The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Yoichiro Ito - One of the best experts on this subject based on the ideXlab platform.
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elution extrusion and back extrusion Counter Current Chromatography using three phase solvent system for separation of organic dye mixture
Separation and Purification Technology, 2020Co-Authors: Yi Yang, Jing Meng, Shuai Wang, Yoichiro ItoAbstract:Abstract In the present study, high-speed Counter-Current Chromatography with a three-phase solvent system composed of n-hexane-acetonitrile-400 mM ammonium sulfate (1:1:1, v/v) was developed to recover four mixed dyes (methyl green, acridine orange, Congo red and oil red O) with diverse polarities. As a result, four dyes were successfully separated in a single HSCCC run using a step-wise gradient elution. Then, elution-extrusion and back-extrusion Counter-Current Chromatography were used to reduce the separation time and solvent consumption. Among them back-extrusion CCC can save more time. Thus, the present study provides an effective method for dye recycling.
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a multilayer coil in type i Counter Current Chromatography
Journal of Chromatography A, 2018Co-Authors: Jiao Yang, Yi Yang, Chen Fang, Yoichiro ItoAbstract:In the present study, a novel model of type-I Counter-Current Chromatography was developed to simplify the separation column manufacture and extend its application ranges. In this system, a multilayer coil was used as the separation column of type-I Counter-Current Chromatography for the first time. The chromatographic performance of this apparatus was evaluated in terms of retention of the stationary phase (Sf), theoretical plate (N) and peak resolution (Rs) using dipeptides and DNP-amino acids as test samples with two classic solvent systems composed of 1-butanol-acetic acid-water (4:1:5, v/v) (BAW) and hexane-ethyl acetate-methanol-0.1 M HCl (1:1:1:1, v/v) (HEMW), respectively. The results indicated that the performance was optimal at the revolution speed of 200 rpm. The lower flow rate was more beneficial to retention of stationary phase and peak resolution. Over all results of our study revealed that the new type-I Counter-Current Chromatography with a multilayer coil has a high application potential.
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isolation of high purity casticin from artemisia annua l by high speed Counter Current Chromatography
Journal of Chromatography A, 2007Co-Authors: Xiao Han, Tianyou Zhang, Yabin Zhang, Qinghui Liu, Yoichiro ItoAbstract:Abstract Following an initial clean-up step on silica, high-speed Counter-Current Chromatography (HSCCC) was used to purify a flavone, casticin (5,3′-dihydroxy-3,6,7, 4′-tetramethoxyflavone), from an extract of the dried leaves of Artemisia annua L. The two-phase solvent system used was composed of n-hexane–ethyl acetate–methanol–water at an optimized volume ratio of 7:10:7:10 (v/v). HSCCC separation of 226.4 mg of crude sample (containing casticin at 16.5% purity after silica gel clean-up) yielded 36.3 mg of casticin with a purity of over 99% and 96.2% recovery. Identification of the target compound was performed by 1H NMR, 13C NMR, two-dimensional NMR, electrospray ionization MS, IR and UV.
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preparative isolation of imperatorin oxypeucedanin and isoimperatorin from traditional chinese herb bai zhi angelica dahurica fisch ex hoffm benth et hook using multidimensional high speed Counter Current Chromatography
Journal of Chromatography A, 2006Co-Authors: Yun Wei, Yoichiro ItoAbstract:Abstract Preparative high-speed Counter-Current Chromatography (CCC) was successfully used for isolation and purification of imperatorin, oxypeucedanin and isoimperatorin from traditional Chinese herb “bai zhi” Angelica dahurica (Fisch. ex Hoffm) Benth. et Hook using multidimensional Counter-Current Chromatography with a pair of two-phase solvent systems composed of n -hexane–ethyl acetate–methanol–water at volume ratios of 1:1:1:1 (v/v) and 5:5:4.5:5.5 (v/v), which had been selected by analytical high-speed Counter-Current Chromatography (HSCCC). Using two preparative units of the CCC centrifuge, which are connected by a column switching valve, about a 300 mg amount of the crude extract was separated, yielding 19.9 mg of imperatorin, 8.6 mg of oxypeucedanin and 10.4 mg of isoimperatorin all at a high purity of over 98%.
