JOURNAL OF LUMINESCENCE
·
2013
·
IF 2.144
Ruiyong Wang,Xiaohui Kang,Ruiqiang Wang,Rui Wang,Huanjing Dou,Jing Wu,Chuanjun Song,Junbiao Chang
The interactions between trypsin and caffeine/theophylline were investigated by fluorescence spectroscopy , UV–visible absorption spectroscopy , resonance light scattering and synchronous fluorescence spectroscopy under mimic physiological conditions . The results revealed that the fluorescence quenching of trypsin by caffeine and theophylline was the result of the formed complex of caffeine–trypsin and theophylline–trypsin. The binding constants and thermodynamic parameters at three different temperatures were obtained. The hydrophobic interaction was the predominant intermolecular forces to stabilize the complex. Results showed that caffeine was the stronger quencher and bound to trypsin with higher affinity than theophylline .
研究领域:
生物化学
·
分子药理学
·
药物代谢
·
蛋白质-配体相互作用
·
光谱学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Bo Wang,Jinyu Wang,Yuan Chen,Zhiyong Xu,Wenbo Zhao
N-Benzyl-N-methyl-1-(methyl diphenyl silyl) methanamine (MPSA) with high thermal stability was synthesized for the absorption of SO 2 in the present work. The absorption capacity was measured at low partial pressures ranging from 0.002 to 0.016 bar and thermodynamic parameters, including enthalpy change (Δ H ) and entropy change (Δ S ) were calculated to analyze the absorption behavior. The desulphurization rates and absorption capacities at different temperatures and partial pressures were simulated based on thermodynamic parameters. An optimal absorption temperature T 1 that maximizes the absorption capacity, and an optimal desorption temperature T 2 that minimizes the desorption residual capacity and thermal desorption energy consumption were defined, and a function was proposed to calculate them. The kinetic behavior of the absorption was described using a pseudo-first-order model, and kinetic data at different temperatures and partial pressures were simulated based on a combination of kinetic and thermodynamic parameters. Ultimately, selectivity and cycles experiment showing MPSA has excellent CO 2 selectivity and thermal regeneration performance.
研究领域:
环境化学
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气体分离
·
热力学
·
化学工程
·
功能材料
·
大气污染控制
✓ 已验证
DOI
高影响因子
FOOD CHEMISTRY
·
2019
·
IF 5.399
Hui Shen,Mouming Zhao,Weizheng Sun
The influence of pH-induced structural modifications of myofibrillar proteins (MPs) on their interaction mechanisms with pyrazine compounds was investigated. At a lower pH (4.9, 5.5), MPs aggregated to larger particle sizes due to enhanced the protein–protein interactions. The binding with pyrazine compounds was strongly affected by pH and the nature of flavor compounds. MPs exhibited flavor releasing behavior, probably due to protein–protein interactions and surface tension. Fluorescence analysis revealed that the interaction of pyrazine compounds with MPs followed a combination of static and dynamic quenching. The changes in quenching constant ( K sv ) might be attributed to a dynamic quenching, probably due to protein aggregation. The percentages of free 2,5-Dimethylpyrazine (2,5-DMP) were similar to K sv . Thermodynamic parameters indicated that electrostatic interactions and hydrophobic interactions were the major acting forces in the binding of MPs to 2,5-DMP. The binding of 2,5-DMP increased the α-helix content of MPs.
