Direct chiral separation of azelnidipine enantiomers with Pirkle-type Sumichiral OA-2500 column was studied by normal phase and reserve phase conditions. By normal phase, azelnidipine enantiomers were well separated w...Direct chiral separation of azelnidipine enantiomers with Pirkle-type Sumichiral OA-2500 column was studied by normal phase and reserve phase conditions. By normal phase, azelnidipine enantiomers were well separated with Rs as 4.0 using hexane–ethanol （90：10, v/v） as mobile phase, and Rs as 2.7 in shorter time （no more than 13 min） using hexane–ethanol （60：40, v/v） as the recommended mobile phase. They were only partially separated by reverse phase using methanol or methanol containing 0.05 mol/L ammonium acetate. Using same chiral column, the chiral separation of other dihydropyridine calcium antagonist analogues almodipine and nimodipine were also studied and showed partial chiral separation in normal phase.展开更多
In the present study, we developed a novel open-tubular capillary dectrochromatographic method using avidin-phospholipid vesicle complex as the stationary phase for chiral separation of mexiletine hydrochloride. The a...In the present study, we developed a novel open-tubular capillary dectrochromatographic method using avidin-phospholipid vesicle complex as the stationary phase for chiral separation of mexiletine hydrochloride. The avidin immobilized on the phospholipid vesicle consisting of 1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine （DPPE） and L-u-phosphatidyl-L-serine （PS） （80：20, mg%） was coated in the capillary. The homogeneity and separation performance of the coating were evaluated in terms o f phospholipid vesicle characterization and the resolution of D,L-Tryptophan. As for mexiletine hydrochloride, four vital parameters affecting the separation efficiency of coating capillary, including buffer type, buffer pH, buffer concentration and the applied voltage, were studied in detail. Under the optimum conditions, the enantiomers could be separated well with good resolution. All the satisfactory results indicated that this method using avidin-phospholipid vesicle complex as the stationary phase was suitable and feasible, which had great potential in pharmaceutical separation Of enantiomers.展开更多
A non-linear non-ideal model, taking into account non-linear competitive isotherms, axial dispersion, film mass transfer, intraparticle diffusion, and port periodic switching, was developed to simulate the dynamics of...A non-linear non-ideal model, taking into account non-linear competitive isotherms, axial dispersion, film mass transfer, intraparticle diffusion, and port periodic switching, was developed to simulate the dynamics of simulated moving bed chromatography (SMBC). The model equations were solved by a new efficient numerical technique of orthogonal collocation on finite elements with periodical movement of concentration vector. The simulated SMBC performance is in accordance with the experimental results reported in the literature for separation of l,1'-bi-2-naphthol enantiomers using SMBC. This model is useful for design, operation, optimization and scale-up of non-linear SMBC for chiral separations with significant non-ideal effects, especially for high solute concentration and small intraparticle diffusion coefficient or large chiral stationary phase particle.展开更多
Molecularly imprinted polymers （MIPs）, using （S）-naproxen as template and the combination of butyl methacrylate （BMA） and MAA （1：1 molar ratio） as functional monomers were synthesized by an in situ polymeriza...Molecularly imprinted polymers （MIPs）, using （S）-naproxen as template and the combination of butyl methacrylate （BMA） and MAA （1：1 molar ratio） as functional monomers were synthesized by an in situ polymerization reaction. The rendered monolithic column was evaluated in HPLC mode. The result showed that the monolithic MIPs with the combination of two monomers produced better chiral resolution of rac-naproxen （Rs = 1.55） and column efficiencies of imprinted molecules （N = 2860 plates/m） than that with pure MAA.展开更多