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golden rules and pitfalls in selecting optimum conditions for high speed Counter Current Chromatography
Journal of Chromatography A, 2005Co-Authors: Yoichiro ItoAbstract:This paper aims to be an aid to those chemists who are interested in utilizing high-speed Counter-Current Chromatography (HSCCC), which is free of irreversible adsorption and offers high resolution comparable to column Chromatography. It explains the selection of HSCCC conditions step by step including the selection of two-phase solvent systems, determination of partition coefficient (K) of analytes, preparation of two-phase solvent system and sample solution, selection of elution mode, flow rate, rotation speed, and on-line monitoring of the eluate. The paper covers both standard HSCCC and pH-zone-refining CCC techniques. Technical terms (italic) unfamiliar to the beginner are comprehensively explained in Glossary. Various examples of two-phase solvent systems used in HSCCC are listed in Appendices A and B. The commercial sources of HSCCC and other CCC instruments are described in detail in the study edited by Berthod [A. Berthod (Ed.), Counter-Current Chromatography, Elsevier, Amsterdam, 2003].
Tianyou Zhang - One of the best experts on this subject based on the ideXlab platform.
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isolation of high purity casticin from artemisia annua l by high speed Counter Current Chromatography
Journal of Chromatography A, 2007Co-Authors: Xiao Han, Tianyou Zhang, Yabin Zhang, Qinghui Liu, Yoichiro ItoAbstract:Abstract Following an initial clean-up step on silica, high-speed Counter-Current Chromatography (HSCCC) was used to purify a flavone, casticin (5,3′-dihydroxy-3,6,7, 4′-tetramethoxyflavone), from an extract of the dried leaves of Artemisia annua L. The two-phase solvent system used was composed of n-hexane–ethyl acetate–methanol–water at an optimized volume ratio of 7:10:7:10 (v/v). HSCCC separation of 226.4 mg of crude sample (containing casticin at 16.5% purity after silica gel clean-up) yielded 36.3 mg of casticin with a purity of over 99% and 96.2% recovery. Identification of the target compound was performed by 1H NMR, 13C NMR, two-dimensional NMR, electrospray ionization MS, IR and UV.
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separation of flavonoids from the seeds of vernonia anthelmintica willd by high speed Counter Current Chromatography
Journal of Chromatography A, 2004Co-Authors: Guilian Tian, Tianyou Zhang, Fuquan Yang, Ubin Zhang, Yoichiro ItoAbstract:Several flavonoids including 2',3,4,4'-tetrahydroxychalcone, 5,6,7,4'-tetrahydroxyflavone and butin, were separated from the seeds of Vernonia anthelmintica Willd by high-speed Counter-Current Chromatography using a two-step operation. Two different types of solvent systems were used: chloroform-dichloromethane-methanol-water (2:2:3:2, v/v) and 1,2 dichloroethane-methanol-acetonitrile-water (4:1.1:0.25:2, v/v). From 1 kg of seeds of Vernonia anthelmintica Willd the method yielded about 45 mg of 2',3,4,4'-tetrahydroxychalcone, 40mg of 5,6,7,4'-tetrahydroxyflavone, and 55 mg of butin. Each isolated component showed 95-97% purity as determined by high-performance liquid Chromatography analysis. These purified compounds were characterized by MS and NMR.
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preparative isolation of osthol and xanthotoxol from common cnidium fruit chinese traditional herb using stepwise elution by high speed Counter Current Chromatography
Journal of Chromatography A, 2004Co-Authors: Yun Wei, Tianyou Zhang, Yoichiro ItoAbstract:Preparative high-speed Counter-Current Chromatography (HSCCC) was successfully used for isolation and purification of osthol and xanthotoxol from Cnidium monnieri (L.) Cusson (Common Cnidium Fruit) using stepwise elution with a pair of two-phase solvent systems composed of n-hexane-ethyl acetate-methanol-water at (1:1:1:1, v/v), and (5:5:6:4, v/v), which had been selected by analytical high-speed Counter-Current Chromatography. Using a preparative unit of the HSCCC centrifuge, about a 308 mg amount of the crude extract was separated, yielding 88.3 mg of osthol and 19.4 mg of xanthotoxol at a high purity of over 98%.
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preparative separation of rhein from chinese traditional herb by repeated high speed Counter Current Chromatography
Journal of Chromatography A, 2003Co-Authors: Yun Wei, Tianyou Zhang, Yoichiro ItoAbstract:High-speed Counter-Current Chromatography (HSCCC) was repeatedly used for isolation and purification of rhein from Rheum officinale Baill (Dahuang) with a two-phase solvent system composed of n-hexane-ethyl acetate-methanol-water (3:7:5:5, v/v), which had been selected by analytical (HSCCC). Using two preparative units of the HSCCC centrifuge, about a 500 mg amount of the crude extract was separated, yielding 6.7 mg of rhein at a high purity of over 97%.
