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51.
Nabil Smichi Ahmed Fendri Raja Chaabouni Faouzi Ben Rebah Youssef Gargouri Nabil Miled 《Applied biochemistry and biotechnology》2010,162(5):1483-1496
A lipolytic activity was located in the sardine digestive glands (pyloric caeca), from which a sardine digestive lipase (SaDL)
was purified. Pure SaDL has a molecular mass of 43 kDa as determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis
analysis. The enzyme was found to be more active on short-chain triacylglycerols than on long-chain ones. SaDL does not present
the interfacial activation phenomenon. Control experiments were performed under the same experimental conditions, with dromedary
and turkey pancreatic lipases and showed a positive interfacial activation phenomenon. Sodium deoxycholate (NaDC) has an inhibitory
effect on the lipase activity. The pure enzyme lost 40% of its activity in presence of 8 mM NaDC. SaDL was found to be mostly
stable at low pH values. Interestingly, no colipase was detected in the sardine pyloric caeca. Analogous results were reported
for the scorpion and the crab digestive systems. This is in line with the idea that colipase might has evolved in mammal animals
simultaneously with the appearance of an exocrine pancreas. No similarity was found between the NH2-terminal amino acid residues of SaDL and those of lipases from the digestive tract of other species. Altogether, these results
suggest that SaDL is a member of a new group of lipases belonging to aquatic species. 相似文献
52.
Synthesis and Reversible Hydration of a Pseudoprotein,a Fully Organic Polymeric Desiccant by Multiple Single‐Crystal‐to‐Single‐Crystal Transformations 下载免费PDF全文
Raja Mohanrao Prof. Dr. Kana M. Sureshan 《Angewandte Chemie (International ed. in English)》2018,57(38):12435-12439
A diphenylalanine derivative, N3‐Phe‐Phe‐NHCH2CCH, was designed for topochemical azide–alkyne cycloaddition (TAAC) polymerization. This dipeptide adopted β‐sheet arrangement as designed, in its crystals, but the azide and alkyne were not fitly aligned for their topochemical reaction. However, the voids present around these groups allowed them to attain a reactive geometry upon heating and their consequent TAAC polymerization to a pseudoprotein in a single‐crystal‐to‐single‐crystal (SCSC) fashion. This motion led to the creation of channels in the product crystal and it absorbed water from the surroundings to fill these channels as H‐bonded water wire. The pseudoprotein undergo reversible hydration/dehydration in SCSC fashion many times under mild conditions: hydration at low relative humidity and dehydration at low temperature. Vapor sorption analyses suggest that this fully organic polymer might be useful as an energy‐efficient desiccant material for controlling indoor humidity. 相似文献
53.
Duraiswamy SukanyaDuraisamy Senthil Raja Nattamai S.P. BhuvaneshKaruppannan Natarajan 《Polyhedron》2011,30(6):1108-1113
New hexa-coordinated Ru(III) complexes of the type [Ru(H2Pzdc)(EPh3)3X2] have been synthesized by reacting 3,5-pyrazole dicarboxylic acid (H3Pzdc) with the appropriate starting complexes [RuX3(EPh3)3] (where X = Cl or Br; E = P or As). The ligand behaves as a bidentate monobasic chelate. All the complexes have been characterized by analytical and spectroscopic (IR, electronic and EPR) data. Single-crystal X-ray analysis of the complex [Ru(H2Pzdc)(PPh3)2Cl2]·C6H6·C2H5OH revealed that the coordination environment around the ruthenium center consists of an NOP2Cl2 octahedron. The planar ligand occupies the equatorial position along with two chlorine atoms, while the triphenylphosphine groups occupy the axial positions. The electrochemical behavior of the new complexes was studied using cyclic voltammetry. The new mononuclear ruthenium complexes are capable of acting as catalysts for the oxidation of alcohols. 相似文献
54.
Calcined Mg-Al hydrotalcites (Mg/Al=3) can be used as an efficient catalyst in the selective O-methylation of phenol and catechol and N-monomethylation of aniline employing dimethylcarbonate (DMC) as a methylating agent in vapor phase at 275°C. 相似文献
55.
56.
Remarkable Effect of Chalcogen Substitution on an Enzyme Mimetic for Deiodination of Thyroid Hormones 下载免费PDF全文
Karuppusamy Raja Prof. Dr. Govindasamy Mugesh 《Angewandte Chemie (International ed. in English)》2015,54(26):7674-7678
Iodothyronine deiodinases are selenoenzymes which regulate the thyroid hormone homeostasis by catalyzing the regioselective deiodination of thyroxine (T4). Synthetic deiodinase mimetics are important not only to understand the mechanism of enzyme catalysis, but also to develop therapeutic agents as abnormal thyroid hormone levels have implications in different diseases, such as hypoxia, myocardial infarction, critical illness, neuronal ischemia, tissue injury, and cancer. Described herein is that the replacement of sulfur/selenium atoms in a series of deiodinase mimetics by tellurium remarkably alters the reactivity as well as regioselectivity toward T4. The tellurium compounds reported in this paper represent the first examples of deiodinase mimetics which mediate sequential deiodination of T4 to produce all the hormone derivatives including T0 under physiologically relevant conditions. 相似文献
57.
Ortho‐Quinone Methides as Reactive Intermediates in Asymmetric Brønsted Acid Catalyzed Cycloadditions with Unactivated Alkenes by Exclusive Activation of the Electrophile 下载免费PDF全文
MSc. Chien‐Chi Hsiao Dr. Sadiya Raja MSc. Hsuan‐Hung Liao Prof. Dr. Magnus Rueping 《Angewandte Chemie (International ed. in English)》2015,54(19):5762-5765
An efficient method for the highly enantioselective synthesis of chiral chromanes bearing multiple stereogenic centers was developed. A chiral BINOL‐based N‐triflylphosphoramide proved to be an effective catalyst for the in situ generation of ortho‐quinone methides (o‐QMs) and their subsequent cycloaddition reaction with unactivated alkenes provided chromanes with excellent diastereo‐ and enantioselectivity. 相似文献
58.
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
59.
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
60.
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