Results 61 to 70 of about 410 (110)
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Journal of Separation Science, 2007
AbstractThree novel pyridine derivatives were successfully separated from their partially purified synthetic mixtures by pH‐zone‐refining counter‐current chromatography using a multilayer coil planet centrifuge designed in our laboratory. After equilibration of a two‐phase solvent system consisting of methyl tert‐butyl ether–tetrahydrofuran–water at an
Shengqiang, Tong +3 more
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AbstractThree novel pyridine derivatives were successfully separated from their partially purified synthetic mixtures by pH‐zone‐refining counter‐current chromatography using a multilayer coil planet centrifuge designed in our laboratory. After equilibration of a two‐phase solvent system consisting of methyl tert‐butyl ether–tetrahydrofuran–water at an
Shengqiang, Tong +3 more
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Separations of basic amino acid benzyl esters by pH-zone-refining counter-current chromatography
Journal of Chromatography A, 1994pH-Zone-refining counter-current chromatography was applied to the separation of basic amino acid benzyl esters. The method uses a retainer base in the stationary phase to retain analytes in the column and an eluent acid to elute the analytes in the decreasing order of pKa and hydrophilicity.
Y, Ma, Y, Ito
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Journal of Chromatography A, 2011
Alkaloids in Gelsemium elegans possess a variety of therapeutic properties, including tumor suppression, analgesic and anti-inflammatory effects. In China, G. elegans has been used for centuries to treat a variety of medical conditions, including chronic pain and skin ulcer. Methods currently used to separate the active components of G.
Yan-Ping, Su +4 more
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Alkaloids in Gelsemium elegans possess a variety of therapeutic properties, including tumor suppression, analgesic and anti-inflammatory effects. In China, G. elegans has been used for centuries to treat a variety of medical conditions, including chronic pain and skin ulcer. Methods currently used to separate the active components of G.
Yan-Ping, Su +4 more
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Biomedical Chromatography, 2021
AbstractPhenolic acids are the main active components in Salvia yunnanensis Radix, which have significant effects such as cardiovascular protection, anti‐thrombosis, anti‐oxidant, and anti‐inflammation. In this study, pH‐zone‐refining counter‐current chromatography (pH‐ZRCCC) was successfully applied to the preparative separation of phenolic acids from
Tianyu Ma +5 more
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AbstractPhenolic acids are the main active components in Salvia yunnanensis Radix, which have significant effects such as cardiovascular protection, anti‐thrombosis, anti‐oxidant, and anti‐inflammation. In this study, pH‐zone‐refining counter‐current chromatography (pH‐ZRCCC) was successfully applied to the preparative separation of phenolic acids from
Tianyu Ma +5 more
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Journal of Chromatography A, 2002
Two modes of high-speed counter-current chromatography (HSCCC) were applied to separate 3- and 4-sulfophthalic acid from a mixture. Conventional HSCCC was useful for the separation of up to several hundred milligram quantities of these positional isomers, while pH-zone-refining CCC was implemented successfully to separations at the multigram level. The
Adrian, Weisz +3 more
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Two modes of high-speed counter-current chromatography (HSCCC) were applied to separate 3- and 4-sulfophthalic acid from a mixture. Conventional HSCCC was useful for the separation of up to several hundred milligram quantities of these positional isomers, while pH-zone-refining CCC was implemented successfully to separations at the multigram level. The
Adrian, Weisz +3 more
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Journal of Chromatography A, 2007
This work involves the preparative separation of some isomeric dicarboxylic acids using pH-zone-refining counter-current chromatography (CCC), a relatively new preparative technique for the separation of ionizable compounds. The paper concentrates especially on the separation of a synthetic mixture of closely related cis and trans pairs of 1-methyl ...
Adrian, Weisz +5 more
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This work involves the preparative separation of some isomeric dicarboxylic acids using pH-zone-refining counter-current chromatography (CCC), a relatively new preparative technique for the separation of ionizable compounds. The paper concentrates especially on the separation of a synthetic mixture of closely related cis and trans pairs of 1-methyl ...
Adrian, Weisz +5 more
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Journal of Chromatography A, 2006
pH-zone-refining counter-current chromatography was successfully applied to the separation of cichoric acid from Echinacea Purpurea (L.) Moench. A 3.0 g quantity of sample was separated using the following two-phase solvent system: MtBE-CH3CN-water (4:1:5, v/v), 10 mM trifluoroacetic acid in organic stationary phase and 10 mM ammonia in aqueous mobile ...
Xiao, Wang +4 more
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pH-zone-refining counter-current chromatography was successfully applied to the separation of cichoric acid from Echinacea Purpurea (L.) Moench. A 3.0 g quantity of sample was separated using the following two-phase solvent system: MtBE-CH3CN-water (4:1:5, v/v), 10 mM trifluoroacetic acid in organic stationary phase and 10 mM ammonia in aqueous mobile ...
Xiao, Wang +4 more
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Journal of Chromatography A, 2006
pH-zone-refining counter-current chromatography was successfully applied to the separation of alkaloids from a crude extract of Corydalis decumbens (Thunb.) Pers. using a multilayer coil planet centrifuge (CPC). The experiment was performed with a two-phase solvent system composed of methyl tert-butyl ether (MtBE)-acetonitrile-water (2:2:3, v/v) where ...
Xiao, Wang +4 more
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pH-zone-refining counter-current chromatography was successfully applied to the separation of alkaloids from a crude extract of Corydalis decumbens (Thunb.) Pers. using a multilayer coil planet centrifuge (CPC). The experiment was performed with a two-phase solvent system composed of methyl tert-butyl ether (MtBE)-acetonitrile-water (2:2:3, v/v) where ...
Xiao, Wang +4 more
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Journal of Chromatography B, 2010
In this paper, five isoquinoline alkaloids were successfully separated from a crude extract of Stephania yunnanensis using pH-zone-refining counter-current chromatography in single-step. With a two-phase solvent system composed of methyl-tert-butyl ether (MtBE)-acetonitrile-water (2:2:3, v/v) where triethylamine (10 mM) was added to the upper organic ...
Ruilin, Hu +3 more
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In this paper, five isoquinoline alkaloids were successfully separated from a crude extract of Stephania yunnanensis using pH-zone-refining counter-current chromatography in single-step. With a two-phase solvent system composed of methyl-tert-butyl ether (MtBE)-acetonitrile-water (2:2:3, v/v) where triethylamine (10 mM) was added to the upper organic ...
Ruilin, Hu +3 more
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Journal of Chromatography A, 2007
pH-zone-refining counter-current chromatography was successfully applied to purify four hydroxyanthraquinones, rhein, emodin, aloe-emodin and chrysophanol, from three crude extracts of Rheum palmatum L.. After the two-phase solvent system methyl tert-butyl ether-tetrahydrofuran-water at an optimized volume ratio of 2:2:3 (v/v) was equilibrated ...
Shengqiang, Tong, Jizhong, Yan
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pH-zone-refining counter-current chromatography was successfully applied to purify four hydroxyanthraquinones, rhein, emodin, aloe-emodin and chrysophanol, from three crude extracts of Rheum palmatum L.. After the two-phase solvent system methyl tert-butyl ether-tetrahydrofuran-water at an optimized volume ratio of 2:2:3 (v/v) was equilibrated ...
Shengqiang, Tong, Jizhong, Yan
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