The separation method using chiral stationary phase （CSP） for the preparation of enantioselective compound was widely used. In this work, supercritical fluid chromatography（SFC） was proposed to resolve the chiral ...The separation method using chiral stationary phase （CSP） for the preparation of enantioselective compound was widely used. In this work, supercritical fluid chromatography（SFC） was proposed to resolve the chiral mixtures. To determine the optimum operating conditions for the chiral separation of the racemic ibuprofen, the retention factors and resolutions with the change in pressure, temperature and the content of IPA （%, by volume） in supercritical CO2 were investigated. Experiments showed that the retention factor decreased with the increase of pressure and decrease in temperature. The retention factor was also influenced by the content of IPA in mobile phase, as the content of IPA in the supercritical fluid increased, the retention factor decreased. The resolution of the enantiomers became worse with the increase of IPA in the supercritical fluid. Through optimizing the experimental conditions, a SFC procedure with 13MPa, 311.15K and 4% IPA in CO2 was obtained. The peak shape of the enantiomers was symmetric with supercritical fluid chromatography when compared to the asymmetric peak shape obtained by the conventional liquid chromatography. This work demonstrated that the developed supercritical fluid chromatography procedure was suitable for the chiral separation of ibuprofen enantiomers.展开更多
Capillary electrochromatography(CEC)plays a significant role in chiral separation via the double separation principle,partition coefficient difference between the two phases,and electroosmotic flow-driven separation.G...Capillary electrochromatography(CEC)plays a significant role in chiral separation via the double separation principle,partition coefficient difference between the two phases,and electroosmotic flow-driven separation.Given the distinct properties of the inner wall stationary phase(SP),the separation ability of each SP differs from one another.Particularly,it provides large room for promising applications of open tubular capillary electrochromatography(OT-CEC).We divided the OT-CEC SPs developed over the past four years into six types:ionic liquids,nanoparticle materials,microporous materials,biomaterials,non-nanopolymers,and others,to mainly introduce their characteristics in chiral drug separation.There also added a few classic SPs that occurred within ten years as supplements to enrich the features of each SP.Additionally,we discuss their applications in metabolomics,food,cosmetics,environment,and biology as analytes in addition to chiral drugs.OT-CEC plays an increasingly significant role in chiral separation and may promote the development of capillary electrophoresis(CE)combined with other instruments in recent years,such as CE with mass spectrometry(CE/MS)and CE with ultraviolet light detector(CE/UV).展开更多
A series of cellulose 3,5-dimethylphenylcarbamates （CDMPCs） with different degrees of substitution （DS） and degrees of polymerization （DP） were homogeneously synthesized in 1-allyl-3-methylimidazolium chloride ...A series of cellulose 3,5-dimethylphenylcarbamates （CDMPCs） with different degrees of substitution （DS） and degrees of polymerization （DP） were homogeneously synthesized in 1-allyl-3-methylimidazolium chloride （AmimC1）. Then, the CDMPCs were coated on silica gel and used as chiral stationary phases （CSPs）, and their chiral recognition abilities for seven racemates were evaluated by high performance liquid chromatography. The results showed that DS and DP of CDMPCs had a great influence on chiral recognition abilities of the CSPs. The CSPs with the DS ~ 1 gives a low chiral recognition to most racemates. On the contrast, the CSPs with the DS _〉 2 exhibited high chiral separation abilities. For example, six racemates could be separated on the CSP with CDMPC of DS ~ 2 （CSP-2）. Especially, for the enantioseparation of 1-（2-naphthyl） ethanol and Tr6ger＇s base, CSP-2 gave the highest separation ability in all of CSPs. On the other hand, when the DP of cellulose was in a range from 39 to 220, the chiral separation abilities of CDMPCs increased as the DP increased. This work demonstrates that the structure of cellulose esters such as DS and DP has important effect on their chiral separation ability, and therefore provides a practical method to design and prepare desirable CSPs for different racemates.展开更多
A method using carboxymethyl-b-cyclodextrin (CM-b-CD) as selector for chiral separation of amino acids by capillary electrophoresis and laser-induced fluorescence detection was studied. Resolution was better than tha...A method using carboxymethyl-b-cyclodextrin (CM-b-CD) as selector for chiral separation of amino acids by capillary electrophoresis and laser-induced fluorescence detection was studied. Resolution was better than that obtained by b-CD or HP-b-CD.展开更多
