RESUMEN
The binding between two surface-active substituted 3H-indole fluorescence probes, i. e., iodo-dihexadecyl methyl-2-(p-dodecyl amino phenyl)-3, 3-dimethyl-5-carboethoxy-3H-indole ammonium and iodo-dimethyloctadecyl-2-(p-dodecyl amino phenyl)-3,3-dimethyl-5-carboethoxy-3H-indole ammonium, and bovine serum albumin (BSA) in aqueous solution was studied using fluorescence. The binding constant and binding site number of molecule 1 and molecule 2 with BSA were obtained. It was confirmed that electrostatic interaction is the primary driving force for the combination of BSA with molecule 1 or molecule 2. According to the Förster resonance energy transfer theory, the distances between molecule 1, molecule 2 and tryptophan of BSA were calculated to be 2.90 nm and 4.02 nm, respectively.
Asunto(s)
Colorantes Fluorescentes/química , Albúmina Sérica Bovina/química , Algoritmos , Animales , Bovinos , Colorantes Fluorescentes/metabolismo , Indoles/química , Indoles/metabolismo , Cinética , Estructura Molecular , Unión Proteica , Albúmina Sérica Bovina/metabolismo , Espectrometría de Fluorescencia , Electricidad EstáticaRESUMEN
A substituted 3H-indole quaternary ammonium molecule was designed and synthesized using hexamethylphosphoramide (HMPA) as a solvent. The products were purified and characterized by IR, 1H-NMR, MS and elemental analysis. The binding reaction of this compound with bovine serum albumin (BSA) in aqueous solution was studied using fluorescence. Their binding constant is Ka = 1.995 x 10(5) dm3 x mol(-1) and the binding site number is n = 1.12. It is confirmed that the combination is a single static quenching process.
Asunto(s)
Fluorescencia , Indoles/química , Compuestos de Amonio Cuaternario/química , Albúmina Sérica Bovina/química , Algoritmos , Animales , Sitios de Unión , Bovinos , Hempa/química , Cinética , Modelos Químicos , Estructura Molecular , Unión Proteica , Compuestos de Amonio Cuaternario/síntesis química , Compuestos de Amonio Cuaternario/metabolismo , Albúmina Sérica Bovina/metabolismo , Espectrometría de Fluorescencia , Agua/químicaRESUMEN
The interactions between a fluorescent molecular probe, i. e., [2-(p-hexylamino) phenyl-3, 3-dimethyl-5-ethoxycarbonyl-3H-indole] methyldioctadecylammonium iodide (A) and Triton X-100/heptane/hexanol/water reverse micelle have been investigated by spectroscopy. Micropolarity of the environment, fluorescence anisotropy parameter and the pH effect of A in Triton X-100 reverse micelle were determined. Furthermore, the state of water in reverse micellar systems was studied by FTIR. According to the above experimental results, some information on the structure of Triton X-100 reverse micelle was obtained and the probable site of A in this system was discussed.
Asunto(s)
Colorantes Fluorescentes/química , Indoles/química , Micelas , Octoxinol/química , Polarización de Fluorescencia , Cinética , Estructura Molecular , Espectrometría de Fluorescencia , Espectroscopía Infrarroja por Transformada de FourierRESUMEN
Steady-state fluorescence and anisotropy measurements have been used to investigate the interaction of 2,2'-biquinoline (BQ) and 1,1'-(methylenedi-1,4-phenylene)bismaleimide (MDP-BMI) with alpha-, beta-, and gamma-cyclodextrins (CDs). It was found that the reaction patterns between fluorescence molecules and CDs are remarkably different. They can form a simple inclusion complex with alpha-CD, while nanotubes can be formed in the presence of gamma-CD. Moreover, MDP-BMI can form nanotube with beta-CD at higher concentration.
