Optimization of pressurized liquid extraction for Z-ligustilide, Z-butylidenephthalide and ferulic acid in Angelica sinensis

Pressurized liquid extraction, one of the most promising and recent sample preparation techniques, offers the advantages of reducing solvent consumption and allowing for automated sample handling. It is being exploited in diverse areas because of its distinct advantages. However, because the extraction is performed at elevated temperatures using PLE, thermal degradation could be a concern. Z-ligustilide, one of the biologically active components in Angelica sinensis, is an unstable compound, which decomposes rapidly at high temperature. In this study, we carried out a comparative study to evaluate PLE as a possible alternative to current extraction methods like Soxhlet and sonication for simultaneous extraction of Z-ligustilide, Z-butylidenephthalide and ferulic acid in A. sinensis. The operating parameters for PLE including extraction solvent, particle size, pressure, temperature, static extraction time, flush volume and numbers of extraction were optimized by using univariate approach coupled with central composite design (CCD) in order to obtain the highest extraction efficiency. Determination of Z-ligustilide, Z-butylidenephthalide and ferulic acid were carried out by means of high performance liquid chromatography with diode-array detector. The results showed that PLE was a simple, high efficient and automated method with lower solvent consumption compared to conventional extraction methods such as Soxhlet and sonication. PLE could be used for simultaneous extraction of Z-ligustilide, Z-butylidenephthalide and ferulic acid in A. sinensis.     

Quantitative determination of penicillin V and amoxicillin in feed samples by pressurised liquid extraction and liquid chromatography with ultraviolet detection

A rapid and simple method is proposed for the routine determination of amoxicillin (AMOX) and penicillin V (PENV) in swine feedingstuffs. The method is based on pressurised liquid extraction (PLE) followed by high performance liquid chromatography with ultraviolet detection (PLE–HPLC–UV) for antibiotic analysis. Parameters affecting PLE procedure, such as temperature, solvent composition, number of extraction cycles and sample cell size, were evaluated in order to achieve the highest extraction efficiency. The optimised method employed 11 mL extraction cells, acetonitrile–water mixtures (25:75, v/v) for AMOX and (50:50, v/v) for PENV, as extraction solvent, 102.07 atm of extraction pressure, 50 °C of extraction temperature, 5 min of static time and 60% flush volume of the cell size. Extracts were filtered and directly analysed by HPLC–DAD/UV without further clean-up. Mean recovery rates for feed samples fortified with 200–500 mg kg⁻¹ of both antibiotics were 86% for AMOX (RSD ≤ 6%) and 95% for PENV (RSD ≤ 3%). The method was successfully applied to the analysis of a commercial medicated swine feedingstuff, and the results were in good agreement with those obtained using mechanical shaking or ultrasonic extraction combined with solid phase extraction (UE-SPE), previously applied in the literature for feed analysis. The extraction efficiencies were evaluated by statistical comparison (analysis of variance, ANOVA-single factor) of the results obtained using the different extraction methods. Compared to the alternative techniques, PLE offers several practical advantages: easy to perform, fast, savings in solvent volume and in time, all steps are fully automated and further clean-up is not necessary for penicillin analysis.     

压力液体提取乐脉颗粒处方中的多种活性成分

目的建立乐脉颗粒的压力液体提取方法。方法采用HPLC法,以处方中6个主要生物活性成分的提取总量为指标,优化提取条件。结果优化的压力液体提取条件为:以水为溶剂,样品粒径为0.15～0.18 mm,按11∶0.75(mL∶g)的溶剂样品比,温度140℃、压力5 MPa,提取1次,提取时间5 min;6个活性成分的总提取率比药典方法高30.6%。结论压力液体提取法提取时间短、溶剂和能耗低,活性成分的产率大大提高,有望成为传统中成药生产的新技术。     

