首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 265 毫秒
1.
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   

2.
A preparative high‐speed counter‐current chromatography method for separation and purification of liensinine, isoliensinine and neferine from seed embryo of Nelumbo nucifera GAERTN was successfully established by using n‐hexane‐ethyl acetate‐methanol‐water (5:8:4:5, v/v, containing 0.5% NH4OH) as the two‐phase solvent system. From 200 mg of crude extract, 18.4 mg of liensinine, 19.6 mg of isoliensinine and 58.4 mg of neferine were obtained with the purity of 96.8, 95.9, and 98.6%, respectively. The identification of the three alkaloids was performed with 1H NMR and 13C NMR.  相似文献   

3.
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   

4.
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   

5.
An efficient method for the preparative separation of four structurally similar caged xanthones from the crude extracts of gamboge was established, which involves the combination of pH‐zone‐refining counter‐current chromatography and conventional high‐speed counter‐current chromatography for the first time. pH‐zone‐refining counter‐current chromatography was performed with the solvent system composed of n‐hexane/ethyl acetate/methanol/water (7:3:8:2, v/v/v/v), where 0.1% trifluoroacetic acid was added to the upper organic stationary phase as a retainer and 0.03% triethylamine was added to the aqueous mobile phase as an eluter. From 3.157 g of the crude extract, 1.134 g of gambogic acid, 180.5 mg of gambogenic acid and 572.9 mg of a mixture of two other caged polyprenylated xanthones were obtained. The mixture was further separated by conventional high‐speed counter‐current chromatography with a solvent system composed of n‐hexane/ethyl acetate/methanol/water (5:5:10:5, v/v/v/v) and n‐hexane/methyl tert‐butyl ether/acetonitrile/water (8:2:6:4,v/v/v/v), yielding 11.6 mg of isogambogenic acid and 10.4 mg of β‐morellic acid from 218.0 mg of the mixture, respectively. The purities of all four of the compounds were over 95%, as determined by high‐performance liquid chromatography, and the chemical structures of the four compounds were confirmed by electrospray ionization mass spectrometry and NMR spectroscopy. The combinative application of pH‐zone‐refining counter‐current chromatography and conventional high‐speed counter‐current chromatography shows great advantages in isolating and enriching the caged polyprenylated xanthones.  相似文献   

6.
This study presents an efficient strategy for separation of three phenolic compounds with high molecular weight from the crude extract of Terminalia chebula Retz. by ultrasound‐assisted extraction and high‐speed counter‐current chromatography. The ultrasound‐assisted extraction conditions were optimized by response surface methodology and the results showed the target compounds could be well enriched under the optimized extraction conditions. Then the crude extract was directly separated by high‐speed counter‐current chromatography without any pretreatment using n‐hexane/ethyl acetate/methanol/water (1:7:0.5:3, v/v/v/v) as the solvent system. In 180 min, 13 mg of A, 18 mg of B, and 9 mg of C were obtained from 200 mg of crude sample. Their structures were identified as Chebulagic acid (A, 954 Da), Chebulinic acid (B, 956 Da), and Ellagic acid (C) by 1H NMR spectroscopy.  相似文献   

7.
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   

8.
Four flavonoids, isoastilbin, astilbin, isoengelitin, and engelitin were isolated and purified simultaneously from Smilacis Glabrae Roxb. for the first time by high performance counter‐current chromatography using a system consisting of n‐hexane–n‐butanol–water (1:2:3, v/v/v). A total of 392.6 mg of astilbin, 71.4 mg of isoastilbin, 47.4 mg of engelitin, and 10.3 mg of isoengelitin were purified from 1.89 g of the ethyl acetate extract of Smilacis Glabrae Roxb. in six runs, each at over 94.51% purity as determined by HPLC. The structures of the four compounds were identified by their retention time, the LC‐ESI‐MSn in the negative ion mode, and confirmed by 1H‐NMR experiments. The characteristic LC‐ESI‐MS fragmentation patterns of the four compounds were discussed.  相似文献   

9.
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   

10.
Efficient high‐performance countercurrent chromatography methods were developed to isolate five typical compounds from the extracts of Gentiana macrophylla. n‐Butanol‐soluble extract of G. macrophylla contained three hydrophilic iridoids, loganic acid ( 1 ), swertiamarin ( 2 ) and gentiopicroside ( 3 ), and a chromene derivative, macrophylloside D ( 4 ) which were successfully isolated by flow rate gradient (1.5 mL/min in 0–60 min, 5.0 mL/min in 60–120 min), and consecutive flow rate gradient HPCCC using n‐butanol/0.1% aqueous trifluoroacetic acid (1:1, v/v, normal phase mode) system. The yields of 1 – 4 were 22, 16, 122, and 6 mg, respectively, with purities over 97% in a flow rate gradient high‐performance countercurrent chromatography, and consecutive flow rate gradient high‐performance countercurrent chromatography gave 1 , 2 , 3 (54, 41, 348 mg, respectively, purities over 97%) and 4 (13 mg, purity at 95%) from 750 mg of sample. The main compound in methylene chloride soluble extract, 2‐methoxyanofinic acid, was successfully separated by n‐hexane/ethyl acetate/methanol/water (4:6:4:6, v/v/v/v, flow‐rate: 4 mL/min, reversed phase mode) condition. The structures of five isolates were elucidated by 1H, 13C NMR and ESI‐Q‐TOF‐MS spectroscopic data which were compared with previously reported values.  相似文献   

