The adsorption of sodium acetohydroxamate on the goethite or hematite surface was investi- gated by Fourier transform infrared spectroscopy （FT-IR）, X-ray photoemission spectroscopy and periodic plane-wave density f...The adsorption of sodium acetohydroxamate on the goethite or hematite surface was investi- gated by Fourier transform infrared spectroscopy （FT-IR）, X-ray photoemission spectroscopy and periodic plane-wave density functional theory （DFT） calculations. The core-level shifts and charge transfers of the adsorbed surface iron sites calculated by DFT with periodic in- terfacial structures were confronted to the X-ray photoemission experiments. FT-IR results reveal that the interracial structure of sodium acetohydroxamate adsorbed on the goethite or hematite surface may be assigned to a five-membered ring complex. In agreement with the adsorption energies determined by the DFT calculations, a five-membered ring complex is formed via bonding of one surface iron atom of goethite （101） or （100） to both oxygen atoms of hydroxamate group, and these two oxygen atoms of the hydroxamate group correspond- ingly attach to two neighboring iron atoms of the goethite surface. But a five-membered ring complex between two oxygen atoms of the hydroxamate group and one surface iron atom of hematite （001） is formed without any extra attachments. The calculated core-level shifts of Fe2p for the interracial structures are correspondingly in good agreement with the experimental observed one, which confirmed the reliability of the calculated results.展开更多
We isolated the essential oils from Boswellia ovalifoliolata N.P.Balakr and A.N.Henry using hydrodistillation,identified the obtained compounds using gas chromatography–mass spectrometry(GC–MS) and Fourier transform...We isolated the essential oils from Boswellia ovalifoliolata N.P.Balakr and A.N.Henry using hydrodistillation,identified the obtained compounds using gas chromatography–mass spectrometry(GC–MS) and Fourier transform-infrared spectroscopy(FT-IR),and studied the photophysical and electrochemical properties using UV–visible and fluorescence spectroscopy and cyclic voltammetry.On the basis of GC–MS spectra,38 compounds were identified in the essential oil from leaves and 26 in the oil from bark.The bark oil contained 13.44% b-Farnesene(sesquiterpene),10.45% caryophyllene oxide(sesquiterpene) and 6.6% spathulenol,(2 Z,6 E)-(sesquiterpene alcohol); the leaf oil contained 11.1% spathulenol(sesquiterpene alcohol),9.0% caryophyllene oxide(sesquiterpenoids) and 6.3% decyl acetate(ester).FT-IR spectra confirmed the presence of aliphatic aldehydes and ketones,carboxylic acid,alcohols,esters and ethers in both oil types.UV–visible absorption spectra showed maximum absorbance at 245,290 and 402 nm for bark oil,and 250,285 and 325 nm for leaf.Bark oil showed strong emission with maximum emission wavelength at 456 nm was higher than that of leaf oil at 414 nm.The essential oil had significant anti-inflammatory activity,and the reduction potential of the leaf oil was-0.44 and-0.56 e V for bark.展开更多
This report describes the use of ethnolic extract of Fagopyrum esculentum leaves for the synthesis of gold nanoparticles. UV-visible spectroscopy analysis indicated the successful formation of gold nanoparticles. The ...This report describes the use of ethnolic extract of Fagopyrum esculentum leaves for the synthesis of gold nanoparticles. UV-visible spectroscopy analysis indicated the successful formation of gold nanoparticles. The synthesized nanoparticles were characterized by transmission electron microscopy （TEM）, high resolution TEM （HRTEM） and were found to be spherical, hexagonal and triangular in shape with an average size of 8.3 nm. The crystalline nature of the gold nanoparticles was confirmed from X.ray diffraction （XRD） and selected-area electron diffraction （SAED） patterns. Fourier transform infrared （FT-IR） and energy.dispersive X-ray analysis （EDX） suggested the presence of organic biomolecules on the surface of the gold nanoparticles. Cytotoxicity tests against human HeLa, MCF-7 and IMR-32 cancer cell lines revealed that the gold nanoparticles were non-toxic and thus have potential for use in various biomedical applications.展开更多
Fluorescence spectroscopy, Fourier transform infrared （FT-IR） spectroscopy, circular dichroism （CD） and FT-Raman spectroscopy were employed to analyze the binding of the asiatic acid （AA） to bovine serum albumin...Fluorescence spectroscopy, Fourier transform infrared （FT-IR） spectroscopy, circular dichroism （CD） and FT-Raman spectroscopy were employed to analyze the binding of the asiatic acid （AA） to bovine serum albumin （BSA） under simulative physiological conditions. Fluorescence data revealed that the fluorescence quenching of BSA by AA was the result of the formation of BSA-AA complex. The fluorescence quenching mechanism of BSA by AA was a static quenching procedure. According to the Van＇t Hoff equation, the thermodynamic parameters enthalpy change （△H0） and entropy change （△S0） for the reaction were evaluated to be --12.55 kJ·mol^-1 and 67.08 kJomol 1, respectively, indicating that hydrophobic and electrostatic interactions played a major role in stabilizing the complex. The influence of AA on the conformation of BSA has also been analyzed on the basis of FT-IR, CD and FT-Raman spectra.展开更多
文摘The adsorption of sodium acetohydroxamate on the goethite or hematite surface was investi- gated by Fourier transform infrared spectroscopy （FT-IR）, X-ray photoemission spectroscopy and periodic plane-wave density functional theory （DFT） calculations. The core-level shifts and charge transfers of the adsorbed surface iron sites calculated by DFT with periodic in- terfacial structures were confronted to the X-ray photoemission experiments. FT-IR results reveal that the interracial structure of sodium acetohydroxamate adsorbed on the goethite or hematite surface may be assigned to a five-membered ring complex. In agreement with the adsorption energies determined by the DFT calculations, a five-membered ring complex is formed via bonding of one surface iron atom of goethite （101） or （100） to both oxygen atoms of hydroxamate group, and these two oxygen atoms of the hydroxamate group correspond- ingly attach to two neighboring iron atoms of the goethite surface. But a five-membered ring complex between two oxygen atoms of the hydroxamate group and one surface iron atom of hematite （001） is formed without any extra attachments. The calculated core-level shifts of Fe2p for the interracial structures are correspondingly in good agreement with the experimental observed one, which confirmed the reliability of the calculated results.
