High-speed Counter-current Chromatography Method Research Articles

Separation and Purification of Baishouwubenzophenone, 4-Hydroxyacetophenone and 2,4-Dihydroxyacetophenone from Cynanchum auriculatum Royle ex Wight by HSCCC

A preparative high-speed counter-current chromatography method for isolation and purification of three acetophenones, baishouwubenzophenone, 4-hydroxyacetophenone and 2,4-dihydroxyacetophenone from the Chinese medicinal plant Cynanchum auriculatum Royle ex Wight was successfully established. With a two-phase solvent system composed of light petroleum (b.p. 60–90 °C)–ethyl acetate–methanol–water (4:9:6:6, v/v), about 20.2 mg compound 1, 35.0 mg compound 2 and 8.3 mg compound 3, each at over 95% purity as determined by LC, were obtained in one-step elution from 400 mg of the ethanol extract. The structures of these compounds were identified by UV, IR, ESI-MS, 1H NMR and 13C NMR spectroscopy. Among them, compounds 2,4-dihydroxyacetophenone and 4-hydroxyacetophenone were obtained from C. auriculatum for the first time.

Isolation and purification of flavonoid glucosides from Radix Astragali by high-speed counter-current chromatography

High-speed counter-current chromatography methods, combined with resin chromatography were applied to the separation and purification of flavonoid glycosides from the Chinese medicinal herb, Radix Astragali. Five flavonoid glycosides, namely calycosin-7- O-β- d-glucoside, ononin, (6aR, 11aR)-9,10-dimethoxypterocarpan-3- O-β- d-glucoside, (3R)-2′-hydroxy-3′,4′-dimethoxyisoflavan-7- O-β- d-glucoside and calycosin-7- O-β- d-glucoside-6′′- O-acetate, were obtained. Among them, calycosin-7- O-β- d-glucoside-6′′- O-acetate was preparatively separated from Radix Astragali for the first time. Their structures were identified by ESI–MS, 1H NMR, 13C NMR, and 2D NMR.

Purification of patulin from Penicillium expansum culture: high-speed counter-current chromatography (HSCCC) versus preparative high-performance liquid chromatography (prep-HPLC)

Patulin is a mycotoxin produced by species of Penicillium and Aspergillus and is toxic to a wide range of organisms, including humans and livestock. To produce large amount of pure patulin for research purposes, high-speed counter-current chromatography (HSCCC) and preparative high-performance liquid chromatography (prep-HPLC) were applied to the purification of patulin. Apple juice was inoculated with P. expansum and containing 0.5 mg patulin per ml was used as a starting material for separation. For HSCCC, a biphasic solvent system consisted of ethyl acetate–hexane–pH 4 acetic acid (7.5:2.5:10, v/v/v) was used. For prep-HPLC, the separation was carried out in a C18 reversed-phase preparative column with a mobile phase containing acetonitrile–pH 4 acetic acid (5:95, v/v). Fractions containing patulin were collected and analysed by analytical HPLC and identified by congruent retention time and ultraviolet/visible (UV–VIS) spectrum of the standard. The structure of the purified patulin was confirmed by mass spectrometry and nuclear magnetic resonance. HSCCC produced 21.9 mg of patulin from 50 ml apple juice culture whereas the prep-HPLC yielded 18.1 mg. HSCCC also produced purer patulin than the prep-HPLC (98.6 versus 96.3%) and higher recovery (86.2 versus 71.3%). In addition, the HSCCC method is advantageous for its lower cost and a simpler procedure compared with the prep-HPLC. This one-step HSCCC method can potentially provide a simple, effective and environmentally friendly tool for obtaining gram-level pure patulin for toxicology, detoxification and many other patulin-related studies.

Application of high‐speed counter‐current chromatography for the isolation of antiviral eremophilenolides from Ligularia atroviolacea

Ligularia is mainly distributed in the western regions of China. Most of the species have been traditionally used in folk medicine for the treatment of hepatitis B, asthma, hemoptysis and pulmonary tuberculosis. In our continuation of research on antiviral components from traditional Chinese medicine, Ligularia atroviolacea was tested for inhibitory effects on hepatitis B virus (HBV). A bioassay-guided phytochemical examination of L. atroviolacea disclosed that its ethyl acetate extract, which was made up of two eremophilenolides, showed suppressive activity on the expression of HBV surface antigen (HBsAg) in the HepG2.2.15 cell line. Then a simple and effective preparative high-speed counter-current chromatography method was successfully developed for the isolation and purification of two main active metabolites, 8beta-hydroxyeremophil-3,7(11)-dien-12,8alpha;15,6alpha-diolide and 8beta-methoxyeremophil-3,7(11)-dien-12,8alpha;15,6alpha-diolide from the ethyl acetate extract of L. atroviolacea by a one-step separation using a two-phase solvent system composed of light petroleum (60-90 degrees C)-ethyl acetate-methanol-water (9:1:8:2, v/v/v). The chemical structures of the two eremophilenolides were identified by ESI-MS, (1)H-NMR and (13)C-NMR analysis. The anti-HBV activity of the two purified compounds was measured; both of them showed suppressive activity on the expression of HBsAg in the HepG2.2.15 cell line. The results support the continued and expanded exploitation and utilization of L. atroviolacea.

