Preparative separation and enrichment of four taxoids from Taxus chinensis needles extracts by macroporous resin column chromatography

An environment‐friendly method was established for the preparative separation and enrichment of four taxoids, namely 10‐deacetylbaccatin III (10‐DAB III), 7‐xylosyl‐10‐deacetyltaxol (7‐xyl‐10‐DAT), cephalomannine and paclitaxel from Taxus chinensis needles extracts. Characteristics of seven widely used macroporous resins for four taxoids were compared, AB‐8 resin offered better adsorption and desorption capacities than others. AB‐8 resin column chromatography was used to study the desorption process for four taxoids. The optimum parameters for desorption were 30% ethanol 5 RV for removing impurities, following 15 RV for 10‐DAB III, after the desorption of impurities with 35% ethanol 10 RV, 45% ethanol 30 RV for 7‐xyl‐10‐DAT, then 65% ethanol 10 RV for cephalomannine and paclitaxel, the flow rate was 6 RV/h. After separation on AB‐8 resin column chromatography, the contents of 10‐DAB III, 7‐xyl‐10‐DAT, cephalomannine and paclitaxel in the product reached 4.58, 13.17, 1.36 and 3.08%, respectively, which were 7.63‐, 3.68‐, 6.18‐ and 6.55‐fold to those in T. chinensis needles extracts. The recovery yields were 94.96, 77.32, 88.09 and 95.25%. In general, the AB‐8 resin column chromatography has the advantages of lower cost, high efficiency and simple procedure. Therefore, it may provide scientific references for the preparative separation and enrichment of taxoids from other T. species.     

Preparative separation of vitexin and isovitexin from pigeonpea extracts with macroporous resins

Vitexin and isovitexin are a pair of isomeric compounds known as the major constituents in pigeonpea leaves and possess various pharmacological activities. In the present study, the preparative separation of vitexin and isovitexin with macroporous resins (Nankai Hecheng S & T, Tianjin, China) was studied. The performance and adsorption characteristics of eight macroporous resins including ADS-5, ADS-7, ADS-8, ADS-11, ADS-17, ADS-21, ADS-31 and ADS-F8 have been evaluated. The research results indicate that ADS-5 resin is most appropriate for the separation of vitexin and isovitexin. Langmuir and Freundlich isotherms were used to describe the interactions between solutes and resin at different temperatures, and the equilibrium experimental data were well fitted to the two isotherms. Column packed with ADS-5 resin was used to perform dynamic adsorption and desorption tests to optimize the separation process. The optimum parameters for adsorption were as follows: the concentration of vitexin and isovitexin in sample solution: 0.22 and 0.40mg/mL, respectively, processing volume: 3 BV, flow rate: 1mL/min, pH 4, temperature: 25 degrees C; for desorption: ethanol-water (40:60, v/v), 5 BV as an eluent, flow rate: 1mL/min. After one run treatment with ADS-5 resin, the contents of vitexin and isovitexin were increased 4.07-fold and 11.52-fold from 0.86%, 1.53% to 3.50% and 17.63%, the recovery yields were 65.03% and 73.99%, respectively. In conclusion, the preparative separation of vitexin and isovitexin can be easily and effectively achieved via adsorption and desorption on ADS-5 resin, and the method can be referenced for the separation of other flavone C-glucosides from herbal materials.     

An Effective Chromatography Process for Simultaneous Purification and Separation of Total Lignans and Flavonoids from Valeriana amurensis

An effective chromatography process was developed and validated for simultaneous purification and separation of total lignans and flavonoids from Valeriana amurensis. The total lignans and flavonoids in Valeriana amurensis extract were prepurified with macroporous resin column chromatography, and the conditions were optimized as follows: 40 mg/mL Valeriana amurensis extract (2.0 g) solution was loaded onto an AB-8 resin column with a diameter-to-height ratio of 1:7, followed by adsorption for 6 h; then, the column was eluted successively with 5 BV water and 10% and 50% ethanol at a flow rate 2 BV/h. The obtained 50% ethanol fraction was further repurified and separated by polyamide resin column chromatography to obtain the total lignans and flavonoids, respectively. The chromatography conditions were optimized as follows: a 50% ethanol fraction (1.0 g) was mixed with 1.0 g polyamide resin and loaded onto a polyamide resin (60–100 mesh) column with a diameter-to-height ratio of 1:3; then, the column was eluted successively with 6 BV water and 40% and 80% ethanol at a flow rate of 4 BV/h. The total lignans and flavonoids were obtained from water and 80% ethanol fraction, respectively. The content and recovery of standard compounds in total lignans and flavonoids were analyzed with HPLC-PDA, and the feasibility of the process was confirmed.     

