An Efficient One‐Pot Regioselective Approach Towards the Synthesis of Thiopyrano[2,3‐d]thiazole‐2‐thiones Catalyzed by Basic Ionic Liquid under Microwave Irradiation

A green, regioselective protocol for the synthesis of thiopyrano[2,3‐d]thiazole‐2‐thiones catalyzed by basic ionic liquid [bmIm]OH has been developed. The reaction proceeds smoothly under microwave irradiation, and high yields of the products are obtained in very short reaction times (5–11 min). The ionic liquid plays a dual solvent‐catalyst role.     

用于吖内酯合成的二氧化钛纳米晶体材料PriyankaAnandgaonker,GaneshKulkarni,SureshGaikwad,AnjaliRajbhoj简

Titanium dioxide nanoparticles were prepared by a electrochemical reduction method using parameters such as current density, solvent polarity, distance between electrodes, and concentration of stabilizers to control the size of the nanoparticles. The nanoparticles were characterized by UV-Vis spectroscopy, X-ray diffraction, scanning electron microscopy and transmission electron microscopy, and their catalytic performance was tested for the synthesis of a series of 4-aryldiene-2-phenyl-5(4)-oxazolones from the cyclodehydration and condensation of the respective aldehyde, hippuric acid and acetic anhydride. Easy availability, reusability and eco-friendliness were some prominent features of the nanocrystalline titanium dioxide catalyst.     

用于吖内酯合成的二氧化钛纳米晶体材料(英文)

Titanium dioxide nanoparticles were prepared by a electrochemical reduction method using para-meters such as current density, solvent polarity, distance between electrodes, and concentration of stabilizers to control the size of the nanoparticles. The nanoparticles were characterized by UV-Vis spectroscopy, X-ray diffraction, scanning electron microscopy and transmission electron microsco-py, and their catalytic performance was tested for the synthesis of a series of 4-aryldiene-2-phenyl-5(4)-oxazolones from the cyclodehydration and condensation of the respec-tive aldehyde, hippuric acid and acetic anhydride. Easy availability, reusability and eco-friendliness were some prominent features of the nanocrystalline titanium dioxide catalyst.     

Combined ligand-based and structure-based design of PDE 9A inhibitors against Alzheimer’s disease

Molecular Diversity - PDE9 enzyme hydrolyzes cGMP, which is involved in the regulation of synaptic plasticity through the NMDA pathway (a well-known excitotoxic target for AD) via activation of...     

Static foam destruction: role of ultrasound

High intensity ultrasonic vibrations were used for destabilizing the static foam structure. Ultrasonic horn as a source of ultrasonic vibration was used for the destruction of the foam. The effect of the ratio of the horn to the column diameter on the drainage and collapse rate of foam has been analyzed. Further, an empirical correlation for the initial foam collapse rate in the presence of ultrasonic horn has been developed in terms of the initial liquid hold-up, surface tension of the surfactant solution and the ratio of horn diameter to the column diameter. Efficiency of the ultrasonic horn is related to the position of the tip of the horn. Periodic supply of ultrasonic vibrations was found to be a more viable option than the continuous supply in terms of saving in energy and operating cost for defoaming using ultrasound.     

Synthesis of 2-Benzoyl-3-aryl-N-arylsulphonylaziridines from the Reaction of N-Arylsulphonylimines with Dimethylsulphonium Phenacylide - The First Example of A Functionalized-Methylene Transfer to Azomethines

The first example of phenacyl group transfer from dimethylsulphonium phenacylide to N-arylsulphonylimines to yield 2-benzoyl-1-arylsulphonylaziridines is described.     

Discovering New Classes of <Emphasis Type="Italic">Brugia malayi</Emphasis> Asparaginyl-tRNA Synthetase Inhibitors and Relating Specificity to Conformational Change

SLIDE software, which models the flexibility of protein and ligand side chains while docking, was used to screen several large databases to identify inhibitors of Brugia malayi asparaginyl-tRNA synthetase (AsnRS), a target for anti-parasitic drug design. Seven classes of compounds identified by SLIDE were confirmed as micromolar inhibitors of the enzyme. Analogs of one of these classes of inhibitors, the long side-chain variolins, cannot bind to the adenosyl pocket of the closed conformation of AsnRS due to steric clashes, though the short side-chain variolins identified by SLIDE␣apparently bind isosterically with adenosine. We hypothesized that an open conformation of the motif 2 loop also permits the long side-chain variolins to bind in the adenosine pocket and that their selectivity for Brugia relative to human AsnRS can be explained by differences in the sequence and conformation of this loop. Loop flexibility sampling using Rigidity Optimized Conformational Kinetics (ROCK) confirms this possibility, while scoring of the relative affinities of the different ligands by SLIDE correlates well with the compounds’ ranks in inhibition assays. Combining ROCK and SLIDE provides a promising approach for exploiting conformational flexibility in structure-based screening and design of species selective inhibitors.     

Absorption and emission properties of 5-phenyl tris(8-hydroxyquinolinato) M(III) complexes (M = Al,Ga, In) and correlations with molecular electrostatic potential

Substituent effect for a series of 5-phenyl tris(8-hydroxyquinolinato) M(III) complexes (Mq3) of aluminum, gallium, and indium are investigated using density functional theory (DFT) for the ground state properties and the time-dependent version of DFT (TDDFT) for their absorption and emission properties. A comparison between the ground state energy of mer and fac isomers of all the complexes revealed that the mer configuration is always more stable than fac. The substituent effect is significantly reflected at the fluorescence maximum (λ_F) values whereas the effect is moderate at the absorption maximum (λ_abs) values. The molecular electrostatic potential (MESP) at the metal center (V_M) and the most electron rich region indicated by MESP minimum (V_min), located at the oxygen of phenoxide ring exhibit excellent correlations with the λ_F and Stokes shift (λ_F−λ_abs) values. The study suggests the use of Stokes shift as an experimental quantity to measure the excited state substituent effect while the V_min or V_M emerge as theoretical quantities to measure the same.