A new chromatographic purification of single-walled carbon nanotubes using high-speed countercurrent chromatography is reported. The purification was accomplished on the basis of experiment that dispersed the single-w...A new chromatographic purification of single-walled carbon nanotubes using high-speed countercurrent chromatography is reported. The purification was accomplished on the basis of experiment that dispersed the single-walled carbon nanotubes with sodium dodecyl sulfate, and the result mixture was separated using the two phase system composed of n-butanol/water = 1/1 （v/v）. The sizes of SWNTs separated were observed by scanning electron microscopy. The results demonstrated that the high-speed countercurrent chromatography possessed a good efficency for purification of single-walled carbon nanotubes.展开更多
Enantioseparation of aminoglutethimide was performed by high-speed counter-current chromatography with a two-phase system composed of ethyl acetate： methanol： water = 10： 1： 9. The lower phase contained 20 mmol/L ...Enantioseparation of aminoglutethimide was performed by high-speed counter-current chromatography with a two-phase system composed of ethyl acetate： methanol： water = 10： 1： 9. The lower phase contained 20 mmol/L of carboxymethly-β-cyclodextrin as chiral selector. The enantiomers were separated in 1.2 h and identified by chiral HPLC. This method was very efficient for the chiral preparative separation.展开更多
Rice false smut is an emerging plant disease worldwide.Ustiloxin A(UstA)is the major mycotoxin found in rice false smut balls,which are fungal colonies in rice florets.In this study,a new method consisting of macropor...Rice false smut is an emerging plant disease worldwide.Ustiloxin A(UstA)is the major mycotoxin found in rice false smut balls,which are fungal colonies in rice florets.In this study,a new method consisting of macroporous resin column chromatography and high-speed countercurrent chromatography(HSCCC)was developed for UstA separation.UstA was extracted by a 3.81%HCOOH solution and adsorbed by XAD-4 resin.UstA was then eluted by a 40%methanol solution supplemented with 0.1%trifluoroacetic acid(TFA).Further purification was achieved by HSCCC using a two-phase solvent system consisting of n-butanol/TFA/H_(2)O(1/0.05/1,v/v/v).Under the optimized conditions,225 mg of UstA was obtained with a purity of 97.39%in a single run,with a final recovery of 65.2%.An inhibitory effect on seed germination of wheat and maize caused by UstA was observed in a preliminary phytotoxicity assay.展开更多
A high-speed counter-current chromatography （HSCCC） method was successfully developed for the preparative separation and purification of deoxyschizandrin from Schisandrae Sphenantherae Fructus in one step. The purit...A high-speed counter-current chromatography （HSCCC） method was successfully developed for the preparative separation and purification of deoxyschizandrin from Schisandrae Sphenantherae Fructus in one step. The purity of deoxyschizandrin was 98.5%, and the structure was identified by MS, UV and NMR. This method was simple, fast, convenient and appropriate to prepare pure compound as reference substances for related research on Schisandrae Sphenantherae Fmctus.展开更多
1 INTRODUCTIONCountercurrent chromatography(CCC)is a true liquid-liquid partition chromatographywhich totally eliminates the use of a solid support.Being a support-free system,themethod offers a number of advantages o...1 INTRODUCTIONCountercurrent chromatography(CCC)is a true liquid-liquid partition chromatographywhich totally eliminates the use of a solid support.Being a support-free system,themethod offers a number of advantages over other chromatographic methods byminimizing problems arising from the use of solid supports such as adsorptive loss andinactivation of samples,tailing of solute peaks,contamination,etc.In practice,CCCprovides its greatest advantage in preparative-scale separations where high-performanceliquid chromatography(HPLC)suffers loss of partition efficiency and high展开更多
1 INTRODUCTIONCountercurrent chromatography(CCC)[1,2] is distinguished from other chromatographicmethods by its eliminating the solid support matrix from the separation column.Themethod employs an open tubular column ...1 INTRODUCTIONCountercurrent chromatography(CCC)[1,2] is distinguished from other chromatographicmethods by its eliminating the solid support matrix from the separation column.Themethod employs an open tubular column where the partition process takes place be-tween the flowing mobile phase and the stationary phase retained by the effect of展开更多