Separation of 7-xylosyl-10-deacetyl paclitaxel and 10-deacetylbaccatin III from the remainder extracts free of paclitaxel using macroporous resins

The separation and enrichment of 10-deacetylbaccatin III (10-DAB III) and 7-xylosyl-10-deacetyl paclitaxel were studied on seven macroporous resins with special structures. The performance of 7-xylosyl-10-deacetyl paclitaxel and 10-DAB III on macroporous resins including AB-8, ADS-17, ADS-21, ADS-31, ADS-8, H1020 and NKA-II was compared according to their adsorption and desorption properties. AB-8 provided a much higher adsorption capacity for 7-xylosyl-10-deacetyl paclitaxel and 10-DAB III than other resins, and its adsorption data fitted well to the Langmuir and Freundlich isotherm. According to the adsorption and desorption capacities and the adsorption isotherms, AB-8 demonstrated a remarkable capability for the preparative separation of 7-xylosyl-10-deacetyl paclitaxel and 10-DAB III from the remainder extracts free of paclitaxel. In order to optimize parameters of separation, dynamic adsorption and desorption experiments were carried out on the columns packed with AB-8 resin. The optimal conditions were: the processing volume 15 BV; concentrations of 7-xylosyl-10-deacetyl paclitaxel and 10-DAB III in feed solution 0.0657 mg/mL and 0.1494 mg/mL; flow rate 1 mL/min; temperature 35 degrees C. The gradient elution program was as follows: 30% ethanol for 3 BV, then 80% of ethanol for 6 BV, flow rate 1 mL/min. After the AB-8 resin treatment, the contents of 7-xylosyl-10-deacetyl paclitaxel and 10-DAB III in the product had increased from 0.053% and 0.2% to 3.34% and 1.69%, which were 62.43-fold and 8.54-fold of those in the untreated extracts, respectively, and the recoveries of 7-xylosyl-10-deacetyl paclitaxel and 10-DAB III were 85.85% and 52.78%. The performance achieved good separation and higher recovery of 7-xylosyl-10-deacetyl paclitaxel and 10-DAB III from remainder extracts free of paclitaxel by using AB-8 resin. It is a fast and effective method for the separation and enrichment of 7-xylosyl-10-deacetyl paclitaxel and 10-DAB III.     

大孔吸附树脂分离纯化金银花中黄酮类物质的研究

比较了AB-8、S-8、NKA-9和D-101 4种大孔吸附树脂对金银花提取液中黄酮类物质的吸附及解吸附性能.在静态吸附试验基础上,筛选出效果较好的D-101树脂进行动态试验研究,结果表明,D-101树脂在30℃下对金银花黄酮类物质的静态吸附-动态解吸较优的工艺参数为:上样液pH值2.46,解吸液为95%乙醇,解吸液的流速为3mL/min,pH值11,4.5BV解吸液即可完全洗脱被树脂吸附的黄酮类物质,其解吸率高达98.00%.在试验研究范围内,树脂吸附金银花黄酮是自发性放热过程,并且符合Langmuir方程,此外树脂对黄酮的吸附动力学可用Pseudo-second-order模型较好地拟合,其表观吸附速率常数为Kso℃=3.43×10-2g/(mg·min).     

