An Efficient Method for Extraction, Separation and Purification of Naphthoquinone Pigments from Lithospermum erythrorhizon Sieb. et Zucc. by SFE and HSCCC

Supercritical fluid extraction was used to extract naphthoquinone pigments from Lithospermum erythrorhizon Sieb. et Zucc. The crude extracts were separated and purified by high-speed counter-current chromatography with light petroleum–ethyl acetate–methanol–water (5:5:8:2, v/v) as the two-phase solvent system. Three kinds of naphthoquinone pigments including 17.6 mg of β-hydroxyisovalerylshikonin (I), 17.6 mg of acetylshikonin (II), and 19.7 mg of isobutyrylshikonin (III) were obtained from 150 mg crude sample. The purity of these compounds was 96.7, 99.3 and 95.5%, respectively, as determined by liquid chromatograph. Their structures were identified by ¹H NMR and ¹³C NMR.     

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.     

Preparative Isolation and Purification of Two Phenylpropanoids from Daphne giraldii Nitsche by HSCCC

Preparative high-speed counter-current chromatography (HSCCC) was successfully applied to purify phenylpropanoids from the stem and root bark of Daphne giraldii Nitsche, a traditional Chinese medicine. Their structures were identified on the basis of ¹H NMR and ¹³C NMR technology. The two-phase solvent system composed of n -hexane–ethyl acetate–methanol–water (2: 3: 0.5: 4, v/v/v/v) was selected for HSCCC. A total of 8.0 mg woonenoside XI (1) and 18.0 mg daphnetin (2) were obtained in one-step separation from 200 mg of the crude extract with purity of 96.0 and 99.1%, respectively, as determined by LC. And the major compound (2) showed antithrombotic activity in vitro.     

Use of pH-Zone Refining Countercurrent Chromatography for Preparative Separation of Fangchinoline and Tetrandrine from Stephania tetrandra

pH-Zone-refining countercurrent chromatography with a multilayer coil planet centrifuge has been successfully used for separation of fangchinoline and tetrandrine from crude extracts of Stephania tetrandra. The two target compounds were completely resolved by use of the two-phase solvent system petroleum ether (60–90 °C)–ethyl acetate–methanol–water 5:5:1:9 (v/v), with 10 mm triethylamine in the organic stationary phase and 5 mm hydrochloric acid in the aqueous mobile phase. Separation of 3.5 g sample yielded 126 mg fangchinoline (LC purity >93%) and 249 mg tetrandrine (LC purity >95%). The structures of the compounds were confirmed by use of electrospray ionization mass spectrometry and ¹H NMR.     

Preparative Isolation and Purification of Flavonoids and Protocatechuic Acid from Sea Buckthorn Juice Concentrate (Hippophaë rhamnoides L. ssp. rhamnoides) by High-Speed Counter-Current Chromatography

High-speed counter-current chromatography (HSCCC)—a support free all liquid–liquid chromatography technique—has been successfully used for the preparative isolation of isorhamnetin 3-O-β-d-glucoside, isorhamnetin 3-O-β-rutinoside, quercetin 3-O-β-d-glucoside, syringetin 3-O-β-d-glucoside and protocatechuic acid from sea buckthorn juice concentrate (Hippophaë rhamnoides L. ssp. rhamnoides, Elaeagnaceae). The preparative HSCCC instrument was a multilayer coil planet centrifuge equipped with three preparative coils. Separation was performed with a two phase solvent system (n-hexane–n-butanol–water, 1:1:2 v/v/v) in ‘head-to-tail’ mode. Each injection of 4.1 g crude ethyl acetate extract yielded isorhamnetin 3-O-β-d-glucoside (95 mg), isorhamnetin 3-O-β-rutinoside (10 mg), quercetin 3-O-β-d-glucoside (5 mg), and protocatechuic acid (34 mg) with purities >98%. The flavonoid syringetin 3-O-β-d-glucoside (2 mg) was a novel compound for H. rhamnoides. Chemical structures of all compounds were determined by HPLC–ESI–MS–MS, 1D-NMR (¹H, ¹³C, DEPT 135) spectroscopy and for elucidation of glycosidic linkages 2D-NMR (HMBC) spectroscopy was used.     

