Ionic Liquid-based Ultrasonic-assisted Extraction Research Articles

Ionic liquid-based ultrasonic-assisted extraction coupled with HPLC to analyze isoquercitrin, trifolin and afzelin in Amygdalus persica L. flowers

This study aimed to establish a method for the simultaneous determination of isoquercitrin, trifolin and afzelin in A. persica flowers by high performance liquid chromatography (HPLC) with ionic liquid as extractant and ultrasonic-assisted extraction. The effects of ionic liquid concentration, solid–liquid ratio, number of crushing mesh, ultrasonic time, extraction temperature, and ultrasonic power on the extraction yield of three target compounds were investigated using the extraction yield of target analytes as the index. According to the results of single factor experiment, the Box-Behnken design-response surface methodology (BBD) was used to optimize the extraction method and compared with the traditional extraction method. The results showed that, calibration curves had excellent linearity (R2 > 0.9990) within the test ranges. In combination with other validation data, this method demonstrated good reliability and sensitivity, and can be conveniently used for the quantification of isoquercitrin, trifolin and afzelinin A. persica flowers. And the contents of isoquercitrin, trifolin and afzelin were 64.08, 20.55 and 75.63 μg/g, respectively. The optimal process obtained by BBD was as follows: ionic liquid concentration was 1.0 mol/L, solid–liquid ratio was 1:40 g/ml, mesh sieve was 50 mesh, ultrasonic time was 40 min, extraction temperature was 50 °C, and ultrasonic power was 400 W. Under the optimal conditions, the theoretical predicted total extraction yield of the three target compounds was 159.77 μg/g, which was close to the actual extraction value (160.26 μg/g, n = 3), this result indicating that the optimal process parameters obtained by response surface methodology analysis were accurate and reliable. The method was simple, accurate and rapid for determination the contents of three active ingredients in A. persica flowers.

A Study of the Ionic Liquid-Based Ultrasonic-Assisted Extraction of Isoliquiritigenin from Glycyrrhiza uralensis.

We successfully extracted isoliquiritigenin from Glycyrrhiza uralensis through the utilization of an ionic liquid-based ultrasonic-assisted extraction (ILUAE) approach. Briefly, we utilized the solution of 1-butyl-3-methylimidazolium bromide ([BMIM]Br) as solvent and optimized key ILUAE parameters such as solid-liquid ratios, concentrations of ionic liquids, and the times of ultrasonication. Based on a single-factor experiment, we utilized the response surface method (RSM) approach to optimize the extraction procedure. The approach revealed that the optimal energy consumption time was 120 min, with the ultrasonic extraction temperature of 60°C. Using these optimized parameters together with the solid-liquid ratio (dried G. uralensis powder: [BMIM]Br of 0.3 mol/L) of 1 : 16.163 and the [BMIM]Br of 0.3 mol/L, we achieved a 0.665 mg/g extraction yield. Overall, these findings thus indicate that we were able to effectively use ILUAE as an efficient approach to reliably extract isoliquiritigenin in a reproducible and environmentally friendly manner.

Ionic liquid-based ultrasonic-assistedextraction model for solvent design

Ionic liquid is a favourable solvent in separation process due to the vast possibilities of ionic liquid structures. Many researches showed that ionic liquid extract higheramount of phytochemicals compared to conventional solvents. Even better, ionic liquid extraction coupled with ultrasonic-assisted extraction produced higher yield and less hassle. Therefore, ionic liquid can be considered as a suitable solvent for herbal extraction. This study is a part of a solvent design framework to obtain an extraction process model. It focuses on the process of ionic liquid-based ultrasonic-assisted extraction of flavonoid and phenolic acid from Labisiapumila. A two level, four factor of central composite design (CCD) was employed to determine the effect of the process factors towards yield of flavonoid and phenolic acid extracted from the herb. The process factors are the temperature (Celsius), extraction time (min), power (W) and type of ionic liquid (based on their dielectric point). The extracted samples were analysed to determine the yield of flavonoid and phenolic acid. Two models were developed for flavonoid and phenolic acid extraction based on the optimization results. The models are important as yield prediction in solvent process performance stage of the development of ionic liquid design framework.

