Application of response surface methodology to optimise ultrasonic-assisted extraction of four chromones in Radix Saposhnikoviae

Introduction – Radix Saposhnikoviae is one of the most famous Chinese herbal medicines with many pharmacological activities towards inflammatory symptoms and antioxidation. Chromones are considered as one of the effective components. It is important to find a reasonable method to extract the chromones in S. divaricata. Objective – To develop an ultrasonic‐assisted extraction (UAE) to extract chromones in Radix Saposhnikoviae and to optimise extraction conditions. Methodology – Four chromones (prim‐O‐glucosylcimifugin, cimifugin, 5‐O‐methylvisammioside and sec‐O‐glucosylhamaudol) were extracted by the UAE method combined with response surface methodology (RSM). Box–Behnken design (BBD) was applied to evaluate the effects of three independent variables (ethanol concentration, extraction time and extraction temperature) on the chromones yield of Radix Saposhnikoviae. Results – Correlation analysis of the mathematical‐regression model indicated that a quadratic polynomial model could be employed to optimise the extraction of chromones by UAE method. The optimal conditions to obtain the highest chromones yield of Radix Saposhnikoviae were a solvent of 75% ethanol, an extraction time of 48 min and an extraction temperature of 67°C. Conclusion – Under these optimal conditions, the experimental values agreed closely with the predicted values. The analysis of variance indicated a high goodness of model fit and the success of RSM method for optimising chromones extraction in Radix Saposhnikoviae. Copyright © 2011 John Wiley & Sons, Ltd.     

Optimisation of enzyme assisted extraction of silybin from the seeds of Silybum marianum by Box–Behnken experimental design

Introduction – Silybin, a standardised extract of flavanolignans from the seeds of Silybum marianum, has been used for centuries as a natural remedy in the treatment of hepatitis and cirrhosis. The higher yield of silybin by using more efficient extraction technique is of particular interest in the herbal products manufacture. Objective – To systematically investigate the important factors of enzyme‐assisted extraction of flavanolignans from the seeds of Silybum marianum to enhance the extraction yield of silybin. Methodology – The important factors of enzyme‐assisted extraction were optimised by employing Box–Behnken design with the aid of the orthogonal array design (OAD) OA₈ (2⁷). The effects of enzyme incubation temperature (EIT), the pH of enzyme solution (PES) and the size of seeds (SS) on the yield of silybin were visualised as three‐dimensional response surface and contour plots. Results – The predictive yield was 24.6 mg/g defatted seeds under the optimum enzymolysis conditions (EIT 40°C, PES 4.5 and SS 7003 μm). The coefficient of the model was r² > 0.97 (n = 15). The actual yield of silybin was 24.81 ± 1.93 mg/g defatted seeds, higher by 138 and 123.6% than that from ethanol extraction in this study and in the previous literature, respectively. IR spectra and HPLC of the extracts by EAE were in agreement with those from ethanol extraction. SEM and TEM pictures of defatted seeds by variant extractions demonstrate that the extraction of silybin depends on the destruction of cell walls. Conclusion – The results suggest that EAE is a promising alternative for the extraction of silybin by the use of traditional ethanol extraction. Copyright © 2009 John Wiley & Sons, Ltd.     

响应面优化超声辅助法提取拐枣种子中二氢杨梅素的工艺

二氢杨梅素和杨梅素是拐枣种子中的重要成分。通过超声辅助法从拐枣种子中提取二氢杨梅素，采用单因素法考察乙醇体积分数、超声辐照功率、提取温度、液料比和超声辐照时间影响参数的基础上，并选用Box-Behnken响应面设计法分析建立了超声辐照功率、超声辐照时间和液料比的二次多项式模型，优化提取工艺。结果得到超声辅助法提取拐枣种子中二氢杨梅素的最佳工艺参数为：乙醇体积分数为60%、超声辐照功率140 W、超声辐照时间30 min、液料比20.5 mL·g^-1，提取温度40℃。在此最佳条件下，二氢杨梅素得率为2.14±0.09 mg·g^-1。本提取方法简单快速，效率高，有利于拐枣资源的综合加工利用。     

