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81.
Jahangeer Patujo Amin Badshah Raja Azadar Hussain Muhammad Nawaz Tahir Shaista Tahir Muhammad Khawar Rauf 《中国化学会会志》2015,62(11):1020-1027
In the present work new nitro substituted thioureas, and their copper complexes have been synthesized and characterized by FTIR and multinuclear NMR techniques. Some of the compounds namely 1‐benzoyl‐3‐(4‐chloro‐3‐nitrophenyl) thiourea (A‐1), 1‐benzoyl‐3‐(4‐chloro‐3‐nitrophenyl) thiourea (A‐2) and 1‐benzoyl‐3‐(2‐methoxy‐4‐nitrophenyl) thiourea (A‐2) have also been characterized by single crystal XRD. All the synthesized compounds have been screened for DNA binding potencies (using cyclic voltametry, UV‐vis spectroscopy) and free radical scavanging activities. 相似文献
82.
The Lie group of point transformations, which leave the equations for a simplified model of one dimensional ideal gas in magnetogasdynamics invariant, are used to obtain some exact solutions for the governing system of hyperbolic partial differential equations (PDEs). Similarity variables which reduces the governing system of PDEs into system of ordinary differential equations (ODEs) are determined through the transformations. The resulting ODEs are solved analytically to obtain some exact solutions that exhibits space-time dependence. Further, we study the propagation of weak discontinuity through a state characterized by one of the solutions. 相似文献
83.
Thermal and salt dual stimuli-responsive filter-paper-based membranes were prepared by UV-induced grafting of NIPAM-based polymers on paper surface. The grafting ratio could be controlled by monomer concentration during grafting polymerization. The results from pressure drop measurement of the mobile phase flowed cross the membrane demonstrate that an appropriate grafting ratio would be 8%-10%. Protein adsorption on the membrane through hydrophobic interaction could be promoted by increasing temperature and lyotropic salt concentration. The effect of grafted polymer structure on protein binding performance was studied. Filter paper grafted with NIPAM-based branched copolymer consisting of hydrophobic monomer moieties shows ten times higher protein binding capacity than that of the original filter paper. The separation of plasma proteins using the dual stimuli-responsive membrane was examined to demonstrate feasible application for hydrophobic interaction chromatographic separation of proteins. 相似文献
84.
Soumava Biswas Himanshu Sekhar Jena Suresh Sanda Prof. Dr. Sanjit Konar 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(39):13793-13801
Three isostructural lanthanide‐based two‐ dimensional coordination polymers (CPs) {[Ln2(L)3(H2O)2]n ? 2n CH3OH) ? 2n H2O} (Ln=Gd3+ ( 1 ), Tb3+ ( 2 ), Dy3+ ( 3 ); H2L=cyclobutane‐1,1‐dicarboxylic acid) were synthesized by using a low molecular weight dicarboxylate ligand and characterized. Single‐crystal structure analysis showed that in complexes 1 – 3 lanthanide centers are connected by μ3‐bridging cyclobutanedicarboxylate ligands along the c axis to form a rod‐shaped infinite 1D coordination chain, which is further linked with nearby chains by μ4‐connected cyclobutanedicarboxylate ligands to form 2D CPs in the bc plane. Viewing the packing of the complexes down the b axis reveals that the lattice methanol molecules are located in the interlayer space between the adjacent 2D layers and form H‐bonds with lattice and coordinated water molecules to form 1D chains. Magnetic properties of complexes 1 – 3 were thoroughly investigated. Complex 1 exhibits dominant ferromagnetic interaction between two nearby gadolinium centers and also acts as a cryogenic magnetic refrigerant having a significant magnetic entropy change of ?ΔSm=32.8 J kg?1 K?1 for ΔH=7 T at 4 K (calculated from isothermal magnetization data). Complex 3 shows slow relaxation of magnetization below 10 K. Impedance analysis revealed that the complexes show humidity‐dependent proton conductivity (σ=1.5×10?5 S cm?1 for 1 , σ=2.07×10?4 S cm?1 for 2 , and σ=1.1×10?3 S cm?1 for 3 ) at elevated temperature (>75 °C). They retain the conductivity for up to 10 h at high temperature and high humidity. Furthermore, the proton conductivity results were correlated with the number of water molecules from the water‐vapor adsorption measurements. Water‐vapor adsorption studies showed hysteretic and two‐step water vapor adsorption (182000 μL g?1 for 1 , 184000 μL g?1 for 2 , and 1874000 μL g?1 for 3 ) in the experimental pressure range. Simulation of water‐vapor adsorption by the Monte Carlo method (for 1 ) confirmed the high density of adsorbed water molecules, preferentially in the interlayer space between the 2D layers. 相似文献
85.