Ionic Liquid-Based Ultrasonic-Assisted Extraction Coupled with HPLC and Artificial Neural Network Analysis for Ganoderma lucidum.

Ganoderma lucidum is widely used in traditional Chinese medicine (TCM). Ganoderic acid A and D are the main bioactive components with anticancer effects in G. lucidum. To obtain the maximum content of two compounds from G. lucidum, a novel extraction method, an ionic liquid-based ultrasonic-assisted method (ILUAE) was established. Ionic liquids (ILs) of different types and parameters, including the concentration of ILs, ultrasonic power, ultrasonic time, rotational speed, solid–liquid ratio, were optimized by the orthogonal experiment and variance analysis. Under these optimal conditions, the total extraction yield of the two compounds in G. lucidum was 3.31 mg/g, which is 36.21% higher than that of the traditional solvent extraction method. Subsequently, an artificial neural network (ANN) was developed to model the performance of the total extraction yield. The Levenberg–Marquardt back propagation algorithm with the sigmoid transfer function (logsig) at the hidden layer and a linear transfer function (purelin) at the output layer were used. Results showed that single hidden layer with 9 neurons presented the best values for the mean squared error (MSE) and the correlation coefficient (R), with respectively corresponding values of 0.09622 and 0.93332.

Efficient Extraction of Anti-Inflammatory Active Ingredients from Schefflera octophylla Leaves Using Ionic Liquid-Based Ultrasonic-Assisted Extraction Coupled with HPLC.

Schefflera octophylla (Lour.) Harms, a kind of traditional Chinese medicine (TCM), is commonly used for anti-inflammatory, analgesic, rheumatism, fever, and hemostasis therapy. In our previous studies, two major triterpenoids were isolated and identified from leaves of S. octophylla, and evaluated for their inhibitory effects on lipopolysaccharide (LPS)-induced nitric oxide production in RAW264.7 cells; both of them displayed significant anti-inflammatory activities at their noncytotoxic concentrations. Therefore, it is very useful to establish an efficient and green extraction method to isolated the two major triterpenoids from leaves of S. octophylla. In this paper, ionic liquid based ultrasonic-assisted extraction (ILUAE) was successfully applied to extract the two major triterpenoids from leaves of S. octophylla. Four single factors (ionic liquids (ILs) concentration, solid–liquid ratio, centrifugal speed, mesh number), with a greater impact on extraction rate, were selected from a variety of influencing factors, and the optimal conditions were obtained by Box–Behnken response surface methodology (RSM). Under optimal conditions, the total extraction yield and extraction rate of two triterpenoids were 288.03 mg/g and 28.80%, respectively, which was 6.80% higher than that of 70% Ethanol (220 mg/g and 22%, respectively).

Ionic Liquid-Based Ultrasonic-Assisted Extraction to Analyze Seven Compounds in Psoralea Fructus Coupled with HPLC.

Psoralea Fructus is widely used in traditional Chinese medicine (TCM), and the content of psoralen, isopsoralen, neobavaisoflavone, bavachin, psoralidin, isobavachalcone, and bavachinin A is the main quality control index of Psoralea Fructus because of its clinical effects. Thus, a fast and environmentally-benign extraction method of seven compounds in Psoralea Fructus is necessary. In this work, an ionic liquid-based ultrasonic-assisted method (ILUAE) for the extraction of seven compounds from Psoralea Fructus was proposed. Several ILs of different types and parameters, including the concentration of ILs, concentration of ethanol (EtOH), solid–liquid ratio, particle size, ultrasonic time, centrifugal speed, and ultrasonic power, were optimized by the Placket–Burman (PB) design and Box–Behnken response surface analysis. Under this optimal condition, the total extraction yield of the seven compounds in Psoralea Fructus was 18.90 mg/g, and significantly greater than the conventional 75% EtOH solvent extraction.

