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1.
An effective column‐switching counter‐current chromatography (CCC) protocol combining stepwise elution mode was successfully developed for simultaneous and preparative separation of anti‐oxidative components from ethyl acetate extract of traditional Chinese herbal medicine Rubia cordifolia. The column‐switching CCC system was interfaced by a commercial low‐pressure six‐port switching valve equipped with a sample loop, allowing large volume introduction from the first dimension (1st‐D) to the second dimension (2nd‐D). Moreover, to extend the polarity window, three biphasic liquid systems composed of n‐hexane/ethyl acetate/methanol/water (1:2:1:2, 2:3:2:3, 5:6:5:6 v/v) were employed using stepwise elution mode in the 1st‐D. By valve switching technique the whole interested region of 1st‐D could be introduced to second dimension for further separation with the solvent system 5:5:4:6 v/v. Using the present column‐switching CCC protocol, 500 mg of crude R. cordifolia extract were separated, producing milligram‐amounts of four anti‐oxidative components over 90% pure. Structures of purified compounds were identified by 1H and 13C NMR.  相似文献   

2.
Counter‐current chromatography is a chromatographic technique with a support‐free liquid stationary phase. In the present study, a successful application of linear gradient counter‐current chromatographic method for preparative isolation of bioactive components from the crude ethanol extract of Zanthoxylum planispinum was presented. The application of n‐hexane/ethyl acetate/methanol/water quaternary solvents, in terms of “HEMWat” or “Arizona” solvent families, in gradient elution mode was evaluated. Results indicated that slightly proportional changes of biphasic liquid systems provided the possibility of gradient elution in counter‐current chromatography, maintaining stationary phase retention in the column. With the selected quaternary solvent systems composed of n‐hexane/ethyl acetate/methanol/water (2:1:2:1 and 3:2:3:2, v/v), and optimized gradient programs, in total seven fractions were separated in 4.5 h. Most of the purified compounds could be obtained at the milligram level with over 80% purity. The present study indicated that the linear gradient counter‐current chromatographic approach possessed unique advantages in terms of separation efficiency, exhibiting great potential for the comprehensive separation of complex natural extracts.  相似文献   

3.
Stilbenoids are the main components of leaves and stems of Pholidota chinensis. In the present investigation, high‐speed counter‐current chromatography was used for the separation and purification of two classes of stilbenoids, namely, bibenzyls and 9,10‐dihydrophenanthrenes, on a preparative scale from whole plants of P. chinensis with different solvent systems after silica gel column chromatography fractionation. n‐Hexane/ethyl acetate/methanol/water (1.2:1:1:0.8, v/v/v/v) was selected as the optimum solvent system to purify 1‐(3,4,5‐trimethoxyphenyl)‐1′,2′‐ethanediol ( 1 ), coelonin ( 2 ), 3,4′‐dihydroxy‐5,5′‐dimethoxybibenzyl ( 3 ), and 2,?7‐?dihydroxy‐?3,?4,?6‐?trimethoxy‐?9,?10‐?dihydrophenanthrene ( 4 ). While 2,7‐dihydroxy‐3,4,6‐trimethoxy‐?9,?10‐?dihydrophenanthrene ( 5 ), batatasin III ( 6 ), orchinol ( 7 ), and 3′‐O‐methylbatatasin III ( 8 ) were purified by n‐hexane/ethyl acetate/methanol/water (1.6:0.8:1.2:0.4, v/v/v/v). After the high‐speed counter‐current chromatography isolation procedure, the purity of all compounds was over 94% assayed by ultra high performance liquid chromatography. The chemical structure identification of all compounds was carried out by mass spectrometry and 1H and 13C NMR spectroscopy. To the best of our knowledge, the current investigation is the first study for the separation and purification of bibenzyls and 9,10‐dihydrophenanthrenes by high‐speed counter‐current chromatography from natural resources.  相似文献   

