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Lagrangian description of nonlinear chromatography

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Science China Chemistry 2004年第6期47卷 443-452页

作者： LIANG Heng LIU Xiaolong The Key Laboratory of Biomedical Information Engineering of Education Ministry Separation Science InstituteXi'an Jiaotong University Xi'an 710049 China The Key Laboratory of Biomedical Information Engineering of Education Ministry Separation Science InstituteXi'an Jiaotong University Xi'an 710049 China

Under the framework of non-equilibrium thermodynamic separation theory (NTST), Local Lagrangian approach (LLA) was proposed to deal with the essential issues of the convec- tion and diffusion (shock waves) phenomena in nonlinear chromatography with recursion equa- tions based on the three basic theorems, Lagrangian description, continuity axiom and local equilibrium assumption (LEA). This approach remarkably distinguished from the system of con- temporary chromatographic theories (Eulerian description-partial differential equations), and can felicitously match modern cybernetics.

关键词： nonlinear chromatography, Lagrangian description, recursion equations, convection-diffusion equations, shock waves.

Applying flexible molecular docking to simulate protein retention behavior in hydrophobic interaction chromatography

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Science China Chemistry 2007年第5期50卷 675-682页

作者： ZHOU Peng1, TIAN FeiFei1 & LI ZhiLiang1,2 1 College of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400044, China 2 State Key Laboratory of Chemo/Biosensing and Chemometrics, Changsha 410082, China College of Chemistry and Chemical Engineering Chongqing University Chongqing China State Key Laboratory of Chemo/Biosensing and Chemometrics Changsha China

Interaction between proteins and stationary phase in hydrophobic interaction chromatography (HIC) is differentiated into two thermodynamic processes involving direct nonbonding/conformation interac- tion and surface hydrophobic effect of proteins, hence quantitatively giving rise to a binary linear rela- tion between HIC retention time (RT) at concentrated salting liquid and ligand-protein binding free en- ergy. Then, possible binding manners for 27 proteins of known crystal structures with hydrophobic ligands are simulated and analyzed via ICM flexible molecular docking and genetic algorithm, with re- sults greatly consistent with experimental values. By investigation, it is confirmed local hydrophobic effects of proteins and nonbinding/conformation interaction between ligand and protein both notably influence HIC chromatogram retention behaviors, mainly focusing on exposed portions on the protein surface.

关键词： hydrophobic interaction chromatography, flexible molecular docking, genetic algorithm, protein, salting-in factor

Retention and chiral recognition mechanism of organo-phosphorus compounds in high-performance liquid chromatography

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Science China Chemistry 2001年第2期44卷 147-153页

作者：黄君珉陈慧高如瑜王琴孙陈茹玉 Research Institute of Elemento-organic Chemistry Nankai University Tianjin China

In normal phase condition, a series of chiral phosphorus organic compounds have been separated by high-performance liquid chromatography. In order to study the retention and chiral recognition mechanism, the method of quantitative structure-enantioselectivity retention relationships (QSERRs) has been investigated from the quantitative equations established between the chromatographic retention of enantiomers and their molecular descriptors of physicochemical properties. The results show that on the Pirkle-type chiral stationary phase (CSP) of Sumichiral OA4700, it is the parameter of LUMO that gives the most contribution to the chromatographic retention of O-ethyl O-(substituted) phenyl N-isopropyl phosphoroamidothioates resulting from the interaction of hydrogen bond and (or) π-π interaction. Meanwhile, the chiral recognition is formed from the contribution of logP and LUMO.

关键词： high-performance liquid chromatography, chiral phosphorus organic compounds, chiral recognition mechanism, quantitative structure-enantioselectivity retention relationships.

Characteristics of elution profile in radial chromatography under linear conditions

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Science China Chemistry 2005年第4期48卷 352-360页

作者： Andreas Seidel-Morgenstern Max-Planck-Institut für Dynamik Komplexer Technischer Systeme 39106MagdeburgGermany

Based on the mass balance equations of solute transfer in the radial chroma-tographic column,the theoretical expression to describe the column efficiency and shape of elu-tion profile is obtained under linear isotherm ***,the tendency for the variation of column efficiency and symmetry of peak profile is systematically *** results showed that in radial chromatography the relationship between the column efficiency and volumetric flow rate is similar with that relationship in axial chromatography;relatively high column efficiency still can be obtained under high flow rate in radial *** the increase of retention factor of solutes and injection time,the column efficiency decreases *** effect of column diameter and column length on the column efficiency interfere with each *** is more advantageous to increase the column efficiency by applying columns with larger column diameter and shorter column *** to the discussion of the effect of diffusion on the column efficiency,radial chromatography is proved to be suitable for the separation of samples with relatively high diffusion coefficient,which predicts its obvious advantage in the preparative separation of samples such as proteins and DNA.

关键词： radial chromatography, column efficiency, elution profile, symmetry.

On-line parallel reversed phase two-dimensional liquid chromatography for high-throughput analysis of complex proteomic samples

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Science China Chemistry 2006年第6期49卷 527-533页

作者： WANG Zhicong1,3, ZHANG Qinghe2, LI Tong2, ZHAO Zhongyi3 & ZHANG Weibing1 1. Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116011, China 2. Dalian Elite Analytical Instrument Co., Ltd., Dalian 116011, China 3. Faculty of Material Science and Chemical Engineering, China University of Geosciences, Wuhan 430074, China Dalian Institute of Chemical Physics Chinese Academy of Sciences Dalian China Faculty of Material Science and Chemical Engineering China University of Geosciences Wuhan China Dalian Elite Analytical Instrument Co. Ltd. Dalian China

A comprehensive two-dimensional liquid chromatographic system (2D SCX/RP) is con- structed with a 10-port-2-way valve using strong cation exchange chromatography (Hypersil SCX, 100 mm×4.6 mm I.D.) followed by reversed phase chromatography (Hypersil BDS C18, 15 mm×4.6 mm I.D.) to separate the complex peptides from globin peptic hydrolysate. After the sample was loaded on the SCX column, the phosphate buffer (pH 4.0) was used to elute the peptides. Then, elutes flowed through the interface and the peptides focused on the head of the trapping columns (Hypersil BDS C18, 15 mm×4.6 mm I.D.) but salt passed into the waste. After the valve was switched, the samples were flushed with a backward flow into the RP analytical column. The peptides on the SCX were eluted with 12 discontinuous steps linearly increasing salt concentrations. The peptides enriched on the trapping column were desalted and separated by the RP columns. The resolution and the resolved peaks of the 2D SCX/RP system were greatly increased and the total peak capacity reached as high as 2280.