Preparative isolation of closely‐related xanthones from Gentianella amarella ssp. acuta by High‐speed countercurrent chromatography

A methanolic extract from Gentianella amarella ssp. acuta was shown to contain several xanthones exhibiting acetylcholinesterase inhibitory activity. These xanthones were difficult to separate by conventional LC techniques, which prevented the isolation of pure compounds in sufficient amounts to perform in-depth biological testing. To develop a suitable preparative method for the separation of closely related xanthones. The methanolic extract was first partitioned with solvents of increasing polarity, in order to separate glycosides from xanthone aglycones. High-speed countercurrent chromatography (HSCCC) methods were then optimised for the fractionation of both polar and non-polar extracts. The use of HSCCC enabled the separation of xanthones which co-eluted by HPLC. Ten closely related xanthones--three of which were isomeric--were successfully isolated by developing suitable solvent systems. All compounds were obtained in sufficient amounts to allow further biological assays (e.g. up to 250 mg), including even minor compounds that were not detectable by analytical HPLC. The orthogonality of HSCCC with HPLC and the absence of solid-phase supports enabled the detection, separation and preparative isolation of closely related compounds which were difficult to resolve by other techniques.

Simultaneous Isolation and Purification of Mollugin and Two Anthraquinones from Rubia cordifolia by HSCCC

A preparative high-speed countercurrent chromatography (HSCCC) method for isolation and purification of three bioactive components, tectoquinone; 1-hydroxy-2-methylanthraquinone and mollugin from the Chinese medicinal plant Rubia cordifolia was successfully established. With a two-phase solvent system composed of light petroleum/ethanol/diethyl ether/water (5:4:3:1, v/v), 10 mg tectoquinone, 19 mg 1-hydroxy-2-methylanthraquinone and 16 mg mollugin were obtained from 100 mg of the crude petroleum extract in a one-step separation at a purity of 98.8, 95.8 and 98.3%, respectively. The structures of mollugin and anthraquinones were identified by 1H NMR and 13C NMR.

Separation and purification of four chromones from radix saposhnikoviae by high‐speed counter‐current chromatography

A preparative high-speed counter-current chromatography (HSCCC) method for the isolation and purification of 1''-O-glucosylcimifugin (1), 4'-O-beta-d-glucosyl-5-O-methylvisamminol (2), cimifugin (3) and 3'-O-glucosylhamaudol (4) from the Chinese medicinal herb radix saposhnikoviae has been successfully developed. A sample of 300 mg of crude extract was separated using ethyl acetate:n-butanol:1% aqueous acetic acid (1:4:5, v/v) as the two-phase solvent system and yielded 102.4 mg of 1 and 81.6 mg of 2. During this separation 3 and 4 remained in the stationary phase, which was collected, evaporated to dryness and separated with another two-phase solvent system involving ethyl acetate:n-butanol:1% aqueous acetic acid (5:0.5:5, v/v) to yield 31.4 mg of 3 and 12.7 mg of 4. The purities of compounds 1-4 were 98.4, 98.7, 99.3 and 98.2%, respectively, as determined by HPLC. The chemical structures of these components were established by (1)H-NMR and (13)C-NMR.

Separation and Identification of Ergosta-4,6,8(14),22-tetraen-3-one from Ganoderma atrum by High-Speed Counter-Current Chromatography and Spectroscopic Methods

High speed counter-current chromatography in semi-preparative scale was used to separate and purify ergosta-4,6,8(14),22-tetraen-3-one from Ganoderma atrum, a famous traditional Chinese medicine. A two-phase solvent system composed of a mixture of n-hexane–ethanol–water (6: 5: 1, v/v/v) was used and the separation conditions were optimized. In a typical run in less than 400 min, 100 mg of samples can be separated to yield 14 mg of ergosta-4,6,8(14),22-tetraen-3-one with 99.1% purity. The structure of this compound was elucidated by UV, EI-MS, 1H NMR and 13C NMR.