超声波法提取野生石蒜中加兰他敏

石蒜是我国丰富的野生资源之一,其鳞茎富含重要药用成分加兰他敏。为了获得石蒜中加兰他敏的超声波提取方法,以野生石蒜为原料,用乙醇作提取剂,探讨了超声波提取加兰他敏的工艺条件,并与常规溶剂法进行了比较。分析了料液比、超声波功率、提取温度、提取时间、提取次数等因素对加兰他敏提取效果的影响,运用正交实验L9(34)确定了最佳提取工艺条件。结果显示,超声波提取加兰他敏的最佳工艺条件为:料液比1:6,超声波功率250 W,提取温度60℃,提取时间1.5 h,提取2次;加兰他敏的提取率为94.6%,产率为0.0543%;提取物中加兰他敏含量为15.53%。与常规溶剂法相比,超声波法具有用时少、提取率高、提取次数少等优点,整体效果优于常规溶剂法。     

Microwave‐assisted extraction of total bioactive saponin fraction from Gymnema sylvestre with reference to gymnemagenin: a potential biomarker

Objective – To develop a fast and ecofriendly microwave assisted extraction (MAE) technique for the effective and exhaustive extraction of gymnemagenin as an indicative biomarker for the quality control of Gymnema sylvestre. Methodology – Several extraction parameters such as microwave power, extraction time, solvent composition, pre‐leaching time, loading ratio and extraction cycle were studied for the determination of the optimum extraction condition. Scanning electron micrographs were obtained to elucidate the mechanism of extraction Results – The final optimum extraction conditions as obtained from the study were: 40% microwave power, 6 min irradiation time, 85% v/v methanol as the extraction solvent, 15 min pre‐leaching time and 25 : 1 (mL/g) as the solvent‐to‐material loading ratio. The proposed extraction technique produced a maximum yield of 4.3% w/w gymnemagenin in 6 min which was 1.3, 2.5 and 1.95 times more efficient than 6 h of heat reflux, 24 h of maceration and stirring extraction, respectively. A synergistic heat and mass transfer theory was also proposed to support the extraction mechanism Conclusion – Comparison with conventional extraction methods revealed that MAE could save considerable amounts of time and energy, whilst the reduction of volume of organic solvent consumed provides an ecofriendly feature. Copyright © 2009 John Wiley & Sons, Ltd.     

核桃楸叶片中总黄酮的最佳提取工艺研究

利用超声波法对核桃楸叶片中总黄酮的提取工艺进行了研究,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核桃楸叶片总黄酮提取率的影响。结果表明：超声波法辅助提取核桃楸叶片总黄酮的最适工艺参数是浸提剂乙醇浓度为70%,提取温度为50℃,液料比为20：1,提取时间为20 min,且总黄酮提取率可达4.458%。     

Microwave-assisted extraction of glycyrrhizic acid from licorice root

In the present study, a microwave-assisted extraction (MAE) technique has been developed for the extraction of glycyrrhizic acid (GA) from licorice root. Various experimental conditions, such as extraction time, different ethanol and ammonia concentration, liquid/solid ratios, pre-leaching time before MAE and material size for the MAE procedure were investigated to optimize the efficiency of the extraction. Under appropriate MAE conditions, such as extraction times of 4-5min, ethanol concentrations of 50-60% (v/v), ammonia concentrations of 1-2% (v/v) and liquid/solid ratios of 10:1(ml/g), the recovery of GA from licorice root with MAE was equivalent with conventional extraction methods. Those methods include extraction at room temperature (ERT), the traditional Soxhlet extraction, heat reflux extraction and ultrasonic extraction. Due to the considerable savings in time and solvent, MAE was more effective than the conventional methods. This novel method is suitable for fast extraction of GA from licorice root.     