4.
Enrichment of the anti‐tumor compound barbigerone along with a rotenoid derivative from Millettia pachycarpa Benth. was performed by a two‐step high‐speed counter‐current chromatography (HSCCC) separation process. In the first step, 155.8 mg of target fraction (Fra6) was obtained from 400 mg ethyl acetate extract of M. pachycarpa Benth. with an increase in barbigerone from 5.1 to 13% via HSCCC using a solvent system of n‐hexane–ethyl acetate–methanol–water (5:4:5:3, v/v) under normal phase head to tail elution. HSCCC was repeated to eliminate the major contaminant in this initial fraction 6. After a separation time of 65 min, 22.1 mg barbigerone of 87.7% purity was obtained from Fra6 with the ternary solvent system of n‐hexane–methanol–water (2:2:1, v/v) under normal phase elution. Finally, preparative HPLC was employed for the further isolation of barbigerone and the rotenoid derivative. The structures were confirmed by ESI‐MS, 1H NMR and 13C NMR.  相似文献   

5.
A selective and sensitive ultra‐performance liquid chromatography method with tandem mass spectrometric detection for simultaneous determination of gestodene (GES) and ethinyl estradiol (EE) in rat plasma was developed and validated. GES, EE and the internal standard, norgestrel, were extracted with ethyl acetate, derivatized (EE only) with dansyl chloride and then back‐extracted into diethyl ether‐hexane (2:1, v/v). The separation was performed on an ACQUITY UPLC? BEH C18 column with gradient elution using mobile phase consisting of acetonitrile and water (both containing 0.1% formic acid). The detection was carried out by means of electrospray ionization (ESI) mass spectrometry in positive ion mode with multiple‐reaction monitoring. Calibration curves of GES and EE were linear (r2 ≥ 0.99) over the concentration ranges 1.59–159 and 0.196–78.4 ng/mL, respectively. The intra‐ and inter‐day precisions were not more than 6.9 and 12.9% for GES and 10.6 and 9.0% for EE, and the accuracies were ?2.5–8.0% for GES, and ?7.2–0.19% for EE, respectively. The method herein described was superior to previous methods and was applicable to the pharmacokinetic study of GES and EE in rats. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

6.
Nine compounds were successfully separated from Salvia plebeia R.Br. using two‐step high‐speed counter‐current chromatography with three elution modes. Elution–extrusion counter‐current chromatography was applied in the first step, while classical counter‐current chromatography and recycling counter‐current chromatography were used in the second step. Three solvent systems, n‐hexane/ethyl acetate/ethanol/water (4:6.5:3:7, v/v), methyl tert‐butyl ether/ethyl acetate/n‐butanol/methanol/water (6:4:1:2:8, v/v) and n‐hexane/ethyl acetate/methanol/water (5:5.5:5:5, v/v) were screened and optimized for the two‐step separation. The separation yielded nine compounds, including caffeic acid ( 1 ), 6‐hydroxyluteuolin‐7‐glucoside ( 2 ), 5,7,3′,4′‐tetrahydroxy‐6‐methoxyflavanone‐7‐glucoside ( 3 ), nepitrin ( 4 ), rosmarinic acid ( 5 ), homoplantaginin ( 6 ), nepetin ( 7 ), hispidulin ( 8 ), and 5,6,7,4′‐tertrahydroxyflavone ( 9 ). To the best of our knowledge, 5,7,3′,4′‐tetrahydroxy‐6‐methoxyflavanone‐7‐glucoside and 5,6,7,4′‐tertrahydroxyflavone have been separated from Salvia plebeia R.Br. for the first time. The purities and structures of these compounds were identified by high‐performance liquid chromatography, electrospray ionization mass spectrometry, 1H and 13C NMR spectroscopy. This study demonstrates that high‐speed counter‐current chromatography is a useful and flexible tool for the separation of components from a complex sample.  相似文献   