11.
An off‐line 2D high‐speed counter‐current chromatography technique in preparative scale has been successfully applied to separate and purify the main compounds from the ethyl acetate extract of Desmodium styracifolium. A two‐phase solvent system composed of n‐hexane/ethyl acetate/methanol/water at an optimized volume ratio of 1:2:1:2 v/v/v/v was used. Conventional high‐speed counter‐current chromatography was used as the first dimension, and the upper phase of the solvent system was used as the stationary phase in the head‐to‐tail elution mode at a flow rate of 2.0 mL/min and a rotation speed of 900 rpm. Recycling high‐speed counter‐current chromatography served as the second dimension to separate an impure fraction of the first dimension. A total of four well‐separated substances including vanillic acid ( 1 ), β‐sitosterol ( 2 ), formononetin ( 3 ), and aromadendrin ( 4 ) were obtained, and their purities and structures were identified by HPLC–MS and 1H NMR spectroscopy. The results illustrated that off‐line 2D high‐speed counter‐current chromatography is an effective way to isolate compounds in complex samples.  相似文献   

12.
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   

13.
An efficient separation method of using high‐speed counter‐current chromatography was successfully established to directly purify cytotoxic transformed products of cinobufagin by Cordyceps militaris. The two‐phase solvent system composed of n‐hexane–ethyl acetate–methanol–water (4:6:3:4, v/v) was used in high‐speed counter‐current chromatography. A total of 9 mg of 4β,12α‐dihydroxyl‐cinobufagin ( 1 ), 15 mg of 12β‐hydroxyl‐cinobufagin ( 2 ), 8 mg of 5β‐hydroxyl‐cinobufagin ( 3 ), 12 mg of deacetylcinobufagin ( 4 ) and 6 mg of 3‐keto‐cinobufagin ( 5 ) were obtained in a one‐step separation from 400 mg of the crude extract with purity of 98.7, 97.2, 90.6, 99.1 and 99.4%, respectively, as determined by HPLC. Their chemical structures were identified on the basis of 1H‐NMR and 13C‐NMR technology. All products ( 1 – 5 ) showed the potent activities against human carcinoma cervicis (Hela) and malignant melanoma (A375) cells in vitro.  相似文献   

14.
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   

15.
The chemical constituents of the Siraitia grosvenorii leaf extract were studied. Firstly, high‐speed counter‐current chromatography was applied to the one‐step separation of four compounds from S. grosvenorii leaf extract with the solvent system composed of 0.01% acetic acid water/n‐butanol/n‐hexane/methanol (5:3:1:1, v/v/v/v). In this work, 270 mg of crude sample yielded four compounds, a new kaempferol O‐glycoside derivative, kaempferol 3‐O‐α‐L‐[4‐O‐(4‐carboxy‐3‐hydroxy‐3‐methylbutanoyl)]‐rhamnopyranoside‐7‐OαL‐rhamnopyranoside, named kaempferitrin A (2.1 mg, 90%), and three known compounds, grosvenorine (3.4 mg, 93%), kaempferitrin (14.4 mg, 99%) and afzelin (4 mg, 98%), and the structures of these compounds were identified by NMR spectroscopy and mass spectrometry. Then, ultra high performance liquid chromatography with electrospray ionization quadrupole time‐of‐flight mass spectrometry was used to illustrate the dominant flavonoids in S. grosvenorii leaf extract. 34 flavonoids including 19 kaempferol O‐glycosides, 4 quercetin O‐glycosides, 6 flavanone derivatives, and 5 polymethoxyflavones, were accurately or tentatively identified by carefully comparing their retention times, UV data, precise masses, the typical fragments of the standards and literature data. Most of these compounds were reported for the first time. This study establishes a foundation for the further development and utilization of S. grosvenorii leaves in future.  相似文献   

16.
In order to utilize and control the invasive weed, bioactive compounds from essential oil of Flaveria bidentis (L.) Kuntze were studied. Steam distillation extraction and one step high‐speed counter‐current chromatography were applied to separate and purify the caryophyllene oxide, 7,11‐dimethyl‐3‐methylene‐1,6,10‐dodecatriene, and caryophyllene from essential oil of Flaveria bidentis (L.) Kuntze. The two‐phase solvent system containing n‐hexane/acetonitrile/ethanol (5:4:3, v/v/v) was selected for the one step separation mode according to the partition coefficient values (K) of the target compounds and the separation factor (α). The purity of each isolated fraction after a single high‐speed counter‐current chromatography run was determined by high performance liquid chromatography. A 3.2 mg of caryophyllene oxide at a purity of 92.6%, 10.4 mg of 7,11‐dimethyl‐3‐methylene‐1,6,10‐dodecatriene at a purity of 99.1% and 5.7 mg of caryophyllene at a purity of 98.8% were obtained from 200 mg essential oil of Flaveria bidentis (L.) Kuntze. The chemical structures of these components were identified by GC‐MS, 1H‐NMR, and 13C‐NMR.  相似文献   

