One-pot multi-component synthesis of novel chromeno[4,3-b]pyrrol-3-yl derivatives as alpha-glucosidase inhibitors

Molecular Diversity - A green and efficient one-pot multi-component protocol was developed for the synthesis of some novel dihydrochromeno[4,3-b]pyrrol-3-yl derivatives through the reaction of...     

Novel Fe3O4/hydroxyapatite/β‐cyclodextrin nanocomposite adsorbent: Synthesis and application in heavy metal removal from aqueous solution

The increased global concern on environmental protection has made researchers focus their attention on new and more efficient methods of pollutant removal. In this research, novel nanocomposite adsorbents,i.e., magnetic hydroxyapatite (Fe₃O₄@HA) and magnetic hydroxyapatite β‐cyclodextrin (Fe₃O₄@HA‐CD) were synthesized and used for heavy metal removal. The adsorbents were characterized by FTIR, XRD, TGA, VSM, and SEM. In order to investigate the effect of β‐cyclodextrin (β‐CD) removal efficiency, adsorption results of nine metal ions were compared for both adsorbents. β‐CD showed the most increasing effect for Cd²⁺ and Cu²⁺ removal, so these two ions were selected for further studies. The effect of diverse parameters including pH, contact time, initial metal ion concentration and adsorbent dosage on the adsorption process was discussed. The optimum pH was 6 and adsorption equilibrium was achieved after 1 hr. Adsorption kinetic data were well fitted by pseudo‐second‐order model proposing that metal ions were adsorbed via chemical reaction. Adsorption isotherm was best described by the Langmuir model, and maximum adsorption capacity for Cd²⁺ and Cu²⁺ was 100.00 and 66.66 (mg/g), respectively. Desorption experiment was also done, and the most efficient eluent used for desorption of metal ions was EDTA (0.001 M) with 91% and 88% of Cd²⁺ and Cu²⁺ release, respectively. Recyclability studies also showed a 19% decrease in the adsorption capacity of the adsorbent after five cycles of regeneration. Therefore, the synthesized adsorbents were recognized as potential candidates for heavy metal adsorption applications.     

Calculation of surface tension of metals using density gradient theory and PC-SAFT equation of state

The Cahn-Hilliard theory was combined with PC-SAFT equation of state (EOS), in order to describe both the phase behaviors and the surface tension of different types of metals (Li, Na, K, Rb, Cs, Mg, Ca, Sr, Ba, Fe, Zn, Cd, In, Sn, Pb, and Bi). The only two inputs of the theory are the Helmholtz free-energy density and the influence parameter. The PC-SAFT equation of state was applied to determine Helmholtz free-energy density and bulk properties. The influence parameter is obtained by fitting to the experimental data of surface tension. The results show a useful possibility to calculate surface tensions which are in satisfactory agreement with experimental data.     

Voltammetric investigation and amperometric detection of the bisphosphonate drug sodium alendronate using a copper nanoparticles-modified electrode

The electrochemical behavior of sodium alendronate on copper microparticle- and copper nanoparticle-modified carbon paste electrodes was investigated. In the voltammograms recorded using microparticles, a single anodic oxidation peak appeared, while using nanoparticles, two anodic peaks appeared. The anodic currents were related to the electrocatalytic oxidation of alendronate via the active species of Cu(III). The catalytic rate constant for the electrocatalytic oxidation process and the diffusion coefficient of alendronate were obtained to be 1.57 × 10³ cm³ mol⁻¹ s⁻¹ and 2.44 × 10⁻⁶ cm² s⁻¹, respectively. A sensitive and time-saving detection procedure was developed for the analysis of alendronate, and the corresponding analytical parameters were reported. Alendronate was determined with a limit of detection of 11.26 μmol L⁻¹ with a linear range of 50–6,330 μmol L⁻¹. The proposed amperometric method was applied to the analysis of commercial pharmaceutical tablets, and the results were in good agreement with the declared values.     

Enzymatic Treatment and Detoxification of Acid Orange 7 from Textile Wastewater

A crude preparation of horseradish roots was used as a low-purity source of horseradish peroxidase (HRP) in dye decolorization experiments. The technical feasibility of the process was studied in bench scale for enzymatic removal of acid orange 7 (AO7), a synthetic dye. Further studies were carried out to understand the effects of process parameters such as pH value, H(2)O(2) level, concentrations of the synthetic dye, and HRP during enzyme-mediated dye degradation. Experimental data revealed that the concentration of AO7, pH of the aqueous phase, amount of the enzyme, and H(2)O(2) level played significant roles on the overall enzymatic reaction. Polyethylene glycol, as an anti-inactivation of HRP, in various concentrations showed no significant effect on the decolorization. The experimental data of initial reaction rates were fitted using an analytical equation proposed by Michaelis-Menten. The acute toxicity tests using Daphnia magna exhibited that the enzymatic treatment significantly decreased the toxicity of the dye solution.     

Photoluminescent zinc oxide polymer nanocomposites fabricated using picosecond laser ablation in an organic solvent

Nanocomposites made of ZnO nanoparticles dispersed in thermoplastic polyurethane were synthesized using picosecond laser ablation of zinc in a polymer-doped solution of tetrahydrofuran. The pre-added polymer stabilizes the ZnO nanoparticles in situ during laser ablation by forming a polymer shell around the nanoparticles. This close-contact polymer shell has a layer thickness up to 30 nm. Analysis of ZnO polyurethane nanocomposites using optical spectroscopy, high resolution transmission electron microscopy and X-ray diffraction revealed that oxidized and crystalline ZnO nanoparticles were produced. Those nanocomposites showed a green photoluminescence emission centred at 538 nm after excitation at 350 nm, which should be attributed to oxygen defects generated during the laser formation mechanism of the monocrystalline nanoparticles. Further, the influence of pulse energy and polymer concentration on the production rate, laser fluence and energy-specific mass productivity was investigated.     

Synthesis of 4-alkylaminoimidazo[1,2-a]pyridines linked to carbamate moiety as potent α-glucosidase inhibitors

Molecular Diversity - In this work, various imidazo[1,2-a]pyridines linked to carbamate moiety were designed, synthesized, and evaluated for their α-glucosidase inhibitory activity. Among...     

New ciprofloxacin–dithiocarbamate–benzyl hybrids: design,synthesis, antibacterial evaluation,and molecular modeling studies

Research on Chemical Intermediates - We designed and synthesized a series of new ciprofloxacin–dithiocarbamate–benzyl hybrids 5a–n as potential antibacterial agents. All of the...     

Synthesis and antibacterial activity of new N-[2-(thiophen-3-yl)ethyl] piperazinyl quinolones

As a part of continuing search for potential antibacterial agents in the quinolones field, we have synthesized novel quinolone agents bearing N-[2-(thiophen-3-yl)ethyl] piperazinyl moiety in the 7-position of the quinolone ring. In vitro antibacterial evaluation of the target compounds showed that N-[2-(thiophen-3-yl)ethyl] group attached to piperazine ring served as promising C-7 substituent for piperazinyl quinolone antibacterials. Among these derivatives, ciprofloxacin analogues, containing N-[2-(thiophen-3-yl)-2-hydroxyiminoethyl] or N-[2-(thiophen-3-yl)-2-methoxyiminoethyl] residue provided a high inhibition against all the tested Gram-positive organisms including methicillin-resistant Staphylococcus aureus comparable or superior with respect to the reference drugs norfloxacin and ciprofloxacin.