7.
Seven hydroxyanthraquinones were successfully separated from the traditional Chinese medicinal herb Cassiae semen by conventional and pH‐zone‐refining countercurrent chromatography with an environmentally friendly biphasic solvent system, in which elution–extrusion mode was investigated for pH‐zone‐refining countercurrent chromatography for the first time. A two‐phase solvent system composed of n‐hexane/ethyl acetate/ethanol/water (5:3:4:4, v/v/v/v) was used for the conventional countercurrent chromatography while the same system with a different volume ratio n‐hexane/ethyl acetate/ethanol/water (3:5:2:6, v/v/v/v) was used for pH‐zone‐refining countercurrent chromatography, in which 20 mmol/L of trifluoroacetic acid was added in the organic phase as a retainer and 15 mmol/L of ammonia was added to the aqueous phase as an eluter. A 400 mg crude sample could be well separated by pH‐zone‐refining countercurrent chromatography, yielding 53 mg of aurantio‐obtusin, 40 mg of chryso‐obtusin, 18 mg of obtusin, 24 mg of obtusifolin, 10 mg of emodin, and 105 mg of the mixture of chrysophanol and physcion with a purity of over 95.8, 95.7, 96.9, 93.5, 97.4, 77.1, and 19.8%, as determined by high‐performance liquid chromatography. Furthermore, the difference in elution sequence between conventional and pH‐zone‐refining mode was observed and discussed.  相似文献   

8.
High‐speed countercurrent chromatography combined with preparative high‐performance liquid chromatography was successfully used to separate seven phenolic compounds from Stenoloma chusanum Ching. A biphasic solvent system composed of hexane/ethyl acetate/methanol/water (1:2:1:2, v/v) was used for the first step high‐speed countercurrent chromatography separation in elution–extrusion mode. A mobile phase composed of acetonitrile (18%) and pure water (82%) was used for further preparative high‐performance liquid chromatography purification. In total, the combined separation yielded seven compounds, including 3,4‐dihydroxy benzoic acid, 3,4‐dihydroxy benzaldehyde, esculetin, caffeic acid, syringic acid, luteolin, and apigenin, at a purity of over 90%. Esculetin was separated from Stenoloma chusanum Ching for the first time. The results suggest that the proposed combination method is a useful strategy for separating compounds from complex samples.  相似文献   

9.
C19‐diterpenoid alkaloids are the main components of Aconitum duclouxii Levl. The process of separation and purification of these compounds in previous studies was tedious and time consuming, requiring multiple chromatographic steps, thus resulted in low recovery and high cost. In the present work, five C19‐diterpenoid alkaloids, namely, benzoylaconine ( 1 ), N‐deethylaconitine ( 2 ), aconitine ( 3 ), deoxyaconitine ( 4 ), and ducloudine A ( 5 ), were efficiently prepared from A. duclouxii Levl (Aconitum L.) by ethyl acetate extraction followed with counter‐current chromatography. In the process of separation, the critical conditions of counter‐current chromatography were optimized. The two‐phase solvent system composed of n‐hexane/ethyl acetate/methanol/water/NH3·H2O (25%) (1:1:1:1:0.1, v/v) was selected and 148.2 mg of 1 , 24.1 mg of 2 , 250.6 mg of 3 , 73.9 mg of 4, and 31.4 mg of 5 were obtained from 1 g total Aconitum alkaloids extract, respectively, in a single run within 4 h. Their purities were found to be 98.4, 97.2, 98.2, 96.8, and 96.6%, respectively, by ultra‐high performance liquid chromatography analysis. The presented separation and purification method was simple, fast, and efficient, and the obtained highly pure alkaloids are suitable for biochemical and toxicological investigation.  相似文献   

10.
10‐Deacetylbaccatin III, an important semisynthetic precursor of paclitaxel and docetaxel, can be extracted from Taxus wallichiana Zucc. A process for the isolation and purification of 10‐deacetylbaccatin III ( 1 ), baccatin III ( 2 ), and 7β‐xylosyl‐10‐deacetyltaxol ( 3 ) from the leaves and branches of Taxus wallichiana Zucc. via macroporous resin column chromatography combined with high‐speed countercurrent chromatography or reversed‐phase flash chromatography was developed in this study. After fractionation by macroporous resin column chromatography, 80% methanol fraction was selected based on high‐performance liquid chromatography and liquid chromatography with mass spectrometry qualitative analysis. A solvent system composed of n‐hexane, ethyl acetate, methanol, and water (1.6:2.5:1.6:2.5, v/v/v/v) was used for the high‐speed countercurrent chromatography separation at a flow rate of 2.5 mL/min. The reversed‐phase flash chromatography separation was performed using methanol/water as the mobile phase at a flow rate of 3 mL/min. The high‐speed countercurrent chromatography separation produced compounds 1 (10.2 mg, 94.4%), 2 (2.1 mg, 98.0%), and 3 (4.6 mg, 98.8%) from 100 mg of sample within 110 min, while the reversed‐phase flash chromatography separation purified compounds 1 (9.8 mg, 95.6%) and 3 (4.9 mg, 97.9%) from 100 mg of sample within 120 min.  相似文献   