Two green approaches for extraction of dihydromyricetin from Chinese vine tea using β-Cyclodextrin-based and ionic liquid-based ultrasonic-assisted extraction methods

Dihydromyricetin (DMY) is the main flavonoid present in vine tea and is also known to possess various beneficial health effects. Extractions of DMY from vine tea were investigated by ultrasonic-assisted extraction (UAE) with β-Cyclodextrin (β-CD) and ionic liquid (IL), which were the two green extraction methods attracting more attentions in recent years. Single factor and response surface methodology (RSM) were used in order to optimize the extraction conditions for obtaining maximum amount of DMY in the two approaches. The results of HPLC analysis showed that the addition of β-CD or 1-hexyl-3-methylimidazolium bromide ([HMim] Br) to the water solution had excellent effects on the extraction of DMY. In β-CD-UAE, the optimum conditions were 3.6% β-CD, ultrasonic time 8 min, liquid–solid ratio of 33 (mL/g), and ultrasonic power 360 W. Molecular docking results indicated that the ‘host-guest’ effect between β-CD and the molecule of DMY in water solution, which utilized molecular recognition and interactions through non-covalent bonding and hydrogen bonding is the main driver of the binding. And for IL-UAE, the optimal conditions were 1.25 mol/L [HMim] Br, ultrasonic time 5.5 min, liquid–solid ratio of 45 (mL/g), and ultrasonic power 240 W. Under above suitable conditions, the extraction yield of DMY can reach to about 40%; moreover, β-CD-UAE and IL-UAE can be easily applied for experimental or industrial scale in food or functional food use.

Extraction and Separation of Eight Ginsenosides from Flower Buds of Panax Ginseng Using Aqueous Ionic Liquid-Based Ultrasonic-Assisted Extraction Coupled with an Aqueous Biphasic System.

Ionic liquids (ILs) are recognized as a possible replacement of traditional organic solvents, and ILs have been widely applied to extract various compounds. The present work aims to extract ginsenosides from Panax ginseng flower buds using aqueous ionic liquid based ultrasonic assisted extraction (IL-UAE). The extraction yields of 1-alkyl-3-methylimidazolium ionic liquids with different anions and alkyl chains were evaluated. The extraction parameters of eight ginsenosides were optimized by utilizing response surface methodology (RSM). The model demonstrated that a high yield of total ginsenosides could be obtained using IL-UAE, and the optimum extraction parameters were 0.23 M [C4mim][BF4], ultrasonic time of 23 min, temperature of extraction set to 30 °C, and liquid-solid ratio of 31:1. After that, an aqueous biphasic system (ABS) was used to separate ginsenosides further. The nature and concentration of salt, as well as the value of pH in ionic liquid were evaluated, and the optimal conditions (6.0 mL IL extract, 3 g NaH2PO4, and pH 5.0) were obtained. The preconcentration factor was 2.58, and extraction efficiency reached 64.53%. The results indicate that as a simple and efficient method, an IL-UAE-ABS can be considered as a promising method for extracting and separating the natural active compounds from medicinal herbs.

Determination of Lignans in Schisandra sphenanthera and Schisandra chinensis Using Ionic Liquid-based Ultrasonic-assisted Extraction and High-performance Liquid Chromatography

A green, rapid and precise sample pretreatment technique, IL-based UAE(ionic liquid-based ultrasonic-assisted extraction), was coupled with high-performance liquid chromatographic separation to identify the main effective components in Schisandra sphenanthera(S. sphenanthera) and Schisandra chinensis(S. chinensis) including schisantherin A, schisandrin A, and deoxyschizandrin. Four different types of ionic liquids have been investigated, finally [C6MIM][BF4] was used as the extraction solvent. A powder form of S. sphenanthera and S. chinensis was mixed with the [C6MIM][BF4] to produce a suspension. This suspension was ultrasonically extracted in a water bath at room temperature. Several of the process parameters were optimized, including the type of ionic liquid used and its volume, the sample amount, the size of the sample particle, the extraction time, etc. HPLC calibration curves were established for all the analytes and proved to be linear(r>0.9999). The lowest detection level for schisandrin A was 0.12 μg/mL, for schisantherin A was 0.08 μg/mL, and for deoxyschizandrin was 0.10 μg/mL. The recoveries of the target compounds were from 74.19% to 109.33%. The standard deviations for detection were generally no more than 6.31%. In contrast to conventional extraction methods, the IL-based UAE did not involve volatile organic volatile solvents, and the analysis time, required sample and solvent volumes were also lower than those of the conventional techniques.

