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41.
The first report of natural l-vasicine as tridentate chiral ligand for the enantioselective addition of diethylzinc to a variety of aliphatic and aromatic aldehydes is described. The ligand generates R-isomer of the secondary alcohols upto 98% ee. The quinazoline structure possibly imparts rigidity to the ligand and hence, consistently high enantioselectivity. The importance of the quinazoline ring was also supported by the reaction with other related ligands, partially lacking the structural features, thus resulting in poor enantioselectivity. 相似文献
42.
Malik Abdul Rub Dileep Kumar Naved Azum Farah Khan Abdullah M. Asiri 《Journal of solution chemistry》2014,43(5):930-949
In the present paper, the micellization of an amphiphilic drug, promazine hydrochloride, and gemini surfactants (16-s-16) with s = 4–6 and the monomeric hexadecyltrimethylammonium bromide (CTAB) counterparts has been examined conductometrically in the pure and mixed states in aqueous solutions at different compositions and temperatures (298.15–308.15 K). Dicationic gemini surfactants provide much better environment for the micellization behavior than the corresponding monocationic counterpart CTAB. The critical micelle concentration (cmc) values are lower than the cmc for ideal mixing, cmc id, suggesting attractive interactions between the two components in mixed micelles. The micellar mole fractions of surfactants, evaluated by different models, show greater contributions of surfactants in mixed micelles and increase with increasing concentrations of these surfactants. The negative values of β suggest synergism in the mixtures, which is highly beneficial as it reduces the total amount of surfactants required in a particular application, leading to reductions of cost and environmental impact. Activity coefficients (f 1 and f 2) are always less than unity showing nonideality in the systems. The data have been also used for evaluation of thermodynamic parameters. 相似文献
43.
K.K. Abdul Khader Ayyiliath M. Sajith M. Syed Ali Padusha H.P. Nagaswarupa A. Muralidharan 《Tetrahedron letters》2014
In this Letter we report a rapid and facile access to C2-substituted imidazo[4,5-b]pyridine analogues utilizing palladium mediated Buchwald–Hartwig cross-coupling reactions. The use of enolizable heterocycles as cross-coupling partners resulted in a wide range of imidazo[4,5-b]pyridine analogues which are prone to have medicinal relevance. Xantphos and Pd(OAc)2 were found to be more effective for the coupling of 2-halo imidazo[4,5-b]pyridines with pyridone nucleophiles. A regioselective approach for the synthesis of 2-substituted 3H-imidazo[4,5-b]pyridine and 1H-imidazo[4,5-b]pyridine is also reported. 相似文献
44.
Saadi Bayat Emilia Abd Malek Normi M. Yahaya Abu Bakar Salleh Bimo Ario Tejo Mohd Basyaruddin Abdul Rahman 《Tetrahedron letters》2014
The promiscuous aldo–ketoreductase (AKR) enzyme is used as a sustainable biocatalyst for the first time to catalyze asymmetric aldol reactions in aqueous medium. The reactions between aromatic aldehydes and cyclic/acyclic ketones give the corresponding products in moderate yields and enantioselectivities in the presence of water. The influence of solvents, the mole ratio of substrates, and enzyme concentration are investigated. The mechanism of the AKR1A1-catalyzed aldol reaction is also discussed. 相似文献
45.
