The importance of immunoglobulin Y(IgY) as a specific antibody equivalent to mammalian immunoglobulin G(IgG) is well recognized. However, production of highly purified IgY is still difficult due to the lack of specifi...The importance of immunoglobulin Y(IgY) as a specific antibody equivalent to mammalian immunoglobulin G(IgG) is well recognized. However, production of highly purified IgY is still difficult due to the lack of specific purification methods. In this study, adsorption behaviors of Ig Y on four mixed-mode resins with functional ligands of 4-mercatoethyl-pyridine(MEP), 2-mercapto-1-methyli-midazole(MMI), 5-aminobenzi-midazole(ABI) and tryptophan-5-aminobenzi-midazole(W-ABI) were evaluated. The results showed that high adsorption ratio were found at p H 6.0–7.0 with little adsorption under acidic conditions. The resin with ABI ligand was then used to separate IgY from immunized chicken serum. An efficient process with Ig Y purity of 95% and recovery of 90% was developed after optimization of loading and elution p H and injection volume. The biological activity of the purified Ig Y was fully maintained. These results indicated that mixed-mode chromatography with specially-designed ligands has great potential for the separation of Ig Y from crude feedstock.展开更多
Five tryptophan analogues with a hydrophobic indole ring and an amino group on each molecule were used as functional ligands of mixed-mode resins for human serum albumin(HSA) purification. Their adsorption performance...Five tryptophan analogues with a hydrophobic indole ring and an amino group on each molecule were used as functional ligands of mixed-mode resins for human serum albumin(HSA) purification. Their adsorption performance was evaluated and the effects of p H and salt addition on HSA adsorption were studied. The resins prepared showed typical p H-dependent adsorption and the highest adsorption capacity and affinity were found at pH 5.0for all the resins tested. The saturated adsorption capacity was 138.02 mg·g^(-1)with the tryptaminefunctionalized resin, which significantly decreased at p H below 4.0 due to electrostatic repulsion between ligands and HSA. Moreover, the addition of Na Cl or(NH_4)_2SO_4in media reduced HSA adsorption capacity, although the two salts showed different affecting profiles. The tryptamine-functionalized resin showed the best salt-tolerant performance, and its high adsorption capacity was maintained under high salt concentrations. In addition, the five resins prepared showed good adsorption selectivity for recombinant HSA from Pichia pastoris broth. Molecular docking results between tryptamine and HSA indicated that tryptamine was favorable to bind on Site II(indole-binding site) of HSA.展开更多
In this study, a system involving two-dimensional, column-switching high-performance liquid chromatography （HPLC） coupled with tandem mass spectrometry （LC-MS/MS） was developed and optimized for the analysis of an...In this study, a system involving two-dimensional, column-switching high-performance liquid chromatography （HPLC） coupled with tandem mass spectrometry （LC-MS/MS） was developed and optimized for the analysis of antibiotics and their related substances. In the first-dimensional chromatography, the analytes were separated on a zwitterion exchange-reversed phase-hydrophitic interaction （ZIC-RP-HILIC） mixed-mode column coupled with tandem mass spectrometry （LC-MS/MS）. A commonly used reversed phase LC column was employed in the second-dimensional chromatography. The mobile phase for the ZIC-RP-HILIC mixed-mode chromatography consisted of a volatile buffer that was compatible with LC-MS/MS, which enhanced the efficiency of ionization for structure elucidation. The antibiotic impurities eluted in the ion-pairing reversed phase chromatography were directly characterized by the ZIC-RP-HILIC-MS system, and the orthogonal separation of ZIC-RP-HILIC mixed-mode chromatography and reversed phase LC provided extra confidence that no impurity was missed. The efficiency of this method was demonstrated in the analysis of penicillin V potassium, oxacillin sodium, ceftriaxone sodium, and their impurities. In addition, this method is convenient for impurity profiling of antibiotics, and may be used for the analysis of other pharmaceutical ingredients.展开更多