Extraction and purification of isochlorogenic acid C from Chrysanthemum morifolium using ionic liquid-based ultrasound-assisted extraction and aqueous two-phase system.

Ionic liquid‐based ultrasonic‐assisted extraction (IL‐UAE) was developed to extract and separate the isochlorogenic acid C (ICGA) from a cultivar of Chrysanthemum morifolium (Chrysanthemummorifolium Ra Tnat.). The influencing parameters, including IL concentration, liquid‐to‐solid ratio, and ultrasonic time, were optimized using response surface methodology. Of the ILs studied, 1‐butyl‐3‐methylimidazolium bromide [(Bmim)Br] exhibited the best extraction ability. The optimized conditions included liquid‐to‐solid ratio of 23.44:1, ultrasonic time of 48.99 min, and IL concentration of 0.65 mol/L. Under the optimal conditions, the extraction yield of ICGA could reach to 4.20 mg/g. An aqueous two‐phase system was applied for purification and separation of ICGA. The maximum extraction efficiency of 98.18% was obtained under the conditions of (NH 4)2 SO 4 of 4.5 g, pH of 3.0, and a temperature of 20°C at aqueous solution. Furthermore, the thermodynamic parameters showed that the purification of ICGA from salt‐rich phase to IL‐rich phase was a spontaneous and exothermic process. The results indicated that the proposed system is simple, rapid, and effective to serve as a viable and sustainable platform for the extraction and purification of ICGA from Chrysanthemum morifolium flowers.

Application of Ionic Liquid-Based Ultrasonic-Assisted Extraction of Flavonoids from Bamboo Leaves.

Ionic liquids (ILs), known as environmentally benign “green” solvents, were developed as an optimal solvent for the green extraction and separation field. In this paper, an ionic liquid-based ultrasonic-assisted extraction (IL-UAE) of flavonoids (FVs) from bamboo leaves of Phyllostachys heterocycla was developed for the first time. First, 1-butyl-3-methylimidazolium bromide ([Bmim] Br), with the best extraction efficiency, was selected from fifteen ionic liquids with diverse structure, like carbon chains or anions. Then, the influencing parameters of ionic liquid (IL) concentration, liquid-solid ratio, ultrasonic time, and ultrasonic power, were investigated by single factor tests, and further optimized using response surface methodology (RSM). In the optimization experiment, the best conditions were 1.5 mol/L [BMIM]Br aqueous solution, liquid-solid ratio 41 mL/g, ultrasonic time 90 min, and ultrasonic power 300 W. Furthermore, the microstructures of bamboo leaves and the recovery of FVs and [BMIM]Br were also studied. Therefore, this simple, green and effective IL-UAE method has potentiality for the extraction of FVs from bamboo leaves for the large-scale operations.

A sequential separation of linderane and norisoboldine using supercritical fluid and ionic liquid-based ultrasonic-assisted extraction from Lindera aggregate

ABSTRACT Linderane (LDR) and norisoboldine (NOR) are two typical active compounds in Lindera aggregate (Sims.) Kosterm. In this study, a new method of sequential extraction of LDR and NOR from L. aggregate was developed by supercritical fluid extraction (SFE) and ionic liquid-based ultrasonic-assisted extraction (IL-UAE) for the first time. The suitable SFE with CO2 conditions for LDR were 60 min dynamic extraction time, 40°C temperature and 30 MPa pressure. And the optimal IL-UAE factors for NOR were 2.06 mol/L 1-butyl-3-methylimidazolium bromide ([Bmim] Br) aqueous solution, 44 mL/g liquid–solid ratio, and 67 min ultrasonic time. Compared with the traditional extraction process, the sequential methods not only can obtain higher extraction efficiency, but also can realize the selective extraction for two different kinds of constituents with less consumption of traditional organic solvent. In addition, this environmentally friendly method could be used in a large-scale industry.

