Selective oxidation of cyclohexane by a Ru(III) analogue of the gif-system. RuIIIacetic acid-pyridine-KHSO5

Selective oxidation of cyclohexane to cyclohexanone was carried out in a RuCl₃-pyridine-acetic acid-KHSO₅ mixture. This system yields 2.8% of cyclohexanone (based on oxone concentration) under the conditions employed. Mechanistic postulate for the oxidation reaction involves the formation of a carbene intermediate (Ru=C) prior to the ketone formation.     

Cell Penetrating Synthetic Antimicrobial Peptides (SAMPs) Exhibiting Potent and Selective Killing of Mycobacterium by Targeting Its DNA

Naturally occurring antimicrobial peptides (AMPs) are powerful defence tools to tackle pathogenic microbes. However, limited natural production and high synthetic costs in addition to poor selectivity limit large‐scale use of AMPs in clinical settings. Here, we present a series of synthetic AMPs (SAMPs) that exhibit highly selective and potent killing of Mycobacterium (minimum inhibitory concentration <20 μg mL^?1) over E. coli or mammalian cells. These SAMPs are active against rapidly multiplying as well as growth saturated Mycobacterium cultures. These SAMPs are not membrane‐lytic in nature, and are readily internalized by Mycobacterium and mammalian cells; whereas in E. coli, the lipopolysaccharide layer inhibits their cellular uptake, and hence, their antibacterial action. Upon internalization, these SAMPs interact with the unprotected genomic DNA of mycobacteria, and impede DNA‐dependent processes, leading to bacterial cell death.     

Devitrification properties of lead borate glasses

Lead borate glasses containing 30 to 60?mol% PbO were prepared by melt quenching technique and devitrified by long duration heat treament in the supercooled region. Glasses crystallized on heating above their glass transition temperature, and the crystalline phases produced on devitrification were characterized by XRD and DSC analyses. Glass with 30?mol% PbO slowly formed a solid solution of Pb₆B₁₀O₂₁ and Pb₅B₈O₁₇ crystalline phases, while glasses with 40 and 50?mol% PbO formed a mixture of Pb₆B₁₀O₂₁, Pb₅B₈O₁₇ and the remanent glassy phase. Glasses with higher PbO concentration of 56 to 60?mol% devitrified completely and produced only Pb₅B₈O₁₇ crystalline phase. Lead borate glasses with PbO concentration of 40 to 50?mol% showed maximum thermal stability against devitrification, the ease of crystallization of glasses was correlated with the fraction of tetrahedral borons in them.     

INVERSION OF ELECTRON TOMOGRAPHY IMAGES USING L^2-GRADIENT FLOWS -- COMPUTATIONAL METHODS

In this paper,we present a stable,reliable and robust method for reconstructing a three dimensional density function from a set of two dimensional electric tomo...     

Applicability of Reddish-Orange Light Emitting Samarium (III) Complexes for Biomedical and Multifunctional Optoelectronic Devices

Six crimson samarium (III) complexes based on β-ketone carboxylic acid and ancillary ligands were synthesized by adopting the grinding technique. All synthesized complexes were investigated via elemental analysis, infrared, UV–Vis, NMR, TG/DTG and photoluminescence studies. Optical properties of these photostimulated samarium (III) complexes exhibit reddish-orange luminescence due to ⁴G_5/2?→?⁶H_7/2 electronic transition at 606 nm of samarium (III) ions. Further, energy bandgap, color purity, CIE color coordinates, CCT and quantum yield of all complexes were determined accurately. Replacement of water molecules by ancillary ligands enriched these complexes (S2-S6) with decay time, quantum yield, luminescence, energy bandgap and biological properties than parent complex (S1). Interestingly, these efficient properties of complexes may find their applications in optoelectronics and lighting systems. In addition to these, the antioxidant and antimicrobial assays were also investigated to explore the applications in biological assays.

     

Palladium acetate assisted synthesis of five-membered N-polyheterocycles

Abstract

The metal-assisted synthesis of heterocyclic compounds is known to be one of the extremely developing as well as significant concepts of organic chemistry. Because of their expensive, complex working of the instrument and difficult procedures, the methodologies used earlier for the heterocycle synthesis were less amicable to the researchers. The Pd(OAc)₂-mediated cyclic reactions have been recognized to be very effective for both the stereoselective as well as regioselective formation of the 5-membered N-bearing heterocyclic compounds. The different uses of palladium acetate, as a catalyst in the formation of 5-membered N-containing polyheterocycles, are covered in this review article.