Chiral spirocyclic compounds have attracted the attention of scholars and scientists owing to their potential applications in the pharmaceutical industry as either active pharmaceutical ingredients, catalysts in synth...Chiral spirocyclic compounds have attracted the attention of scholars and scientists owing to their potential applications in the pharmaceutical industry as either active pharmaceutical ingredients, catalysts in synthesizing active enantiomers, or as surface modifiers on silica particles to resolve entantiomers. In this study, five spiro compounds of 3,9-diphenyl-2,4,8,10-tetraoxaspiro[5.5]-undecane（1）, 3,9-（4-methoxyphenyl）-2,4,8,10-tetraoxaspiro [5.5] -undecane（2）, 3,9-（4-methylphenyl）-2,4,8,10-tetraoxaspiro [5.5] -undecane（3）, 4,4＇-（2,4,8,10-tetraoxaspiro[5.5]undecane-3,9-diyl）dibenzoic acid（4） and 3,9-di（4-formyl-phenyl）-2,4,8,10-tetraoxa-spiro[5.5]-undecane（5） were synthesized by grinding pentaerythritol with benzaldehyde, 4-methoxybenzaldehyde, 4-methylbenzaldehyde, 4-carboxybenzaldehyde or terephthalaldehyde monoacetal in the presence of InI3r3 under solvent-free conditions. A normal phase HPLC method was successfully developed to resolve entantiomers of compounds 1--5 on a chiral column. Specific optical rotation of R or S entantiomers（1） was determined and the corresponding configurations were proposed based on Lowe＇s rule.展开更多
Two new stationary phases : (Ⅰ) [bikis(2,6-di-O-pentyl-3-O-hex-6O-pentyl-3-O-methyl)-β-CD-polysiloxane] and (Ⅱ) [heptkis(2,6-di-O-methyl-3-O-hex-6-enyl)-β-CD-polysiloxane] were synthesized and successfully used fo...Two new stationary phases : (Ⅰ) [bikis(2,6-di-O-pentyl-3-O-hex-6O-pentyl-3-O-methyl)-β-CD-polysiloxane] and (Ⅱ) [heptkis(2,6-di-O-methyl-3-O-hex-6-enyl)-β-CD-polysiloxane] were synthesized and successfully used for GC separation of chiral isomers.The possess high column efficiency and exhibit fine chiral separation ability.展开更多
Dinucleotide (TpAZT) phosphoramidates were synthesized by Todd reaction of dinucleoside H-phosphonates and amino acid methyl esters, and their diastereomers (Rp and Sp) were separated by crystallization, and the resul...Dinucleotide (TpAZT) phosphoramidates were synthesized by Todd reaction of dinucleoside H-phosphonates and amino acid methyl esters, and their diastereomers (Rp and Sp) were separated by crystallization, and the results showed that natural and cheap methyl esters of alanine and phenylalanine can be used for large-scale synthesis of dinucleotide analogs.展开更多
Molecular imprinting chiral stationary phase against Cbz-L-Serine (Cbz-L-Ser) and Cbz-L-Alaine (Cbz-L-Ala) were prepared utilizing acrylamide + 2-vinylpyridine as combined basic functional monomers. Cross-selectivity ...Molecular imprinting chiral stationary phase against Cbz-L-Serine (Cbz-L-Ser) and Cbz-L-Alaine (Cbz-L-Ala) were prepared utilizing acrylamide + 2-vinylpyridine as combined basic functional monomers. Cross-selectivity was used to obtain simultaneous chiral separations of Cbz-DL-Ser and Cbz-DL-Ala by connecting two columns packed with Cbz-L-Ser and Cbz-L-Ala imprinted chiral stationary phase, respectively.展开更多
A successful chiral separation of N-benzoyl phenylalanine methyl ester has been achieved by nonaqueous capillary electrophoresis (NACE) using P-CD as chiral selector in formamide (FA). Some experimental parameters inf...A successful chiral separation of N-benzoyl phenylalanine methyl ester has been achieved by nonaqueous capillary electrophoresis (NACE) using P-CD as chiral selector in formamide (FA). Some experimental parameters influencing the chiral separation such as concentration of P-CD, ionic strength and apparent pH (pH*) are discussed.展开更多
Four basic drugs were separated by capillary electrophoresis (CE) usingcarboxymethyl-β-yclodextrin (CM-0-CD) as chiral selector. The effects of CM-β-CDconmptration, applied voltage. operation temperature were invest...Four basic drugs were separated by capillary electrophoresis (CE) usingcarboxymethyl-β-yclodextrin (CM-0-CD) as chiral selector. The effects of CM-β-CDconmptration, applied voltage. operation temperature were investigated. Under the selectedconditions. norephedrine. ofloxacin. terbutaline and chlorpheniramine were enantiomerallybaieline-separated using H3PO4-triethanolamine buffer at PH 3 containing 10, 5.5, 2. 2mmol/LCM-β-CD respectively.展开更多
Cyclodextrin-modified CZE was applied to the chiral separation of two basic drugs, i.e., esmolol and terazosin. Selector screening and concentration optimization experiments were performed. Resolution 3.1 for esmolol,...Cyclodextrin-modified CZE was applied to the chiral separation of two basic drugs, i.e., esmolol and terazosin. Selector screening and concentration optimization experiments were performed. Resolution 3.1 for esmolol, 1.2 for terazosin were achieved when using 60 mmol/L gamma-CD and 60 mmoL/L DM-P-CD, respectively, in 50 mmol/L pH 2.5 sodium phosphate buffer.展开更多
