离子液体辅助超声波法提取猫眼草中黄酮的研究

目的 优化离子液体辅助超声波法提取猫眼草中的黄酮工艺，为进一步提取猫眼草中的黄酮类化合物提供依据。方法 以离子液体为提取溶剂，辅助超声波法提取猫眼草中的黄酮。依次改变离子液体的种类、浓度，提取溶剂总体积与药材质量比，超声时间，超声温度。以总黄酮提取率为指标，确定单因素最佳条件，在单因素试验结果的基础上结合响应曲面设计优化最佳提取条件，再用HPLC测定山柰酚和金丝桃苷的含量探究不同离子液体对猫眼草中黄酮提取的变化规律。结果 最佳提取条件：离子液体种类为1-丁基-3-甲基咪唑溴盐、离子液体与醇的体积比为1∶6、提取溶剂总体积与药材质量比为50∶1、温度为40℃、超声时间为1h。在最佳条件下提取率为(15.8±0.9)%，相比传统提取率5.14%，提取率明显增加。结论 用离子液体法提取猫眼草植物黄酮可行。黄酮提取率与离子液体母核碳链长短不成正相关性。     

索氏提取法提取青蒿挥发油的研究

青蒿学名黄花蒿(ArtemisiaannuaL),属菊科春黄菊族蒿属。具有很高的药用价值。青蒿挥发油属于青蒿活性成分,具有抗菌、平喘、解热、止咳等药理作用。青蒿挥发油的提取方法主要有蒸馏法,溶剂提取法,压榨法,二氧化碳超临界流体提取法。本实验采用索氏提取法,以乙醚为溶剂,研究青蒿挥发油提取的优化条件是:料液比为1∶7.8,蒸馏时间为3h,青蒿挥发油得率最高。     

酶法提取苦豆草生物碱研究

目的在实验室酶法提取的基础上,优化苦豆草生物碱酶法提取小试工艺条件。方法以苦豆草生物碱的提取率为指标,在小试条件下优化提取次数、料液比、提取时间,并与传统提取法比较。结果酶法提取最佳的小试工艺条件为:酶解时间4h,溶剂pH=6,温度为50℃,加酶量为1∶1 000,酶解后,加入盐酸至浓度为4mL·L-1,料液比1∶16,提取2次,第1次2h,第2次1h。苦豆草生物碱的提取率达到2.17%结论实验室提取工艺与小试生产存在差异,经条件优化基本达到实验室提取生物碱的提取率。     

响应面法优化凤仙花中2种1,4-萘醌类的提取工艺及其抑菌活性研究

目的利用响应面法同时优化凤仙花中指甲花醌(HNQ)和指甲花甲醚(MeONQ)的提取工艺,并检测其抑菌活性。方法以凤仙花为原料,采用浸提法,选取提取溶剂、料液比和提取时间3个因素进行单因素考察,利用HPLC法测定含量;采用Design Expert 8.0.6软件进行Box-Behnken响应面设计,得到关于HNQ和MeONQ提取率的多元回归模拟方程和响应面图,提高HNQ和MeONQ的提取率,考察2种1,4-萘醌类成分的体外抑菌活性。结果凤仙花中HNQ和MeONQ的最佳提取工艺为:提取溶剂为体积分数为40%的乙醇,料液比为1∶24,提取时间为3.6 h,在此条件下HNQ和MeONQ的提取率最高,分别为7.611 1和2.378 5 mg·g~(-1);抑菌实验结果表明,HNQ和MeONQ对红色毛癣菌有一定的抑制作用。结论该方法便捷、操作简单、稳定、提取率高,2种1,4-萘醌类均有良好的抑菌活性。     

微波萃取-HPLC法快速分析牵牛子中的咖啡酸

目的 建立简便、快速分析牵牛子中咖啡酸的提取方法.方法 采用微波萃取-HPLC法,以甲醇为提取溶剂,在微波功率450 W、微波时间5 min、液固比为20∶1的条件下,快速提取牵牛子中的咖啡酸,并采用HPLC法测定其含量.结果 微波萃取法在5 min内即可完成咖啡酸的提取,大大缩短了样品的前处理时间,提取率比超声法提高66％、比索氏提取法提高42％,其平均回收率为98.4％,RSD=1.3％ (n =5),咖啡酸2.83 ～90.4 mg·L-1与峰面积的线性关系良好(r=0.9996).结论 所用方法简便、快速,提取率高,重复性好,结果准确,为牵牛子中咖啡酸成分的快速提取与分析提供了有效手段.     