Separation and purification of hydroxytysol and oleuropein from Olea europaea L. (olive) leaves using macroporous resins and a novel solvent system

The separation and purification of hydroxytysol and oleuropein from Olea europaea L. (olive) using a macroporous resin with a novel solvent system was systematically investigated. Static adsorption experiments with BMKX–4 resin revealed that the experimental data of both hydroxytysol and oleuropein fitted best to the pseudo‐second‐order kinetic and Freundlich isotherm models. The thermodynamic parameters indicated spontaneous and exothermic adsorption processes. The novel solvent system, composed of n–hexane:ethyl acetate:methanol:water in a (v/v/v/v) ratio of 1:9:1:9, had two phases (upper and lower). The separation and purification parameters of hydroxytysol and oleuropein were optimized using dynamic adsorption/desorption on a column packed with BMKX–4 resin. The effects of flow rates and volumes of the upper and lower phases on the separation efficiency were systematically studied. Under optimal conditions, the fraction of hydroxytysol in the final product increased by 6.34‐fold from 0.46 to 2.96%, with a yield rate of 88.58% w/w, while that of oleuropein increased 4.17‐fold from 11.40 to 47.59%, with a 93.31% w/w yield rate. These results may be help in selecting a suitable eluent for improved separation of macroporous adsorption resins.     

Optimization of luteolin separation from pigeonpea [Cajanus cajan (L.) Millsp.] leaves by macroporous resins

In the present study, the performance and separation characteristics of eight macroporous resins for the separation of luteolin (LU) from pigeonpea leaves extracts have been evaluated. The adsorption and desorption properties of LU on macroporous resins including AB-8, NKA-9, NKA-2, D3520, D101, H1020, H103 and AL-2 have been compared. AL-2 resin offers the best adsorption and desorption capacity for LU than other resins based on the research results, and its adsorption data at 25 degrees C fit best to the Freundlich isotherm. Dynamic adsorption and desorption experiments have been carried out with the column packed by AL-2 resin to optimize the separation process of LU from pigeonpea leaves extracts. The optimum parameters for adsorption were sample solution LU concentration 65.5 microg/ml, pH 5, processing volume 3 BV, flow rate 1.5BV/h, temperature 25 degrees C; for desorption were elution solvent ethanol-water (50:50, v/v) 2 BV and followed by ethanol-water (60:40, v/v) 2 BV, and flow rate 1BV/h. After treated with AL-2 resin, the LU content in the product was increased 19.8-fold from 0.129% to 2.55%, with a recovery yield of 78.54%. The results showed that AL-2 resin revealed a good ability to separate LU. Therefore, we conclude that results in this study may provide scientific references for the large-scale LU production from pigeonpea or other plants extracts.     

Enrichment of total steroidal saponins from the extracts of Trillium tschonoskii Maxim by macroporous resin and the simultaneous determination of eight steroidal saponins in the final product by HPLC

An effective and simple method was established for the separation and enrichment of steroidal saponins from Trillium tschonoskii Maxim. The adsorption and desorption properties of seven macroporous resins were investigated. Among the tested resins, AB‐8 resin showed the best adsorption and desorption capacities. The adsorption of steroidal saponins on AB‐8 at 25°C was quite consistent with both the Freundlich isotherm model and the pseudo‐second‐order kinetics model. By optimizing the dynamic adsorption and desorption parameters, the content of steroidal saponins increased from 5.20% in the crude extracts to 51.93% in the final product, with a recovery yield of 86.67%. Furthermore, by scale‐up separation, the concentration and recovery of total steroidal saponins were 43.8 and 85.5%, respectively, which suggested that AB‐8 resin had great industrial and pharmaceutical potential because of its high efficiency and cost‐effectiveness. In addition, a high‐performance liquid chromatography method for the simultaneous determination of eight steroidal saponins was established for the first time, which was employed to qualitatively and quantitatively analyze the final product. Based on the methodological validation results, the high‐performance liquid chromatography method can be widely applied to the quality control of steroidal saponins from Trillium tschonoskii Maxim due to its excellent accuracy, stability, and repeatability.     