Bandi Madhu B. Raja sekar C. H. Venkata Ramana Reddy P. K. Dubey 《Research on Chemical Intermediates》2017,43(12):6993-7012
The intermediate-dependent green and efficient synthesis of dimeric quinolones 4a–l and 7a–l by the Knoevenagel condensation followed by Michael-type addition of 4-hydroxy-1-methylquinolin-2(1H)-one 1a, b to indole-3-aldehydes 2a–f and aromatic aldehydes 5a–l in water through the condensed compound 3a–l under catalyst-free conditions is described. This reaction was found to be environmentally friendly, has easy-workup and shorter reaction times giving good yields of the product without the need for its isolation using column chromatography. 相似文献
86.
Archana Sivasubramaniyan Ranganathan Raja Dinesh Murugan Arul Ponnusamy Ponnuswamy Alagusundaram Kalaiselvi Patchaiah Chellammal Subbiah Subramanian Gopalan 《Research on Chemical Intermediates》2017,43(4):2471-2490
Research on Chemical Intermediates - A library of pyrazolinyltriazole hybrids (3a–l, 4a–l) was synthesized via azide–alkyne dipolar (Huisgen) cycloaddition of azidoacetyl... 相似文献
87.
Fluoro-substituted aliphatic nitriles are shown to undergo the Houben-Hoesch reactions with arenes in CF3SO3H to give fluoro-substituted ketones in good yields. The fluorine substituents appear to enhance the reactivities of the nitriles (and the nitrilium ion intermediates) compared to similar aliphatic nitriles. Fluoro-substituted ketones are also shown to be accessible through the reactions of organometallic reagents and fluoro-substituted nitriles. 相似文献
88.
Goverdhan Mehta Raja MohanraoSreenivas Katukojvala Yannick LandaisSaikat Sen 《Tetrahedron letters》2011,52(22):2893-2897
A stereocontrolled synthesis of nine-membered aminocarbasugar analogs (amino-cyclononanoses) from a rigid bicyclo[4.3.1]deca-2,4-dien-10-one platform, harboring a latent functionalized cyclononane ring, is described. 相似文献
89.
Flavonoids are secondary metabolites synthesized by plants shown to exhibit health benefits such as anti-inflammatory, antioxidant,
and anti-tumor effects. Thus, due to the importance of this compound, several enzymes involved in the flavonoid pathway have
been cloned and characterized in Escherichia coli. However, the formation of inclusion bodies has become a major disadvantage of this approach. As an alternative, chalcone
synthase from Physcomitrella patens was secreted into the medium using a bacteriocin release protein expression vector. Secretion of P. patens chalcone synthase into the culture media was achieved by co-expression with a psW1 plasmid encoding bacteriocin release protein
in E. coli Tuner (DE3) plysS. The optimized conditions, which include the incubation of cells for 20 h with 40 ng/ml mitomycin C at
OD600 induction time of 0.5 was found to be the best condition for chalcone synthase secretion. 相似文献
90.
Cheong KW Leow TC Rahman RN Basri M Rahman MB Salleh AB;Enzyme Microbial Technology Research Group 《Applied biochemistry and biotechnology》2011,164(3):362-375
A thermostable lipase from Geobacillus zalihae strain T1 was chemically modified using propionaldehyde via reductive alkylation. The targeted alkylation sites were lysines,
in which T1 lipase possessed 11 residues. Far-UV circular dichroism (CD) spectra of both native and alkylated enzyme showed
a similar broad minimum between 208 and 222 nm, thus suggesting a substantial amount of secondary structures in modified enzyme,
as compared with the corresponding native enzyme. The hydrolytic activity of the modified enzymes dropped drastically by nearly
15-fold upon chemical modification, despite both the native and modified form showed distinctive α-helical bands at 208 and
222 nm in CD spectra, leading us to the hypothesis of formation of a molten globule (MG)-like structure. As cooperative unfolding
transitions were observed, the modified lipase was distinguished from the native state, in which the former possessed a denaturation
temperature (T
m) in lower temperature range at 61 °C while the latter at 68 °C. This was further supported by 8-anilino-1-naphthalenesulfonic
acid (ANS) probed fluorescence which indicated higher exposure of hydrophobic residues, consequential of chemical modification.
Based on matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) analysis, a small number
of lysine residues were confirmed to be alkylated. 相似文献