Prediction of Inhibitory Activity of Epidermal Growth Factor Receptor Inhibitors Using Grid Search-Projection Pursuit Regression Method

The epidermal growth factor receptor (EGFR) protein tyrosine kinase (PTK) is an important protein target for anti-tumor drug discovery. To identify potential EGFR inhibitors, we conducted a quantitative structure–activity relationship (QSAR) study on the inhibitory activity of a series of quinazoline derivatives against EGFR tyrosine kinase. Two 2D-QSAR models were developed based on the best multi-linear regression (BMLR) and grid-search assisted projection pursuit regression (GS-PPR) methods. The results demonstrate that the inhibitory activity of quinazoline derivatives is strongly correlated with their polarizability, activation energy, mass distribution, connectivity, and branching information. Although the present investigation focused on EGFR, the approach provides a general avenue in the structure-based drug development of different protein receptor inhibitors

Synthesis of Organic Dye-Impregnated Silica Shell-Coated Iron Oxide Nanoparticles by a New Method

A new method for preparing magnetic iron oxide nanoparticles coated by organic dye-doped silica shell was developed in this article. Iron oxide nanoparticles were first coated with dye-impregnated silica shell by the hydrolysis of hexadecyltrimethoxysilane (HTMOS) which produced a hydrophobic core for the entrapment of organic dye molecules. Then, the particles were coated with a hydrophilic shell by the hydrolysis of tetraethylorthosilicate (TEOS), which enabled water dispersal of the resulting nanoparticles. The final product was characterized by X-ray diffraction, transmission electron microscopy, Fourier transform infrared spectroscopy, photoluminescence spectroscopy, and vibration sample magnetometer. All the characterization results proved the final samples possessed magnetic and fluorescent properties simultaneously. And this new multifunctional nanomaterial possessed high photostability and minimal dye leakage

Bi-Functional Silica Nanoparticles Doped with Iron Oxide and CdTe Prepared by a Facile Method

Cadmium telluride (CdTe) and iron oxide nanoparticles doped silica nanospheres were prepared by a multistep method. Iron oxide nanoparticles were first coated with silica and then modified with amino group. Thereafter, CdTe nanoparticles were assembled on the particle surfaces by their strong interaction with amino group. Finally, an outer silica shell was deposited. The final products were characterized by X-ray powder diffraction, transmission electron microscopy, vibration sample magnetometer, photoluminescence spectra, Fourier transform infrared spectra (FT-IR), and fluorescent microscopy. The characterization results showed that the final nanomaterial possessed a saturation magnetization of about 5.8 emu g−1and an emission peak at 588 nm when the excitation wavelength fixed at 380 nm

Spectrofluorimetric determination of palladium(II) using 4,4'-bis (8-aminoquinoline- 5-azo )-biphenyl

1029-1031A new spectrofluorimetric method has been developed for the determination of palladium(II) using the reagent 4,4¢-bis(8-aminoquinoline-5-azo)-biphenyl(BAQABP).In slightly basic medium, BAQABP reacts with palladium(II) forming a complex which exhibits intense fluorescence at λcx/λcm. =298nm/383nm in the presence of Tween-80. The fluorescence intensity is proportional to the concentration of palladium(II) in the range 4.0-180 mg/l with a detection limit of 1.0 mg/l. The method is selective, sensitive and has been satisfactorily used for the determination of palladium in catalysts

Study on the flow injection method for the determination of L-cysteine with a Cu(II) complex by fluorescence quenching

1344-1347A flow injection method for fluorescence determination of cysteine using 5-(3-fluo-4-chloropheny lazo)-8-benzenesulfonamidoquinoline (FCPBSQ), a new fluorescence reagent, has been proposed. The method is based on the quenching of fluorescence in the Cu(II)-FCPBSQ system by cysteine in nearly neutral medium. Under the optimum conditions, the fluorescence quenching intensity increases linearly with increase in the concentration of cysteine in the range of 0.050-6.0 μg/ml. The detection limits of this method is 0.010 μg/ml with a sample frequency of 64h-1. The method is free of interference from several metal ions and amino acids without -SH group and has been successfully applied for the determination of cysteine in the pharmachemical samples. The mechanism of the fluorescence quenching is also discussed

Bi-Functional Silica Nanoparticles Doped with Iron Oxide and CdTe Prepared by a Facile Method

Abstract Cadmium telluride (CdTe) and iron oxide nanoparticles doped silica nanospheres were prepared by a multistep method. Iron oxide nanoparticles were first coated with silica and then modified with amino group. Thereafter, CdTe nanoparticles were assembled on the particle surfaces by their strong interaction with amino group. Finally, an outer silica shell was deposited. The final products were characterized by X-ray powder diffraction, transmission electron microscopy, vibration sample magnetometer, photoluminescence spectra, Fourier transform infrared spectra (FT-IR), and fluorescent microscopy. The characterization results showed that the final nanomaterial possessed a saturation magnetization of about 5.8 emu g&#8722;1and an emission peak at 588 nm when the excitation wavelength fixed at 380 nm.</p