大孔吸附树脂分离纯化异甘草素的研究

研究大孔吸附树脂分离纯化异甘草素的工艺条件及参数。通过研究HPD-600、D4020、D101、AB-8、NKA-II、AL-2和NKA-9树脂对异甘草素的吸附和解吸附能力,筛选最佳树脂为AB-8,并研究了其对异甘草素的吸附和解吸附性能,确定了最佳的吸附与解吸附工艺参数,吸附:pH=5,室温,流速1.5BV/h,溶液处理量为5BV;脱附:洗脱剂为70%的乙醇溶液,流速1BV/h,洗脱剂用量4.5BV。异甘草素样品溶液经AB-8树脂吸附与脱附后回收率为76.7%,纯度由2.02%提高到29.1%,提高了14.4倍。实验结果表明,AB-8树脂对异甘草素的吸附量大,脱附容易,可以应用于异甘草素的分离纯化。     

Ultrasound‐assisted extraction and preliminary purification of proanthocyanidins and chlorogenic acid from almond (Prunus dulcis) skin

An aqueous solution of polyethylene glycol (PEG) as a green solvent was employed for the first time to develop the ultrasound‐assisted extraction of proanthocyanidins (PA) and chlorogenic acid (CA) from almond skin. The optimized extraction parameters were determined based on response surface methodology, and corresponded to an ultrasound power of 120 W, a liquid‐to‐solid ratio of 20:1 (mL/g), and a PEG concentration of 50% (v/v). Under these optimized conditions, the extraction yields of PAs and CA from almond skin were 32.68 ± 0.22 and 16.01 ± 0.19 mg/g, respectively. Compared with organic solvent extraction, PEG solution extraction produced higher yields. Different macroporous resins were compared for their performance in purifying PAs and CA from almond skin extract. Static adsorption/desorption experimental results demonstrated that AB‐8 resin exhibits excellent purification performance at pH 4. Under the optimized dynamic adsorption/desorption conditions on the AB‐8 column, the total recovery of purification for PAs and CA was 80.67%. The total content of PAs and CA in the preliminarily purified extract was 89.17% (with respective contents of 60.90 and 28.27%).     

大孔吸附树脂分离提取多杀菌素

采用大孔吸附树脂法分离提取多杀菌素.从11种大孔吸附树脂中筛选出DM11进行了静态、动态吸附性能实验,并考察了不同吸附、解吸条件的影响.结果表明,DM11的静态吸附容量为25.63mg/g(wet resin),其吸附等温线符合Langmuir吸附等温式.采用丙酮做洗脱剂,洗脱率为97.5%,动态吸附最佳吸附pH为9.5,吸附流速为6BV/h,穿透吸附容量为21.2mg/ml(wet resin),洗脱流速1.5BV/h.     

Separation and purification of both tea seed polysaccharide and saponin from camellia cake extract using macroporous resin

A novel method to separate and purify tea seed polysaccharide and tea seed saponin from camellia cake extract by macroporous resin was developed. Among four kinds of resins (AB‐8, NKA‐9, XDA‐6, and D4020) tested, AB‐8 macroporous resin possessed optimal separating capacity for the two substances and thus was selected for the separation, in which deionized water was used to elute tea seed polysaccharide, 0.25% NaOH solution to remove the undesired pigments, and 90% ethanol to elute tea seed saponin. Further dynamic adsorption/desorption experiments on AB‐8 resin‐based column chromatography were conducted to obtain the optimal parameters. Under optimal dynamic adsorption and desorption conditions, 18.7 and 11.8% yield of tea seed polysaccharide and tea seed saponin were obtained with purities of 89.2 and 96.0%, respectively. The developed method provides a potential approach for the large‐scale production of tea seed polysaccharide and tea seed saponin from camellia cake.     

大孔吸附树脂富集板蓝根中(R,S)-告依春工艺研究

采用静态吸附法考察了D101、AB-8、NKA-2、NKA-9、HPD 100、HPD600等6种大孔吸附树脂对(R,S)-告依春的吸附及解吸性能,筛选出效果最佳的AB-8树脂,并对其进行动态考察.最佳富集条件为:上样液pH 6,生药质量-体积浓度为0.200g/mL,解吸液为2BV量70％乙醇,在优化条件下(R,S)-告依春在浸膏中含量可从0.76％提高到12.48％.结果表明,AB-8型大孔吸附树脂可用来从板蓝根水提取液中富集(R,S)-告依春.     

