A new saikosaponin was isolated from Bupleurum chinense DC., and its structure was identified as 3β,16α,23,28,30_pentahydroxy_olean_11,13(18)_dien_3_O_β_D_glucopyranosyl(1→6)_[α_L_rhamnopyranosyl (1→4)]_β_D...A new saikosaponin was isolated from Bupleurum chinense DC., and its structure was identified as 3β,16α,23,28,30_pentahydroxy_olean_11,13(18)_dien_3_O_β_D_glucopyranosyl(1→6)_[α_L_rhamnopyranosyl (1→4)]_β_D_glucopyranoside on the basis of chemical and spectral evidence, named as saikosaponin q_1. In addition, two known saikosaponins, 3″_O_acetyl_saikosaponin d and 3″_O_acetyl_saikosaponin b 2, were also isolated and identified from this plant for the first time.展开更多
An HPLC-DAD-ELSD method was developed and validated for the simultaneous quantitation of seven active components（liquiritin, baicalin, wogonoside, baicalein, wogonin, ginsenosides Re and ginsenosides Rb1） in n-butan...An HPLC-DAD-ELSD method was developed and validated for the simultaneous quantitation of seven active components（liquiritin, baicalin, wogonoside, baicalein, wogonin, ginsenosides Re and ginsenosides Rb1） in n-butanol effective fraction of Xiao Chai Hu Tang. A Diamonsil C18（2） column（4.6 mm × 250 mm, 5 μm） was used as the stationary phase and the mobile phase was consisted of acetonitrile and aqueous phosphate acid（0.05%, v/v）. Gradient elution was carried out at the flow rate of 1 m L/min. The detection wavelength was set at 276 nm and an evaporative light scattering detector was also used. Good linearity for all the seven active components was observed. The established method is simple, fast, reliable, and suitable for the quality control of n-butanol effective fraction of Xiao Chai Hu Tang.展开更多
A fundamental property of solid materials is their stress state. Stress state of a solid or thin film material has profound effects on its thermodynamic stability and physical and chemical properties. The classical me...A fundamental property of solid materials is their stress state. Stress state of a solid or thin film material has profound effects on its thermodynamic stability and physical and chemical properties. The classical mechanical stress （σ^M） originates from lat- tice strain （e）, following Hooke＇s law： σ^M=Cε, where C is elastic constant matrix. Recently, a new concept of quantum electronic stress （o-QE） is introduced to elucidate the extrinsic electronic effects on the stress state of solids and thin films, which follows a quantum analog of classical Hooke＇s law： ~QE=E（An）, where E is the deformation potential of electronic states and An is the variation of electron density. Here, we present mathematical derivation of both the classical and quantum Hooke＇s law from density functional theory. We further discuss the physical origin of quantum electronic stress, arising purely from electronic excitation and perturbation in the absence of lattice strain （g=0）, and its relation to the degeneracy pressure of electrons in solid and their interaction with the lattice.展开更多
The stability of β-carotene microcapsules using Maillard reaction products（MRPs） derived from whey protein isolate（WPI） and galactose as coating materials, was studied under the varying environmental conditions o...The stability of β-carotene microcapsules using Maillard reaction products（MRPs） derived from whey protein isolate（WPI） and galactose as coating materials, was studied under the varying environmental conditions of temperature, pH, air, incandescent light, and ultraviolet（UV） light.Scanning electron microscopy showed that microcapsules prepared by WPI-galactose MRPs displayed a smooth and less concave-convex surface and that the particle size（D_（50）） of the microcapsules made with WPI-galactose MRPs was smaller than those made with WPI-galactose mixture.The storage stability of β-carotene microencapsulated in WPI-galactose MRPs was remarkably better than that of β-carotene microencapsulated in the WPI-galactose mixture and that of β-carotene crystal, in respect of temperature, pH, air, incandescent light, and UV light measurements.When the storage temperature was increased from 5 to 105 ℃, the retention rate of β-carotene microcapsules significantly decreased（P〈0.05）.When p H values were increased from 1 to 12, the β-carotene retention rate of the microcapsules significantly increased and afterward decreased.Compared with the retention rate of β-carotene microencapsulated in a WPI-galactose mixture, the retention rate of β-carotene microencapsulated in WPI-galactose MRPs was at a maximum between pH 8 and 9.Under the actions of air, incandescent light, and UV light, the retention rates of β-carotene microcapsules in WPI-galactose MRPs and WPI-galactose mixture, as well as in β-carotene crystal, decreased significantly as the storage time increased（P〈0.05）.Therefore, the use of WPI-galactose MRPs as coating materials can aid in improving the storage stability of β-carotene microcapsules.展开更多
文摘A new saikosaponin was isolated from Bupleurum chinense DC., and its structure was identified as 3β,16α,23,28,30_pentahydroxy_olean_11,13(18)_dien_3_O_β_D_glucopyranosyl(1→6)_[α_L_rhamnopyranosyl (1→4)]_β_D_glucopyranoside on the basis of chemical and spectral evidence, named as saikosaponin q_1. In addition, two known saikosaponins, 3″_O_acetyl_saikosaponin d and 3″_O_acetyl_saikosaponin b 2, were also isolated and identified from this plant for the first time.