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separation of salidroside from rhodiola crenulata by high speed Counter Current Chromatography
Journal of Chromatography A, 2002Co-Authors: Xiao Han, Tianyou Zhang, Yun Wei, Xueli Cao, Yoichiro ItoAbstract:Abstract High-speed Counter-Current Chromatography (HSCCC) was used to purify salidroside from an extract of Rhodiola crenulata with two steps using a two-phase solvent system composed of ethyl acetate–n-butanol–water (1:4:5, v/v) in the first run and chloroform–methanol–isopropanol–water (5:6:1:4) in the second run. The method yielded 21.9 mg of salidroside from 1.216 g of the crude sample at 98% purity determined by HPLC analyses. Identification was performed by 1H NMR, 13C NMR, and MS.
Feng Chen - One of the best experts on this subject based on the ideXlab platform.
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separation and purification of astaxanthin from phaffia rhodozyma by preparative high speed Counter Current Chromatography
Journal of Chromatography B, 2016Co-Authors: Congcong Dong, Kai Wang, Zedong Jiang, Yanhong Chen, Yuanfan Yang, Feng ChenAbstract:An effective high-speed Counter-Current Chromatography (HSCCC) method was established for the preparative isolation and purification of astaxanthin from Phaffia rhodozyma. With a two-phase solvent system composed of n-hexane-acetone-ethanol-water (1:1:1:1, v/v/v/v), 100mg crude extract of P. rhodozyma was separated to yield 20.6mg of astaxanthin at 92.0% purity. By further one step silica gel column Chromatography, the purity reached 99.0%. The chemical structure of astaxanthin was confirmed by thin layer Chromatography (TLC), UV spectroscopy scanning, high performance liquid Chromatography with a ZORBAX SB-C18 column and a Waters Nova-pak C18 column, and ESI/MS/MS.
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isolation and purification of the bioactive carotenoid zeaxanthin from the microalga microcystis aeruginosa by high speed Counter Current Chromatography
Journal of Chromatography A, 2005Co-Authors: Feng Chen, Ricky N S Wong, Yue JiangAbstract:High-speed Counter-Current Chromatography was successfully applied for the first time to the isolation and purification of the bioactive carotenoid zeaxanthin from the cyanobacterium Microcystis aeruginosa. The crude zeaxanthin was obtained by extraction with organic solvents after the microalgal sample had been saponified. Preparative high-speed Counter-Current Chromatography with a two-phase solvent system composed of n-hexane-ethyl acetate-ethanol-water (8:2:7:3, v/v/v/v) was successfully performed yielding zeaxanthin at 96.2% purity from 150 mg of the crude extract in a one-step separation. The recovery of zeaxanthin was 91.4%. This was also the first report that zeaxanthin was successfully separated and purified from microalgae. (C) 2004 Published by Elsevier B.V.
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preparative isolation and purification of chuanxiongzine from the medicinal plant ligusticum chuanxiong by high speed Counter Current Chromatography
Journal of Chromatography A, 2004Co-Authors: Feng ChenAbstract:Ligusticum chuanxiong Hort has been used widely in traditional medicines for the treatment of various kinds of disorders such as cardiovascular and cerebrovascular diseases. High-speed Counter-Current Chromatography was applied to the isolation and purification of the bioactive component chuanxiongzine from L. chuanxiong Hort. The crude chuanxiongzine was obtained by extraction with ethanol from the dried roots of L. chuanxiong Hort under sonication. Preparative high-speed Counter-Current Chromatography with a two-phase solvent system composed of n-hexane-ethyl acetate-ethanol-water (5:5:3:7, v/v) was successfully performed yielding 11.5 mg chuanxiongzine at 96.8% purity from 300 mg of the crude extract (4.2% chuanxiongzine) with the recovery of 91% in a one-step separation.
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purification of paeoniflorin from paeonia lactiflora pall by high speed Counter Current Chromatography
Journal of Chromatography A, 2004Co-Authors: Feng Chen, Haitao Lu, Yue JiangAbstract:Abstract High-speed Counter-Current Chromatography was successfully used for the first time for the preparative separation and purification of paeoniflorin from the Chinese medicinal plant Paeonia lactiflora Pall. using a two-phase solvent system composed of n-butanol–ethyl acetate–water (1:4:5, v/v) in a single run. From 160 mg of the crude sample containing 22.0% paeoniflorin, 33.2 mg of paeoniflorin was yielded at 98.2% purity as determined by HPLC analysis. The recovery of paeoniflorin was 94.3%.