文摘We isolated the essential oils from Boswellia ovalifoliolata N.P.Balakr and A.N.Henry using hydrodistillation,identified the obtained compounds using gas chromatography–mass spectrometry(GC–MS) and Fourier transform-infrared spectroscopy(FT-IR),and studied the photophysical and electrochemical properties using UV–visible and fluorescence spectroscopy and cyclic voltammetry.On the basis of GC–MS spectra,38 compounds were identified in the essential oil from leaves and 26 in the oil from bark.The bark oil contained 13.44% b-Farnesene(sesquiterpene),10.45% caryophyllene oxide(sesquiterpene) and 6.6% spathulenol,(2 Z,6 E)-(sesquiterpene alcohol); the leaf oil contained 11.1% spathulenol(sesquiterpene alcohol),9.0% caryophyllene oxide(sesquiterpenoids) and 6.3% decyl acetate(ester).FT-IR spectra confirmed the presence of aliphatic aldehydes and ketones,carboxylic acid,alcohols,esters and ethers in both oil types.UV–visible absorption spectra showed maximum absorbance at 245,290 and 402 nm for bark oil,and 250,285 and 325 nm for leaf.Bark oil showed strong emission with maximum emission wavelength at 456 nm was higher than that of leaf oil at 414 nm.The essential oil had significant anti-inflammatory activity,and the reduction potential of the leaf oil was-0.44 and-0.56 e V for bark.
文摘This report describes the use of ethnolic extract of Fagopyrum esculentum leaves for the synthesis of gold nanoparticles. UV-visible spectroscopy analysis indicated the successful formation of gold nanoparticles. The synthesized nanoparticles were characterized by transmission electron microscopy （TEM）, high resolution TEM （HRTEM） and were found to be spherical, hexagonal and triangular in shape with an average size of 8.3 nm. The crystalline nature of the gold nanoparticles was confirmed from X.ray diffraction （XRD） and selected-area electron diffraction （SAED） patterns. Fourier transform infrared （FT-IR） and energy.dispersive X-ray analysis （EDX） suggested the presence of organic biomolecules on the surface of the gold nanoparticles. Cytotoxicity tests against human HeLa, MCF-7 and IMR-32 cancer cell lines revealed that the gold nanoparticles were non-toxic and thus have potential for use in various biomedical applications.
基金Project supported by the National Natural Science Foundation of China （Nos. 20671023, 30460153, 21061002）, the Key Project of Chinese Ministry of Education （Nos. 03101, 204111）, Guangxi Natural Science Foundation of China （No. 2010GXNSFF013001）, and the Innovation Project of Guangxi Graduate Education （No. 2009106020703M42）.
文摘Fluorescence spectroscopy, Fourier transform infrared （FT-IR） spectroscopy, circular dichroism （CD） and FT-Raman spectroscopy were employed to analyze the binding of the asiatic acid （AA） to bovine serum albumin （BSA） under simulative physiological conditions. Fluorescence data revealed that the fluorescence quenching of BSA by AA was the result of the formation of BSA-AA complex. The fluorescence quenching mechanism of BSA by AA was a static quenching procedure. According to the Van＇t Hoff equation, the thermodynamic parameters enthalpy change （△H0） and entropy change （△S0） for the reaction were evaluated to be --12.55 kJ·mol^-1 and 67.08 kJomol 1, respectively, indicating that hydrophobic and electrostatic interactions played a major role in stabilizing the complex. The influence of AA on the conformation of BSA has also been analyzed on the basis of FT-IR, CD and FT-Raman spectra.