11.
An effective high‐speed countercurrent chromatography method was successfully established by using ionic liquids as the modifier of the two‐phase solvent system. Adding a small amount of ionic liquids significantly shortens the separation time and improves the separation efficiency. The conditions of ionic‐liquid‐modified high‐speed countercurrent chromatography including solvent systems, types and content of added ionic liquids, and ionic liquids posttreatment were investigated. The established method was successfully applied to separate alkaloids from lotus leaves using a two‐phase solvent system composed of petroleum ether/ethyl acetate/methanol/water/[C4mim][BF4] (1:5:1:5:0.15, v/v/v/v/v). Four alkaloids pronuciferine (1.7 mg), N‐nornuciferine (4.3 mg), nuciferine (3.1 mg), and roemerine (2.1 mg) were obtained with the purities of 90.53, 92.25, 99.86, and 98.63%, respectively, from 100 mg crude extract of lotus leaves. The results indicated that the ionic‐liquid‐modified high‐speed countercurrent chromatography method was suitable for alkaloid separation from lotus leaves and would be a promising method for the separation of alkaloids from other natural products.  相似文献   

12.
A rapid method combining microwave‐assisted extraction (MAE) and high‐speed counter‐current chromatography (HSCCC) was applied for preparative separation of six bioactive compounds including loganic acid ( I ), isoorientin‐4′‐O‐glucoside ( II ), 6′‐O‐β‐d ‐glucopyranosyl gentiopicroside ( III ), swertiamarin ( IV ), gentiopicroside ( V ), sweroside ( VI ) from traditional Tibetan medicine Gentiana crassicaulis Duthie ex Burk. MAE parameters were predicted by central composite design response surface methodology. That is, 5.0 g dried roots of G. crassicaulis were extracted with 50 mL 57.5% aqueous ethanol under 630 W for 3.39 min. The extract (gentian total glycosides) was separated by HSCCC with n‐butanol/ethyl acetate/methanol/1% acetic acid water (7.5:0.5:0.5:3.5, v/v/v/v) using upper phase mobile in tail‐to‐head elution mode. 16.3, 8.8, 12., 25.1, 40.7, and 21.8 mg of compounds I–VI were obtained with high purities in one run from 500 mg of original sample. The purities and identities of separated components were confirmed using HPLC with photo diode array detection and quadrupole TOF‐MS and NMR spectroscopy. The study reveals that response surface methodology is convenient and highly predictive for optimizing extraction process, MAE coupled with HSCCC could be an expeditious method for extraction and separation of phytochemicals from ethnomedicine.  相似文献   

13.
Pine knots are a rich source of lignans, flavonoids, and stilbenes. These bioactive compounds are widely known for their roles to combat human disorders but also to protect plants against pathogens. In order to gain knowledge inside their potential activities, a suitable isolation and purification of these high‐added value compounds is required. To this end, centrifugal partition chromatography, as a rapid and useful methodology of separation, was employed and developed. The coefficient partition values (KD) of six major compounds in nine biphasic solvent systems were determined to evaluate the most appropriate system. Two‐step centrifugal partition chromatography was required to separate lignans using ARIZONA system K (n‐heptane/ethyl acetate/methanol/water 1:2:1:2, v:v) and to isolate stilbenes and flavonoids using ARIZONA system P (n‐heptane/ethyl acetate/methanol/water 6:5:6:5, v:v). Eight one‐compound enriched‐fractions were obtained as follows: nortrachelogenin (70.1%), secoisolariciresinol (53.7%), isolariciresinol (61.1%), taxifolin (48.4%), pinocembrin (91.3%), pinobanksin (91.1%), pinosylvin (91.4%), and pinosylvin monomethyl ether (91.1%). Additionally, the centrifugal partition chromatography allowed to unravel the composition of pine knot owing to the several fractions generated. Twenty‐two compounds were characterized by liquid chromatography‐mass spectrometry and NMR spectroscopy, some of which are described for the first time in literature.  相似文献   