研究领域:
食品科学
·
蛋白质化学
·
风味化学
·
分子互作
·
生物物理化学
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DOI
高影响因子
CHIRALITY
·
2012
·Vol. 24
·期 5
·391-399
·
IF 2.35
Hui Yu,Chenghua Yin,Cunyu Jia,Yu Jin,Yanxiong Ke,Xinmiao Liang
Two “click” binaphthyl chiral stationary phases were synthesized and evaluated by liquid chromatography. Their structures incorporate S-(−)-1,1'-binaphthyl moiety as the chiral selector and 1,2,3-triazole ring as the spacer. These chiral stationary phases (CSPs) allowed the efficient resolution for a wide range of racemic BINOL derivatives, particularly for nonpolar diether derivatives and 3-phenyl indolin-2-one analogs. The chromatographic data showed that the π–π interaction was crucial for enantiorecognition of these CSPs. Loss of enantioselectivity observed on CSP3 , which are lacking the triazole ring linkage, indicated that the triazole ring linkage took part in the enantioseparation process, although it was remote from the chiral selector of the CSP. The substitution of the phenyl group at 6 and 6' positions can significantly improve the separation ability of the CSP. The chiral recognition mechanism was also investigated by tracking the elution orders and studying the thermodynamic parameters. Chirality 24:391–399, 2012 . Copyright © 2012 Wiley Periodicals, Inc.
研究领域:
分析化学
·
药物化学
·
色谱学
·
手性分离
·
有机合成
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DOI
高影响因子
JOURNAL OF CHEMICAL THERMODYNAMICS
·
2019
·
IF 2.29
Junjie Chen,Bo Jin,Guan Luo,Huihui Liu,Qingchun Zhang,Qi Huang,Rufang Peng
The thermodynamics and kinetics of the curing reactions between polyglycidyl nitrate (PGN) and toluene diisocyanate, isophorone diisocyanate, and polyaryl polymethylene isocyanate (PAPI) were studied by microcalorimetry. The reaction rate between PGN and PAPI was the fastest among the three reactions above. Three thermodynamics ( i.e. , activation enthalpy, entropy, and free energy), rate constant, and three thermokinetic parameters ( i.e. , activation energy, pre-exponential constant, and reaction order) of the curing reactions were obtained by calculating the results of the reaction between PGN and PAPI at a series of temperature from 303.15 K to 318.15 K. The linear relationship between ln k and the mole ratio of the isocyanate and hydroxyl groups was observed. The corresponding kinetic equation describing the curing reaction between PGN and PAPI was d α /d t = 10 −3.83 (1 − α ) 3.04 at 318.15 K.
研究领域:
高分子化学
·
热力学
·
反应动力学
·
功能材料
·
含能材料
✓ 已验证
DOI
高影响因子
JOURNAL OF LUMINESCENCE
·
2013
·
IF 2.144
XiaoDan Zeng,Lin Zhu,FuSheng Zhang,LiYun Feng
The interaction of bovine serum with leucomalachite green (LMG) was investigated by spectroscopic methods . LMG was found to quench the intrinsic fluorescence of BSA by dynamic quenching. High quenching constant suggested that LMG can form a complex with BSA. Binding constant and number of binding site were determined. The thermodynamic parameters suggested the main interacting force is hydrophobic forces . The effect of LMG on the conformation of BSA was analyzed by synchronous fluorescence spectroscopy . RLS spectra were also used to reconfirm the formation of complex between BSA and LMG.
研究领域:
生物化学
·
分子生物学
·
光谱学
·
药物代谢
·
蛋白质-配体相互作用
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DOI
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2013
·
IF 3.535
Kelei Zhuo,Yujing Wei,Jingjing Ma,Yujuan Chen,Guangyue Bai
Several alkylmethylimidazolium tetraphenylborates (C n mim-TPB, n = 2–10) were synthesized and explored as ion exchangers in plasticized PVC membranes with very attractive sensing behaviors. And then a series of ion-selective electrodes (ISEs) were prepared and their potentiometric properties were investigated. The proposed electrodes exhibited Nernstian responses to alkylmethylimidazolium-based ionic liquid cations [C n mim] + . These electrodes were successfully applied in the determination of thermodynamic parameters of ionic liquids in aqueous solutions and in the detection of [C n mim] + in tap water and distilled water with satisfactory results. For the as-prepared ISEs, one special and important relationship was observed between the selectivity coefficients and the length of alkyl side chains of interfering cations [C n mim] + . The proper understanding of this relationship should facilitate the development of new method for the determination of ionic liquids using ISEs.
研究领域:
分析化学
·
电化学
·
环境监测
·
离子传感
·
药物分析
·
水处理
·
生物传感器
·
物理化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）