Preparative isolation and purification of phenolic acids from Smilax china by high-speed counter-current chromatography

A preparative high-speed counter-current chromatography (HSCCC) method for separation and purification of phenolic acids from the Chinese medicinal herb Smilax china was successfully established by using n-hexane–ethyl acetate–methanol–water (1:2:1:2, v/v/v/v) as the two-phase solvent system. The experiment yielded 26.7 mg of gallic acid, 16.5 mg of protocatechuic acid, 21.8 mg of caffeic acid, 31.3 mg of gentisic acid, and 24.1 mg of trans- o-coumaric acid from 250 mg of crude extract in one-step separation, of each at over 98% purity as determined by high-performance liquid chromatography (HPLC). The structures of these compounds were identified by electron spray ionization mass spectroscopy (ESI-MS), 1H and 13C nuclear magnetic resonance (NMR).

Combination of HSCCC and Sephadex LH-20 methods: An approach to isolation and purification of the main individual theaflavins from black tea

In order to separate the main individual theaflavin monomers from black tea, high-speed countercurrent chromatography (HSCCC) and Sephadex LH-20 column chromatography were applied. The results showed that theaflavin (TF1), theaflavin-3-gallate (TF2A), theaflavin-3′-gallate (TF2B) and theaflavin-3,3′-digallate (TF3) can be obtained by HSCCC using a solvent system composed of n-hexane–ethyl acetate–methanol–water (1:3:1:6, v/v/v/v), but the TF1 was containing epicatechin-3-gallate (ECG). Similarly, Sephadex LH-20 can also effectively separate TF2A(B) and TF3, but epigallocatechin-3-gallate (EGCG) contaminated TF1, too. Combination of HSCCC and Sephadex LH-20, the preferably purified TF1, TF2A(B) and TF3 were obtained than single separation technique. In addition, ECG and EGCG were also suggested to be able to be comprehensively separated by combination of the two techniques.

Purification and identification of antiviral components from Laggera pterodonta by high-speed counter-current chromatography

Although Laggera pterodonta, a folk medicine has been widely used for several centuries as an antiviral agent, there have been no studies to identify its antiviral components. A bioassay-guided phytochemical examination of L. pterodonta disclosed that its aqueous extract, which was made up of three dicaffeoylquinic acids showed significant inhibitory activity of virus replication. Then a simple and efficient preparative high-speed counter-current chromatography (HSCCC) method was successfully established by using ethyl acetate– n-butanol–water (3:2:5, v/v) as the two-phase solvent system to isolate and purify three bioactive dicaffeoylquinic acids, 3,5- O-dicaffeoylquinic acid, 3,4- O-dicaffeoylquinic acid and 4,5- O-dicaffeoylquinic acid. The flow rate was 1.5 ml/min and revolution speed was 800 rpm. The isolation was done in less than 6 h, and 34.6 mg of 3,5- O-dicaffeoylquinic acid, 29.4 mg of 3,4- O-dicaffeoylquinic acid and 27.1 mg of 4,5- O-dicaffeoylquinic acid was yielded from 600 mg of the crude sample in one-step separation with the purity of 98.3%, 96.7% and 96.2%, respectively, as determined by high-performance liquid chromatography (HPLC). The structures of these three bioactive dicaffeoylquinic acids were identified by ultraviolet (UV), electrospray ionization mass spectrometry (ESI-MS), proton nuclear magnetic resonance ( 1H NMR) and carbon-13 nuclear magnetic resonance ( 13C NMR). In the antiviral experiment, three dicaffeoylquinic acids all showed significant inhibitory activity against herpes simplex virus-1 (HSV-1), herpes simplex virus-2 (HSV-2) and influenza viruses A (IVA) in vitro with high selectivity indexes. However, among the three compounds, 3,5- O-dicaffeoylquinic acid and 4,5- O-dicaffeoylquinic acid were the more active than 3,4- O-dicaffeoylquinic acid against HSV-1, HSV-2 and IVA. This study demonstrated a direct link between the antiviral activity of L. pterodonta and the three dicaffeoylquinic acids.

Isolation and purification of ginkgo flavonol glycosides from Ginkgo biloba leaves by high‐speed counter‐current chromatography

A high-speed counter-current chromatography method was developed for the separation and purification of bioactive flavonol glycosides from a crude ethanol extract of Ginkgo biloba leaves. The separation was performed with a two-phase solvent system composed of n-hexane-butanol-ethyl acetate-methanol-0.5% acetic acid (1:0.5:3.5:1:4, v/v) and three pure compounds were eluted in high purities in a one-step separation. Their purities were determined by HPLC and identified by MS,(1)H-NMR, and(13)C-NMR.