Rapid screening of lignans from Phyllanthus myrtifolius and stilbenoids from Syagrus romanzoffiana by HPLC-SPE-NMR

Introduction – Application of on‐line solid‐phase extraction (SPE) as an interface between HPLC and NMR has gained great improvement in solving sensitivity problems and signal interferences by the eluents. Objective – Rapid analysis and characterisation by HPLC‐SPE‐NMR and LC/MS of the arylnaphthalene‐type lignans present in Phyllanthus myrtifolius and the minor stilbenoids present in the polyphenol‐rich fraction from the ethanol extract of the seeds of Syagrus romanzoffiana. Methodology – Pretreatment of fractions by liquid–liquid partitioning, followed by Sephadex LH‐20 fractionation, was found very useful to facilitate the focusing and analysis of the polyphenolic fraction. HPLC‐DAD‐SPE‐NMR (400 MHz and 600 MHz) analysis was carried out using an Agilent 1100 liquid chromatography, followed by a Prospekt 2 automated solid‐phase extraction unit, containing 96 HySphere‐Resin GP cartridges (10 × 2 mm, 10–12 µm), which was connected to a 120 or 60 µL LC probe. Results – Seven arylnaphthalene‐type lignans from the chloroform‐soluble fraction of P. myrtifolius and nine stilbenoids from a polyphenol‐rich butanol‐soluble fraction of the seeds of S. romanzoffiana were characterised. Conclusion – HPLC‐SPE‐NMR associated with HR‐ESI/MS, which consumed only analytical amounts of partially purified mixtures, was demonstrated to be a good tool for rapid screening of both known and new natural products. Copyright © 2011 John Wiley & Sons, Ltd.     

超声法提取虎杖色素及其稳定性的研究

用乙醇作为提取溶剂,以提取得率和色价为评价指标,通过单因素实验,探讨料液比、提取温度、超声功率、提取时间、乙醇体积分数对色素提取效果的影响;通过正交实验优化提取条件,并对提取的色素进行了稳定性考察。实验结果表明:虎杖色素的最佳提取工艺条件为乙醇体积分数80%,料液比1∶30,超声温度25℃,超声功率50 W,超声时间20 min,其中料液比为显著影响因素;虎杖色素对热、光、蔗糖、NaCl、维生素C(Vc)等因素的影响较稳定,而pH、H2O2、柠檬酸对虎杖色素稳定性影响较大。     

Ethanol fermentation from molasses at high temperature by thermotolerant yeast Kluyveromyces sp. IIPE453 and energy assessment for recovery

High temperature ethanol fermentation from sugarcane molasses B using thermophilic Crabtree-positive yeast Kluyveromyces sp. IIPE453 was carried out in batch bioreactor system. Strain was found to have a maximum specific ethanol productivity of 0.688 g/g/h with 92 % theoretical ethanol yield. Aeration and initial sugar concentration were tuning parameters to regulate metabolic pathways of the strain for either cell mass or higher ethanol production during growth with an optimum sugar to cell ratio 33:1 requisite for fermentation. An assessment of ethanol recovery from fermentation broth via simulation study illustrated that distillation-based conventional recovery was significantly better in terms of energy efficiency and overall mass recovery in comparison to coupled solvent extraction–azeotropic distillation technique for the same.     