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preparative purification of glycyrrhizin extracted from the root of liquorice using high speed Counter Current Chromatography
Journal of Chromatography A, 2004Co-Authors: Yue Jiang, Feng ChenAbstract:Glycyrrhizin is one of the main bioactive components in liquorice (Glycyrrhiza uralensis Fisch) which has recently been found to be highly active in inhibiting replication of the severe acute respiratory syndrome (SARS)-associated virus. The separation and purification of glycyrrhizin from a methanol-water (70:30 (v/v)) extract of liquorice roots was achieved using high-speed Counter-Current Chromatography. The separation was performed at a preparative scale in a one-step separation with a two-phase solvent system composed of ethyl acetate-methanol-water (5:2:5 (v/v)). The lower phase was used as the mobile phase in the head-to-tail elution mode. The present method yielded 42.2 mg glycyrrhizin at 96.8% purity from 130 mg of the crude exact with 95.2% recovery as determined by HPLC analysis.
Fuquan Yang - One of the best experts on this subject based on the ideXlab platform.
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separation of flavonoids from the seeds of vernonia anthelmintica willd by high speed Counter Current Chromatography
Journal of Chromatography A, 2004Co-Authors: Guilian Tian, Tianyou Zhang, Fuquan Yang, Ubin Zhang, Yoichiro ItoAbstract:Several flavonoids including 2',3,4,4'-tetrahydroxychalcone, 5,6,7,4'-tetrahydroxyflavone and butin, were separated from the seeds of Vernonia anthelmintica Willd by high-speed Counter-Current Chromatography using a two-step operation. Two different types of solvent systems were used: chloroform-dichloromethane-methanol-water (2:2:3:2, v/v) and 1,2 dichloroethane-methanol-acetonitrile-water (4:1.1:0.25:2, v/v). From 1 kg of seeds of Vernonia anthelmintica Willd the method yielded about 45 mg of 2',3,4,4'-tetrahydroxychalcone, 40mg of 5,6,7,4'-tetrahydroxyflavone, and 55 mg of butin. Each isolated component showed 95-97% purity as determined by high-performance liquid Chromatography analysis. These purified compounds were characterized by MS and NMR.
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ph zone refining Counter Current Chromatography of lappaconitine from aconitum sinomontanum nakai i separation of prepurified extract
Journal of Chromatography A, 2001Co-Authors: Fuquan Yang, Yoichiro ItoAbstract:pH-Zone-refining Counter-Current Chromatography was applied to the separation of diterpenoid alkaloids from a crude sample from a crude prepurified sample containing lappaconitine at about 90% purity using a multilayer coil planet centrifuge. The experiment was performed with a two-phase solvent system composed of methyl tert.-butyl ether-tetrahydrofuran-distilled water (2:2:3, v/v) where triethylamine (10 mM) was added to the upper organic stationary phase as a retainer and hydrochloric acid (10 mM) to the aqueous mobile phase as an eluter. The separation of 10.5 g of the sample yielded 9.0 g of lappaconitine at a high purity of over 99% as determined by HPLC.
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high speed Counter Current Chromatography separation and purification of resveratrol and piceid from polygonum cuspidatum
Journal of Chromatography A, 2001Co-Authors: Lei Chen, Fuquan Yang, Yashan Han, Tianyou ZhangAbstract:Abstract High-speed Counter-Current Chromatography (HSCCC) was applied to the separation and purification of resveratrol and piceid from the dried roots (20.0 g) of Polygonum cuspidatium . The EtOAc extracts were separated with chloroform–methanol–water (4:3:2, v/v). Resveratrol was identified in fraction 5. The water extracts were separated first with EtOAc–EtOH–water (10:1:10, v/v) and then with the same solvent system at the modified volume ratio of 70:1:70. Yields of resveratrol and piceid obtained were 2.18% and 1.07%. Chemical structures of the purified resveratrol and piceid were confirmed by electrospray ionization MS and 1 H nuclear magnetic resonance spectroscopy.