Separation of the main flavonoids and essential oil from seabuckthorn leaves by ultrasonic/microwave-assisted simultaneous distillation extraction.

Volatile essential oils (EOs), non-volatile rutin (RU), quercetin (QU), kaempferol (KA) and isorhamnetin (IS) were effectively extracted and isolated from seabuckthorn (Hippophae rhamnoides L.) leaves by ionic liquid-based ultrasound/microwave-assisted simultaneous distillation extraction (ILUMASDE). After optimization by response surface methodology, EOs, RU, QU, KA and IS were separated under the following optimum conditions: an ionic liquid of 1.0 M 1-butyl-3-methyl imidazole bromine salt ([C4mim]), liquid/solid ratio of 12 ml g−1, extraction time of 34 min, microwave power of 540 W and a fixed ultrasonic power of 50 W. Under the optimized conditions of ILUMASDE, the extraction yields of RU, QU, KA, IS and EOs were 9.18 ± 0.35, 5.52 ± 0.23, 3.03 ± 0.11, 5.64 ± 0.24 mg g−1 and 0.095 ± 0.004%, respectively. The yield of EOs obtained using ILUMASDE was 1.07-fold higher than that obtained by conventional hydrodistillation extraction (HDE). In addition, the components of the EOs obtained using ILUMASDE and HDE were similar. The extraction yields of RU, QU, KA, IS obtained by ILUMASDE were 1.03–1.35-fold higher than that obtained by the ethanol ultrasonic-assisted extraction (EUAE), ionic liquid-based ultrasonic-assisted extraction (ILUAE) and ionic liquid-based microwave-assisted extraction (ILMAE). And the extraction time used by ILUMASDE was 34 min, which is 14.17%, 56.67%, 56.67% and 85.00% less than those used by HDE, EUAE, ILUAE and ILMAE, respectively. Therefore, ILUMASDE can be considered a rapid and efficient method for extracting flavonoids and EO from seabuckthorn (Hippophae rhamnoids L.) leaves.

Ionic Liquid-Based Ultrasonic-Assisted Extraction of Alkaloids from Cacao (Theobroma cacao)

Recent advances in the solid-liquid extraction have brought a large number of new techniques as ultrasonic assisted extraction (UAE). Different solvents such as alcohols, acetonitrile and chloroform are reported as extractors of added-value compounds. Ionic liquids (ILs) have been used the last few years as a non- conventional solvent for the extraction of alkaloids from natural sources. This work aims to extract efficiently alkaloids such as Caffeine (CF) and Theobromine (TB) from cacao, using protic ionic liquids (PILs) based onultrasonic assisted extraction (PIL-UAE). In order to optimize the extraction, a 23 factorial design was appliedusing three parameters (extraction time, ratio of mass/volume, solvent concentration). The extraction method was applied to cacao seeds, using 2-hydroxy ethylammonium acetate (2HEAA) as PIL. The results indicated that protic ionic liquids showed remarkable effects on the extraction yields of alkaloids. The main variable that influences the extraction process of the alkaloids is the solid / liquid ratio; however, the ultrasonic power has no effect.