The presence of chirality,a fundamental attribute found in nature,is of great significance in the field of pharmaceutical science.Chiral drugs are unique in that their molecular structure is non-superimposable on its ...The presence of chirality,a fundamental attribute found in nature,is of great significance in the field of pharmaceutical science.Chiral drugs are unique in that their molecular structure is non-superimposable on its mirror image.This stereoisomerism significantly impacts the functionality,metabolic pathway,effectiveness,and safety of chiral medications.The enantiomers of chiral drugs can exhibit diverse pharmacological effects in the human body.As a result,it is essential to separate and purify chiral drugs effectively.Despite the abundance of reports on chiral drug separation membranes,there is a dearth of comprehensive reviews.This paper aims to fill this gap by providing a thorough review from a materials perspective,with a focus on the design and construction of chiral drug separation membranes.Furthermore,it systematically analyzes the separation mechanisms employed by these membranes.The paper also delves into the challenges and prospects related to chiral drug separation membranes,with the intention of imparting valuable insights for further research and development in this field.展开更多
Covalent organic frameworks(COFs), covalently assembled from the condensation reactions of organic building blocks, are a fascinating class of functional porous materials with two-or three-dimensional crystalline orga...Covalent organic frameworks(COFs), covalently assembled from the condensation reactions of organic building blocks, are a fascinating class of functional porous materials with two-or three-dimensional crystalline organic structures. Generally, it is preferable to use symmetric and rigid building blocks to construct highly crystalline COFs with desired topology. On the other hand, the incorporation of chiral functional moieties in the building blocks would open up new applications such as asymmetric catalysis and chiral separation. This mini review highlights the principle strategies in the design and synthesis of chiral COFs. The interesting and potential applications of these chiral COFs for asymmetric catalysis and chiral separation are also summarized.This mini review aims to provide an up-to-date advancement of chiral COFs for asymmetric catalysis and chiral separation.展开更多
Reverse micelles create unique environment in organic media. They are capable of solubilizing hydrophilic biomolecules （e.g., proteins, peptides, amino acids, and DNAs） in their aqueous interior. This feature brings...Reverse micelles create unique environment in organic media. They are capable of solubilizing hydrophilic biomolecules （e.g., proteins, peptides, amino acids, and DNAs） in their aqueous interior. This feature brings about the practical use of biomaterials in organic media because reverse micelles solubilize them with the intrinsic activity. In this paper, we focus on recent two topics concerning protein extraction and chiral separation of biomolecules using liquid membranes. In the first topic, we present recent attempts to extract proteins from an aqueous solution into isooctane using reverse micelles, and some important operational parameters to achieve an efficient protein transfer are discussed. Furthermore, novel function of reverse micelles as a protein activation medium is introduced. In the reverse micellar phase, denatured proteins were completely reactivated in the reverse micellar solution. The reverse micellar technique is found to be a useful tool not only for protein separation but also for protein refolding. Furthermore, we found that a cyclic ligand carixarene has an extraction ability to set up optimum conditions for protein transfer. In the second topic, we have found that a supported liquid membrane （SLM） encapsulating enzymes shows high enantioselectivity （enantioselective excess value is over 96%） in the transport of racemic pharmaceutical compound ibuprofen. A different experiment also suggests that the α-chymotrypsin-catalyzed reactions droved the enantioselective transport of L-phenylalanine based on the enantioselectivity of the enzyme. The SLM encapsulating the surfactant-enzyme complex enabled the highly enantioselective separation of racemic mixtures. It can be envisioned that arrangement of appropriate enzymes in the SLM system will allow enantioselective separation of various useful organic compounds.展开更多
Chiral separation of dansyl amino acids by capillary electrophoresis using mixed selectors of Mn(II)- L -alanine complex and β -cyclodextrin ( β -CD) was studied. Resolution was considerably superior to that obtaine...Chiral separation of dansyl amino acids by capillary electrophoresis using mixed selectors of Mn(II)- L -alanine complex and β -cyclodextrin ( β -CD) was studied. Resolution was considerably superior to that obtained by using either Mn(II)- L -alanine complex or β -CD alone. The effects of separation parameters,such as pH value of buffer solution,capillary temperature,the concentration of Mn(II)- L -alanine complex,the types of CD and ligand on the migration times and resolutions were investigated. Six different transition metal complexes, Cu(II), Zn(II),Co(II),Ni(II),Hg(II) and Cd(II)- L -alanine complexes have been employed and compared with Mn(II) complex. Differences in retention and selectivity were found. The substitution of Cu(II),Zn(II),Co(II) and Ni(II) for Mn(II) resulted in a better chiral resolution while Hg(II) and Cd(II) showed poorer resolution abilities. The chiral separation mechanism was also discussed briefly.展开更多