Optimization of the Cellulase−Ultrasonic Synergistic Extraction Conditions of Polysaccharides from Lenzites betulina

Lenzites betulina has been recognized as a rich source of chemical components, including polysaccharides, sterides and sugar alcohols. In this study, cellulase?ultrasonic synergistic extraction method was applied to extract polysaccharides from L. betulina, and the response surface methodology was used to optimize the extraction conditions. The eight basic factors affecting extraction yield were evaluated by Plackett?Burman design (PBD). Then, the four important factors significantly affecting the yield of polysaccharides from L. betulina, including enzymolysis temperature, enzymolysis time, ultrasound time and ultrasound temperature, were optimized by Box?Behnken design (BBD). Maximum extraction yield of L. betulina polysaccharides was 13.64±0.09 % at a cellulase dosage of 0.8 %, enzymolysis temperature of 60 °C, enzymolysis time of 180 min, pH of 4.5, liquid‐solid ratio of 45 ml/g, ultrasound power of 300 W, ultrasound time of 20 min and ultrasound temperature of 45 °C. Subsequently, the characteristic structure of crude polysaccharides was determined by FT‐IR. Results indicated that cellulase?ultrasonic synergistic treatment is suitable for L. betulina polysaccharides extraction, and it has good prospect for development and utilization.     

响应面法优化余甘叶中黄酮提取工艺

以余甘叶为试材,利用超声波辅助提取余甘叶黄酮,研究料液比、乙醇浓度、超声时间、超声功率对黄酮提取率的影响,并在单因素试验的基础上,通过响应面分析法优化提取工艺。结果表明,余甘叶中黄酮最佳超声提取条件为：料液比1∶73、乙醇浓度50%、超声时间30 min、超声功率210 W,在此条件下黄酮实际提取率为19.51%。     

超声辅助低共熔溶剂提取沙棘籽粕多酚的工艺优化

以一系列低共熔溶剂为提取剂,采用超声波辅助法从沙棘籽粕中提取多酚。在单因素试验结果基础上,利用Box-Behnken实验设计,运用响应面分析法对影响沙棘籽粕多酚得率的主要因素（超声功率、超声时间、超声温度）进行优化。结果表明,沙棘籽粕多酚最佳提取工艺条件为：以含水量为30%的氯化胆碱-草酸低共熔溶剂为最佳提取剂,液料比为14∶1,超声功率420 W,超声时间56 min,超声温度44℃。在此条件下,多酚得率为3.31±0.008%。对比试验发现：氯化胆碱-草酸低共熔溶剂对沙棘籽粕多酚的得率明显优于传统溶剂;与热回流提取相比,超声提取法具有明显的优势。     

青橄榄浸膏的提取及其抗氧化活性研究

为优化青橄榄浸膏提取工艺,并探讨其抗氧化性。以茂名盛产的青橄榄为原料,采用超声波辅助乙醇提取法,以总黄酮和总多酚得率为评价指标,考察各因素对青橄榄浸膏提取效果的影响。采用邻苯三酚自氧化法、结晶紫法和DPPH清除能力评价青橄榄浸膏的抗氧化活性。结果显示,浸膏的最佳提取工艺为:乙醇体积分数70%,料液比1∶18 (g∶mL),超声提取温度50℃,时间6 min(超声提取阶段);单纯有机溶剂提取温度60℃,时间45 min(有机溶剂浸提阶段);此条件下总黄酮得率为1. 76%,总多酚得率为15. 53%。终产物浸膏在0. 3 mg/mL浓度下对超氧阴离子自由基抑制率为22. 74%,相当于同等质量浓度的抗坏血酸抑制效果的23. 47%;在0. 02 mg/mL浓度下对羟基自由基的清除率为67. 32%,相当于同等质量浓度的抗坏血酸清除效果的112. 58%;在0. 2 mmol/mL的DPPH溶液体系中,0. 15 mg/mL的浸膏对DPPH的清除率为95. 40%,相当于同等质量浓度的抗坏血酸清除效果的140. 83%;总体来讲,浸膏具有良好的抗氧化能力,虽然对超氧阴离子自由基抑制率弱于抗坏血酸,但羟基自由基的清除率及DPPH清除率均优于抗坏血酸。     

Superheated water extraction of essential oils from Cinnamomum zeylanicum (L.)