基金Foundation for Young Scholars of Shanxi Province,China(Grant No.2011021007-2)
文摘An HPLC-DAD-ELSD method was developed and validated for the simultaneous quantitation of seven active components（liquiritin, baicalin, wogonoside, baicalein, wogonin, ginsenosides Re and ginsenosides Rb1） in n-butanol effective fraction of Xiao Chai Hu Tang. A Diamonsil C18（2） column（4.6 mm × 250 mm, 5 μm） was used as the stationary phase and the mobile phase was consisted of acetonitrile and aqueous phosphate acid（0.05%, v/v）. Gradient elution was carried out at the flow rate of 1 m L/min. The detection wavelength was set at 276 nm and an evaporative light scattering detector was also used. Good linearity for all the seven active components was observed. The established method is simple, fast, reliable, and suitable for the quality control of n-butanol effective fraction of Xiao Chai Hu Tang.
基金supported by the DOE-BES program(Grant No.DE-04ER46148)NSF-MRSEC(Grant No.DMR-1121252)
文摘A fundamental property of solid materials is their stress state. Stress state of a solid or thin film material has profound effects on its thermodynamic stability and physical and chemical properties. The classical mechanical stress （σ^M） originates from lat- tice strain （e）, following Hooke＇s law： σ^M=Cε, where C is elastic constant matrix. Recently, a new concept of quantum electronic stress （o-QE） is introduced to elucidate the extrinsic electronic effects on the stress state of solids and thin films, which follows a quantum analog of classical Hooke＇s law： ~QE=E（An）, where E is the deformation potential of electronic states and An is the variation of electron density. Here, we present mathematical derivation of both the classical and quantum Hooke＇s law from density functional theory. We further discuss the physical origin of quantum electronic stress, arising purely from electronic excitation and perturbation in the absence of lattice strain （g=0）, and its relation to the degeneracy pressure of electrons in solid and their interaction with the lattice.
基金Project supported by the Natural Science Foundation of Heilongjiang Province of China(No.C2017029)the Academic Research Program of Northeast Agricultural University(No.16XG21)the National“Twelfth Five-Year”Plan for Science and Technology Support Program of China(No.2013BAD18B06)
文摘The stability of β-carotene microcapsules using Maillard reaction products（MRPs） derived from whey protein isolate（WPI） and galactose as coating materials, was studied under the varying environmental conditions of temperature, pH, air, incandescent light, and ultraviolet（UV） light.Scanning electron microscopy showed that microcapsules prepared by WPI-galactose MRPs displayed a smooth and less concave-convex surface and that the particle size（D_（50）） of the microcapsules made with WPI-galactose MRPs was smaller than those made with WPI-galactose mixture.The storage stability of β-carotene microencapsulated in WPI-galactose MRPs was remarkably better than that of β-carotene microencapsulated in the WPI-galactose mixture and that of β-carotene crystal, in respect of temperature, pH, air, incandescent light, and UV light measurements.When the storage temperature was increased from 5 to 105 ℃, the retention rate of β-carotene microcapsules significantly decreased（P〈0.05）.When p H values were increased from 1 to 12, the β-carotene retention rate of the microcapsules significantly increased and afterward decreased.Compared with the retention rate of β-carotene microencapsulated in a WPI-galactose mixture, the retention rate of β-carotene microencapsulated in WPI-galactose MRPs was at a maximum between pH 8 and 9.Under the actions of air, incandescent light, and UV light, the retention rates of β-carotene microcapsules in WPI-galactose MRPs and WPI-galactose mixture, as well as in β-carotene crystal, decreased significantly as the storage time increased（P〈0.05）.Therefore, the use of WPI-galactose MRPs as coating materials can aid in improving the storage stability of β-carotene microcapsules.