分心木中总黄酮的提取工艺考察

目的：考察分心木中总黄酮的最佳提取工艺。方法：利用超声波法对分心木中总黄酮的提取工艺进行研究,在单因素试验的基础上,采用正交试验法,确立最佳提取条件,考察乙醇浓度、提取温度、液料比和提取时间对提取物中分心木总黄酮含量的影响。结果：超声波法辅助提取分心木中总黄酮的最适工艺参数是浸提剂乙醇浓度为50％,提取温度为50℃,液料比为20：1．提取时间为30min,总黄酮含量可达4．745％。结论：超声法对分心木总黄酮的提取简单易行,产率较好。     

超临界流体萃取法测定川芎中藁本内酯含量的研究

系统研究了压力、温度、静态萃取时间、动态萃取量、改性剂加入量等因素对超临界流体萃取(SFE)中药川芎中藁本内酯的影响,确定最佳萃取条件为:压力27.6MPa,温度40℃,静态萃取时间3min,动态萃取量7ml,改性剂加入量0.1ml。并对超临界流体萃取的收集方法作了研究,发现固液收集法在收集效率和精密度方面比溶剂收集法效果好。并用离线的SFE RPHPLC对川芎药材中藁本内酯的含量进行了测定。     

PLE in the analysis of plant compounds. Part I. The application of PLE for HPLC analysis of caffeine in green tea leaves

A broad spectrum of sample preparation methods is currently used for the isolation of pharmacologically active compounds from plant and herbal materials. The paper compares the effectiveness of infusion, microwave assisted solvent extraction (MASE), matrix solid-phase dispersion (MSPD) and pressurised liquid extraction (PLE) as sample preparation methods for the isolation of caffeine from green tea leaves. The effect of PLE variables, such as extraction temperature, pressure and time, on the yield of caffeine from the investigated matrix is discussed.

The obtained results revealed that PLE, in comparison with other sample preparation methods applied, has significantly lower efficacy for caffeine isolation from green tea leaves. The evaluation of PLE conditions leads to the conclusion that elevated pressure applied in the PLE process is the factor hindering the extraction.     

超声提取裙带菜中岩藻黄素的工艺研究

目的运用超声提取法对裙带菜Undaria pinnatifida中岩藻黄素的提取工艺进行研究。方法以HPLC法检测岩藻黄素的量,通过单因素实验考察了提取溶剂、乙醇体积分数、提取时间、提取液料比、提取温度对岩藻黄素提取率的影响;并用正交试验得到超声波法提取岩藻黄素的最佳工艺。结果超声提取的最佳工艺是：乙醇体积分数为90%,超声时间为30min,提取温度为40℃,液料比10∶1。此条件下测得岩藻黄素的提取量为1.362mg/g。结论裙带菜中岩藻黄素的含量丰富,超声法提取岩藻黄素操作简单、方便快捷。     

Pressurized liquid extraction of toxins from cyanobacterial cells

The suitability of pressurized liquid extraction (PLE) of cyanotoxins from cells was investigated. The stability of cyanotoxins (MCYST-RR, MCYST-LR, and anatoxin-a) was evaluated at nine combinations of pressure and temperature (7, 10, and 14 MPa and 60 degrees C, 80 degrees C and 100 degrees C) using 75% (v/v) methanol in water (MeOH) as solvent. Additional experiments investigated the stability of cyanotoxins when water was used as solvent (at a pressure of 14 MPa and a temperature of 40 degrees C, 50 degrees C, 60 degrees C, 80 degrees C, or 100 degrees C). Results using 75% MeOH showed that the MCYST-RR and MCYST-LR were stable under the tested pressures up to 80 degrees C. At 100 degrees C MCYST recovery decreased by 10% to 17%. When water was used as the solvent, no differences in recovery were observed for MCYST-LR, whereas for MCYST-RR, maximum recovery was obtained at 60 degrees C, and degradation occurred at 100 degrees C. In contrast, anatoxin-a was labile under all experimental conditions; the best recoveries (ca. 50%) were obtained at 60 degrees C at the three pressures using 75% MeOH. However, only 17%-23% recovery was obtained with water extraction at all temperatures. The extraction of MCYST-LR and variants from cells (Microcystis aeruginosa, UTCC299) was studied using two solvents, 75% MeOH and 100% water, at 14 MPa and 60 degrees C and 100 degrees C. PLE extracts were compared with extracts obtained with 75% MeOH and ultrasonication. Complete extraction was achieved in both solvents in one 5-min cycle (at 100 degrees C). Although lower recovery was obtained using PLE (79%-105%), shorter extraction time and automation are advantageous over ultrasonication.     