Enrichment and purification of deoxyschizandrin and γ-schizandrin from the extract of Schisandra chinensis fruit by macroporous resins

In present study, the performance and separation characteristics of 21 macroporous resins for the enrichment and purification of deoxyschizandrin and γ-schizandrin, the two major lignans from Schisandra chinensis extracts, were evaluated. According to our results, HPD5000, which adsorbs by the molecular tiers model, was the best macroporous resin, offering higher adsorption and desorption capacities and higher adsorption speed for deoxyschizandrin and γ-schizandrin than other resins. Columns packed with HPD5000 resin were used to perform dynamic adsorption and desorption tests to optimize the technical parameters of the separation process. The results showed that the best adsorption time is 4 h, the rate of adsorption is 0.85 mL/min (4 BV/h) and the rate of desorption is 0.43 mL/min (2 BV/h). After elution with 90% ethanol, the purity of deoxy-schizandrin increased 12.62-fold from 0.37% to 4.67%, the purity of γ-schizandrin increased 15.8-fold from 0.65% to 10.27%, and the recovery rate was more than 80%.     

A simple and efficient protocol for large‐scale preparation of three flavonoids from the flower of Daphne genkwa by combination of macroporous resin and counter‐current chromatography

In this paper, macroporous resin column chromatography and counter‐current chromatography (CCC) were applied for large‐scale preparative separation of three flavonoids from the flower of Daphne genkwa, a famous Chinese medicinal herb. Nine kinds of resins were investigated by adsorption and desorption tests and D101 macroporous resin was selected for the first cleaning‐up, in which 40% aqueous ethanol was used to remove the undesired constituents and 90% aqueous ethanol was used to elute the targets. The crude extract after the first step was directly subjected to the preparative CCC purification using the solvent system composed of n‐hexane–ethyl acetate–methanol–water (4:5:4:5, v/v). The compounds apigemin (823 mg), 3‐hydroxyl‐genkwanin (842 mg) and genkwanin (998 mg) with the purities of 98.79, 97.71 and 93.53%, respectively, determined by HPLC were produced from 3‐g crude extract only in one CCC run. Their chemical structures were identified by MS, UV and the standards.     

Purification of spinosin from Ziziphi Spinosae Semen using macroporous resins followed by preparative high‐performance liquid chromatography

As a well‐known traditional Chinese medicine, Ziziphi Spinosae Semen has been used for treating anxiety and insomnia for a long time. Spinosin, the main active C‐glycoside flavonoid in Ziziphi Spinosae Semen, has attracted much attention because of its many pharmacological activities including strong hypnotic effects, anxiolytic‐like effects, and so on. In the present work, high‐purity spinosin was separated from Ziziphi Spinosae Semen using the HPD‐300 resin followed by preparative high‐performance liquid chromatography. The adsorption kinetics curve of spinosin on the HPD‐300 resin was studied and fitted well by the pseudo‐second‐order equation. The adsorption isotherms were also constructed and low temperature favored the adsorption reaction. The separation parameters were optimized using dynamic adsorption and desorption tests. After a one‐run treatment with HPD‐300 resin, the concentration of spinosin increased 11.8‐fold from 0.99 to 11.7% with a recovery yield of 80.4%. Furthermore, the purity of spinosin could surpass above 98% after separation by preparative high‐performance liquid chromatography and recrystallization with a recovery yield of 72.6%. The developed method was effective and suitable for the large‐scale preparation of spinosin. Moreover, it was confirmed that HPD‐300 resin could enable good selection for the enrichment of flavonoids from different plants.     

