1 INTRODUCTIONThe production of secondary metabolites using plant cells has been the subject of much inter-est in recent years.Despite that tremendous research efforts had been made in this topic,notmany products have...1 INTRODUCTIONThe production of secondary metabolites using plant cells has been the subject of much inter-est in recent years.Despite that tremendous research efforts had been made in this topic,notmany products have reached the commercial stage.It is generally acknowledged that the mainproblem in this field is the lack of basic knowledge of the biosynthetic routes,and the mechanisms found to bring about the production of such secondary metabolites.There are,however,some techniques that have beneficial effects on the production and ex-展开更多
The synthesis of dipeptide AcPheLeuNH2 catalyzed by immobilized pancreatic lipase was carried out in a two- liquid-phase hollow-fiber membrane reactor, operated in a batch mode. Kinetic properties of free and immobili...The synthesis of dipeptide AcPheLeuNH2 catalyzed by immobilized pancreatic lipase was carried out in a two- liquid-phase hollow-fiber membrane reactor, operated in a batch mode. Kinetic properties of free and immobilized enzyme, partition behavior between aqueous buffer phase and organic solvent phase, and effective diffusion coefficients of substrates and products through the membrane were investigated respectively. Based on the preliminary experimental results, the performance of the enzyme membrane reactor, which is evaluated by the purity and the yield, is discussed.展开更多
The solubility curve and density curve of 1-butyl-3-methylimidazolium tetrafluoroborate-water-sodium carbonate system ([Bmim]BF4-H2O-Na2CO3) were measured with the turbidity titration method at 30℃ under atmospheric ...The solubility curve and density curve of 1-butyl-3-methylimidazolium tetrafluoroborate-water-sodium carbonate system ([Bmim]BF4-H2O-Na2CO3) were measured with the turbidity titration method at 30℃ under atmospheric pressure and were correlated with empirical equations.The liquid-liquid equilibrium data of the system were measured with the turbidity-density method and the phase diagram was constructed.As shown by experimental results, one phase of the aqueous two-phase system was composed mainly of water and ionic liquid whereas the sodium carbonate concentration was very low, the other phase was composed mainly of water and sodium carbonate whereas the ionic liquid concentration was very low.The system could be used for extraction and separation.It could also be used for primary separation and recovery of ionic liquids from aqueous solution.Othmer-Tobias and Bancroft equations were used for correlation of the liquid-liquid equilibrium data, but the result was not satisfactory.The maximum relative error was about 94.99%, and the maximum average relative error was about 15.69%.A new method for the correlation by using Othmer-Tobias and solubility equations was proposed.The maximum relative error was about 4.52%, and the maximum average relative error was about 2.77%.The calculated results were in good agreement with experimental data.The method could be used for correlation of liquid-liquid equilibrium for the system with a low content of one component.展开更多
This study was about the effect of pH and small molecule organic compound on the phase behavior of SDS/CTAB/H 2O mixture.The ATPS regions and LC regions were mainly discussed.It was shown that when the pH of the syste...This study was about the effect of pH and small molecule organic compound on the phase behavior of SDS/CTAB/H 2O mixture.The ATPS regions and LC regions were mainly discussed.It was shown that when the pH of the system was not neutral LC regions enlarged but ATPS regions reduced.In the condition of strong acid,the ATPS a region in which anionic surfactant in excess would extend to the SDS-H 2O axis of the pseudo phase diagram of SDS/CTAB/H 2O system.Small molecule organic compound that was not ionized in aqueous solution combined with water in the form of hydrogen bond.For this reason,the hydration of surfactant decrease and cationic surfactant and anionic surfactant integrate to form precipitate.So the surfactant-rich phase of ATPS showed milky white and the polarizing appearance was not clear.展开更多
文摘1 INTRODUCTIONThe production of secondary metabolites using plant cells has been the subject of much inter-est in recent years.Despite that tremendous research efforts had been made in this topic,notmany products have reached the commercial stage.It is generally acknowledged that the mainproblem in this field is the lack of basic knowledge of the biosynthetic routes,and the mechanisms found to bring about the production of such secondary metabolites.There are,however,some techniques that have beneficial effects on the production and ex-
基金Supported by the National Natural Science Foundation of China andExtraction Separation branch of United Chemical Engineeing
文摘The synthesis of dipeptide AcPheLeuNH2 catalyzed by immobilized pancreatic lipase was carried out in a two- liquid-phase hollow-fiber membrane reactor, operated in a batch mode. Kinetic properties of free and immobilized enzyme, partition behavior between aqueous buffer phase and organic solvent phase, and effective diffusion coefficients of substrates and products through the membrane were investigated respectively. Based on the preliminary experimental results, the performance of the enzyme membrane reactor, which is evaluated by the purity and the yield, is discussed.
文摘The solubility curve and density curve of 1-butyl-3-methylimidazolium tetrafluoroborate-water-sodium carbonate system ([Bmim]BF4-H2O-Na2CO3) were measured with the turbidity titration method at 30℃ under atmospheric pressure and were correlated with empirical equations.The liquid-liquid equilibrium data of the system were measured with the turbidity-density method and the phase diagram was constructed.As shown by experimental results, one phase of the aqueous two-phase system was composed mainly of water and ionic liquid whereas the sodium carbonate concentration was very low, the other phase was composed mainly of water and sodium carbonate whereas the ionic liquid concentration was very low.The system could be used for extraction and separation.It could also be used for primary separation and recovery of ionic liquids from aqueous solution.Othmer-Tobias and Bancroft equations were used for correlation of the liquid-liquid equilibrium data, but the result was not satisfactory.The maximum relative error was about 94.99%, and the maximum average relative error was about 15.69%.A new method for the correlation by using Othmer-Tobias and solubility equations was proposed.The maximum relative error was about 4.52%, and the maximum average relative error was about 2.77%.The calculated results were in good agreement with experimental data.The method could be used for correlation of liquid-liquid equilibrium for the system with a low content of one component.
文摘This study was about the effect of pH and small molecule organic compound on the phase behavior of SDS/CTAB/H 2O mixture.The ATPS regions and LC regions were mainly discussed.It was shown that when the pH of the system was not neutral LC regions enlarged but ATPS regions reduced.In the condition of strong acid,the ATPS a region in which anionic surfactant in excess would extend to the SDS-H 2O axis of the pseudo phase diagram of SDS/CTAB/H 2O system.Small molecule organic compound that was not ionized in aqueous solution combined with water in the form of hydrogen bond.For this reason,the hydration of surfactant decrease and cationic surfactant and anionic surfactant integrate to form precipitate.So the surfactant-rich phase of ATPS showed milky white and the polarizing appearance was not clear.