加压溶剂提取-高效液相色谱法测定天然和人工虫草中的麦角甾醇、核苷及其碱基

目的建立同时测定虫草中麦角甾醇、核苷及其碱基含量的简便方法。方法正交法优化加压溶剂提取条件；HPLC法同时测定天然和人工虫草中上述成分的含量。结果以甲醇为提取溶剂，提取温度160 ℃，提取时间5 min，提取压力10 MPa，循环1次，提取1次。采用Zorbax NH₂分析柱(250 mm×4.6 mm ID, 5 μm)，流动相为A(乙腈)-B(10 mmol·L^-1醋酸铵溶液)二元梯度洗脱：0-5.0 min，B%为0→15%；5.0-25.0 min，B%为15%→20%；25.0-35.0 min，B%为20%→ 40%；35.0-45.0 min，B%为40%→ 80%；45.0-50.0 min，B%为80%。结论本法能够快速、简便地测定虫草中麦角甾醇、核苷及其碱基的含量。     

亚临界水提取法提取黄连中的4种生物碱

目的 建立黄连中小檗碱、巴马汀、黄连碱和药根碱4种生物碱的亚临界水提取方法.方法 分别考察了提取温度、时间和溶剂样品比以及提取次数对提取量的影响,并与有机溶剂提取法进行比较.结果 4种生物碱的亚临界水提取法的最佳条件为:溶剂样品比0.08 ml·mg-1、提取温度140℃、5 MPa提取两次,每次5 min,提取回收率大于97.7%(n=3).结论 亚临界水提取法较传统溶剂提取法,提取时间缩短,避免了使用有机溶剂造成的污染,可用于黄连生物碱的工业化提取.     

Pressurized liquid extraction of phenolic compounds from Anatolia propolis and their radical scavenging capacities

Propolis samples from important honey producing locations of Anatolia namely; Bingol (BG), Rize (RZ), Tekirdag (TK) and Van (VN), were evaluated for their antiradical capacities, total phenolic contents and individual phenolic compounds which was recovered by means of pressurized liquid extraction (PLE). Several extraction parameters of PLE such as; temperature, pressure, solvent type, extraction time and cell size were investigated for their effects on the extraction performances. The results showed that, 40 °C, 1500 psi, Ethanol:water:HCl; (70:25:5, v/v/v) containing 0.1% tert-butylhydroquinone (tBHQ) as solvent, three extraction cycles within 15 min, and a cell size of 11 mL was the most favorable PLE operating conditions. Results of the tests performed to designate the success of the polyphenol analysis showed that the recovery was in the range of 97.2% and 99.7%.Major phenolic compounds in all samples were found to be gallocatechin (GCT), catechin (CT), epicatechin gallate (ECTG), caffeic acid (CA), chlorogenic acid (ChA), and myricetin (Myr). ChA level of BG propolis was 4.5, 3 and 23 times higher than that of RZ, TK and VN region, respectively. Antiradical tests showed that all propolis samples have superior antiradical capacities up to 500 mg Trolox equivalent activity per gram of extract.     

