P. italicum, and C. albicans) in vitro. The activity data show that the metal complexes have higher biological activity than the parent MCNZ drug. 相似文献
282.
Nahla Nour El Din Ahmed Salama Maissa Yacoub Salem Lobna Mohammed Abd El Halim Laila El‐Sayed Abdel Fattah 《中国化学》2012,30(1):183-189
Spectrofluorimetric and spectrophotometric stability‐indicating methods were developed and validated for analysis of veralipride (Ver) in presence of its hydrolytic and oxidative degradants. The spectrofluorimetric method was based on direct measurement of the intrinsic fluorescence of Ver at 366 nm after excitation at 299 nm using sodium lauryl sulfate (SLS) as micelle enhancer. The fluorescence intensity plot was linear over the concentration range 1.0–10.0 µg·mL?1. The high sensitivity of the method allowed its successful application to the analysis of Ver in spiked human plasma. Two other methods were developed. They are based on the oxidative coupling reaction of Ver with 3‐methyl benzothiazolin‐2‐one hydrazone (MBTH) hydrochloride in presence of ceric ammonium sulphate in an acidic medium. The first method depends on spectrophotometric measurement of the stable green colored oxidative coupling product at 660 nm. The different experimental parameters affecting the reaction were optimized. Linearity range is 10.0–100.0 µg·mL?1. The second method depends on a fluorescence quenching effect of Ver on the fluorescence of Ce3+. The difference in fluorescence intensity was measured at 380 nm after excitation at 300 nm. This method is applicable over the concentration ranges 0.25–2.50 µg·mL?1. The methods were validated according to the ICH guidelines. They were successfully applied for the analysis of Ver in drug substance, drug product and in laboratory prepared mixtures containing different percentages of hydrolytic and oxidative degradants. 相似文献
283.
Alaa A. Hassan Ahmed M. Nour El-Din Fathy F. Abdel-Latif Sara M. Mostafa Stefan Bräse 《Chemical Papers》2012,66(4):295-303
The reaction of (substituted) alkenylidene-hydrazinecarbothioamides with 2-(1,3-dioxo-2,3-dihydro-1H-inden-2-ylidene)propanedinitrile led to the formation of 1,3-dioxospiroindene[1,3]-thiazine and thioxoindeno[2,1-d]imidazolone derivatives in modest yields. In addition, 1,3-dihydroxyindan-2-ylidenepropanedinitrile was found. Explanations
of these conversions involving nucleophilic reactions and condensations are presented. 相似文献
284.
Dr. Nicolas Panel Dr. Duc Duy Vo Nour Aldin Kahlous Dr. Harald Hübner Dr. Stephanie Tiedt Dr. Pierre Matricon Dr. Jody Pacalon Dr. Oliver Fleetwood Dr. Stefanie Kampen Andreas Luttens Dr. Lucie Delemotte Prof. Jan Kihlberg Prof. Peter Gmeiner Prof. Jens Carlsson 《Angewandte Chemie (International ed. in English)》2023,62(22):e202218959
G-protein-coupled receptors (GPCRs) play important roles in physiological processes and are modulated by drugs that either activate or block signaling. Rational design of the pharmacological efficacy profiles of GPCR ligands could enable the development of more efficient drugs, but is challenging even if high-resolution receptor structures are available. We performed molecular dynamics simulations of the β2 adrenergic receptor in active and inactive conformations to assess if binding free energy calculations can predict differences in ligand efficacy for closely related compounds. Previously identified ligands were successfully classified into groups with comparable efficacy profiles based on the calculated shift in ligand affinity upon activation. A series of ligands were then predicted and synthesized, leading to the discovery of partial agonists with nanomolar potencies and novel scaffolds. Our results demonstrate that free energy simulations enable design of ligand efficacy and the same approach can be applied to other GPCR drug targets. 相似文献
285.
Yan Zhang Jiande Wang Petru Apostol Darsi Rambabu Alae Eddine Lakraychi Xiaolong Guo Xiaozhe Zhang Xiaodong Lin Shubhadeep Pal Vasudeva Rao Bakuru Xiaohua Chen Alexandru Vlad 《Angewandte Chemie (International ed. in English)》2023,62(42):e202310033
A new phosphonate-based anionic bimetallic organic framework, with the general formula of A4−Zn−DOBDP (wherein A is Li+ or Na+, and DOBDP6− is the 2,5-dioxido-1,4-benzenediphosphate ligand) is prepared and characterized for energy storage applications. With four alkali cations per formula unit, the A4−Zn−DOBDP MOF is found to be the first example of non-solvated cation conducting MOF with measured conductivities of 5.4×10−8 S cm−1 and 3.4×10−8 S cm−1 for Li4- and Na4- phases, indicating phase and composition effects of Li+ and Na+ shuttling through the channels. Three orders of magnitude increase in ionic conductivity is further attained upon solvation with propylene carbonate, placing this system among the best MOF ionic conductors at room temperature. As positive electrode material, Li4−Zn−DOBDP delivers a specific capacity of 140 mAh g−1 at a high average discharge potential of 3.2 V (vs. Li+/Li) with 90 % of capacity retention over 100 cycles. The significance of this research extends from the development of a new family of electroactive phosphonate-based MOFs with inherent ionic conductivity and reversible cation storage, to providing elementary insights into the development of highly sought yet still evasive MOFs with mixed-ion and electron conduction for energy storage applications. 相似文献
286.
Yu Chen Zhong Shen Lionel Gehringer Holger Frey Salah‐Eddine Stiriba 《Macromolecular rapid communications》2006,27(1):69-75
Summary: Supramolecular interaction of fully methylated hyperbranched polyethylenimines (PEI) with a mesogen‐based carboxylic acid, 5‐(p‐cyanobiphenoxy)pentanoic acid, results in the formation of supramolecular complexes exhibiting thermotropic liquid crystalline (LC) mesophases. In contrast to the common smectic mesophases of most dendritic LC polymers, nematic LC phases were observed. The complexation of PEI and the mesogen units is due to electrostatic interaction between the carboxylate groups and the ammonium end groups of PEI. LC properties were investigated by a combination of differential scanning calorimetry, polarizing light optical microscopy, and X‐ray diffractometry.