14.
In this paper, high‐speed counter‐current chromatography (HSCCC), assisted with ESI‐MS, was first successfully applied to the preparative separation of three macrolide antibiotics, brefeldin A (12.6 mg, 99.0%), 7′‐O‐formylbrefeldin A (6.5 mg, 95.0%) and 7′‐O‐acetylbrefeldin A (5.0 mg, 92.3%) from the crude extract of the microbe Penicillium SHZK‐15. Considering the chemical nature and partition coefficient (K) values of the three target compounds, a two‐step HSCCC isolation protocol was developed in order to obtain products with high purity. In the two‐step method, the crude ethyl acetate extract was first fractionated and resulted in two peak fractions by HSCCC using solvent system n‐hexane/ethyl acetate/methanol/water (HEMWat) (3:7:5:5 v/v/v/v), then purified using solvent systems HEMWat (3:5:3:5 v/v/v/v) and HEMWat (7:3:5:5 v/v/v/v) for each fraction. The purities and structures of the isolated compounds were determined by HPLC, X‐ray crystallography, ESI‐MS and NMR. The results demonstrated that HSCCC is a fast and efficient technique for systematic isolation of bioactive compounds from the microbes.  相似文献   

15.
Millettia griffithii is a unique Chinese plant located in the southern part of Yunnan Province. Up to now, there is no report about its phytochemical or related bioactivity research. In our previous study, the n‐hexane crude extract of Millettia griffithii revealed significant anti‐inflammatory activity at 100 μg/mL, inspiring us to explore the anti‐inflammatory constituents. Four fractions (I, II, III, and A) were fractionated from n‐hexane crude extract by high‐performance counter‐current chromatography with solvent system composed of n‐hexane/ethyl acetate/methanol/water (8:9:8:9, v/v) and then were investigated for the potent anti‐inflammatory activity. Fraction A, with the most potent inhibitory activity was further separated to give another four fractions (IV, V, VI, and B) with solvent system composed of n‐hexane/ethyl acetate/methanol/water (8:4:8:4, v/v). Compound V and fraction B exhibited remarkable anti‐inflammatory activity with nitric oxide inhibitory rate of 80 and 65%, which was worth further fractionation. Then, three fractions (VII, VIII, and IX) were separated from fraction B with a solvent system composed of n‐hexane/ethyl acetate/methanol/water (8:1:8:1, v/v), with compound VIII demonstrating the most potent inhibitory activity (80%). Finally, the IC50 values of compound V and VIII were tested as 38.2 and 14.9 μM. The structures were identified by electrospray ionization mass spectrometry and1H and 13C NMR spectroscopy.  相似文献   

16.
This study presents an efficient strategy based on liquid–liquid extraction, high‐speed counter‐current chromatography, and preparative HPLC for the rapid enrichment, separation, and purification of four anthraquinones from Rheum tanguticum. A new solvent system composed of petroleum ether/ethyl acetate/water (4:2:1, v/v/v) was developed for the liquid–liquid extraction of the crude extract from R. tanguticum. As a result, emodin, aloe‐emodin, physcion, and chrysophanol were greatly enriched in the organic layer. In addition, an efficient method was successfully established to separate and purify the above anthraquinones by high‐speed counter‐current chromatography and preparative HPLC. This study supplies a new alternative method for the rapid enrichment, separation, and purification of emodin, aloe‐emodin, physcione, and chrysophanol.  相似文献   