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.     

Separation and purification of six compounds from the flowers of Cerasus yedoensis (Matsum.) by high-speed countercurrent chromatography in stepwise elution mode

Six compounds from the flower of Cerasus yedoensis (Matsum.) were successfully isolated by high-speed countercurrent chromatography (HSCCC) and preparative high performance liquid chromatography using stepwise elution with a pair of two-phase solvent systems composed of ethyl acetate–n-butanol–formic acid–water at volume ratio of 4:1.5:0.15:5 and ethyl acetate–ethanol–formic acid–water at volume ratio of 4:1:0.15:5 for the first time. This separation process produced (a) 141 mg of 1-O-caffeoyl-β-D-glucopyranoside, (b) 28 mg of p-coumaric acid glucoside, (c) 13 mg of chlorogenic acid, (d) 21 mg of quercetin-3-O-β-D-glucopyranoside, (e) 19 mg of kaempferol 3-O-β-D-glucopyranoside, and (f) 25 mg of caffeic acid from 400 mg of crude sample with the purities of 96.51, 98.82, 94.96, 99.01, 82.51, and 82.45%, respectively. MS, ¹H NMR, and ¹³C NMR analyses were used for the chemical structure identification.     

Separation of Delphinidin-3-O-sambubioside, Cyanidin-3-O-sambubioside and p-Coumaric Acid from Cranberry by CCC Followed by prep-HPLC Using Robotic CCC Solvent System Selection

High-performance counter-current chromatography has been used for the separation of delphinidin-3-O-sambubioside, cyanidin-3-O-sambubioside and p-coumaric acid from crude extract of cranberry. The separation was performed with a two-phase solvent system composed of butanol/0.05% aqueous trifluoroacetic acid/methanol at a volume ratio of 4:5:1. The two-phase solvent system was selected following the determination of partition coefficients (K) in a range of solvent systems using a robotic solvent system selection method. Analytical scale CCC confirmed that this phase system separated the components from a crude cranberry extract (40 mg scale) with acceptable purities. Preparative CCC of 400 mg of crude yielded 4.2 mg of p-coumaric acid at a purity of over 98%, 3.6 mg of delphinidin-3-O-sambubioside at a purity of over 97% and 4.5 mg of cyanidin-3-O-sambubioside at a purity of 73%, which was further purified by preparative high-performance liquid chromatography to yield 3 mg cyanidin-3-O-sambubioside at 95% purity. The identification of delphinidin-3-O-sambubioside, cyanidin-3-O-sambubioside and p-coumaric acid was performed by ESI-MS, 1H-NMR and 13C-NMR spectra.     

Improving the Determination of Nitrovin in Feeds by Reversed-Phase LC with SPE

A simple reversed-phase liquid chromatographic method with ultraviolet detector (378 nm) for the determination of nitrovin in feeds was improved and validated. The mobile phase was a mixture of acetonitrile and 0.1% formic acid solution (v/v) in the ratio of 50:50 (v/v), and the flow rate was set at 1.2 mL min^?1. The extraction solution was a mixture of dimethyl formamide, acetonitrile and methanol (50:25:25, v/v), the sample was cleaned-up with reversed-phase solid phase extraction cartridge. The standard nitrovin was purified with crude nitrovin product by ethylene glycol monoethyl ether and identified by elemental analyzer. The limit of detection was 0.05 mg kg^?1 and the limit of quatification was 0.2 mg kg^?1 in feeds. The assay had satisfactory selectivity, recovery, linearity and precise repeatability and trueness.     

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.     

High-Speed Counter-Current Chromatography Combined with Column Chromatography for Isolation of Methyllycaconitine from Delphinium pseudocyanthum

Preparative high-speed counter-current chromatography (HSCCC) combined with conventional column chromatography (CC) has been used for isolation and purification of methyllycaconitine from Delphinium pseudocyanthum. n-Hexane-ethyl acetate-methanol-water, 1:1:1:2 (v/v), was used as the solvent system for HSCCC. Separation of methyllycaconitine from an HSCCC fraction was successfully achieved by CC on silica gel using chloroform-methanol, 7:1 (v/v), as mobile phase. A total of 113.45 mg methyllycaconitine of purity >95% was obtained from 1.044 g extract of D. pseudocyanthum. Its structure was identified by MS and NMR.     