[Objectives] To develop a method for separation and purification of acetophenones from Cynanchum bengei Decne root bark by combination of silica gel and high-speed counter-current chromatography( HSCCC). [Methods]The ...[Objectives] To develop a method for separation and purification of acetophenones from Cynanchum bengei Decne root bark by combination of silica gel and high-speed counter-current chromatography( HSCCC). [Methods]The crude extract of Cynanchum bengei Decne root bark was separated by silica gel column chromatography,and parts A and B containing acetophenones were obtained. Then,parts A and B were separated by HSCCC with a two-phase solvent system composed of petroleum ether-ethyl acetate-methanol-water( 4∶ 6∶ 4. 5∶ 5. 5 and4∶ 6 ∶ 3 ∶ 7, V/V), respectively. [Results] From 260 mg of part A, four compounds with p-dihydroxybenzene 3. 9 mg(Ⅰ),4-hydroxyacetophenone 17. 1 mg( Ⅱ),2,5-di-hydroxyacetophenone 13. 3 mg(Ⅲ) and 2,4-dihydroxyaceto-phenone 21. 0 mg(Ⅳ) were obtained. And from 300 mg of part B,136 mg of Radix Cynanchi Bungei benzophenone(Ⅴ) was obtained. The purity of compounds determined by HPLC was 97. 0%,96. 6%,99. 2%,99. 7%,99. 5%,respectively. [Conclusions] The established method is simple and efficient. It can be used for separation of acetophenones from Cynanchum bengei Decne root bark and has better practical value,which could provide a reference basis for development and utilization of Cynanchum bengei Decne root bark.展开更多
Objective To develop an efficient method to isolate and purify the main components isoaloeresin D and aloin from Aloe vera for its industrial production.Methods High-speed counter-current chromatography was used to is...Objective To develop an efficient method to isolate and purify the main components isoaloeresin D and aloin from Aloe vera for its industrial production.Methods High-speed counter-current chromatography was used to isolate isoaloeresin D and aloin in a one-step separation from dried crude extract of A.vera.The biphasic solvent system composed of hexane-ethyl acetate-acetone-water(0.2:5:1.5:5) was used at a flow rate of 1.0 mL/min,while the lipophilic phase was selected as the mobile phase and the apparatus was rotated at 840 r/min.The effluent was detected at 254 nm.Results Isoaloeresin D(53.1 mg) and aloin(106.9 mg) were separated from the crude extract(384.7 mg) with the purities of 98.6% and 99.5%,respectively.Conclusion HSCCC is a powerful technique for isolation and separation of chemical composition from aloe.展开更多
Objective To develop an efficient preparative method for the separation of Gelsemium alkaloids from Gelsemium elegans. Methods High-speed counter-current chromatography （HSCCC） with several two-phase solvent systems...Objective To develop an efficient preparative method for the separation of Gelsemium alkaloids from Gelsemium elegans. Methods High-speed counter-current chromatography （HSCCC） with several two-phase solvent systems was investigated for the separation of Gelsemium alkaloids. The purity and structure identification of the purified compounds were performed with HPLC and NMR spectra, respectively. Results In a single operation, 206.6 mg of crude alkaloid sample was separated to yield 28.7 mg of koumine, 24.9 mg of gelsemine, 26.9 mg of humantenine, and 7.2 mg of gelsevirine, with the purities of 97.8%, 95.4%, 97.4%, and 93.5%, respectively. Conclusion A preparative HSCCC method is successfully established for the separation of four Gelsemium alkaloids from G. elegans with a modified two-phase solvent system com posed of n-hexane-ethyl acetate-ethanol-O. 5% triethylamine-H2O （3：5：3：4）.展开更多
基金supported by National Natural Science Foundation (No.20775066)Yunnan Province's Natural Science Foundations of China (Nos.2005E0006Z and 2007B203M).
文摘A new chromatographic purification of single-walled carbon nanotubes using high-speed countercurrent chromatography is reported. The purification was accomplished on the basis of experiment that dispersed the single-walled carbon nanotubes with sodium dodecyl sulfate, and the result mixture was separated using the two phase system composed of n-butanol/water = 1/1 （v/v）. The sizes of SWNTs separated were observed by scanning electron microscopy. The results demonstrated that the high-speed countercurrent chromatography possessed a good efficency for purification of single-walled carbon nanotubes.
基金The work is supported by National Natural Science Foundation of China （No. 30160092） TRAP0YT and Yunnan Province＇s Natural Science Foundation.
文摘Enantioseparation of aminoglutethimide was performed by high-speed counter-current chromatography with a two-phase system composed of ethyl acetate： methanol： water = 10： 1： 9. The lower phase contained 20 mmol/L of carboxymethly-β-cyclodextrin as chiral selector. The enantiomers were separated in 1.2 h and identified by chiral HPLC. This method was very efficient for the chiral preparative separation.
基金This work was financially supported by the National Key Research and Development Project(2018YFE0206000)National Natural Science Foundation of China(31901805,U1604234,31872914)Jiangsu Agriculture Science and Technology Innovation Fund(CX(19)3004).
文摘Rice false smut is an emerging plant disease worldwide.Ustiloxin A(UstA)is the major mycotoxin found in rice false smut balls,which are fungal colonies in rice florets.In this study,a new method consisting of macroporous resin column chromatography and high-speed countercurrent chromatography(HSCCC)was developed for UstA separation.UstA was extracted by a 3.81%HCOOH solution and adsorbed by XAD-4 resin.UstA was then eluted by a 40%methanol solution supplemented with 0.1%trifluoroacetic acid(TFA).Further purification was achieved by HSCCC using a two-phase solvent system consisting of n-butanol/TFA/H_(2)O(1/0.05/1,v/v/v).Under the optimized conditions,225 mg of UstA was obtained with a purity of 97.39%in a single run,with a final recovery of 65.2%.An inhibitory effect on seed germination of wheat and maize caused by UstA was observed in a preliminary phytotoxicity assay.