关键词： two-dimensional liquid chromatography, interface, trapping column, proteomics, globin.

Establishment of the model of white blood cell membrane chromatography and screening of antagonizing TLR_4 receptor component from Atractylodes macrocephala Koidz

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Science China(Life Sciences) 2006年第2期49卷 182-189页

作者： LI Cuiqin HE Langchong School of Medicine Xi'an Jiaotong University Xi'an 710061 China School of Medicine Xi'an Jiaotong University Xi'an 710061 China

A model of white blood cell membrane chromatography (WB-CMC) was established to screen active component from Atractylodes macrocephala Koidz. The component can antagonize Toll-like receptor 4 (TLR4); inhibit inflammatory reaction. In the model of WB-CMC, cell membrane stationary phase (CMSP) was prepared by immobilizing the rabbit white blood cell membrane (WBCM) onto the surface of silica carrier; taxinol was used as a model molecule. The active component which can act on WBCM; its receptor (such as TLR4) as an effective target in A. macrocephala was determined by using a replacement experiment. The anti-inflammatory effects of the active component were tested by using pharmacological methods in vivo. The results indicated that the retention characteristics of atractylenolide I as active component was similar to that of taxinol in the model of WB-CMC. And so, atractylenolide I acted on the WBCM; TLR4; its anti-inflammatory activity was related with antagonizing TLR4. Therefore, the interaction between the active component; WBCM; its receptor can be simulated by the model of WB-CMC in vitro. This model can be used to screen active components; to study effective characteristics for acting on definite targets.

关键词： white blood cell membrane chromatography, TLR4 receptor, atractylenolide I, anti-inflammatory effect.

Two-peak phenomena and formation origin in micellar electrokinetic capillary chromatography

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Science China Chemistry 2003年第5期46卷 473-480页

作者：陈冠华杨更亮田益玲陈义 College of Chemistry & Environmental Science Hebei University Baoding 071002China College of Life Science Hebei Agricultural University Baoding 071001 China College of Chemistry & Environmental Science Hebei University Baoding 071002 China Molecular Science Center Institute of Chemistry Chinese Academy of Sciences Beijing 100080 China

The formation origin of two peaks in micellar electrokinetic capillary chromatography by using cetyltrimethylaminium bromide (or sodium dodecyl sulfate) as pseudo stationary phase is studied. It is pointed out that two peaks may appear for one component in certain conditions. Experiments show that the relative areas of the two peaks of the corresponding component depend on the time and temperature of reaction between the analyte and the surfactant, and the concentration of surfactant in the sample solution. One of the two peaks increase with the increase of surfactant concentration in the sample solution while reverse for another peak. Temperature can accelerate the reaction process. This means that the interaction between analyte and surfactant is a slow process, and a stable substance can be produced from the interaction and leads to the formation of two peaks. The standpoint is confirmed by the infrared and nuclear magnetic resonance spectra of the product from the reaction between cetyltrimethylaminium bromide and m-hydroxyl benzoic acid.

关键词： two peaks, interaction, micellar electrokinetic capillary chromatography, surfactant.

Competing binding of metal ions with protein studied by microdialysis

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Science China Chemistry 2002年第2期45卷 151-157页

作者：郭明历欣邹汉法孔亮毛希琴 National Chromatographic R & A Center Dalian Institute of Chemical Physics Chinese Academy of Sciences Dalian China Deparment of Chemistry and Chemical Technology Dalian University Dalian China

A method has been established to study the competing binding of metal ions with protein by a combined technique of microdialysis with high performance liquid chromatography (HPLC). Ni2+, Cd2+, Zn2+, Cu2+ and human serum albumin (HSA) were chosen as model metal ions and protein. The experimental results show that Ni2+ and Cu2+ share a common primary binding site on HSA, and Zn2+ and Cd2+ share a different common primary binding site from them, but there is a common multi-metal binding site for all of those four metal ions. This method show advantages of fast sampling, easily to be operated and especially to be useful when ideal spectroscopic probes are not available for the study of interaction between protein and metal ions.

关键词： microdialysis, high performance liquid chromatography, human serum albumin, metal ions, competing binding.

SYNTHESIS AND APPLICATION OF DISCLIKE LIQUID CRYSTALS

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Chinese Science Bulletin 1988年第14期33卷 1171-1175页

作者：张平城王良御 Insititute of Chemistry Academia Sinica Beijing Department of Chemistry Tsinghua University Beijing

*** In 1977, Chandrasekhar et al. synthesized a new type of disc-like liquid crystals completely different from rod-like liquid crystal molecules in structure. Then other types of disc-like liquid crystals were synthesized by Destrade et al. The disc-like molecules are composed of a disc or elliptic rigid center surrounded by long and soft aliphatic chains (Fig. 1). A research into the structures and properties of these liquid crystals is significant in theory and practice.

关键词： disc-like liquid crystal chromatography, hexa-n-alkylbenzoates of rufigallol