Simultaneous extraction of hydrophobic and hydrophilic bioactive compounds from ginger (Zingiber officinale Roscoe)

Ginger is a commonly used spice around the world. Its bioactive compounds contain hydrophobic gingerols and hydrophilic polysaccharides. Huge physiochemical differences between these compounds and the thermal instability of gingerols impede fast and effective extraction of them using conventional methods. In this research, ionic liquid-based ultrasonic-assisted extraction (ILUAE) was applied to simultaneously extract gingerols and polysaccharides from ginger. Parameters influencing the recovery of gingerols were ionic liquid type, ionic liquid concentration, solid/liquid ratio, ultrasonic power, extraction temperature and extraction time. Compared with traditional methods, LUAE significantly increased the yield of total gingerols and shortened the extraction time. Meanwhile, ginger polysaccharides recovery reached up to 92.82% with ILUAE. Our results indicated that ILUAE has a remarkable capacity to extract gingerols and ginger polysaccharides in one step. Therefore, ILUAE represents a promising technology for simultaneous extraction of hydrophilic and hydrophobic bioactive compounds from plant materials.

Special Effect of Ionic Liquids on Extraction of Diosgenin from Fenugreek (Trigonella foenum-graecum L.) by Ultrasonic Assistance

An Ionic Liquid Based Ultrasonic Assisted Extraction (ILUAE) was developed for profitable extraction of diosgenin from fenugreek leaves. Imidazolium based ionic liquids (ILs) differing in their anions was used as catalytic agent for extraction procedure in order to optimize the diosgenin extraction. Five ionic liquids, concentration of ILs, reaction time and solid to liquid ratio were optimized on one at the time procedure. The particle size was considered the same for all experiments [BMIM]HSO4 was selected as the best IL and in the final optimized condition, the extraction efficiency increased from 0.77 to 10.24 (mg g-1dw) diosgenin. The method was also used to evaluate the concentration of diosgenin in different 13 accessions of Iranian fenugreek cultivated in the same place. The highest concentration of diosgenin with 20.2 and 20.1 (mg g-1dw) were found in the Khash and Qaen accessions, respectively. Accession of Mashhad showed the lowest concentration with 6.8 (mg g-1dw) diosgenin. After the reaction, the ILs from the media was also recovered using SPE column with more than 75% of yield. The result of this study showed that the optimized condition could extract the diosgenin almost five times more than the conventional method which could introduce fenugreek especially the best accession, as a new potential crop and source of diosgenin in the pharmaceutical industry

Investigating acidic ionic liquid-based ultrasonic-assisted extraction of leonurine from Herba Leonuri

ABSTRACTAn ultrasonic-assisted extraction (UAE) method based on the acidic ionic liquid (IL) of 1-methyl-3-H-imidazolium hydrogen sulfate ([HMIM][HSO4]) has been successfully developed to extract leonurine from Herba Leonuri. The results indicate that the acidity of the IL has remarkable effect on the extraction efficiency. In addition, several parameters affecting the extraction efficiency, such as ultrasonic power and time, concentration of IL and solid-liquid ratio, were also optimized. Using the proposed approach, the extraction efficiency of leonurine from Herba Leonuri powder reached 0.136‰ within 30 min using only 20 mL of 1 mol·L−1 [HMIM][HSO4] aqueous solution.

Simultaneous determination of brazilin and protosappanin B in Caesalpinia sappan by ionic-liquid dispersive liquid-phase microextraction method combined with HPLC