Revathy Deivasigamani Nur Shahira Abdul Nasir Mohd Ambri Mohamed Muhamad Ramdzan Buyong 《Electrophoresis》2022,43(4):609-620
This article describes a dielectrophoresis (DEP)-based simulation and experimental study of human epidermal keratinocyte (HEK) cells for wounded skin cell migration toward rapid epithelialization. MyDEP is a standalone software designed specifically to study dielectric particles and cell response to an alternating current (AC) electric field. This method demonstrated that negative dielectrophoresis (NDEP) occurs in HEK cells at a wide frequency range in highly conductive medium. The finite element method was used to characterize particle trajectory based on DEP and drag force. The performance of the system was assessed using HEK cells in a highly conductive EpiLife suspending medium. The DEP experiment was performed by applying sinusoidal wave AC potential at the peak-to-peak voltage of 10 V in a tapered aluminum microelectrode array from 100 kHz to 1 MHz. We experimentally observed the occurrence of NDEP, which attracted HEK cells toward the local electric field minima in the region of interest. The DIPP-MotionV software was used to track cell migration in the prerecorded video via an automatic marker and estimate the average speed and acceleration of the cells. The results showed that HEK cell migration was accomplished approximately at 6.43 μm/s at 100 kHz with 10 V, and FDEP caused the cells to migrate and align at the target position, which resulted in faster wound closures because of the application of an electric field frequency to HEK cells in random locations. 相似文献
46.
Leena V. Bora Manan Rathod Kush Kapadia Sonal Thakkar R.N. Reddy Sandesh S. Chougule Nisha V. Bora 《印度化学会志》2022,99(7):100560
In this study, we report a waste material-ground granulated blast furnace slag (GGBFS) as a low cost geopolymer, hybridised with ZnO to form a novel and efficient photocatalyst capable of discolouring textile wastewater. GGBFS is a waste material in an iron industry. Methylene blue was used as the probe dye and natural sunlight was used for activation of the photocatalyst. It was observed that under the experimental conditions, ZnGP-40 exhibited twice the discoloration efficiency than conventionally used ZnO or TiO2. This enhanced performance is majorly attributed to increased surface area of ZnO when strewn in the GGBFS matrix. The photocatalysts were characterized by SEM, TEM, PSA, TGA, BET and UV–Vis/NIR. The effect of photocatalyst loading, speed of agitation and solar insolation has also been studied. Since this study has been performed in direct sunlight, it exhibits a realizable application of solar energy in the treatment of wastewater. 相似文献
47.
Tribbles homolog 3 (TRIB3) protein is inhibiting the insulin signaling by directly binding to the Akt/PKB leading to insulin resistance in the pancreas causing type 2 diabetes mellitus. Hence, TRIB3 protein is considered as a possible drug target for the new lead identification against type 2 diabetes. In the present study, the homology model of TRIB3 protein was generated to explore its biochemical function and molecular interactions in the new lead identification. The energy minimization of TRIB3 protein was carried out and evaluated by validation protocols for structure reliability. The druggable binding site of TRIB3 protein was identified for the virtual screening and molecular docking studies. The Asinex-fragments library of 22634 small molecules was docked at TRIB3 active site using the Glide module to identify new chemical entities. A total of 9 molecules were identified as final hits from virtual screening and their potency was ranked using Glide score, Glide energies, and residues interactions. The 6 prioritized lead molecules were further optimized using AutoDock, Prime MM/GBSA, and percentage of human oral absorption for the identification of potential leads. The molecules L2, L5, and L6 are identified as lead inhibitors and are showing consistent interactions with key residues Glu194 and Lys196 of TRIB3 protein. The identified potential leads were analyzed by ADME properties for their drug likeness and HergIC50 values are predicted for the prevention of preclinical failures. The present work sheds light on the identification of the best lead molecules against TRIB3 protein and offers a route to design as novel potential drug candidates for T2DM. 相似文献
48.