HPLC column-switching technique for sample preparation and fluorescence determination of propranolol in urine using fused-core columns in both dimensions

A new and fast high-performance liquid chromatography (HPLC) column-switching method using fused-core columns in both dimensions for sample preconcentration and determination of propranolol in human urine has been developed. On-line sample pretreatment and propranolol preconcentration were performed on an Ascentis Express RP-C-18 guard column (5?×?4.6 mm), particle size, 2.7 μm, with mobile phase acetonitrile/water (5:95, v/v) at a flow rate of 2.0 mL min^?1 and at a temperature of 50 °C. Valve switch from pretreatment column to analytical column was set at 4.0 min in a back-flush mode. Separation of propranolol from other endogenous urine compounds was achieved on the fused-core column Ascentis Express RP-Amide (100?×?4.6 mm), particle size, 2.7 μm, with mobile phase acetonitrile/water solution of 0.5 % triethylamine, pH adjusted to 4.5 by means of glacial acetic acid (25:75, v/v), at a flow rate of 1.0 mL min^?1 and at a temperature of 50 °C. Fluorescence excitation/emission detection wavelengths were set at 229/338 nm. A volume of 1,500 μL of filtered urine sample solution was injected directly into the column-switching HPLC system. The total analysis time including on-line sample pretreatment was less than 8 min. The experimentally determined limit of detection of the method was found to be 0.015 ng mL^?1.

Simultaneous Separation of Four Flavonoids and Two Astragalosides from Radix Astragali by Semi-Preparative LC

An effective method for simultaneous separation of four flavonoids and two astragalosides was developed by semi-preparative high-performance liquid chromatography in this work. A crude sample was firstly cleaned-up from ethanol aqueous extract of Radix Astragali by LS-300B resin-based column chromatography and was further isolated by semi-preparative LC with a gradient elution of water–methanol. Six compounds including calycosin (3.5 mg), formononetin (2.6 mg), (6aR,11aR)-10-hydroxy-3,9-dimethoxypterocarpan (2.6 mg), (3R)-7,2′-dihydroxy-3′,4′-dimethoxyisoflavan) (2.0 mg), astragaloside I (5.4 mg) and astragaloside II (9.8 mg) were obtained with a recovery of 67.8, 77.2, 88.4, 85.3, 62.1 and 57.9%, respectively. Their chemical structures were confirmed by MS and NMR analysis. This study developed an effective and rapid method for simultaneous separation of multiple components from Radix astragali.     

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 of Imperatorin, Oxypeucedanin and Isoimperatorin from a Traditional Chinese Herb Using a HSCCC Strategy Based on Optimization of Rapid Flow Rate

Preparative high-speed counter-current chromatography has been used successfully for the isolation and purification of imperatorin, oxypeucedanin and isoimperatorin from traditional Chinese herb “bai zhi”—Angelica dahurica (Fisch. ex Hoffm) Benth. et Hook using high-speed counter-current chromatography (HSCCC). This was achieved in two stages. The first stage used a high flow HSCCC protocol with a two-phase solvent system composed of n-hexane–ethyl acetate–methanol–water (HEMW) with volume ratios of 5:5:5:5, v/v which isolated isoimperatorin but co-eluted imperatorin and oxypeucedanin. The second stage used HEMW 5:5:4:6, v/v at low flow rate to resolve the co-eluted components from the first stage. The flow rate was optimized by preparative HSCCC. 300 mg of the crude extract was separated, yielding 18.5 mg of imperatorin, 8.3 mg of oxypeucedanin and 9.8 mg of isoimperatorin all at a high purity of over 98%.     