Simultaneous determination of salidroside and tyrosol in extracts of Rhodiola L. by microwave assisted extraction and high-performance liquid chromatography

Rhodiola L. has a long history of use in traditional Chinese medicine (TCM) and has shown great promise in recent clinical trials. Salidroside and tyrosol are two important active compounds present in this TCM. In this work, microwave-assisted extraction (MAE) followed by high performance liquid chromatography (HPLC) with a photodiode array detector (DAD) was developed for quantitative analysis of salidroside and tyrosol in Rhodiola L. samples. After systematical investigation, the optimal experimental parameters of soak time (60 min), extraction solvent volume (1g sample, 5 mL), extract solvent composition (50% methanol/water), microwave power (400 W) and extraction time (5 min) were investigated. The optimized method provided satisfactory precision (R.S.D. values less than 7.5%), good recovery (from 94.4 to 123%), and good linear relation in the range of 5.0-500 microg/mL for salidroside and 1.0-100 microg/mL for tyrosol (R2>0.999). The proposed method was applied to quantitative analysis of salidroside and tyrosol in Rhodiola L. samples from five different growing areas. To demonstrate the method feasibility, recirculation was also used to analyze salidroside and tyrosol in Rhodiola L. samples. The proposed MAE-HPLC-DAD is a simple, rapid and low-cost method for quantitative analysis of salidroside and tyrosol, and a potential tool for quality assessment of Rhodiola L. sample.     

响应面法优化CO2超临界萃取紫花地丁总黄酮的工艺研究

目的采用C02超临界萃取技术,优化从紫花地丁中萃取总黄酮的工艺条件。方法采用紫外可见分光光度法测定总黄酮含量,以总黄酮萃取率为指标,通过响应面法考察工艺条件。结果最佳工艺条件为：萃取压力35MPa、萃取温度54℃、夹带剂流速0．48mL·min^-1,乙醇浓度80％,萃取时间120min,实际总黄酮萃取率为5．89％。对萃取率影响最大的因素是萃取压力和萃取温度。结论C02超临界流体萃取紫花地丁总黄酮得率高,溶剂用量少,工序简单可行。     

超临界流体萃取法毛细管气相色谱法分析牡丹皮及制剂中丹皮酚的含量

采用超临界流体萃取法(supercritical fluid extraction,SFE)提取中药牡丹皮及其成方制剂中丹皮酚,以氯仿作改性剂,在温度90℃,压力28MPa下,二氧化碳动态萃取体积3ml;静态萃取时间5min。此法简便快速,萃取完全。用大孔径毛细管柱气相色谱法作含量监测,结果:相关性好(γ=0.9999),中药与制剂的回收率分别为97.8%,RSD=2.35%(n=3);100.3%,RSD=1.89%(n=3)。为中药有效成分的提取和质量控制提供了一种有效可靠的方法。     

Are extraction methods in quantitative assays of pharmacopoeia monographs exhaustive? A comparison with pressurized liquid extraction

The extraction methods in selected monographs of the European and the Swiss Pharmacopoeia were compared to pressurized liquid extraction (PLE) with respect to the yield of constituents to be dosed in the quantitative assay for the respective herbal drugs. The study included five drugs, Belladonnae folium, Colae semen, Boldo folium, Tanaceti herba and Agni casti fructus. They were selected to cover different classes of compounds to be analyzed and different extraction methods to be used according to the monographs. Extraction protocols for PLE were optimized by varying the solvents and number of extraction cycles. In PLE, yields > 97 % of extractable analytes were typically achieved with two extraction cycles. For alkaloid-containing drugs, the addition of ammonia prior to extraction significantly increased the yield and reduced the number of extraction cycles required for exhaustive extraction. PLE was in all cases superior to the extraction protocol of the pharmacopoeia monographs (taken as 100 %), with differences ranging from 108 % in case of parthenolide in Tanaceti herba to 343 % in case of alkaloids in Boldo folium.     