17.
Capsaicin and dihydrocapsaicin are two main bioactive components of Capsicum frutescens and are widely used as food additives and drugs in China and India. Due to their similarity in structures, isolation of capsaicin and dihydrocapsaicin with traditional methods such as silica gel column chromatography, normal‐phase thin‐layer chromatography (TLC) becomes difficult. This study involves separating capsaicin and dihydrocapsaicin with sufficient purity and recovery using high‐speed counter‐current chromatography (HSCCC) with a solvent system composed of n‐hexane–ethyl acetate–methanol–water–acetic acid (20:20:20:20:2, v/v/v/v/v). Separation parameters such as sample volume, and sample concentration were first optimized on analytical HSCCC, and then scaled up to preparative HSCCC. 0.65 g capsaicin and 0.28 g dihydrocapsaicin were obtained from 1.2 g crude extract and their purities were 98.5 and 97.8%, respectively. The recoveries of the two compounds were 86.3 and 85.4%, respectively. The purity of the isolated compounds was analyzed by high‐performance liquid chromatography (HPLC) and their structures were identified by 1H nuclear magnetic resonance (NMR) and 13C NMR analysis.  相似文献   

18.
A preparative high‐speed countercurrent chromatography method was successfully used for the isolation of five minor flavones from Polygonum cuspidatum flowers. Among them, three compounds were obtained from P. cuspidatum for the first time. A twin two‐phase solvent system composed of n‐hexane/ethyl acetate/ethanol/water (1:6:3:6, v/v/v/v) and petroleum ether/ethyl acetate/methanol/water (2:4:3:3, v/v/v/v) was developed. Compounds were obtained from the fraction B and fraction C prepurified by silica gel column chromatography. Five minor compositions, 6.8 mg of hesperidin, 11.2 mg of phloridzin, 4.9 mg of luteolin, 5.3 mg of hyperin, and 3.7 mg of luteoloside were obtained from 140 mg of the fraction B and 110 mg of fraction C with a purity of 95.3, 96.4, 98.0, 96.8, and 95.3%, respectively, as determined by high‐performance liquid chromatography. The structures of these compounds were identified by 1H and 13C NMR spectroscopy.  相似文献   

19.
In our present study, two groups of xanthones isomers (1‐hydroxy‐3,5,8‐trimethoxyxanthone and 1‐hydroxy‐3,7,8‐trimethoxyxanthone; 1,8‐dihydroxy‐3,7‐dimethoxyxanthone and 1,8‐dihydroxy‐3,5‐dimethanolxanthone) and other two xanthones (3‐methoxy‐1,5,8‐trihydroxyxanthone and 3,5‐dimethoxy‐1‐hydroxyxanthone) were separated from Swertia franchetiana . First, a solvent system composed of petroleum ether/methanol/water (2:1:0.6, v/v) was developed for the liquid–liquid extraction of these xanthones from the crude extract. Then, an efficient method was established for the one‐step separation of these six xanthones by high‐speed countercurrent chromatography using n‐hexane/ethyl acetate/methanol/ethanol/water (HEMEW; 6:4:4:2:4, v/v) as the solvent system. The results showed that liquid–liquid extraction could be well developed for efficient enrichment of target compounds. Additionally, high‐speed countercurrent chromatography could be a powerful technology for separation xanthones isomers. It was found ethanol could be a good methanol substitute when the HEMEW system could not provide good separation factors.  相似文献   

20.
An efficient strategy for extracting and separating five lignans from Schisandra chinensis (Turcz.) Baill has been developed using supercritical fluid extraction (SFE) and high‐speed counter‐current chromatography (HSCCC) in the present study. First, the extraction was performed by a preparative SFE system under 15 MPa of pressure at 36°C for 4 h. Then, the SFE extract was successfully separated and purified by HSCCC with a two‐phase solvent system composed of n‐hexane/ethyl acetate/methanol/water (6:4:5:5, 6:4:6:4, 6:4:8:2, v/v) in a stepwise elution mode. The fractions were analyzed by HPLC, and the chemical structures of the products were identified by ESI‐MS and 1H NMR spectroscopy. As a result, a total of 12.5 mg of schisandrin at 98.0% purity, 7.1 mg of gomisin A at 98.1% purity, 1.8 mg of schisantherin B at 93.3% purity, 4.4 mg of deoxyschisandrin at 92.9% purity, and 6.8 mg of γ‐schisandrin at 89.1% purity were obtained from 300 mg crude extract in a one‐step purification.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号