Combined Ultrahigh Pressure Extraction and High-Speed Counter-Current Chromatography for Separation and Purification of Three Glycoside Compounds from Dendrobium officinale Protocorm

As an alternative to Dendrobium candidum, protocorm-like bodies (PLBs) of Dendrobium candidum are of great value due to their high yield and low cost. In this work, three glycoside compounds, β-D-glucopyranose 1-[(E)-3-(4-hydroxyphenyl)-2-propenoat] (I), β-D-glucopyranose 1-[(E)-3-(3, 4-dihydroxyphenyl)-2-propenoat] (II), and 1-O-sinapoyl glucopyranoside (III), were extracted and isolated by ultrahigh pressure extraction (UPE) coupled with high-speed counter-current chromatography (HSCCC) from PLBs of D. officinale. First, the target compounds were optimized and prepared with 50% ethanol solution at a 1:30 (g/mL) solid/liquid ratio in 2 min under 300 MPa by UPE. Then, the crude extract was chromatographed with a silica gel column, and primary separation products were obtained. In addition, the products (150 mg) were separated by HSCCC under the solvent system of MTBE-n-butyl alcohol-acetonitrile-water (5:1:2:6, v/v/v/v), yielding 31.43 mg of compound I, 10.21 mg of compound II, and 24.75 mg of compound III. Their structures were further identified by ESI-MS, ¹H NMR, and ¹³C NMR. The antioxidant results showed that the three compounds expressed moderate effects on the DPPH· scavenging effect. Compound II had the best antioxidant capacity and its IC₅₀ value was 0.0497 mg/mL.     

Enhanced Biodegradation of Alkane Hydrocarbons and Crude Oil by Mixed Strains and Bacterial Community Analysis

In this study, two strains, Acinetobacter sp. XM-02 and Pseudomonas sp. XM-01, were isolated from soil samples polluted by crude oil at Bohai offshore. The former one could degrade alkane hydrocarbons (crude oil and diesel, 1:4 (v/v)) and crude oil efficiently; the latter one failed to grow on alkane hydrocarbons but could produce rhamnolipid (a biosurfactant) with glycerol as sole carbon source. Compared with pure culture, mixed culture of the two strains showed higher capability in degrading alkane hydrocarbons and crude oil of which degradation rate were increased from 89.35 and 74.32?±?4.09 to 97.41 and 87.29?±?2.41 %, respectively. In the mixed culture, Acinetobacter sp. XM-02 grew fast with sufficient carbon source and produced intermediates which were subsequently utilized for the growth of Pseudomonas sp. XM-01 and then, rhamnolipid was produced by Pseudomonas sp. XM-01. Till the end of the process, Acinetobacter sp. XM-02 was inhibited by the rapid growth of Pseudomonas sp. XM-01. In addition, alkane hydrocarbon degradation rate of the mixed culture increased by 8.06 to 97.41 % compared with 87.29 % of the pure culture. The surface tension of medium dropping from 73.2?×?10^?3 to 28.6?×?10^?3 N/m. Based on newly found cooperation between the degrader and the coworking strain, rational investigations and optimal strategies to alkane hydrocarbons biodegradation were utilized for enhancing crude oil biodegradation.     

Utilization of Banana Peel as a Novel Substrate for Biosurfactant Production by Halobacteriaceae archaeon AS65

In this study, biosurfactant-producing bacteria was evaluated for biosurfactant production by using banana peel as a sole carbon source. From the 71 strains screened, Halobacteriaceae archaeon AS65 produced the highest biosurfactant activity. The highest biosurfactant production (5.30 g/l) was obtained when the cells were grown on a minimal salt medium containing 35 % (w/v) banana peel and 1 g/l commercial monosodium glutamate at 30 °C and 200 rpm after 54 h of cultivation. The biosurfactant obtained by extraction with ethyl acetate showed high surface tension reduction (25.5 mN/m), a small critical micelle concentration value (10 mg/l), thermal and pH stability with respect to surface tension reduction and emulsification activity, and a high level of salt tolerance. The biosurfactant obtained was confirmed as a lipopeptide by using a biochemical test FT-IR, NMR, and mass spectrometry. The crude biosurfactant showed a broad spectrum of antimicrobial activity and had the ability to emulsify oil, enhance PAHs solubility, and oil bioremediation.