An effective high‐speed countercurrent chromatographic method for preparative isolation and purification of mollugin directly from the ethanol extract of the Chinese medicinal plant Rubia cordifolia

The medicinal plant Rubia cordifolia has been used widely in traditional Chinese medicine (TCM) for its antibacterial, antioxidant and anti-inflammatory activities. In this study, a preparative high-speed countercurrent chromatography (HSCCC) method for isolation and purification of the bioactive component mollugin directly from the ethanol extract of R. cordifolia was successfully established by using light petroleum (bp 60-90 degrees C)/ethanol/diethyl ether/water as the two-phase solvent system. The upper phase of light petroleum/ethanol/diethyl ether/water (5:4:3:1 v/v) was used as the stationary phase of HSCCC. Under the optimum conditions, 46 mg of mollugin at 98.5% purity, as determined by HPLC, could be yielded from 500 mg of the crude extract in a single HSCCC separation. The peak fraction of HSCCC was identified by 1H NMR and 13C NMR.

Preparative isolation and purification of dicaffeoylquinic acids from the Ainsliaea fragrans champ by high‐speed counter‐current chromatography

Two dicaffeoylquinic acids, namely 3,5-dicaffeoylquinic acid and 4,5-dicaffeoylquinic acid, have been successfully separated by high-speed counter-current chromatography (HSCCC) from an extract of Ainsliaea fragrans Champ, followed by an initial clean-up step using AB-8 resin. A two-phase solvent system composed of chloroform:methanol:water (8:8:4) was selected for the isolation with the aqueous-rich phase as the stationary phase and the organic-rich phase as the mobile phase. The developed HSCCC method yielded 34 mg of 3,5-dicaffeoylquinic acid and 17 mg of 4,5-dicaffeoylquinic acid from 150 mg of the crude sample in a one-step separation with purities of 98 and 95%, respectively, as determined by HPLC. The structures of the two compounds were identified from ESI/MS, (1)H- and (13)C-NMR spectroscopic data.

Preparative separation of four major alkaloids from medicinal plant of Tripterygium Wilfordii Hook F using high-speed counter-current chromatography

A high-speed counter-current chromatography (HSCCC) method was developed for preparative isolation and purification of alkaloids from Tripterygium Wilfordii Hook F. Preparative HSCCC with a two-phase solvent system composed of petroleum ether–ethyl acetate–ethanol–water (6:4:5:8, v/v/v/v). The organic phase was used as the stationary phase of HSCCC, and the aqueous phase as the mobile phase. Seven hundred milligrams total alkaloids yielded 210 mg of wilfortrine, 90 mg of wilfordine, 220 mg of wilforgine and 100 mg of wilforine, with the purity of 90.3%, 92%, 99.5% and 93.5% in one step separation, respectively.

Purification of deoxynivalenol from Fusarium graminearum rice culture and mouldy corn by high-speed counter-current chromatography

Deoxynivalenol (DON) is a mycotoxin produced by several Fusarium species and is toxic to a wide range of organisms, including human beings and livestock. To produce large amounts of pure DON for research purposes, a novel method using high-speed counter-current chromatography (HSCCC) was developed. Rice cultured with Fusarium graminearum and field mouldy corn infected by F. graminearum were extracted with methanol and found to contain 1.16 and 1.30 mg DON/g, respectively. The extracts were concentrated and then separated using a biphasic solvent system consisting of ethyl acetate–water (1:1, v/v). Collected fractions were analyzed by high-performance liquid chromatography (HPLC) and identified by congruent retention time and UV/vis spectrum and mass spectrometric data. Fractions containing DON were combined and freeze-dried. This method produced 116 mg and 65 mg DON with a purity of greater than 94.9% from 200 g of the rice culture and the mouldy corn, respectively. The HSCCC method had a recovery rate of DON at 88% from the crude extracts of both samples. This one-step purification method provided a simple and effective tool for obtaining a large amount of DON, an essential material for studies related to toxicology and detoxification of this mycotoxin.