Abdul Qadir Nausheen Khan Muhammad Arif Shehla Nasar Mir Najib Ullah Sauban Ahmed Khan Asad Ali Mohd Imran 《印度化学会志》2022,99(2):100354
Simmondsia chinensis L. commonly called as Jojoba and belongs to family Simmondsiaceae. It has shown positive pharmacological activities of these compounds which include antidiabetic, antirheumatic, anthelminthic, antipsoriatic, antioxidant, antiepileptic, antigonorrheal, analgesic, anti-inflammatory, and pesticidal activity of jojoba. The multifaceted action of numerous bioactives existing in the seed extract with therapeutic activity have attracted great research interest by pharmaceutical industries. n-hexane extract of Simmondsia chinensis L. (SC) Seeds was analysed by gas chromatography-mass spectroscopy for identification and characterization of phytobioconstituents and its therapeutic claim by traditional system. The major compounds discovered in SC seeds extract are cis-9-octadecen-1-ol (24.85%), 9-octadecen-1-ol, (Z)- (18.24%), Stigmast-5-en-3-ol (14.10%), Ergost-5-en-3-ol, (3-β)-ol (5.26%), (Z)-14-tricosenyl formate (5.24%), Thiositosteroldisulfide (3.64%), Silane, Dimethyl (dimethylpentyloxysilyloxy) tetradecyloxy- (3.41%), Ergost-5-ene, 3-methoxy-, (3β,24R)- (2.55%), Ergosta-5,22-dien-3-ol (2.22%), 1,19-eicosadiene (2.17%), Pentacosane (2.02%), Stigmasta-5,22-dien-3-ol (1.64%), 1,19-eicosadiene (1.57%), 9-octadecen-1-ol, (Z)- (1.46%), 9,19-cyclo-9β-lanostan-3β-ol, 24-methylene- (1.14%), (9Z)-9-octadecenyl palmitate (1.50%), Hexadecanoic acid, 9-octadecenyl ester, (Z) (1.37%), 9Z)-9-octadecenyl (9Z)-9-hexadecenoate (1.01%). The hexane extract of Simmondsia chinensis seeds comprises various polar and nonpolar phytobioconstituents. These compounds were established qualitatively via GC-MS evaluation. GC-MS reports will be promising in pharmaceutical sector in identification of variety of Phytobioconstituents in distinct plant extracts, polyherbal extract and the standardization of particular plant materials. 相似文献
49.
Sadeghi Mohamad Sadegh Anadalibkhah Naghmeh Ghasemiasl Ramin Armaghani Taher Dogonchi Abdul Sattar Chamkha Ali J. Ali Hafiz Asadi Amin 《Journal of Thermal Analysis and Calorimetry》2022,147(1):1-22
Journal of Thermal Analysis and Calorimetry - The ultimate goal of the present review paper is to summarize and discuss the findings of the most recently published literature on natural convection... 相似文献
50.
Sodiq Adeyeye Nafiu Syed Shaheen Shah Dr. Abdul Aziz Dr. M. Nasiruzzaman Shaikh 《化学:亚洲杂志》2021,16(14):1956-1966
Direct attachment of gold nanoparticles to a green support without the use of an external reducing agent and using it for removing toxic pollutants from wastewater, i. e., reduction of nitroarene to amine, are described. A novel approach involving the reduction of gold by the jute plant (Corchorus genus) stem-based (JPS) support itself to form nanoparticles (AuNPs) to be used as a catalytic system (‘dip-catalyst’) and its catalytic activity for the hydrogenation of series of nitroarenes in aqueous media are presented. AuNPs/JPS catalyst was characterized using SEM, UV-Vis, FTIR, TEM, XPS, and ICP-OES. Confined area elemental mapping exhibits uniform and homogeneous distribution of AuNPs on the support surface. TEM shows multi-faceted AuNPs in the range of 20–30 nm. The reactivity of AuNPs/JPS for the transfer hydrogenation of nitroarene as well as hydrogenation of quinoline under molecular H2 pressure was evaluated. Sodium borohydride, when used as the hydrogen source, demonstrates a high catalytic efficiency in the transfer hydrogenation reduction of 4-nitrophenol (4-NP). Quinoline is quantitatively and chemoselectively hydrogenated to 1,2,3,4-tetrahydroquinoline (py-THQ) using molecular hydrogen. Reusability studies show that AuNPs are stable on the support surface and their selectivity is not affected. 相似文献