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Ensuring healthy lives and promoting well-being for all at all ages is the third goal of the sustainable development plan, so it was necessary to identify the most important problems that threaten health in our world. The World Health Organization declared that antibiotic resistance is one of the uppermost global public health threats facing humanity and searching for new antibiotics is slow. This problem can be approached by improving available drugs to combat various bacterial threats. To circumvent bacterial resistance, three copper(II) complexes based on the pefloxacin drug were prepared and characterized using analytical, spectroscopic, and thermal techniques. The resulting data suggested the formation of one octahedral binary and two distorted square pyramidal ternary complexes. Fluorescence spectra results revealed the formation of a turn-on fluorophore for amino acid detection. Computational calculations investigated quantum and reactivity parameters. Molecular electrostatic potential profiles and noncovalent bond interaction-reduced density gradient analysis indicated the active sites on the complex surface. The complexes were subjected to six microbial species, where the octahedral binary complex provoked its antimicrobial potency in comparison with ternary complexes. The enhanced antimicrobial activity against gram-negative bacterium E-coli compared to gentamicin was exhibited by the three complexes. Docking simulation was performed based on the crystal structure of E. coli and S. pneumoniae receptors using 5I2D and 6O15 codes. The binary complex exhibited a potent fitness score with 5I2D (TBE = − 107 kcal/mol) while ternary complexes displayed the highest docked score of fitness with 6O15. [ABSTRACT FROM AUTHOR]

We report the preparation of four nanosized isomers ofN-benzoyl-N′-(hydroxyphenyl) thioureas by nanoprecipitation. Direct reactions with CuCl2·2H2O gave the corresponding complexes in good yields. The structures of the ligands and their copper complexes were characterized using different analytical and spectroscopic measurements. In all complexes, the data revealed non-electrolytic mononuclear three-coordinate copper(I) complexes, where the ligand is hypodentate to copper ion via thioamide sulfur. Thermal studies revealed high thermal stability of the complexes compared to their parent ligands and the mechanism of decomposition and the thermodynamic parameters were evaluated. The ligands and their complexes were screened against different pathogenic microorganisms, and subjected toin vitroantioxidant and cytotoxic activities against three human cell lines. Compared to other isomers,N-benzoyl-N′-(o-hydroxyphenyl) thiourea exhibited significant antimicrobial activity and had higher activity than the standard fungicides and bacteriocides. All copper complexes showed inhibitory potencies, however [Cu(H2L2)2Cl] exhibited remarkable inhibitory activities against the examined cancer cell lines as evident by the range of IC50values (4.0–7.4 μg/mL) and the percentage of cell viability. The results obtained can find medical applications as new therapeutic nanoparticle agents. [ABSTRACT FROM AUTHOR]

We report the preparation of thermally stable spherical sulfonated aramides nanoparticles and their copper(II) complexes. Metal chelation with copper ions furnished polymeric complexes in a 1 : 2 ratio with square planar geometries as judged by their IR, UV, electron spin resonance, and elemental analysis data. The direct-current electrical conductivities demonstrated the semiconducting nature of the polymeric particles and their copper complexes. Dielectric loss analysis studies showed spectral peaks appearing at characteristic frequencies, which suggested the presence of relaxing dipoles in all of the polymers. All loss peaks were shown on a linear frequency scale and appeared in the range of 1 decade, and no overlap was observed in any of the samples, whereas in the normal polymer's dielectric loss behavior, each peak covered more than 1 decade. Moreover, the peak positions did not change with increasing temperature; this indicated a nonactivated process. The reported dielectric results revealed anomalous behavior, which has not been reported before for such polymeric analogues, as the polarization in these cases was limited by nonthermal forces, and a steady-state constant polarization was produced by an applied field. A simple method for the formation of a microporous semiconducting thin film of a polymer derived from isophthalic acid and diaminodiphenylsulfone is described. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 [ABSTRACT FROM AUTHOR]

Background: The introduction of pendent bulky groups along the polymer backbone results in a less ordered polymer matrix and increases the solubility characteristics without affecting thermal properties. The inclusion of chromogenic chemical moieties in the chains can give rise to the luminescent converter material which permits the preparation of materials with potential applications. Aromatic polymers containing heterocyclic rings in the main chain are known for their high thermal resistance, good hydrolytic stability, low dielectric and tough mechanical properties. There is currently much research directed towards the discovery of new blue light-emitting polymers, with characteristics of high efficiency and high reliability. Herein, we describe the preparation of aromatic polyamides and poly (1,3,4-oxadiazole-amide)s nanoparticles with pendant structures comprised of m- and p-acetoxybenzamide groups, where the acetoxybenzamide groups act as signaling units due to their fluorescent and chromogenic characteristics. Results: Aromatic polyamides and poly(1,3,4-oxadiazole-amide)s nanoparticles with pendant structures comprised of m- and p-acetoxybenzamide groups were successfully prepared and characterized using different analytical methods. Most polyamides were obtained as well-separated spherical nanoparticles while aramide containing pyridine produced aggregated particles attributed to the molecular self assembly via H-bond directed organization of molecular precursors. The thermal behavior of all polymers exhibited two major thermal decompositions due to the subsequent breakage of the acetoxy group in the lateral chain and cleavage of the main amide bonds. Photoluminescence studies revealed that the blue emissions for the polyamide derived from benzidine were blue-shifted (shifted to a lower wavelength) compared to that of polyamides containing flexible linkages. Conclusions: We report the synthesis of aromatic polyamides and poly(1,3,4-oxadiazole-amide)s nanoparticles with pendant structures comprised of m- and p-acetoxybenzamide groups. The thermal behavior of all polymers exhibited two major decompositions due to breakage of the acetoxy group in the lateral chain and cleavage of the main amide bonds. Structure- photoluminescence correlation demonstrated an interesting connection between structural modification and optical properties. The blue emissions for the polyamide derived from benzidine, attributed to the highly conjugation system, was blue shifted with the introduction of flexible linkages. The prepared polymers dissolved in warm polar aprotic solvents. Further investigations to obtain films with reasonably good mechanical properties for different applications are in progress. [ABSTRACT FROM AUTHOR]

We report the synthesis of aramide nanoparticles containing a chiral N-phthaloyl valine moiety and their antioxidant activities on hepatic contents of cytochrome P450, amidopyrene N-demethylase, aniline-4-hyroxylase and induced the hepatic content of cytochrome b5 and nicotinamide adenine dinucleotide phosphate (NADPH) cytochrome C-reductase. Polymers were obtained as well-separated spherical nanoparticles while highly aggregated particles via H-bonding organization of the aramide-containing pyridine led to a thin layer formation. The effects of the nanoparticles and CCl4 on enzyme activities and thiobarbituric acid reactive substances (TBARS) levels of male rat liver were studied. Pretreatments of rats with the polyamides prior to the administration of CCl4 decreased the hepatic content of the tested enzymes. Doses reduced the toxic effects exerted by (• CCl3) upon the liver through inhibition of the cytochrome P450 system. Inhibition of such metabolizing enzymes could reduce the carcinogenic effects of chemical carcinogens. [ABSTRACT FROM AUTHOR]