A detailed chemical investigation of the South China Sea nudibranch Hexabranchus sanguineus,as well as its possible sponge-prey Acanthella cavernosa,led to the isolation of fifteen new nitrogenous sesquiterpenoids,nam...A detailed chemical investigation of the South China Sea nudibranch Hexabranchus sanguineus,as well as its possible sponge-prey Acanthella cavernosa,led to the isolation of fifteen new nitrogenous sesquiterpenoids,namely ximaocavernosins A-0,including seven cadinanes(1-7),seven spiroaxanes(12-18)and one aromadendrane(19),together with thirteen known related compounds(8-11 and 20-28).展开更多
文摘Direct chiral separation of azelnidipine enantiomers with Pirkle-type Sumichiral OA-2500 column was studied by normal phase and reserve phase conditions. By normal phase, azelnidipine enantiomers were well separated with Rs as 4.0 using hexane–ethanol （90：10, v/v） as mobile phase, and Rs as 2.7 in shorter time （no more than 13 min） using hexane–ethanol （60：40, v/v） as the recommended mobile phase. They were only partially separated by reverse phase using methanol or methanol containing 0.05 mol/L ammonium acetate. Using same chiral column, the chiral separation of other dihydropyridine calcium antagonist analogues almodipine and nimodipine were also studied and showed partial chiral separation in normal phase.
基金support of Professor Xuan Zhang’s research group,Laboratory of pharmaceutics,School of Pharmaceutical Sciences,Peking UniversityBeijing Kaiao Technology Development Co.,Ltd.
文摘In the present study, we developed a novel open-tubular capillary dectrochromatographic method using avidin-phospholipid vesicle complex as the stationary phase for chiral separation of mexiletine hydrochloride. The avidin immobilized on the phospholipid vesicle consisting of 1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine （DPPE） and L-u-phosphatidyl-L-serine （PS） （80：20, mg%） was coated in the capillary. The homogeneity and separation performance of the coating were evaluated in terms o f phospholipid vesicle characterization and the resolution of D,L-Tryptophan. As for mexiletine hydrochloride, four vital parameters affecting the separation efficiency of coating capillary, including buffer type, buffer pH, buffer concentration and the applied voltage, were studied in detail. Under the optimum conditions, the enantiomers could be separated well with good resolution. All the satisfactory results indicated that this method using avidin-phospholipid vesicle complex as the stationary phase was suitable and feasible, which had great potential in pharmaceutical separation Of enantiomers.
基金Supported by the National Natural Science Foundation of China(No.20206027)and the Natural Science Foundation of Zhejiang Province(No.202046).
文摘A non-linear non-ideal model, taking into account non-linear competitive isotherms, axial dispersion, film mass transfer, intraparticle diffusion, and port periodic switching, was developed to simulate the dynamics of simulated moving bed chromatography (SMBC). The model equations were solved by a new efficient numerical technique of orthogonal collocation on finite elements with periodical movement of concentration vector. The simulated SMBC performance is in accordance with the experimental results reported in the literature for separation of l,1'-bi-2-naphthol enantiomers using SMBC. This model is useful for design, operation, optimization and scale-up of non-linear SMBC for chiral separations with significant non-ideal effects, especially for high solute concentration and small intraparticle diffusion coefficient or large chiral stationary phase particle.
基金This work was supported by the National Natural Science Foundation of China(20575045)outstanding scholar programs of Tianjin Medical University(to Z.S.Liu).
文摘Molecularly imprinted polymers （MIPs）, using （S）-naproxen as template and the combination of butyl methacrylate （BMA） and MAA （1：1 molar ratio） as functional monomers were synthesized by an in situ polymerization reaction. The rendered monolithic column was evaluated in HPLC mode. The result showed that the monolithic MIPs with the combination of two monomers produced better chiral resolution of rac-naproxen （Rs = 1.55） and column efficiencies of imprinted molecules （N = 2860 plates/m） than that with pure MAA.