水栒子果肉低聚原花青素的提取工艺研究

目的:以水栒子果肉为实验材料,利用离子液体微波辅助提取法提取水栒子果肉中低聚原花青素,并对提取条件进行优化.方法:分别考察离子液体种类及浓度、液料比、浸泡时间、微波辐射时间及功率、提取次数,对低聚原花青素提取率的影响.结果:优化后工艺条件如下:1.00mol/L[C4mim]Br作为提取溶剂,液料比20:1(mL/g)...     

罐组式逆流提取刺五加叶中抗氧化活性成分工艺研究

目的研究罐组式逆流提取刺五加叶中抗氧化活性成分的工艺。方法采用正交试验设计,以总黄酮、总酚含量及DPPH自由基(DPPH.)清除率的全概率值为评价指标,考察固液比、提取时间和提取温度对提取工艺的影响。结果最佳提取工艺条件为固液比为1∶16,提取时间为30 min,提取温度为80℃。结论罐组式逆流提取刺五加叶中抗氧化活性成分具有提取率高、节省溶剂用量等优点,具有较好的应用前景。     

内聚能密度结合响应面法优化酿后葡萄皮渣中原花青素的提取工艺

目的探索酿后葡萄皮渣中原花青素的最佳提取条件。方法基于内聚能密度确定提取溶剂,采用UV法测定原花青素的含量,并以其为考察指标,在单因素实验的基础上,利用响应面法优化原花青素的提取条件。结果优化的提取工艺以无水乙醇∶10mL·L~(-1)盐酸(95∶5)为提取溶剂,提取温度为60℃,提取时间为100min,料液比为1∶20,提取2次,原花青素平均含量为49.39mg·g~(-1)(n=3,RSD值为1.7%)。结论基于内聚能密度确定提取溶剂,结合响应面法优化原花青素的提取工艺合理可行,为高效提取原花青素提供了理论依据。     

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.     

正交优化柴胡地上部分总黄酮提取工艺及抑菌活性研究

目的 正交优化柴胡地上部分总黄酮提取工艺,并测定其抑菌活性。方法 以总黄酮提取率为指标,采用正交实验设计法,考察料液比、浸泡时间、提取时间、提取次数4个因素的提取最佳水平;以96孔板法对总黄酮进行4种细菌和4种真菌的抑菌活性测定。结果 柴胡地上部分总黄酮的提取工艺最佳条件为：固液比1∶10,浸泡时间60 min,提取时间72 min,提取次数3次。通过验证在此条件下柴胡地上部分总黄酮提取率可达2.702%;抑菌活性的测定结果表明柴胡地上部分总黄酮对供试的4种细菌和4真菌均有一定的抑菌活性。结论 该提取工艺简单可靠、合理可行,柴胡地上部分总黄酮具有一定的抑菌活性。     

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.     

Optimization of pressurized liquid extraction of five major flavanoids from Lysimachia clethroide

As an alternative of traditional extraction method, pressurized liquid extraction (PLE) was applied for five flavanoids extraction from Lysimachia clethroide. The operational parameters of PLE, such as extraction solvent, temperature, pressure, static extraction time, flush volume and cycles were optimized by univariate approach coupled with central composite design (CCD) in order to obtain the highest extraction efficiency. The optimized result employed 50% acetonitrile aqueous as extraction solvent, 100 degrees C of extraction temperature, 1500 psi of extraction pressure, 25 min of static time, 70% flush volume, and only one cycle to extract the target compounds completely. Finally, the contents of five major flavanoids in L. clethroides from different sources were determined simultaneously by the combination of the presented PLE and HPLC method.     