A reversed phase (RP)/hydrophilic interaction (HILIC)/ion exchange (IEX) mixed tri-mode stationary phase (TMSP) has been prepared via a divergent synthesis scheme starting from propylamine on silica then by amine-epox...A reversed phase (RP)/hydrophilic interaction (HILIC)/ion exchange (IEX) mixed tri-mode stationary phase (TMSP) has been prepared via a divergent synthesis scheme starting from propylamine on silica then by amine-epoxy reactions with 1,4-butanedioldiglycidyl ether and tertiary amines (N,Ndimethyldecylamine, DMDA). Its retention mechanism was found to follow RP/HILIC/IEX mixed-mode.The stop-flow test revealed that TMSP had good compatibility with 100% aqueous mobile phase. It demonstrated effective separation towards several kinds of compounds or drug molecules and their counterions within a single run.展开更多
Here,silica microspheres were decorated with two-dimensional metal-organic frameworks(2 D MOFs)nanosheets and ionic liquids,and evaluated as the mixed-mode stationary phase for chromatographic separation.The ionic liq...Here,silica microspheres were decorated with two-dimensional metal-organic frameworks(2 D MOFs)nanosheets and ionic liquids,and evaluated as the mixed-mode stationary phase for chromatographic separation.The ionic liquids were used to assist the synthesis of 2 D MOFs nanosheets,and also acted as adhesives among the nanosheets and silica.In contrast with the 2 D MOFs-based column without ionic liquids and commercial columns,the prepared column exhibited enhanced chromatographic separation performance for partially hydrophilic compounds such as alkaloids,sulfonamides and antibiotics,etc.In addition to excellent chromatographic repeatability and stability,it has also been verified that the composites could be easily and repeatedly prepared.The relative standard deviation of the retention time of the same type of analyte between the three batches of materials was ranging from 0.21%to 1.7%.In short,these results indicated that the synthesized composites were promising separation material for liquid chromatography,which made it possible to broaden the application of 2 D MOFs in the field of chromatography.展开更多
A novel polymeric ionic liquid grafted porous polymer monolith has been facilely fabricated for mixed-mode chromatography.The column is prepared from poly(glycidyl methacrylate-co-ethylene dimethacrylate)monolith thro...A novel polymeric ionic liquid grafted porous polymer monolith has been facilely fabricated for mixed-mode chromatography.The column is prepared from poly(glycidyl methacrylate-co-ethylene dimethacrylate)monolith through hydrolyzation of the epoxy moieties into hydroxyl groups,followed by“grafting from”polymerization of ionic liquid of 1-vinyl-3-butylimidazolium chloride.Successful modification is characterized by scanning electron microscope,infrared spectroscopy,elemental analysis and mercury intrusion porosimetry.The HPLC performance of developed column is evaluated by separating acidic vitamin B analytes,neutral steroids and basic aromatic amines in mixed-mode chromatography on a single column,respectively.The ionic liquid affords the monolith with both enhanced separation ability and improved column efficiency.展开更多
采用"点击化学"的合成方法制备了一种混合配体的辛基-羧基共同键合硅胶(OCS)材料,经元素分析和红外光谱表征,证明了辛基和羧基官能团均已成功键合到硅胶表面。将其作为混合模式反相弱阳离子交换(RP/W C X)的固定相填料,以3种...采用"点击化学"的合成方法制备了一种混合配体的辛基-羧基共同键合硅胶(OCS)材料,经元素分析和红外光谱表征,证明了辛基和羧基官能团均已成功键合到硅胶表面。将其作为混合模式反相弱阳离子交换(RP/W C X)的固定相填料,以3种同系物阳离子表面活性剂作为探针分子,定量研究了该固定相的混合模式保留机理,考察了溶质保留因子与盐浓度和溶质亚甲基数目的关系,验证了混合模式固定相的单点和两点保留机理的数学模型,并进一步将其应用于一系列标准碱性混合物的分离。结果表明:两点保留机理更加符合实验的结果;根据混合模式两点保留机理的数学方程,可以得到单一的疏水或离子交换作用力对总保留的影响,对混合模式色谱的实际分离应用提供了有价值的参考。本文建立了反相弱阳离子交换混合模式OCS固定相的保留机理的定量模型,并证明了该固定相在碱性化合物的分离中具有很大的应用前景。展开更多
