Removal of methylene blue by two zeolites prepared from naturally occurring Egyptian kaolin as cost effective technique

The optimum condition as well as adsorption behavior of two zeolite types prepared from Egyptian kaolin (namely, zeolite A and zeolite X) with methylene blue (MB) are demonstrated in this study. This will be a step to remove such dyes from textile as well as dying industries.MB removal was investigated using synthetic solutions at initial concentrations 15 mg/L of MB at constant temperature and pH (25 ± 0.1 °C and 7.5 ± 0.2) respectively. The removal efficiency was determined at different contact times and different zeolite doses.The optimum contact times for the removal of MB were 60 min and 75 min for zeolite X and zeolite A, respectively. 0.6 g was the optimum dose for removal of MB with both zeolite types.The batch method has been employed, using MB concentration in solution ranging from 2 to 25 mg/L. The percentage removal and distribution coefficients (K_d) were determined for the adsorption system as a function of sorbate concentration. The isothermal models investigated in this study show that adsorption ratios of MB on both zeolites match to Langmuir and Freundlich equation adding to that every equation constant has been calculated. According to the equilibrium studies, adsorption of zeolite X in higher concentrations is much better than that of zeolite A. Dublin–Kaganer–Radushkevich (DKR) shows physisorption endothermic adsorption process for both zeolites and also linear correlation of Redlich–Peterson and Tekman isothermal models were proved.These results show that zeolites prepared from naturally abundant Egyptian kaolin hold great potential to remove dying materials such as MB from wastewater. This will encourage using such low cost technique in removal of dyes from industrial wastewater.     

Ligational behaviour of lomefloxacin drug towards Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II), Th(IV) and UO(2)(VI) ions: synthesis, structural characterization and biological activity studies

Nine new mononuclear Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II), Th(IV) and UO₂(VI) complexes of lomefloxacin drug were synthesized. The structures of these complexes were elucidated by elemental analyses, IR, XRD, UV–vis, ¹H NMR as well as conductivity and magnetic susceptibility measurements and thermal analyses. The dissociation constants of lomefloxacin and stability constants of its binary complexes have been determined spectrophotometrically in aqueous solution at 25 ± 1 °C and at 0.1 M KNO₃ ionic strength. The discussion of the outcome data of the prepared complexes indicate that the lomefloxacin ligand behaves as a neutral bidentate ligand through OO coordination sites and coordinated to the metal ions via the carbonyl oxygen and protonated carboxylic oxygen with 1:1 (metal:ligand) stoichiometry for all complexes. The molar conductance measurements proved that the complexes are electrolytes. The powder XRD study reflects the crystalline nature for the investigated ligand and its complexes except Mn(II), Zn(II) and UO₂(II). The geometrical structures of these complexes are found to be octahedral. The thermal behaviour of these chelates is studied where the hydrated complexes lose water molecules of hydration in the first steps followed by decomposition of the anions, coordinated water and ligand molecules in the subsequent steps. The activation thermodynamic parameters are calculated using Coats–Redfern and Horowitz–Metzger methods. A comparative study of the inhibition zones of the ligand and its metal complexes indicates that metal complexes exhibit higher antibacterial effect against one or more bacterial species than the free LFX ligand. The antifungal and anticancer activities were also tested. The antifungal effect of almost metal complexes is higher than the free ligand. LFX, [Co(LFX)(H₂O)₄]·Cl₂ and [Zn(LFX)(H₂O)₄]·Cl₂ were found to be very active with IC50 values 14, 11.2 and 43.1, respectively. While, other complexes had been found to be inactive at lower concentration than 100 μg/ml.     

Antioxidant, anti-lipoxygenase and cytotoxic activity of Leptadenia pyrotechnica (Forssk.) decne polyphenolic constituents

Leptadenia pyrotechnica Forssk is a traditional medicinal herb used for treatment of inflammatory diseases and cancer. In this research, the aqueous ethanolic crude extract of Leptadenia pyrotechnica aerial parts, along with its ethyl acetate, n-butanol and water partitioning fractions were evaluated for their antioxidant capacity, polyphenolic content, anti-inflammatory and anti-cancer properties. The total antioxidant capacity was estimated by the FRAP, DPPH, ABTS and β-carotene bleaching assays.The ethyl acetate fraction exhibited the highest polyphenolic content (252.27 mg gallic acid/g) and the best antioxidant activity (1.2, 0.57, 0.45 mmol ascorbic acid equivalent/g in the FRAP, ABTS and DPPH assays, respectively). Furthermore, the same extract showed appreciable anti-inflammatory via lipoxygenase (LOX) inhibitory activity (IC?? = 1.41 μg/mL). Moreover, the ethyl acetate fraction also showed the strongest cytotoxic effect (IC?? = 43.16 μg/mL) against MCF-7 human breast cancer cell line. These results suggest that this plant may be considered an interesting source of compounds with antioxidant, anti-inflammatory and anti-cancer properties for therapeutic, nutraceutical and functional food applications.     

