Synthesis,Characterization, and Antioxidant Evaluation of Some Novel Pyrazolo[3,4‐c][1,2]diazepine and Pyrazolo[3,4‐c]pyrazole Derivatives

5‐Hydrazineyl‐3‐methyl‐1H‐pyrazole ( 1 ) was used as a starting material for the synthesis of novel pyrazolo[3,4‐c][1,2]diazepine derivatives 3 , 4 , and 6a,b by its reaction with acetylacetone, ethyl acetoacetate, and isatylidene derivatives 5a,b , respectively. Also, pyrazolo[3,4‐c][1,2]diazepine derivative 11 was synthesized via multicomponent reaction of 1 , benzaldehyde, and malononitrile. Moreover, compound 1 was used for synthesis novel pyrazolo[3,4‐c]pyrazole derivative 7 by its reaction with isatin. In addition, pyrazolo[3,4‐c]pyrazole derivatives 18a–c were synthesized by treatment of 2‐cyano‐N′‐(3‐methyl‐1H‐pyrazol‐5‐yl)acetohydrazide ( 13 ) with aromatic aldehydes 16a–c . The newly synthesized compounds were valeted by means of analytical and spectral data. All newly synthesized compounds were screened for their antioxidant activities. Compounds 3 , 13 , 18b , and 18c showed higher radical‐scavenging activities.     

Optical Characterization of Zinc Pyrithione

Zinc pyrithione is ubiquitous in commercial products particularly antidandruff shampoos. For the efficacy of zinc pyrithione therapeutic cleansers to be assessed accurately, the distribution of particles on the scalp needs to be visualized. Currently, no technique is available which provides the chemical specificity and sensitivity required. Here, we report application of fluorescence‐lifetime imaging microscopy (FLIM) for high‐contrast mapping of zinc pyrithione distribution on the scalp. Characterization of the zinc pyrithione emission by using both one‐photon excitation at five specific wavelengths and two‐photon excitation in the range of 740–820 nm revealed its FLIM fingerprint—a characteristic short average time‐weighted emission lifetime of Τ_ZnPT = 250 ps. Bandpass‐filtering FLIM signals at Τ_ZnPT enabled an efficient discrimination between the zinc pyrithione and major endogenous skin species in comparison with that of the conventional reflectance confocal microscopy. Our findings provide means for in vivo high‐sensitivity assaying and high‐contrast imaging of zinc pyrithione in biological systems.     

Anti-Influenza a virus of a new oligosaccharide citric acid derivative isolated from Vigna angularis (ohwi et ohashi. var. Dainagon) Seeds

A new oligosaccharide citric acid derivative was isolated by hot aqueous extraction at 85?°C from Vigna angularis seeds, and it was purified using anion exchange chromatography DE-52. The structure was inferred by using UV, 1?D and 2?D NMR spectroscopy and HR-MALDI/MS, and identified as α-D-galactopyranosyl-(1→6)-α-D-galactopyranosyl-(1→6)-α-D-glucopyranosyle-(1→2)-β-D-fructofuranosyle citric acid. The isolated oligosaccharide citric acid derivative revealed promising anti-influenza A virus with 50% inhibition concentration (IC₅₀) of 0.162?nM/mL and 50% cytotoxic dose (CC₅₀) of >2.38?nM/mL.     

Two-Point Resistance on the Centered-Triangular Lattice

The resistance between any two lattice points in an infinite,centered-triangular lattice of equal resistors is determined using the lattice Green function method.It is shown that the two-point resistance on the centeredtriangular lattice is expressed in terms of the resistance of a triangular lattice.Some exact values for the resistance near the origin of the lattice are presented.For large separation between lattice points the asymptotic forms of the resistance are calculated.     

Configurational phase transition in AuxCu1−x nano-alloy: first principle and Monte-Carlo calculations

We report on the calculation of phase transition in the configurational state (i.e. atomic arrangement) of Au_xCu_1?x nanoparticle (or nano-alloy). The cluster expansion, represented by the formation energies of several atomic configurations, has been determined from full potential, linearized augmented-plane-wave first-principle calculation. The cluster expansion was then used as a Hamiltonian for the Monte-Carlo calculation of the phase transition between the configurational ground states (gs). Clear observation of plateau structures, associated with the calculated ‘gs’, in the plane of the composition (x) versus the chemical potential, have been observed at low temperatures <100?K. The plateaus smeared out at higher temperatures, giving rise to the order–disorder transition as the temperature rises. The critical temperature for this transition was estimated at 100?K, agreeing with the reported trend of the transition temperature with the nano-alloy size. Our results are thus relevant to applications concerning deposition of dispersed (i.e. well separated) nano-alloys.     

Synthesis,in vitro $$\alpha $$-glucosidase inhibitory activity,and in silico study of ( E)-thiosemicarbazones and ( E)-2-(2-(arylmethylene)hydrazinyl)-4-arylthiazole derivatives

This study is focused on the identification of thiazole-based inhibitors for the \(\alpha \)-glucosidase enzyme. For that purpose, (E)-2-(2-(arylmethylene)hydrazinyl)-4-arylthiazole derivatives were synthesized in two steps and characterized by various spectroscopic techniques. All derivatives and intermediates were evaluated for their in vitro \(\alpha \)-glucosidase inhibitory activity. Thiosemicarbazones 20 and 35, and cyclized thiazole derivatives 2, 5–11, 13, 15, 21–24, 27–31, and 36–37 showed significant inhibitory potential in the range of \(\hbox {IC}_{50}=6.2\pm 0.19\)–\(43.6\pm 0.23~\upmu \hbox {M}\) as compared to standard acarbose (\(\hbox {IC}_{50}=37.7\pm 0.19~\upmu \hbox {M}\)). A molecular modeling study was carried out to understand the binding interactions of compounds with the active site of enzyme.     