文摘The separation method using chiral stationary phase （CSP） for the preparation of enantioselective compound was widely used. In this work, supercritical fluid chromatography（SFC） was proposed to resolve the chiral mixtures. To determine the optimum operating conditions for the chiral separation of the racemic ibuprofen, the retention factors and resolutions with the change in pressure, temperature and the content of IPA （%, by volume） in supercritical CO2 were investigated. Experiments showed that the retention factor decreased with the increase of pressure and decrease in temperature. The retention factor was also influenced by the content of IPA in mobile phase, as the content of IPA in the supercritical fluid increased, the retention factor decreased. The resolution of the enantiomers became worse with the increase of IPA in the supercritical fluid. Through optimizing the experimental conditions, a SFC procedure with 13MPa, 311.15K and 4% IPA in CO2 was obtained. The peak shape of the enantiomers was symmetric with supercritical fluid chromatography when compared to the asymmetric peak shape obtained by the conventional liquid chromatography. This work demonstrated that the developed supercritical fluid chromatography procedure was suitable for the chiral separation of ibuprofen enantiomers.
基金This study was funded by the Project of National Natural Science Foundation of China(Grant No.:82003705)the Shanghai Science and Technology Innovation Foundation(Grant Nos.:23010500200 and 23ZR1422700).
文摘Capillary electrochromatography(CEC)plays a significant role in chiral separation via the double separation principle,partition coefficient difference between the two phases,and electroosmotic flow-driven separation.Given the distinct properties of the inner wall stationary phase(SP),the separation ability of each SP differs from one another.Particularly,it provides large room for promising applications of open tubular capillary electrochromatography(OT-CEC).We divided the OT-CEC SPs developed over the past four years into six types:ionic liquids,nanoparticle materials,microporous materials,biomaterials,non-nanopolymers,and others,to mainly introduce their characteristics in chiral drug separation.There also added a few classic SPs that occurred within ten years as supplements to enrich the features of each SP.Additionally,we discuss their applications in metabolomics,food,cosmetics,environment,and biology as analytes in addition to chiral drugs.OT-CEC plays an increasingly significant role in chiral separation and may promote the development of capillary electrophoresis(CE)combined with other instruments in recent years,such as CE with mass spectrometry(CE/MS)and CE with ultraviolet light detector(CE/UV).
基金financially supported by the National Natural Science Foundation of China(Nos.5110316721174151 and 51425307)
文摘A series of cellulose 3,5-dimethylphenylcarbamates （CDMPCs） with different degrees of substitution （DS） and degrees of polymerization （DP） were homogeneously synthesized in 1-allyl-3-methylimidazolium chloride （AmimC1）. Then, the CDMPCs were coated on silica gel and used as chiral stationary phases （CSPs）, and their chiral recognition abilities for seven racemates were evaluated by high performance liquid chromatography. The results showed that DS and DP of CDMPCs had a great influence on chiral recognition abilities of the CSPs. The CSPs with the DS ~ 1 gives a low chiral recognition to most racemates. On the contrast, the CSPs with the DS _〉 2 exhibited high chiral separation abilities. For example, six racemates could be separated on the CSP with CDMPC of DS ~ 2 （CSP-2）. Especially, for the enantioseparation of 1-（2-naphthyl） ethanol and Tr6ger＇s base, CSP-2 gave the highest separation ability in all of CSPs. On the other hand, when the DP of cellulose was in a range from 39 to 220, the chiral separation abilities of CDMPCs increased as the DP increased. This work demonstrates that the structure of cellulose esters such as DS and DP has important effect on their chiral separation ability, and therefore provides a practical method to design and prepare desirable CSPs for different racemates.
文摘A method using carboxymethyl-b-cyclodextrin (CM-b-CD) as selector for chiral separation of amino acids by capillary electrophoresis and laser-induced fluorescence detection was studied. Resolution was better than that obtained by b-CD or HP-b-CD.