17.
Preparative high‐speed counter‐current chromatography (HSCCC) was successfully applied to the isolation and purification of three stilbene oligomers from Vitis chunganeniss using stepwise elution with a pair of two‐phase solvent systems composed of n‐hexane–ethyl acetate–methanol–water at (2:5:2:5, v/v) and (1:2:1:2, v/v). The preparative HSCCC separation was performed on 800 mg of crude sample yielding hopeaphenol (21.1 mg), amurensin G (37.2 mg) and vitisin A (95.6 mg) in a one‐step separation, with purities over 95% as determined by HPLC. The structures of these three compounds were identified by MS, 1H NMR and 13C NMR. In addition, their antioxidant activities were screened by DPPH assay, where vitisin A showed strong antioxidant activity. Further EPR experiments with spin‐trapping technique demonstrated that vitisin A is a potent and selective singlet oxygen quencher, which may be used in singlet oxygen‐mediated diseases as a pharmacological agent.  相似文献   

18.
In this paper, an effective method combing fast elution‐extrusion counter‐current chromatography (CCC) and LC/MS for rapid screening of antioxidative phenolic compounds in Chinese Rhubarb is presented. An integrated three‐coil CCC column (40 mL each coil) was used to accomplish the optimization of biphasic liquid system. In a single run (approximately 40 min), the solvent system composed of n‐hexane/ethyl acetate/methanol/water (1:1:1:1, v/v) was selected as optimum CCC liquid system for fast fractionation of the crude ethanol extract. With a 140 mL‐capacity CCC instrument, 100 mg Chinese Rhubarb extract was separated under the optimized conditions, producing six fractions in only 100 min. The quantities of each fraction were ~15 mg. In addition, each fraction was subjected to antioxidant activity assay and characterized by LC/MS analysis. Fifty compounds, including phenolic acids, phenolic glucosides and hydroxyanthraquinones, were detected by LC/MS/MS analysis. As a result, gallic acid together with Fr I showed excellent antioxidant activity, which was well consistent with previous studies and exhibited great potential for natural drug discovery program of the present method.  相似文献   

19.
A preparative high‐speed counter‐current chromatography method for isolation and purification of bufadienolides from ChanSu was developed by using a stepwise elution with two‐phase solvent system composed of n‐hexane/ethyl acetate/methanol/water at the ratios of 4:6:2:4 v/v, 4:6:2.5:4 v/v and 4:6:3.2:4 v/v. A total of 3.8 mg of gamabufotalin (1), 7.2 mg of arenobufagin (2), 3.4 mg of telocinobufagin (3), 5.3 mg of bufotalin (4), 8.5 mg of cinobufotalin (5) and 8 mg of bufalin (6) were obtained in one‐step separation from 80 mg of the crude extract with purity of 92.7, 96.7, 87.2, 97.3, 94.9 and 99.4%, respectively. Their chemical structures were identified on the basis of 1H‐NMR and 13C‐NMR technology.  相似文献   

20.
High‐performance counter‐current chromatography was successfully used for the isolation and purification of terpenoid compounds from the essential oil of Pimpinella anisum L. A two‐phase solvent system composed of n‐heptane/methanol/ethyl acetate/water (5:2:5:2, v/v/v/v) was suitable for the purification of linalool, terpinen‐4‐ol, α‐terpineol, p‐anisaldehyde, while n‐heptane/methanol (1:1, v/v) was used for the isolation of anethole and foeniculin. A scale‐up process from analytical to preparative was developed. Additionally, a stepwise gradient elution was applied and instead of two different runs, 40 min each, one 80 min separation was performed; although the time of separation remains the same, it was possible to repeat the efficiency even if the water‐containing mobile phase was changed to a nonaqueous system. The obtained essential oil, as well as purified compounds, was analyzed by GC. A total of 0.64 mg of linalool, 0.52 mg of terpinen‐4‐ol, 0.10 mg of α‐terpineol, 0.62 mg of p‐anisaldehyde, 15 mg of anethole, and 2.12 mg of foeniculin were obtained from 210 mg of the essential oil of P. anisum L. in a short time with purities of 99, 98, 94, 93.54, 93, and 93.6%, respectively.  相似文献   

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