Design,synthesis, and in vitro anticancer screening of novel pyrazolinyl-pyrazole/1, 2, 3-triazole hybrids

Novel hybrids, pyrazolinylpyrazoles, and pyrazolinyltriazoles were designed, synthesized, and screened for their anticancer activity. Eleven compounds were selected by the National Cancer Institute (NCI)/USA for anticancer screening at single high dose (10⁻⁵ M) in full NCI 60 cell panels. Two compounds: 4-aminopyrazole-5-carbonitrile, 5c (NSC-747630/1) and ethyl 4-aminopyrazole-5- carboxylate, 7d (NSC-747634/1) were the most active candidates of the series and were selected for further evaluation at five dose screening as they displayed significant growth inhibition with full panel median growth inhibition (GI₅₀) 5.47 and 2.24 μM, respectively. Both 5c and 7d hybrids exhibited broad spectrum antitumor activity; however 7d showed moderate selectivity (selectivity ratio 3.6) toward leukemia.     

Pyrazolothiazoles: Synthesis and Applications

Abstract

Methods for the preparation of various fused pyrazolothiazoles were reviewed here for the first time. The main types of fused pyrazolothiazole are pyrazolo[5,1-b]thiazoles, pyrazolo[3,4-d]thiazoles, and pyrazolo[4,3-d]thiazoles. Some research and industrial application of pyrazolothiazoles are reported.     

Synthesis,characterization and cytotoxic activity of ferrocenyl hydrazone complexes containing a furan moiety

A ferrocenyl ligand 1 was prepared from condensation of 5-methyl-2-furaldehyde with l,l′-diacetylferrocene dihydrazone. This ligand forms 1:1 complexes with cobalt(II), nickel(II), copper(II) and zinc(II) 2–5 in good yield. Characterization of the ligand and complexes was carried out using infrared, nuclear magnetic resonance, mass spectra, electronic absorption, magnetic susceptibility, molar conductivity, and elemental analysis. Cytotoxic activity of the prepared ligand and its complexes were tested against different human cancer cell lines. The results suggested that the synthesized compounds were more potent than the comparative standards drugs used in most cases, whereas they had less activity in the others.     

Two fac‐tricarbonylrhenium(I) azadipyrromethene (ADPM) complexes: ligand‐substitution effect on crystal structure

The crystal structures of fac‐(acetonitrile‐κN)(2‐{[3,5‐bis(4‐methoxyphenyl)‐2H‐pyrrol‐2‐ylidene‐κN¹]amino}‐3,5‐bis(4‐<!?tlsb=0.2pt>methoxyphenyl)‐1H‐pyrrol‐1‐ido‐κN¹)tricarbonylrhenium(I)–hexane–acetonitrile (2/1/2), [Re(C₃₆H₃₀N₃O₄)(CH₃CN)(CO)₃]·0.5C₆H₁₄·CH₃CN, (2), and fac‐(2‐{[3,5‐bis(4‐methoxyphenyl)‐2H‐pyrrol‐2‐ylidene‐κN¹]amino}‐3,5‐bis(4‐methoxyphenyl)‐1H‐pyrrol‐1‐ido‐κN¹)tricarbonyl(dimethyl sulfoxide‐κO)rhenium(I), [Re(C₃₆H₃₀N₃O₄)(C₂H₆OS)(CO)₃], (3), at 150 K are reported. Both complexes display a distorted octahedral geometry, with a fac‐Re(CO)₃ arrangement and one azadipyrromethene (ADPM) chelating ligand in the equatorial position. One solvent molecule completes the coordination sphere of the Re^I centre in the remaining axial position. The ADPM ligand shows high flexibility upon coordination, while retaining its π‐delocalized nature. Bond length and angle analyses indicate that the differences in the geometry around the Re^I centre in (2) and (3), and those found in three reported fac‐Re(CO)₃–ADPM complexes, are dictated mainly by steric factors and crystal packing. Both structures display intramolecular C—H...N hydrogen bonding. Intermolecular interactions of the Csp²—H...π and Csp²—H...O(carbonyl) types link the discrete monomers into extended chains.     

Optimal timing decisions for the introduction of new technologies

High technology industries, such as the communications industry, are characterized by frequent development of new technologies. These new technologies are often available before the capacities of existing facilities that use an old technology are exhausted. Whenever a new technology facility is introduced, a fixed set-up cost is generally incurred; however, the annual operating costs are often reduced. The optimal timing of the introduction of new facilities is therefore of interest.In this paper, we examine such timing decisions. The study was motivated by an application involving electronic plug-in units that enhance the operation of communication facilities. First, we develop optimal timing decisions for linearly growing demand. The analysis is then extended to nonlinear demand. For linear demand, one of two decisions is optimal: Either introduce the new technology immediately, or as late as possible. However, for nonlinear demand, these decisions may be nonoptimal.