Synthesis of 2-Azobenzo[b]thiophene Derivatives and Their Application on Nylon Fibre

A series of novel monoazo disperse dyes derived from the coupling of diazotized 2-aminobenzo[b]thiophene derivatives with N-arylmaleimides is described. The monoazo disperse dyes applied to nylon fabric and their dyeing performance has been assessed. These dyes have been found to give light yellow to reddish pink color shades with very good depth and levelness on nylon fabric. The dyed fabric shows moderate light fastness and excellent washing, rubbing, perspiration, and sublimation fastness. The percentage dyebath exhaustion on nylon fabric has been found to be good and acceptable.     

Cyclodehydration of 1,4-butanediol catalyzed by metal(IV) phosphates

Metal(IV) phosphates of tin, zirconium and titanium in different morphological forms, viz. amorphous, calcined and crystalline, have been used as catalysts for selective cyclodehydration of 1,4-butanediol to tetrahydrofuran. A comparative study of the three catalysts for the above reaction has been carried out to understand the effect of their composition and morphology on the catalytic activity.     

In(OTf)3 catalyzed reductive etherification of 2-aryloxybenzaldehydes and 2-(arylthio)benzaldehydes

2-Aryloxybenzaldehydes and 2-(arylthio)benzaldehydes undergo reductive etherification in presence of 5 mol% In(OTf)₃ and stoichiometric amount of Et₃SiH under solvent free conditions to generate novel symmetrical dibenzyl ethers and thioethers in excellent yields. In(OTf)₃ is found to be superior in terms of catalytic activity over the other metal triflates tested for the reaction. Xanthenes and thioxanthenes, as anticipated, could not be obtained under these conditions.     

Palladium catalyzed domino C-H activation strategy: An access to 9- fluorenones

Palladium catalyzed domino C-H functionalization reaction of arylaldehyde with dihaloarene has been developed to access 9-flourenone molecules. Bidentate ligand assisted strategy, single step reaction, high yield and excellent functional group tolerance make this method concise and effective for the synthesis of 9-flourenone. In addition, proposed method has been successfully employed to synthesise Tilorone in gram scale.     

Effect of monovalent ion binding on molecular dynamics of the S100-family calcium-binding protein calbindin D9k

Calbindin D_9k is a member of the S100 subfamily of EF-hand calcium binding proteins, and has served as an important model system for biophysical studies. The fast timescale dynamics of the calcium-free (apo) state is characterized using molecular dynamics simulations. Order parameters for the backbone NH bond vectors are determined from the simulations and compared with experimentally derived values, with a focus on the dynamics of calcium-binding site I. There is a significant discrepancy between simulated and experimental order parameters for site I residues in the case of no ion bound in site I. However, it was found in the simulations that a Na⁺ ion can bind in site I, and the resulting order parameters determined from the simulations are in excellent agreement with experiment. Comparisons are made to X-ray structures of other S100 family members in which Na⁺ ions were observed or suggested to be bound in site I. © 2019 Wiley Periodicals, Inc.     

Directed evolution experiments reveal mutations at cycloartenol synthase residue His477 that dramatically alter catalysis

[reaction: see text] Cycloartenol synthase cyclizes and rearranges oxidosqualene to the protosteryl cation and then specifically deprotonates from C-19. To identify mutants that deprotonate differently, randomly generated mutant cycloartenol synthases were selected in a yeast lanosterol synthase mutant. A novel His477Asn mutant was uncovered that produces 88% lanosterol and 12% parkeol. The His477Gln mutant produces 73% parkeol, 22% lanosterol, and 5% Delta(7)-lanosterol. These are the most accurate lanosterol synthase and parkeol synthase that have been generated by mutagenesis.     

Fluorinated ionic surfactant microemulsions in hydrofluorocarbon 134a (HFC 134a)

The factors influencing the formation of water-in-134a-propellant microemulsions using the fluorinated ionic surfactants ammonium perfluorooctanoate, ammonium perfluoroheptanoate, and sodium perfluorooctanoate has been determined. None of the fluorinated ionic surfactants could be used to prepare clear, one-phase systems when used as sole surfactant, but they could be when combined with a short-chain fluoro- or hydrocarbon alcohol in surfactant:cosurfactant weight-mixing ratios (K(m)) in the range 1:2 to 2:1. When hydrocarbon alcohols were used this clear region extended over a wide range of compositions and was confirmed by means of photon correlation spectroscopy (PCS) to contain microemulsion droplets in the propellant-rich part of the phase diagram. PCS studies performed in the presence of the water-soluble drug terbutaline sulfate showed that it was possible to solubilize the drug within water-in-propellant microemulsion droplets. These studies confirm for the first time that it is possible to prepare water-in-propellant 134a microemulsions using fluorinated ionic surfactants and to solubilize water-soluble drugs within these systems.     

Synthesis,In Vitro Biological Screening,and In Silico Computational Studies of Some Novel Imidazole‐2‐thiol Derivatives

Substituted imidazole analogues 2‐((5‐acetyl‐4‐methyl‐1‐phenyl‐1H‐imidazole‐2‐yl)thio)‐N‐phenylacetamides ( 3a – 3m ) have been synthesized from 1‐[1‐(phenyl)‐2‐mercapto‐4‐methyl‐1H‐imidazol‐5‐yl]‐ethanone ( 1a – 1e ) and 2‐chloro‐N‐phenylacetamide ( 2a – 2i ) in the presence of potassium carbonate as a catalyst in dimethylformamide under microwave irradiation as well as conventional method. Structures of the obtained compounds have been confirmed by advance spectroscopic techniques such as IR, ¹H NMR, ¹³C NMR, and mass spectrometry. All the synthesized compounds were tested for their in vitro antimicrobial and antituberculosis activities. Good antibacterial molecules were further screened for the bacterial resisted cell line, from which compound 3b shows maximum inhibition. In silico molecular docking study was carried out to discover the binding affinity of synthesized compounds with active site of transferase (PDB ID: 1HNJ) and antibiotic resistance (PDB ID: 1W3R) protein. Moreover, molecular dynamics study of the 3b ‐1W3R complex has also been performed, as 3b has a good antibacterial activity as compared with other.