正交试验优选朱砂根中朱砂根皂苷提取工艺

目的:优选朱砂根中朱砂根皂苷的提取工艺。方法:用反相高效液相色谱法测定朱砂根皂苷的含量;以朱砂根皂苷提取质量分数为评价指标,以乙醇体积分数、提取温度、提取时间和提取次数为考察因素,通过正交试验选取最佳提取工艺。结果:最佳提取工艺:80%乙醇为溶剂、提取温度80℃、提取时间20min、提取次数3次;朱砂根皂苷的提取质量分数为6.04%。结论:所选工艺可行、重现性好,可为大批量提取朱砂根皂苷提供理论依据。     

Optimization and comparison of three methods for extraction of volatile compounds from Cyperus rotundus evaluated by gas chromatography-mass spectrometry

The essential oil of Cyperus rotundus has multiple pharmacological activities. Therefore, the extraction with high yield and quality is very important for preparation of essential oil of C. rotundus. In this paper, three methods, namely hydrodistillation (HD), pressurized liquid extraction (PLE) and supercritical fluid extraction (SFE), for extraction of volatile compounds from C. rotundus were optimized and compared by gas chromatography-mass spectrometry. Among eight identified compounds in C. rotundus, five components including alpha-copaene, cyperene, beta-selinene, beta-cyperone and alpha-cyperone were quantitatively determined or estimated using alpha-cyperone as standard, which showed that PLE had the highest extraction efficiency, while SFE had the best selectivity for extraction of beta-cyperone and alpha-cyperone. The contents of ingredients from C. rotundus extracted with HD, PLE and SFE are significantly different, which suggest that comparison of chemical components and pharmacological activities of different extracts is helpful to elucidate the active components in C. rotundus and control its quality.     

Focused microwave-assisted extraction and LC determination of the active ingredient in naproxen-based suppositories

A simple and rapid open-vessel focused microwave-assisted extraction (FMAE) method followed by LC analysis was developed for the determination of naproxen in suppositories. Parameters which might affect the FMAE method, such as nature and volume of the extraction solvent, temperature and extraction time were optimized. The extraction solvent consisted of methanol/sodium hydrogen carbonate (pH 8.7; 0.1 M) (50:50, v/v). Extractions were performed by reaching the target temperature of 70 degrees C in a 7 min linear ramp and then maintaining the target temperature for 3 min. Chromatographic analysis was performed on a Discovery RP-Amide C16 column (250 mm x 4.6 mm i.d., 5 microm particle size). The mobile phase consisted of acetonitrile/potassium dihydrogenphosphate (pH 3.0; 25 mM) (40:60, v/v). The complete analytical procedure was validated with regard to limit of quantification, linearity, precision and accuracy. The advantages of the proposed method in comparison to conventional methods are decreased extraction time, reduced solvent consumption and no further sample clean-up steps required before liquid chromatographic analysis.     

超临界流体萃取法在中药材质量控制中的应用

用超临界流体萃取法(supercriticalfluidextraction,SFE)代替传统的溶剂萃取法对中药材马蓝(Strobilanthescusia)、菘蓝(Isatistinctoria)和蓼蓝(Polygonumtinctorium)中有效成分靛玉红(indirubin)的萃取条件进行了研究,并用微孔高效液相色谱法做了含量监测。结果证明:SFE省时、省力、经济、选择性可调的性能很强,与传统的溶剂萃取法相比,有独特的优点。     

中药刺五加中总皂苷的微波辅助提取方法研究

目的:建立中药刺五加中总皂苷微波辅助提取方法。方法:用微波辅助提取法提取中药刺五加中总皂苷。利用正交实验,考察了微波提取条件(包括溶剂、微波辐射时间、提取压力和料液比)对刺五加中总皂苷提取率的影响规律,优化了最佳提取条件。结果:在所选因素水平下,溶剂为70%乙醇、提取压力为700kPa、提取时间为10min、料液比为1:30时,刺五加中总皂苷提取效率最佳。与传统的索氏提取法进行了比较研究,微波辅助提取效率可提高34%。结论:微波辅助提取法提取中药刺五加中总皂苷,提取时间短,提取效率高。