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preparative isolation and purification of lutein from the microalga chlorella vulgaris by high speed Counter Current Chromatography
Journal of Chromatography A, 2001Co-Authors: Feng Chen, Tianyou Zhang, Fuquan YangAbstract:High-speed Counter-Current Chromatography (HSCCC) was applied to the isolation and purification of lutein from microalgae. Analytical HSCCC was used for the preliminary selection of a suitable solvent system composed of n-hexane-ethanol-water (4:3:1, v/v). Using the above solvent system, preparative HSCCC was successfully performed yielding lutein at 98% purity from 200 mg of the crude extract in a one-step separation.
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separation of tanshinones from salvia miltiorrhiza bunge by high speed Counter Current Chromatography using stepwise elution
Journal of Chromatography A, 2000Co-Authors: Guilian Tian, Tianyou Zhang, Fuquan Yang, Yabin Zhang, Yoichiro ItoAbstract:High-speed Counter-Current Chromatography (HSCCC) was successfully used for isolation and purification of tanshinones from the roots of Salvia miltiorrhiza Bunge by stepwise elution. A set of three solvent systems and other experimental conditions were determined by analytical HSCCC. Using the optimized conditions, the preparative HSCCC separation was performed on 50 mg of crude light petroleum extract yielding pure tanshinones of tanshinone IIA (7 mg), tanshinone I (3 mg) and cryptotanshinone (4 mg) all at purities of over 95% in a single run.
Guilian Tian - One of the best experts on this subject based on the ideXlab platform.
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separation of flavonoids from the seeds of vernonia anthelmintica willd by high speed Counter Current Chromatography
Journal of Chromatography A, 2004Co-Authors: Guilian Tian, Tianyou Zhang, Fuquan Yang, Ubin Zhang, Yoichiro ItoAbstract:Several flavonoids including 2',3,4,4'-tetrahydroxychalcone, 5,6,7,4'-tetrahydroxyflavone and butin, were separated from the seeds of Vernonia anthelmintica Willd by high-speed Counter-Current Chromatography using a two-step operation. Two different types of solvent systems were used: chloroform-dichloromethane-methanol-water (2:2:3:2, v/v) and 1,2 dichloroethane-methanol-acetonitrile-water (4:1.1:0.25:2, v/v). From 1 kg of seeds of Vernonia anthelmintica Willd the method yielded about 45 mg of 2',3,4,4'-tetrahydroxychalcone, 40mg of 5,6,7,4'-tetrahydroxyflavone, and 55 mg of butin. Each isolated component showed 95-97% purity as determined by high-performance liquid Chromatography analysis. These purified compounds were characterized by MS and NMR.
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separation of tanshinones from salvia miltiorrhiza bunge by multidimensional Counter Current Chromatography
Journal of Chromatography A, 2002Co-Authors: Guilian Tian, Tianyou Zhang, Yabin Zhang, Yoichiro ItoAbstract:Analytical and preparative high-speed Counter-Current Chromatography (HSCCC) was successfully used for the isolation and purification of tanshinones from the roots of Salvia miltiorrhiza Bunge. Using multidimensional HSCCC, four major components including tanshinone IIA (16 mg), tanshinone I (10 mg), dihydrotanshinone I (7 mg) and cryptotanshinone (11 mg) were isolated each at high purity of over 95%.
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separation of tanshinones from salvia miltiorrhiza bunge by high speed Counter Current Chromatography using stepwise elution
Journal of Chromatography A, 2000Co-Authors: Guilian Tian, Tianyou Zhang, Fuquan Yang, Yabin Zhang, Yoichiro ItoAbstract:High-speed Counter-Current Chromatography (HSCCC) was successfully used for isolation and purification of tanshinones from the roots of Salvia miltiorrhiza Bunge by stepwise elution. A set of three solvent systems and other experimental conditions were determined by analytical HSCCC. Using the optimized conditions, the preparative HSCCC separation was performed on 50 mg of crude light petroleum extract yielding pure tanshinones of tanshinone IIA (7 mg), tanshinone I (3 mg) and cryptotanshinone (4 mg) all at purities of over 95% in a single run.
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preparative isolation and purification of hydroxyanthraquinones from rheum officinale baill by high speed Counter Current Chromatography using ph modulated stepwise elution
Journal of Chromatography A, 1999Co-Authors: Fuquan Yang, Tianyou Zhang, Guilian Tian, Haifeng Cao, Qinhui Liu, Yoichiro ItoAbstract:Analytical and preparative high-speed Counter-Current Chromatography was successfully used for the isolation and purification of hydroxyanthraquinones from Rheum officinale Baill (Dahuang) using pH-modulated stepwise elution. Four major components including chrysophanol, emodin, physcion and aloe-emodin were isolated each at over 98% purity.