基金Supported by the National Natural Science Foundation of China(21776243,21476198)the International Science&Technology Cooperation Program of China(2015DFG42070)
文摘The importance of immunoglobulin Y(IgY) as a specific antibody equivalent to mammalian immunoglobulin G(IgG) is well recognized. However, production of highly purified IgY is still difficult due to the lack of specific purification methods. In this study, adsorption behaviors of Ig Y on four mixed-mode resins with functional ligands of 4-mercatoethyl-pyridine(MEP), 2-mercapto-1-methyli-midazole(MMI), 5-aminobenzi-midazole(ABI) and tryptophan-5-aminobenzi-midazole(W-ABI) were evaluated. The results showed that high adsorption ratio were found at p H 6.0–7.0 with little adsorption under acidic conditions. The resin with ABI ligand was then used to separate IgY from immunized chicken serum. An efficient process with Ig Y purity of 95% and recovery of 90% was developed after optimization of loading and elution p H and injection volume. The biological activity of the purified Ig Y was fully maintained. These results indicated that mixed-mode chromatography with specially-designed ligands has great potential for the separation of Ig Y from crude feedstock.
基金Supported by the National Natural Science Foundation of China(21476198,21576233)the International Science&Technology Cooperation Program of China(2015DFG42070)
文摘Five tryptophan analogues with a hydrophobic indole ring and an amino group on each molecule were used as functional ligands of mixed-mode resins for human serum albumin(HSA) purification. Their adsorption performance was evaluated and the effects of p H and salt addition on HSA adsorption were studied. The resins prepared showed typical p H-dependent adsorption and the highest adsorption capacity and affinity were found at pH 5.0for all the resins tested. The saturated adsorption capacity was 138.02 mg·g^(-1)with the tryptaminefunctionalized resin, which significantly decreased at p H below 4.0 due to electrostatic repulsion between ligands and HSA. Moreover, the addition of Na Cl or(NH_4)_2SO_4in media reduced HSA adsorption capacity, although the two salts showed different affecting profiles. The tryptamine-functionalized resin showed the best salt-tolerant performance, and its high adsorption capacity was maintained under high salt concentrations. In addition, the five resins prepared showed good adsorption selectivity for recombinant HSA from Pichia pastoris broth. Molecular docking results between tryptamine and HSA indicated that tryptamine was favorable to bind on Site II(indole-binding site) of HSA.
基金The Key Projects in the National Science&Technology Pillar Program during the Twelfth Five-year Plan Period(Grant No.2012BAK25B02)
文摘In this study, a system involving two-dimensional, column-switching high-performance liquid chromatography （HPLC） coupled with tandem mass spectrometry （LC-MS/MS） was developed and optimized for the analysis of antibiotics and their related substances. In the first-dimensional chromatography, the analytes were separated on a zwitterion exchange-reversed phase-hydrophitic interaction （ZIC-RP-HILIC） mixed-mode column coupled with tandem mass spectrometry （LC-MS/MS）. A commonly used reversed phase LC column was employed in the second-dimensional chromatography. The mobile phase for the ZIC-RP-HILIC mixed-mode chromatography consisted of a volatile buffer that was compatible with LC-MS/MS, which enhanced the efficiency of ionization for structure elucidation. The antibiotic impurities eluted in the ion-pairing reversed phase chromatography were directly characterized by the ZIC-RP-HILIC-MS system, and the orthogonal separation of ZIC-RP-HILIC mixed-mode chromatography and reversed phase LC provided extra confidence that no impurity was missed. The efficiency of this method was demonstrated in the analysis of penicillin V potassium, oxacillin sodium, ceftriaxone sodium, and their impurities. In addition, this method is convenient for impurity profiling of antibiotics, and may be used for the analysis of other pharmaceutical ingredients.