Asunto(s)
Ciclodextrinas/química , Nanotubos/química , alfa-Ciclodextrinas , beta-Ciclodextrinas , Anisotropía , Celulosa/química , Fluorescencia , Maleimidas/química , Quinolinas/química , Espectrometría de FluorescenciaRESUMEN
The complexes having the compositions of Eu(L1)(3)2H2O,Eu(L1)3phen,Eu(L2)(3)2H2O,Eu(L2)3phen (phen = 1,10-phenathroline,L1 = Dodecanoic acid, L2 = Stearic acid) were synthesized and characterized by elemental analysis and FTIR spectra. Their fluorescence spectra, UV spectra and TEM (Transmission Electron Microscope) have been investigated. The results show that the 5D0-7F1 and 5D0-7F2 transition of Eu(III) are observed in the emission spectrum of the particles at room temperature. As good photoluminescent materials, they may be useful in the regions of EL (Electroluminescence) or macromolecule composite materials doped with rare earth.
Asunto(s)
Quelantes/química , Europio/química , Ácidos Grasos/química , Luminiscencia , Ácidos Láuricos/química , Metales de Tierras Raras/química , Microscopía Electrónica , Estructura Molecular , Fenantrolinas/química , Espectrometría de Fluorescencia , Espectroscopía Infrarroja por Transformada de Fourier , Ácidos Esteáricos/químicaRESUMEN
Free electron laser (FEL) have been developed as tunable lasers over a wide range of wavelenths. Equipment in the region of 6-16 microns (1,660-630 cm-1) is available in the Beijing free electron laser erected by Institute of High Energy Physics, CAS. In this study we report first measurements of infrared-induced molecular change under irradiation by FEL of 9.414 microns and 6.228 microns, respectively. Taking o-amino-benzoic acid as an example, FTIR characterization indicates that the peak positions of both N-H and C=O stretching vibrations shift before and after the irradiation of FEL. It demonstrates that FEL induces the re-arrangement of H-bonds between COOH and NH2 by stimulating the vibration of carboxyl groups. It suggests that the presence of stable/metastable phases in the title compound.
Asunto(s)
Electrones , Rayos Láser , ortoaminobenzoatos/química , Enlace de Hidrógeno , Estructura Molecular , Fotoquímica , Espectroscopía Infrarroja por Transformada de Fourier , VibraciónRESUMEN
The formation of the third phase during the gold extraction from cyanide solution by quaternary ammonium, tetradecyldimethylbenzylammonium chloride (TDMBAC) was studied by 198Au tracer method. The microstructure of the organic phases was investigated by FTIR, 31P-NMR. With the increasing of gold concentration, aggregations were formed in the gold-loaded organic phase. With the further increasing of gold concentration, the organic phase turned into two layers. Gold, water, and tri-n-butyl phosphate (TBP) were mainly in the down organic phase. In the down layer, distinct O-H stretching vibration peak was found by FTIR; the frequency of P=O stretching vibration shifted to the low frequency; 31P-NMR chemical shift was markedly shifted to the high frequency field. The radius of aggregation was measured by the dynamic laser scattering (DLS) method.
RESUMEN
Two coordination compounds formed between Eu(III) and Tb(III) with ofloxacin have been synthesized. Molecular formula Ln(oflo)3Cl3.8H2O has been deduced from elemental chemical analysis and ICP.FTIR spectroscopy shows that both carbonyl and carboxy groups may coordinate the lanthanide cation(Eu3+/Tb3+) to form a stable six-membered ring. The reaction between lanthanide and ofloxacin can be accomplished without any additional base since FTIR suggests the proton transportation from the carboxyl group to the tertiary nitrogen. The complex containing Eu3+ was proved to be excited with the broad band from 200 to 450 nm. Between the two complexes is studied, Eu3+ is the most efficiently sensitized by ofloxacin, while Tb3+ is the least. The disappearance of the ligand fluorescence and the strong emitting of Eu3+ in the complex, which is ascribed to the transitions 5D0-7F0, 5D0-7F1, 5D0-7F2 respectively, make it clear that some well energy transfer has happened. But complex Tb(oflo)3Cl3.8H2O irradiates lights from both ligand and Tb3+.