Green Synthesis of Zinc Oxide Nanoparticles Using Pomegranate Fruit Peel and Solid Coffee Grounds vs. Chemical Method of Synthesis,with Their Biocompatibility and Antibacterial Properties Investigation

This research aims to investigate the synthesis, characterization, and evaluation of the biocompatibility and antibacterial activity of novel zinc oxide (ZnO) nanoparticles (NPs) prepared by Punica granatum peel and coffee ground extracts as the reducing and capping agents. Chemically synthesized ZnONPs were prepared using zinc acetate dihydrate and sodium hydroxide as reducing precursors. ZnONPs were characterized using an ultraviolet-visible spectrophotometer (UV-VIS), X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), and Fourier transform infrared (FTIR) spectroscopy. Peaks of UV spectra were 300 nm for ZnONPs_PPE, 320 nm (ZnONPs_CE), 290 nm, and 440 nm (ZnONP_Chem), thereby confirming ZnONPs formation. The X-ray diffractograms revealed their hexagonal structure. TEM micrographs of the biosynthesized ZnONPs revealed their hexagonal pattern and nanorod shape for ZnONPs_Chem with particle sizes of 118.6 nm, 115.7 nm, and 111.2 nm, respectively. The FTIR analysis demonstrated the presence of proteins, carboxyl, and hydroxyl groups on ZnONPs surfaces that act as reducing and stabilizing agents. ZnONP_Chem shows the antibacterial effect on Staphylococcus aureus, Enterobacter aerogenes, Pseudomonas aeruginosa, and Klebsiella pneumoniae. Punica peel and coffee ground extracts are effective reducing agents for green ZnONPs synthesis with a lower cytotoxic effect on Vero cells than ZnONPs_Chem with IC50 = 111, 103, and 93 μg/mL, respectively.     

The Use of 2‐Chloro‐4H‐4‐oxo‐pyrido[1,2‐a]pyrimidine as a Building Block in the Synthesis of Some New Heterocyclic Compounds

New approaches for the synthesis of some heterocyclic compounds, such as the pyridopyrimidodiazepine derivative 3 , pyrazolopyrido[1,2‐a]pyrimidine derivative 4 , tetrazolo[1.5‐a][1,8]naphthyridine derivative 9 , pyrazolylpyrido[1,2‐a]pyrimidine derivatives 10a , 10b , 12 , pyrrolopyrido[1,2‐a]pyrimidine derivatives 14a , 14b , 14c , 14d , and 16a , 16b , starting from 2‐chloro‐4H‐4‐oxo‐pyrido[1,2‐a]pyrimidine ( 1 ), are described.     

Radiation Synthesis of Superabsorbent Hydrogels Based on Chitosan and Acrylic Acid for Controlled Drug Release

Superabsorbent hydrogels based on the natural polymer chitosan and acrylic acid (CS/AAc) was prepared using ⁶⁰Co gamma radiation as a source of initiation and crosslinking. The factors, which affect the preparation of CS/AAc hydrogels such as irradiation dose, CS/AAc ratios, and acrylic acid monomer concentrations, to get the best optimum conditions, were investigated. The kinetic studies of the swelling of CS/AAc hydrogel showed that it follows a Fickian type of water diffusion. The Fickian constant value ‘n’ was more than 0.5 with a high swelling capacity of 300 g/g as superabsorbent hydrogel. In addition, the suitability of CS/AAc hydrogel as carrier material for the drug Chlortetracycline-HCl has been investigated by adsorption isotherm studies. The performance of drug release from hydrogel systems, influenced by acrylic acid ratio and the effect of pH of the medium was studied.     

Dual separation mode for simultaneous determination of antihypertensive drug combinations by high-performance liquid chromatography

A simple, reproducible and efficient dual separation mode high performance liquid chromatographic (HPLC) method was developed for simultaneous determination of antihypertensive drug combinations including; hydrochlorothiazide (HCTZ), valsartan (VAL), amiloride (AML) and captopril (CAP). The newly developed Platinum™ column, which provides a dual-mode separation with its polar and non-polar sites, was used for rapid separation of these co-administered drugs. Good resolution was obtained when Platinum™ column was used compared with C₁₈ column. Additionally, simple isocratic mode with mobile phase containing methanol and 0.02 mole L⁻¹ phosphate buffer adjusted to pH 3.0 (45:55, v/v) was used for separation. The flow rate was 0.5 mL min⁻¹ and effluent was monitored at 270 nm. All the investigated drugs were completely separated within less than 6 min. The linearity range obtained for the developed HPLC method was 0.5-100 μg mL⁻¹ with detection limits of 0.13-1.2 μg mL⁻¹ for all the studied drugs. The method was validated in accordance with the requirements of ICH guidelines and shown to be suitable for intended applications. The method was successfully used for determination of the studied drugs in pure form and pharmaceutical dosage forms without prior need for separation. The method is valuable for quality control laboratories for simultaneous determination of these co-administered antihypertensive drugs in binary, ternary and quaternary mixtures.     

PtRe/H-ZSM-5的氢卤化对环己烯转化的影响(英文)

Extended use of supported Pt catalysts causes thermal migration of Pt particles to form large agglomerates,thus decreasing the catalytic activity.The combination of Pt with Re protects Pt against migra...     

Organocatalysis in synthesis: L-proline as an enantioselective catalyst in the synthesis of pyrans and thiopyrans

The multicomponent reaction (MCR) of aromatic aldehydes 1 and malononitrile (2) with active methylenes 5a-h in the presence of L-proline produced pyrans and thiopyrans 6a-h stereospecifically and in good yields. Moreover a novel MCR of ethyl propiolate (8) with 1 and 2 in the presence of L-proline to afford (R)-polysubstituted pyran is also reported. X-ray structures, e.e. and optical activity of the synthesized compounds indicated that L-proline as a catalyst is responsible for the observed enantioselectivity in the studied reactions.     

Lotus bioinspired superhydrophobic,self‐cleaning surfaces from hierarchically assembled templates

The super hydrophobic, self‐cleaning properties of natural species derive from the fine hierarchical topography evolved on their surfaces. Hierarchical architectures which are function‐mimetic of the lotus leaf are here described and created from multi‐scale hierarchical assembled templates. The first level of hierarchy was a micromachined dome structure template and the second level of hierarchy was added by layering a thin nanoporous membrane such as porous anodized alumina or an ion track etch membrane. The assembled templates were nanoimprinted by a single step process on thermoplastic films. The wetting angle of the surfaces reached a value of 160° and the self‐cleaning behavior was observed. The superhydrophobic behavior remained over 1 year after fabrication, which demonstrates the stability of these polymeric self‐cleaning topographies. © 2014 Wiley Periodicals, Inc. J. Polym. Sci. Part B. Polym. Phys. 2014 , 52, 603–609