基金supported by the International Scientific and Technological Cooperation Program of China(No.2009DFA31230)the Industry-University-Research Cooperation Program from Science and Technology Department of Guangdong Province(No.2010B090400533)
文摘A high-speed counter-current chromatography （HSCCC） method was successfully developed for the preparative separation and purification of deoxyschizandrin from Schisandrae Sphenantherae Fructus in one step. The purity of deoxyschizandrin was 98.5%, and the structure was identified by MS, UV and NMR. This method was simple, fast, convenient and appropriate to prepare pure compound as reference substances for related research on Schisandrae Sphenantherae Fmctus.
基金Supported by the Science and Technology Major Plans for 96,Zhejiang Provice(No.961103100).
文摘1 INTRODUCTIONCountercurrent chromatography(CCC)is a true liquid-liquid partition chromatographywhich totally eliminates the use of a solid support.Being a support-free system,themethod offers a number of advantages over other chromatographic methods byminimizing problems arising from the use of solid supports such as adsorptive loss andinactivation of samples,tailing of solute peaks,contamination,etc.In practice,CCCprovides its greatest advantage in preparative-scale separations where high-performanceliquid chromatography(HPLC)suffers loss of partition efficiency and high
文摘1 INTRODUCTIONCountercurrent chromatography(CCC)[1,2] is distinguished from other chromatographicmethods by its eliminating the solid support matrix from the separation column.Themethod employs an open tubular column where the partition process takes place be-tween the flowing mobile phase and the stationary phase retained by the effect of
基金Supported by National Natural Science Foundation Item of 2014(81373941)Shandong Natural Science Foundation Item of 2012(ZR2012HM047)+1 种基金Science and Technology Development Plan Item of Shandong(2014G2X219003)Major Project of the State Administration of Traditional Chinese Medicine(201407002)
文摘[Objectives] To develop a method for separation and purification of acetophenones from Cynanchum bengei Decne root bark by combination of silica gel and high-speed counter-current chromatography( HSCCC). [Methods]The crude extract of Cynanchum bengei Decne root bark was separated by silica gel column chromatography,and parts A and B containing acetophenones were obtained. Then,parts A and B were separated by HSCCC with a two-phase solvent system composed of petroleum ether-ethyl acetate-methanol-water( 4∶ 6∶ 4. 5∶ 5. 5 and4∶ 6 ∶ 3 ∶ 7, V/V), respectively. [Results] From 260 mg of part A, four compounds with p-dihydroxybenzene 3. 9 mg(Ⅰ),4-hydroxyacetophenone 17. 1 mg( Ⅱ),2,5-di-hydroxyacetophenone 13. 3 mg(Ⅲ) and 2,4-dihydroxyaceto-phenone 21. 0 mg(Ⅳ) were obtained. And from 300 mg of part B,136 mg of Radix Cynanchi Bungei benzophenone(Ⅴ) was obtained. The purity of compounds determined by HPLC was 97. 0%,96. 6%,99. 2%,99. 7%,99. 5%,respectively. [Conclusions] The established method is simple and efficient. It can be used for separation of acetophenones from Cynanchum bengei Decne root bark and has better practical value,which could provide a reference basis for development and utilization of Cynanchum bengei Decne root bark.
基金Science and Technology Project of Zhuhai (PC20051072),2005
文摘Objective To develop an efficient method to isolate and purify the main components isoaloeresin D and aloin from Aloe vera for its industrial production.Methods High-speed counter-current chromatography was used to isolate isoaloeresin D and aloin in a one-step separation from dried crude extract of A.vera.The biphasic solvent system composed of hexane-ethyl acetate-acetone-water(0.2:5:1.5:5) was used at a flow rate of 1.0 mL/min,while the lipophilic phase was selected as the mobile phase and the apparatus was rotated at 840 r/min.The effluent was detected at 254 nm.Results Isoaloeresin D(53.1 mg) and aloin(106.9 mg) were separated from the crude extract(384.7 mg) with the purities of 98.6% and 99.5%,respectively.Conclusion HSCCC is a powerful technique for isolation and separation of chemical composition from aloe.
文摘Objective To develop an efficient preparative method for the separation of Gelsemium alkaloids from Gelsemium elegans. Methods High-speed counter-current chromatography （HSCCC） with several two-phase solvent systems was investigated for the separation of Gelsemium alkaloids. The purity and structure identification of the purified compounds were performed with HPLC and NMR spectra, respectively. Results In a single operation, 206.6 mg of crude alkaloid sample was separated to yield 28.7 mg of koumine, 24.9 mg of gelsemine, 26.9 mg of humantenine, and 7.2 mg of gelsevirine, with the purities of 97.8%, 95.4%, 97.4%, and 93.5%, respectively. Conclusion A preparative HSCCC method is successfully established for the separation of four Gelsemium alkaloids from G. elegans with a modified two-phase solvent system com posed of n-hexane-ethyl acetate-ethanol-O. 5% triethylamine-H2O （3：5：3：4）.