Preliminary extraction of tannins by 1‐butyl‐3‐methylimidazole bromide and its subsequent removal from Galla chinensis extract using macroporous resins

In recent years, ionic liquids have become increasingly attractive as ‘green solvents’ used in the extraction of bioactive compounds from natural plant. However, the separation of ionic liquid from the target compounds was difficult, due to their low vapour pressure and high stabilities. In our study, ionic liquid‐based ultrasonic and microwave‐assisted extraction was used to obtain the crude tannins, then the macroporous resin adsorption technology was further employed to purify the tannins and remove the ionic liquid from crude extract. The results showed that XDA‐6 had higher separation efficiency than other tested resins, and the equilibrium experimental data were well fitted to Langmuir isotherms. Dynamic adsorption and desorption were performed on XDA‐6 packed in glass columns to optimise the separation process. The optimum conditions as follows: the ratio of column height to diameter bed was 1:8, flow rate 1 BV/h (bed volume per hour), 85% ethanol was used as eluant while the elution volume was 2 BV. Under the optimised conditions, the adsorption and desoption rate of tannins in XDA‐6 were 94.81 and 91.63%, respectively. The content of tannins was increased from 70.24% in Galla chinensis extract to 85.12% with a recovery of 99.06%. The result of ultra‐performance liquid chromatography (UPLC)‐MS/MS analysis showed that [bmim]Br could be removed from extract.     

Separation of isorhamnetin 3‐sulphate and astragalin from Flaveria bidentis (L.) Kuntze using macroporous resin and followed by high‐speed countercurrent chromatography

D4020 resin offered the best dynamic adsorption and desorption capacity for total flavonoids based on the research results from ten kinds of macroporous resin. A column packed with D4020 resin was used to optimize the separation of total flavonoids from Flaveria bidentis (L.) Kuntze extracts. The content of flavonoids in the product was increased from 4.3 to 30.1% with a recovery yield of 90%. After the treatment with gradient elution on D4020 resin, the contents of isorhamnetin 3‐sulfate and astragalin were increased from 0.49 to 8.70% with a recovery yield of 74.1% and 1.16 to 30.8%, with a recovery yield of 92.2%, respectively. Further purification was carried out by one‐run high‐speed countercurrent chromatography yielding 4.5 mg of isorhamnetin 3‐sulfate at a high purity of 96.48% and yielding 24.4 mg of astragalin at a high purity of over 98.46%.     

大孔树脂-高速逆流色谱分离纯化薇甘菊中的黄酮类化合物

该文建立了大孔树脂-高速逆流色谱分离薇甘菊中黄酮类物质的方法。分离条件为:采用大孔树脂AB-8,洗脱液为50%（v/v）乙醇水溶液,高速逆流色谱溶剂体系为正丁醇-乙酸-水（4：1：5,v/v）。从薇甘菊中分离到4种黄酮类物质:槲皮素-3-O-芸香糖苷（纯度90.2%）、山奈酚-3-O-芸香糖苷（纯度98.55%）、木犀草苷（纯度98.33%）和紫云英苷（纯度99.23%）。建立的大孔树脂-高速逆流色谱方法简单、高效,可扩展应用于从其他植物中分离黄酮类物质。     

Separation of flavonoid and alkaloid using collagen fiber adsorbent

Flavonoids and alkaloids are two major classes of plant compounds with biological activities, and they usually coexist in many medicinal herbs. In this study, a novel collagen fiber adsorbent (CFA) was prepared, and its application for adsorption chromatography separation of flavonoids and alkaloids was systematically investigated. The typical flavonoids, rutin and baicalin, and the typical alkaloids, matrine and caffeine, were selected as probe molecules for the investigations. The batch adsorption behaviors of these compounds on CFA in different solvents indicated that hydrogen bond plays a predominant role for the adsorption of flavonoid and alkaloid in pure ethanol, while the hydrophobic interaction plays a predominant role for the adsorption in water. In column chromatography separation, flavonoids were completely separated from alkaloids by a stepwise elution process with pure ethanol followed by aqueous ethanol solution. The two flavonoids, rutin and baicalin, were also well separated although the two alkaloids, matrine and caffeine, were washed out together. The optimal loading volume of sample solution (10 mg/mL) for the separation was determined as 0.66 mL/g CFA. Under these conditions, flavonoid and alkaloid were effectively separated with a recovery higher than 90% in 8 times repeated applications.