基金financially supported by the National Natural Science Foundation of China(Nos. 21477037, 21322502)the Outstanding Young Talent Cultivation Fund of East China University of Science and Technology
文摘A reversed phase (RP)/hydrophilic interaction (HILIC)/ion exchange (IEX) mixed tri-mode stationary phase (TMSP) has been prepared via a divergent synthesis scheme starting from propylamine on silica then by amine-epoxy reactions with 1,4-butanedioldiglycidyl ether and tertiary amines (N,Ndimethyldecylamine, DMDA). Its retention mechanism was found to follow RP/HILIC/IEX mixed-mode.The stop-flow test revealed that TMSP had good compatibility with 100% aqueous mobile phase. It demonstrated effective separation towards several kinds of compounds or drug molecules and their counterions within a single run.
基金supported by the National Natural Science Foundation of China(Nos.21575149,21575148)the State Key Scientific Special Project(No.2016ZX05011-003)。
文摘Here,silica microspheres were decorated with two-dimensional metal-organic frameworks(2 D MOFs)nanosheets and ionic liquids,and evaluated as the mixed-mode stationary phase for chromatographic separation.The ionic liquids were used to assist the synthesis of 2 D MOFs nanosheets,and also acted as adhesives among the nanosheets and silica.In contrast with the 2 D MOFs-based column without ionic liquids and commercial columns,the prepared column exhibited enhanced chromatographic separation performance for partially hydrophilic compounds such as alkaloids,sulfonamides and antibiotics,etc.In addition to excellent chromatographic repeatability and stability,it has also been verified that the composites could be easily and repeatedly prepared.The relative standard deviation of the retention time of the same type of analyte between the three batches of materials was ranging from 0.21%to 1.7%.In short,these results indicated that the synthesized composites were promising separation material for liquid chromatography,which made it possible to broaden the application of 2 D MOFs in the field of chromatography.
基金We gratefully acknowledge the financial support from NSFC(Nos.21175138,21375132 and 21321003).
文摘A novel polymeric ionic liquid grafted porous polymer monolith has been facilely fabricated for mixed-mode chromatography.The column is prepared from poly(glycidyl methacrylate-co-ethylene dimethacrylate)monolith through hydrolyzation of the epoxy moieties into hydroxyl groups,followed by“grafting from”polymerization of ionic liquid of 1-vinyl-3-butylimidazolium chloride.Successful modification is characterized by scanning electron microscope,infrared spectroscopy,elemental analysis and mercury intrusion porosimetry.The HPLC performance of developed column is evaluated by separating acidic vitamin B analytes,neutral steroids and basic aromatic amines in mixed-mode chromatography on a single column,respectively.The ionic liquid affords the monolith with both enhanced separation ability and improved column efficiency.
文摘采用"点击化学"的合成方法制备了一种混合配体的辛基-羧基共同键合硅胶(OCS)材料,经元素分析和红外光谱表征,证明了辛基和羧基官能团均已成功键合到硅胶表面。将其作为混合模式反相弱阳离子交换(RP/W C X)的固定相填料,以3种同系物阳离子表面活性剂作为探针分子,定量研究了该固定相的混合模式保留机理,考察了溶质保留因子与盐浓度和溶质亚甲基数目的关系,验证了混合模式固定相的单点和两点保留机理的数学模型,并进一步将其应用于一系列标准碱性混合物的分离。结果表明:两点保留机理更加符合实验的结果;根据混合模式两点保留机理的数学方程,可以得到单一的疏水或离子交换作用力对总保留的影响,对混合模式色谱的实际分离应用提供了有价值的参考。本文建立了反相弱阳离子交换混合模式OCS固定相的保留机理的定量模型,并证明了该固定相在碱性化合物的分离中具有很大的应用前景。