Theoretical Study of the Electronic and Optical Properties to Design Dye-Sensitivity for Using in Solar Cell Device

In this work, the structural and optoelectronic properties of phenanthrene-1,3,4-thaidiazoles oligomers were calculated using density functional theory (DFT) at B3LYP/6-31G(d) basis set level, to evaluate their possible application as organic semiconductor materials in photovoltaic and solar cell devices. For this reason, the energy gaps, frontier orbital (HOMO, and LUMO) distributions, total energies, Fermi level energies, work functions and maximum wavelength absorption, vertical absorption energies, and oscillator strengths have been investigated and discussed. The structures of phenanthrene-1,3,4-thiadiazoles oligomers are expanded from 1 to 10 thiadiazole monomeric units, to examine the increase of thiadiazole monomeric units on the optoelectronic properties. We observed that increased the number of monomeric units lead to significantly enhance the optoelectronic properties, which caused to decrease the gap energy from 3.69 eV in the structure with one thiadiazole ring just to 2.36 eV with 10 units. These changes give the shift of maximum absorption wavelengths from 376 to 578 nm. Consequently, these molecules have main absorption bands within the solar spectrum, to give the best performance for photovoltaic and organic solar cells devices.     

An Electric Fish-Based Arithmetic Optimization Algorithm for Feature Selection

With the widespread use of intelligent information systems, a massive amount of data with lots of irrelevant, noisy, and redundant features are collected; moreover, many features should be handled. Therefore, introducing an efficient feature selection (FS) approach becomes a challenging aim. In the recent decade, various artificial methods and swarm models inspired by biological and social systems have been proposed to solve different problems, including FS. Thus, in this paper, an innovative approach is proposed based on a hybrid integration between two intelligent algorithms, Electric fish optimization (EFO) and the arithmetic optimization algorithm (AOA), to boost the exploration stage of EFO to process the high dimensional FS problems with a remarkable convergence speed. The proposed EFOAOA is examined with eighteen datasets for different real-life applications. The EFOAOA results are compared with a set of recent state-of-the-art optimizers using a set of statistical metrics and the Friedman test. The comparisons show the positive impact of integrating the AOA operator in the EFO, as the proposed EFOAOA can identify the most important features with high accuracy and efficiency. Compared to the other FS methods whereas, it got the lowest features number and the highest accuracy in 50% and 67% of the datasets, respectively.     

The Impact of Apple Variety and the Production Methods on the Antibacterial Activity of Vinegar Samples

Apple vinegar is a natural product widely used in food and traditional medicine as it contains many bioactive compounds. The apple variety and production methods are two factors that play a major role in determining the quality of vinegar. Therefore, this study aims to determine the quality of apple vinegar samples from different varieties (Red Delicious, Gala, Golden Delicious, and Starking Delicious) prepared by three methods using small apple pieces, apple juice, and crushed apple, through determining the physicochemical properties and antibacterial activity of these samples. The antibacterial activity was studied against five pathogenic bacteria: Staphylococcus aureus, Klebsiella pneumonia, Escherichia coli (ATB: 57), Escherichia coli (ATB: 97), and Pseudomonas aeruginosa, using two methods, disk diffusion and microdilution, for determining the minimum inhibitory concentrations and the minimum bactericidal concentrations. The results of this study showed that the lowest pH value was 3.6 for Stark Delicious, obtained by liquid fermentation, and the highest acetic acid values were 4.7 and 4% for the vinegar of Red Delicious and Golden Delicious, prepared by solid fermentation, respectively. The results of the antibacterial activity showed considerable activity of apple vinegar on the tested strains. Generally, the Staphylococcus aureus strain appears less sensitive and Pseudomonas aeruginosa seems to be very sensitive against all samples, while the other strains have distinct sensitivities depending on the variety studied and the method used. A higher antibacterial activity was found in vinegar obtained by the apple pieces method and the Red Delicious variety, with a low MIC and MBC recorded, at 1.95 and 3.90 µL/mL, respectively. This study has shown that the choice of both apple variety and production method is therefore an essential step in determining and aiming for the desired quality of apple vinegar.     

Synthesis and stereochemical analysis of some norephedrine‐derived isoxazolidines

The diastereoselectivity in the cycloaddition reactions of several mono‐ and disubstituted alkenes with a (‐)norephedrine‐derived methylenenitrone has been investigated. The stereochemical analysis of the addition products (i.e., isoxazolidines) has been carried out by X‐ray, NMR, and chemical conversions. The NMR spectra of the isoxazolidines at low temperatures indicated the presence of either a single or a predominant invertomer. The stereochemistry of the invertomers and nitrogen inversion barriers are determined using complete line‐shape analysis and their dependence on solvent is discussed. Copyright © 2008 John Wiley & Sons, Ltd.