Fingerprinting of Salvia miltiorrhiza Bunge by Thin‐Layer Chromatography Scan Compared with High Speed Countercurrent Chromatography

The components of the traditional Chinese medicines (TCM) can be influenced by soil, climate, and growth stage. Fingerprinting is an important means for its quality control. Our previous studies showed that high speed countercurrent chromatography (HSCCC) was helpful in the development of TCM fingerprinting. Since the HSCCC method is new, it is necessary to compare it with more conventional ones, such as high performance liquid chromatography (HPLC), high performance capillary electrophoresis (HPCE), and thin‐layer chromatography scan (TLCS). Comparisons with HPLC and HPCE were reported in our previous studies. In this study, HSCCC was compared with the thin‐layer chromatography scan (TLCS). With TLC, a quick, convenient, and cost effective technique, 8 stable components were separated in common within 48 min, respectively, from 3 crude samples of Salvia miltiorrhiza Bunge from different growth locations. In HSCCC separation, 12 components were separated, respectively, with good correspondence and precision within 13 h. Both TLCS and HSCCC were effective in showing the whole concentration distribution of all kinds of constituents in different samples. HSCCC showed better performance in analysis of tanshinones, which produced a fingerprint which contained more chemical information than that of TLCS. It was further proven that HSCCC could be a feasible and cost effective method in the development of the fingerprint of TCM.

Preparative isolation and purification of atractylon and atractylenolide III from the Chinese medicinal plantAtractylodes macrocephala by high-speed counter-current chromatography

The medicinal plant Atractylodes macrocephala (Baizhu in Chinese) has been widely used in traditional Chinese medicine for energy and stomach complaints, treatment of dyspepsia and anorexia, anti-inflammation, anticancer and for increasing assimilation. A high-speed counter-current chromatography (HSCCC) method was developed for the preparative separation and purification of two main bioactive components, namely, atractylon and atractylenolide III from A. macrocephala by using light petroleum (60-90 degrees C)-ethyl acetate-ethanol-water (4:1:4:1 v/v) as the two-phase solvent system in dual-mode elution. Compared with the separation using the normal-mode elution, the dual-mode HSCCC can be achieved with shorter elution time. Atractylenolide III (32.1 mg) at 99.0% purity and 319.6 mg atractylon at 97.8% purity could be obtained from 1000 mg crude sample in a single run. The recoveries of atractylenolide III and atractylon were 95.4 and 92.6%, respectively.

Bioassay-guided purification and identification of antimicrobial components in Chinese green tea extract

The Chinese green tea extract was found to strongly inhibit the growth of major food-borne pathogens, Escherichia coli O157:H7, Salmonella Typhimurium DT104, Listeria monocytogenes, Staphylococcus aureus, and a diarrhoea food-poisoning pathogen Bacillus cereus, by 44–100% with the highest activity found against S. aureus and lowest against E. coli O157:H7. A bioassay-guided fractionation technique was used for identifying the principal active component. A simple and efficient reversed-phase high-speed counter-current chromatography (HSCCC) method was developed for the separation and purification of four bioactive polyphenol compounds, epicatechin gallate (ECG), epigallocatechin gallate (EGCG), epicatechin (EC), and caffeine (CN). The structures of these polyphenols were confirmed with mass spectrometry. Among the four compounds, ECG and EGCG were the most active, particularly EGCG against S. aureus. EGCG had the lowest MIC 90 values against S. aureus (MSSA) (58 mg/L) and its methicilin-resistant S. aureus (MRSA) (37 mg/L). Scanning electron microscopy (SEM) studies showed that these two compounds altered bacterial cell morphology, which might have resulted from disturbed cell division. This study demonstrated a direct link between the antimicrobial activity of tea and its specific polyphenolic compositions. The activity of tea polyphenols, particularly EGCG on antibiotics-resistant strains of S. aureus, suggests that these compounds are potential natural alternatives for the control of bovine mastitis and food poisoning caused by S. aureus.

High-speed counter-current chromatography for the study of defense metabolites in wheat: Characterization of 5,6- O-methyl trans-aconitic acid

High-speed counter-current chromatography (HSCCC) methods were developed for the study of induced defense metabolites in wheat ( Triticum aestivum) against powdery mildew ( Blumeria graminis f. sp. tritici). A single HSCCC purification step afforded extraction of mg-quantities of an induced compound with antifungal activity. Subsequent LC–MS and NMR analyses have led to the characterization of 5,6- O-methyl trans-aconitic acid, the first such report of this compound in a plant species. The inducible nature of aconitic acid was evidenced by comparing the metabolite profiles of leaf extracts from plants treated or not with soluble silicon and infected or not with powdery mildew. In a second step, dual-mode HSCCC was used to enhance the separation of other forms of aconitic acid in wheat. Based on these results, it was concluded that 5,6- O-methyl trans-aconitic acid plays an important role as a defense molecule in wheat plants and that HSCCC is a powerful separation method for purifying such compounds from complex plant–pathogen interactions.