基金the National Natural Science Foundation of China(No.20472064)the Natural Science Foundation of Tian- jin city, China(No.040884311)
文摘Chiral spirocyclic compounds have attracted the attention of scholars and scientists owing to their potential applications in the pharmaceutical industry as either active pharmaceutical ingredients, catalysts in synthesizing active enantiomers, or as surface modifiers on silica particles to resolve entantiomers. In this study, five spiro compounds of 3,9-diphenyl-2,4,8,10-tetraoxaspiro[5.5]-undecane（1）, 3,9-（4-methoxyphenyl）-2,4,8,10-tetraoxaspiro [5.5] -undecane（2）, 3,9-（4-methylphenyl）-2,4,8,10-tetraoxaspiro [5.5] -undecane（3）, 4,4＇-（2,4,8,10-tetraoxaspiro[5.5]undecane-3,9-diyl）dibenzoic acid（4） and 3,9-di（4-formyl-phenyl）-2,4,8,10-tetraoxa-spiro[5.5]-undecane（5） were synthesized by grinding pentaerythritol with benzaldehyde, 4-methoxybenzaldehyde, 4-methylbenzaldehyde, 4-carboxybenzaldehyde or terephthalaldehyde monoacetal in the presence of InI3r3 under solvent-free conditions. A normal phase HPLC method was successfully developed to resolve entantiomers of compounds 1--5 on a chiral column. Specific optical rotation of R or S entantiomers（1） was determined and the corresponding configurations were proposed based on Lowe＇s rule.
文摘Two new stationary phases : (Ⅰ) [bikis(2,6-di-O-pentyl-3-O-hex-6O-pentyl-3-O-methyl)-β-CD-polysiloxane] and (Ⅱ) [heptkis(2,6-di-O-methyl-3-O-hex-6-enyl)-β-CD-polysiloxane] were synthesized and successfully used for GC separation of chiral isomers.The possess high column efficiency and exhibit fine chiral separation ability.
基金The authors would like to thank the financial supports from the National Natural Science Foundation of China(No.29902003,20132020 and 20175026),the Ministry of Science and Technology,the Chinese Ministry of Education and Tsinghua University.
文摘Dinucleotide (TpAZT) phosphoramidates were synthesized by Todd reaction of dinucleoside H-phosphonates and amino acid methyl esters, and their diastereomers (Rp and Sp) were separated by crystallization, and the results showed that natural and cheap methyl esters of alanine and phenylalanine can be used for large-scale synthesis of dinucleotide analogs.
文摘Molecular imprinting chiral stationary phase against Cbz-L-Serine (Cbz-L-Ser) and Cbz-L-Alaine (Cbz-L-Ala) were prepared utilizing acrylamide + 2-vinylpyridine as combined basic functional monomers. Cross-selectivity was used to obtain simultaneous chiral separations of Cbz-DL-Ser and Cbz-DL-Ala by connecting two columns packed with Cbz-L-Ser and Cbz-L-Ala imprinted chiral stationary phase, respectively.
文摘A successful chiral separation of N-benzoyl phenylalanine methyl ester has been achieved by nonaqueous capillary electrophoresis (NACE) using P-CD as chiral selector in formamide (FA). Some experimental parameters influencing the chiral separation such as concentration of P-CD, ionic strength and apparent pH (pH*) are discussed.
文摘Four basic drugs were separated by capillary electrophoresis (CE) usingcarboxymethyl-β-yclodextrin (CM-0-CD) as chiral selector. The effects of CM-β-CDconmptration, applied voltage. operation temperature were investigated. Under the selectedconditions. norephedrine. ofloxacin. terbutaline and chlorpheniramine were enantiomerallybaieline-separated using H3PO4-triethanolamine buffer at PH 3 containing 10, 5.5, 2. 2mmol/LCM-β-CD respectively.
文摘Cyclodextrin-modified CZE was applied to the chiral separation of two basic drugs, i.e., esmolol and terazosin. Selector screening and concentration optimization experiments were performed. Resolution 3.1 for esmolol, 1.2 for terazosin were achieved when using 60 mmol/L gamma-CD and 60 mmoL/L DM-P-CD, respectively, in 50 mmol/L pH 2.5 sodium phosphate buffer.
基金supported by the Foundation Research Project of Kaili University(No.2025ZD007)the National Key Research and Development Program of China(No.2021YFB3801503)the Joint Research Program of Shaoxing University and Shaoxing Institute,Zhejiang University(No.2023LHLG006),China.
文摘The presence of chirality,a fundamental attribute found in nature,is of great significance in the field of pharmaceutical science.Chiral drugs are unique in that their molecular structure is non-superimposable on its mirror image.This stereoisomerism significantly impacts the functionality,metabolic pathway,effectiveness,and safety of chiral medications.The enantiomers of chiral drugs can exhibit diverse pharmacological effects in the human body.As a result,it is essential to separate and purify chiral drugs effectively.Despite the abundance of reports on chiral drug separation membranes,there is a dearth of comprehensive reviews.This paper aims to fill this gap by providing a thorough review from a materials perspective,with a focus on the design and construction of chiral drug separation membranes.Furthermore,it systematically analyzes the separation mechanisms employed by these membranes.The paper also delves into the challenges and prospects related to chiral drug separation membranes,with the intention of imparting valuable insights for further research and development in this field.