The conditions of heating, ionic liquid-based ultrasonic-assisted extraction combined with reverse-phase high performance liquid chromatography were optimized to simultaneously isolate and determinate brazilin and protosappanin B in Caesalpinia sappan. Ionic liquids, including [BMIM]Br, [BMIM]BF4, [BMIM]PF6 and [HMIM]PF6, were selected as extraction solvents while methanol, acetone, acetonitrile, ethanol and water were selected as dispersants. The chromatographic column was Purospher star RP-C18 (250 mm × 4.6 mm, 5 μm), a mixture of methanol and 0.2% phosphoric acid–water was used as mobile phase at a flow rate 0.65 mL/min. The result displayed that the extraction yields of brazilin and protosappanin B were highest when the concentration of [BMIM]Br methanol solution as extraction solvent was 0.5 mol/L and the solid–liquid ratio was 1:50 (g/mL). Under the optimal extraction conditions, the contents of brazilin showed a good linearity (r = 1.0000) within the range of 1.25–7.50 μg with the average recovery of 99.33%, the contents of protosappanin B also showed a good linearity (r = 0.9999) within the range of 0.50–3.00 μg with the average recovery of 98.31%. This experiment, which adopted environmentally friendly reagent as extraction solvent, not only improved the extraction efficiency, but also avoided the environmental pollution caused by organic solvent. Moreover, it was simple and reliable, and can be of important significance in the study of Traditional Chinese Medicine active ingredient extraction methods. The antibacterial activities of the ionic liquids and methanol extracts were determined using the paper disc diffusion method. The ionic liquid extract was found to possess antibacterial activity against Staphylococcus aureus and methicillin-resistant S. aureus (MIC value of 37.5 mg crude drug/mL), β-Lactamase producing S. aureus (MIC values of 18.8 mg crude drug/mL), but not against E. coli, Extended spectrum β-Lactamases E. coli and P. aeruginosa. Compared with the ionic liquid extract, the methanol extract was found to have antibacterial activity against S. aureus and methicillin-resistant S. aureus (MIC value of 75.0 mg crude drug/mL), β-Lactamase producing S. aureus (MIC values of 150.0 mg crude drug/mL). However, the same, the methanol extract did not have antibacterial activity against E. coli, Extended spectrum β-Lactamases E. coli and P. aeruginosa.

Application of ionic liquid-based ultrasonic-assisted extraction followed by rapid resolution LC-ESI/MS to chromone analysis from radix saposhnikoviae

Ionic liquid-based ultrasonic-assisted extraction (ILUAE) was successfully applied to the extraction of the four chromones (prim-O-glucosylcimifugin, cimifugin, 5-O-methylvisammioside, and sec-O-glucosylhamaudol) from Saposhnikovia divaricata (Radix Saposhnikoviae) for the first time. A series of l-alkyl-3-methylimidazolium ILs differing in anion and cation compositions was evaluated for extraction efficiency, and [C3MIM]Br was selected as the optimal solvent. In addition, ultrasound extraction parameters were optimized, and the chromones were directly quantified and analyzed by rapid resolution liquid chromatography-electrospray ionization/mass spectrometry (RRLC-ESI/MS). The optimal conditions were as follows: 0.4 M concentration of [C3MIM]Br, 20:1 solvent to solid ratio, and ultrasonic time, temperature, and frequency of 5 min, 40 °C, and 50 kHz, respectively. This approach obtained the highest extraction yield of 10.188 ± 0.473 mg g−1 for total chromones. Compared with regular UAE, the proposed approach exhibited a higher efficiency (61.56% increase) and shorter extraction time (nine times shorter). Also, ILUAE was an efficient, rapid, and simple sample preparation technique for extraction of chromones, and the established RRLC-DAD method could serve as a rapid and effective technique for extracting chromones from Radix Saposhnikoviae.

Ionic Liquid Based Ultrasonic-Assisted Extraction of Oleanolic Acid from Grape Seeds

Ionic liquid based ultrasonic-assisted extraction (ILUAE) was successfully applied to extract Oleanolic acid (OA) from grape seeds. Different kinds of 1-alkyl-3-methylimidazolium ionic liquids with different kinds of cations and anions were studied and 1-butyl-3-methylimidazolium chloride ([C4mim]Cl) solution was selected as extractants. The optimal conditions of ILUAE were determined by single factor experiments and Box-Behnken design as follows: [C4mim]Cl concentration of 0.7 mol/L, extraction time of 4 h, liquid-solid ratio of 15:1 mL/g, ultrasonic power of 195 W, the ultrasonication time of 13 min, and extraction temperature of 48℃·min. The extraction yield of OA was 13.4 mg/g, which is well in close agreement with the value predicted by the model. Compared with the regular ultrasonic-assisted extraction (UAE), the proposed approach exhibited 1.64 times higher efficiency, which indicated that ILUAE has a broad prospect for sample preparation of the bioactive compounds.