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.     

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.     

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.     

Microwave assisted extraction of curcumin by sample-solvent dual heating mechanism using Taguchi L9 orthogonal design

The present work reports on a novel extraction method using microwaves based on solvent-sample duo-heating synergism, for the extraction of curcumin from Curcuma longa L. The duo-heating mechanism is based on simultaneous heating of sample matrix and extracting solvent under microwave energy. Methanol soaked plant material was used as a modifier to bring about selective and effective heating of the sample under microwave. Acetone was used as the extracting solvent, which has excellent curcumin solubilizing capacity and heats up under microwave owing to its good dissipation factor. Extraction conditions, namely microwave power, irradiation time, particle size and modifier volume were optimized using Taguchi design approach and curcumin was quantified using high performance thin layer chromatography. The optimum conditions as obtained from signal-to-noise ratio analysis and interaction studies between factors were as follows: 20% microwave power, 4 min irradiation time, particles screened through sieve 20 and 8 ml of modifier. Microwave assisted extraction (MAE) under the influence of dual heating mechanism showed better precision and dramatically higher yield with significant reduction in extraction time under optimum extraction conditions, when compared to conventional approaches.     

中药山茱萸中马钱素的提取工艺研究

目的：探讨中药山茱萸中有效成分马钱素的提取工艺。方法：以提取温度、提取时间、溶剂用量作为参考因素,超声波提取工艺,采用L9（34）正交试验表进行工艺优化设计,马钱素含量采用高效液相色谱法进行测定（色谱柱：YWGC18（4.6mm×250mm,2.5μm）,流动相：甲醇：水=30∶70,检测波长为236nm,柱温：25℃,流量1.0mL/min）。结果：山茱萸中马钱素最佳提取工艺为提取温度为80℃,提取时间为105min,溶剂95%乙醇用量为50mL。该方法提取出的马钱素含量为14.25mg/g。结论：超声提取优化工艺后方法简便可行,得到的山茱萸中马钱素含量较高。     

Simultaneous determination of nine saponins from Panax notoginseng using HPLC and pressurized liquid extraction

A HPLC and pressurized liquid extraction (PLE) method was developed for simultaneous determination of nine saponins, including notoginsenoside R1, ginsenoside Rg1, Re, Rf, Rb1, Rc, Rb2, Rb3 and Rd in Panax notoginseng. The analysis was performed on C18 column with water-acetonitrile gradient elution and the investigated saponins were authenticated by comparing retention time and mass spectra with their reference compounds. Several methods including PLE, ultrasonication, soxhlet extraction and immersion were used for sample preparation and their extraction efficiency was compared. The results showed that PLE has the highest extraction efficiency and repeatability, which would be valuable on standardization of sample preparation for quality control of Chinese medicines. The developed HPLC and PLE is an effective approach for simultaneously quantitative determination of sapoinins in P. notoginseng, which could be used for quality control of P. notoginseng and its preparations.     

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.     

PLE in the analysis of plant compounds. Part II: One-cycle PLE in determining total amount of analyte in plant material

Pressurised liquid extraction (PLE) is recognised as one of the most effective sample preparation methods. Despite the enhanced extraction power of PLE, the full recovery of an analyte from plant material may require multiple extractions of the same sample. The presented investigations show the possibility of estimating the true concentration value of an analyte in plant material employing one-cycle PLE in which plant samples of different weight are used. The performed experiments show a linear dependence between the reciprocal value of the analyte amount (E*), extracted in single-step PLE from a plant matrix, and the ratio of plant material mass to extrahent volume (m_p/V_s). Hence, time-consuming multi-step PLE can be replaced by a few single-step PLEs performed at different (m_p/V_s) ratios. The concentrations of rutin in Sambucus nigra L. and caffeine in tea and coffee estimated by means of the tested procedure are almost the same as their concentrations estimated by multiple PLE.