基金supported by the Singapore Academic Research Fund(RG112/15,RG19/16)
文摘Covalent organic frameworks(COFs), covalently assembled from the condensation reactions of organic building blocks, are a fascinating class of functional porous materials with two-or three-dimensional crystalline organic structures. Generally, it is preferable to use symmetric and rigid building blocks to construct highly crystalline COFs with desired topology. On the other hand, the incorporation of chiral functional moieties in the building blocks would open up new applications such as asymmetric catalysis and chiral separation. This mini review highlights the principle strategies in the design and synthesis of chiral COFs. The interesting and potential applications of these chiral COFs for asymmetric catalysis and chiral separation are also summarized.This mini review aims to provide an up-to-date advancement of chiral COFs for asymmetric catalysis and chiral separation.
基金Supported by a Grant-in-Aid for Scientific Research (No. 17656271) from the Ministry of Education, Science, Sports, and Culture of Japan.
文摘Reverse micelles create unique environment in organic media. They are capable of solubilizing hydrophilic biomolecules （e.g., proteins, peptides, amino acids, and DNAs） in their aqueous interior. This feature brings about the practical use of biomaterials in organic media because reverse micelles solubilize them with the intrinsic activity. In this paper, we focus on recent two topics concerning protein extraction and chiral separation of biomolecules using liquid membranes. In the first topic, we present recent attempts to extract proteins from an aqueous solution into isooctane using reverse micelles, and some important operational parameters to achieve an efficient protein transfer are discussed. Furthermore, novel function of reverse micelles as a protein activation medium is introduced. In the reverse micellar phase, denatured proteins were completely reactivated in the reverse micellar solution. The reverse micellar technique is found to be a useful tool not only for protein separation but also for protein refolding. Furthermore, we found that a cyclic ligand carixarene has an extraction ability to set up optimum conditions for protein transfer. In the second topic, we have found that a supported liquid membrane （SLM） encapsulating enzymes shows high enantioselectivity （enantioselective excess value is over 96%） in the transport of racemic pharmaceutical compound ibuprofen. A different experiment also suggests that the α-chymotrypsin-catalyzed reactions droved the enantioselective transport of L-phenylalanine based on the enantioselectivity of the enzyme. The SLM encapsulating the surfactant-enzyme complex enabled the highly enantioselective separation of racemic mixtures. It can be envisioned that arrangement of appropriate enzymes in the SLM system will allow enantioselective separation of various useful organic compounds.
文摘Chiral separation of dansyl amino acids by capillary electrophoresis using mixed selectors of Mn(II)- L -alanine complex and β -cyclodextrin ( β -CD) was studied. Resolution was considerably superior to that obtained by using either Mn(II)- L -alanine complex or β -CD alone. The effects of separation parameters,such as pH value of buffer solution,capillary temperature,the concentration of Mn(II)- L -alanine complex,the types of CD and ligand on the migration times and resolutions were investigated. Six different transition metal complexes, Cu(II), Zn(II),Co(II),Ni(II),Hg(II) and Cd(II)- L -alanine complexes have been employed and compared with Mn(II) complex. Differences in retention and selectivity were found. The substitution of Cu(II),Zn(II),Co(II) and Ni(II) for Mn(II) resulted in a better chiral resolution while Hg(II) and Cd(II) showed poorer resolution abilities. The chiral separation mechanism was also discussed briefly.
基金This research work was financially supported by the National Natural Science Foundation of China(Nos.81991521,82022069,42076099)the Shanghai Rising-Star Program(No.20QA1411100)+1 种基金"Youth Innovation Promotion Association"of Chinese Academy of Sciences(No.Y202065)the SKLDR/SIMM Project(No.SIMM2103ZZ-06).
文摘A detailed chemical investigation of the South China Sea nudibranch Hexabranchus sanguineus,as well as its possible sponge-prey Acanthella cavernosa,led to the isolation of fifteen new nitrogenous sesquiterpenoids,namely ximaocavernosins A-0,including seven cadinanes(1-7),seven spiroaxanes(12-18)and one aromadendrane(19),together with thirteen known related compounds(8-11 and 20-28).
