Estrone derived 2-naphthol analogue in the diastereoselective one-pot Betti-condensation

Molecular Diversity - The utility of deoxy-isoequilenine synthesized from estrone as valuable 2-naphthol analogue is demonstrated in the three components Betti-condensation. A simple, efficient and...     

Spectral characterization,antimicrobial and antibiofilm activity of poly(propylene imine) metallodendrimers in solution and applied onto cotton fabric

Abstract

Poly(propylene imine) dendrimers from first and third generation modified with 1,8-naphthalimide units and their Cu(II) complexes have been characterized by fluorescence and EPR spectroscopy. Cotton fabric has been modified with these dendrimers and their color characteristics were determined. The antimicrobial activity of dendrimer ligands and their Cu(II) complexes in solution and after their deposition on a cotton fabric was investigated. Good antibacterial effect of dendrimer ligands has been obtained, which is enhanced at their Cu(II) complexes. After their deposition on cotton fabric metallodendrimers exhibit good antibiofilm activity.     

Multiresidue determination of pesticides by solid-phase extraction and GC-MS for control of peach production in Bulgaria

A multiresidue analytical method based on acetone extraction and clean-up/pre-concentration on polymeric sorbents was validated for 42 pesticides in peach matrix in order to control safety of fresh production on the Bulgarian market. Matrix-matched calibration was used by addition of pesticides just before SPE. In this way the standards and the samples undergo exactly the same procedure and an improvement of recoveries for the target analytes was observed. The identification and quantification were done by gas chromatographic technique with mass-spectrometric detection (GC-MS). The limits of detection obtained were 0.005?mg?kg^–1 or lower for the most of analytes, and the recovery data were in range 73–109% at three spiked levels 0.01, 0.1 and 0.2?mg?kg^?1. The validated method was used for monitoring of selected pesticides in fresh peach fruits home production. Approximately 30% of the analysed lots (total 33 samples) contained residues mainly of cypermethrin and procymidone, but did not exceed EU MRLs.     

Modulation Effect on Tubulin Polymerization,Cytotoxicity and Antioxidant Activity of 1H-Benzimidazole-2-Yl Hydrazones

1H-benzimidazol-2-yl hydrazones with varying hydroxy and methoxy phenyl moieties were designed. Their effect on tubulin polymerization was evaluated in vitro on porcine tubulin. The compounds elongated the nucleation phase and slowed down the tubulin polymerization comparably to nocodazole. The possible binding modes of the hydrazones with tubulin were explored by molecular docking at the colchicine binding site. The anticancer activity was evaluated against human malignant cell lines MCF-7 and AR-230, as well as against normal fibroblast cells 3T3 and CCL-1. The compounds demonstrated a marked antineoplastic activity in low micromolar concentrations in both screened in vitro tumor models. The most active were the trimethoxy substituted derivative 1i and the positional isomers 1j and 1k, containing hydroxy and methoxy substituents: they showed IC₅₀ similar to the reference podophyllotoxin in both tumor cell lines, accompanied with high selectivity towards the malignantly transformed cells. The compounds exerted moderate to high ability to scavenge peroxyl radicals and certain derivatives—1l containing metha-hydroxy and para-methoxy group, and 1b-e with di/trihydroxy phenyl moiety, revealed HORAC values high or comparable to those of well-known phenolic antioxidants. Thus the 1H-benisimidazol-2-yl hydrazones with hydroxy/methoxy phenyl fragments were recognized as new agents exhibiting promising combined antioxidant and antineoplastic action.     

Optical,film surface and photovoltaic properties of PTB7-Fx-based polymer-organic solar cells prepared in ambient conditions

Bulk heterojunction organic solar cells based on active layer of PTB7-Fx (x?=?0–100), conjugated block copolymer incorporating benzo[1,2-b:4,5-b′]dithiophene and partly fluorinated thieno[3,4-b]thiophene units, and fullerene derivatives as phenyl C₆₁ and phenyl C₇₁ butyric acid methyl esters sandwiched between a transparent anode of indium tin oxide, a hole conducting layer of either poly(ethylene dioxythiophene) : polystyrene sulfonate or magnetron-sputtered molybdenum oxide and evaporated aluminum cathodes were fabricated. Polymer-organic thin films were prepared at 1:1.5 mass ratio of the donor:acceptor mixture and deposited from dichlorobenzene solution of different concentrations by spin coating in ambient conditions. To control the active layer morphology, the films were subjected either to post-deposition treatments (annealing) at different temperatures or incorporation of an additive such as diiodooctane. Optical transmission, film surface topography and thickness measurements were used to characterize the active layer. Test devices with the architecture described above were prepared and their current–voltage characteristics, quantum efficiency and impedance spectra were measured and used to compare the different active layers, architectures and deposition sequences.     

Raman and IR reflection micro‐spectroscopic study of Er:YAG laser treated permanent and deciduous human teeth

Permanent and deciduous human teeth treated by a dental Er‐doped yttrium‐aluminium‐garnet pulse laser (λ = 2940 nm) as well as by classical drilling tools under conditions typical of the clinical practice were studied by ultraviolet Raman and Fourier transform infrared (FTIR) reflection microspectroscopy. Enamel was analyzed by both spectroscopic methods, whereas dentine was studied only by FTIR reflection because of the high level of photoluminescence continuum background even when a wavelength of 325 nm was used in inelastic light scattering experiments. The applied energy and pulse frequency of the dental laser varied between 200 and 500 mJ and between 10 and 30 Hz, respectively. The most important result is that after the laser treatment, the hydroxyapatite structure in both permanent and deciduous enamel is preserved: the apatite Ca‐P‐O framework remains intact, and the content of channel OH^‐ groups is not changed within experimental uncertainties. The calcium‐phosphate framework of dentine also exhibits negligible laser‐induced changes. The only alterations in enamel induced by laser as well as by mechanical drilling are reduction of the amount of CO₃^2‐ in apatite and changes in the protein conformation. The laser impact on the organic material and carbonate groups is strongest for laser power of 8 W; for powers of 4 or 5 W, the combination of higher pulse energy and lower pulse frequency has less impact than the combination of lower energy and higher frequency. No differences between deciduous and permanent teeth in their resistivity to laser irradiation with λ = 2940 nm were detected. Copyright © 2013 John Wiley & Sons, Ltd.     

Thioctic acid amides: convenient tethers for achieving low nonspecific protein binding to carbohydrates presented on gold surfaces

The thioctic acid amides of 2'-aminoethyl alpha-d-mannopyranoside and 2'-aminoethyl alpha-1,3-d-mannopyranosyl (alpha-1,6-d-mannopyranosyl)-alpha-d-mannopyranoside presented on both planar and nanoparticle gold surfaces give higher specific and lower non-specific protein binding than the related 2'-thioethyl glycosides.