Introduction – Superheated water extraction (SHWE) potentially provides an environmentally friendly and clean extraction technique which uses a minimum or no organic solvent. The scope and limitations of the technique have still to be fully explored. Objective – To investigate the application of SHWE to cinnamon (Cinnamomum zeylanicum L.) bark and leaves as typical plant materials to determine if this extraction method can yield a higher quality oil. Methodology – Samples of cinnamon bark or leaves were extracted at 200°C with water under pressure. The essential oils were obtained from the aqueous solution using a solid phase extraction cartridge and were then examined by GC‐MS. Results – Using superheated water extraction, cinnamon bark oil with over 80% cinnamaldehyde and cinnamon leaf oil containing up to 98% eugenol were obtained. Alternative solvent extraction methods were also studied but led to emulsion formation apparently because of the presence of cellulose breakdown products. Conclusion – Superheated water extraction offers a cheap, environmentally friendly technique with a shorter extraction time than hydrodistillation and yielded a higher quality oil with a higher proportion of eugenol than hydrodistillation. Copyright © 2010 John Wiley & Sons, Ltd.     

Task-specific ionic liquid-assisted extraction and separation of astaxanthin from shrimp waste

Astaxanthin, as an outstanding antioxidant reagent, was successfully extracted from shrimp waste by the ionic liquids based ultrasonic-assisted extraction. Seven kinds of imidazolium ionic liquids with different cations and anions were investigated in this work and one task-specific ionic liquid in ethanol with 0.50 mol L⁻¹ was selected as the solvent. At the optimized ultrasonic extraction conditions, the extraction amount of astaxanthin increased 98% (92.7 μg g⁻¹) compared to the conventional method (46.7 μg g⁻¹). Furthermore, the extracted solution was isolated through the solid-phase extraction with a molecularly imprinted polymer sorbent. After loading the samples on molecularly imprinted polymer cartridge, the different washing and elution solvents, such as water, methanol, n-hexane, acetone and dichloromethane, were evaluated, and finally, astaxanthin was separated from the shrimp waste extract.     

响应曲面优化醇法提取桑叶黄酮工艺研究

以含水乙醇为溶剂,在单因素试验基础上,采用响应曲面法优化提取桑叶黄酮工艺条件。结果表明,醇法提取桑叶黄酮的最优工艺条件为:乙醇体积分数71.75%、提取温度67.1℃、料液比23.2:1(醇溶液:桑叶粉,mL:g)、提取时间150 min、提取次数2,桑叶黄酮得率为2.37%。验证试验表明,该优化工艺稳定,与模型预测值相符。     

Enhancement of Neuroprotective Effects of <Emphasis Type="Italic">Spirulina maxima</Emphasis> by a Low-temperature Extraction Process with Ultrasonic Pretreatment

17.5 ± 2.41 mg/g and 15.2 ± 2.09 mg/g of total chlorophyll and chlorophyll a, respectively, were obtained from the marine microalga, Spirulina maxima under an optimal extraction condition of 70% ethanol at 65°C for 4 h associated with ultrasonic pretreatment at 40 kHz for 8 h. In comparison, 14.5 ± 1.36 mg/g and 7.1 ± 0.99 mg/g of total chlorophyll and chlorophyll a, respectively, were obtained from a conventional extraction process using 70% ethanol at 80°C for 12 h. The extract from the optimal conditions had the highest ratio of chlorophyll a to total chlorophyll, approximately 3:4, indicating that more intact chlorophyll a was obtained at low temperature. Moreover, the extract obtained using the optimal extraction condition showed substantial neuroprotective effects such as 92.78 ± 0.04% protection against glutamate-induced mouse hippocampal neuronal cells, compared to 81.64 ± 0.07% protection with the extract from the conventional extraction process. Compared to the control, the activities of two key enzymes related to glutathione synthesis, i.e., glutathione reductase and glutathione peroxidase, were also strongly increased, up to 90%, by the extracts from the optimal conditions. Interestingly, the addition of the same concentration of chlorophyll a as in the optimized extract had lower neuroprotective effects than did the extracts. This finding indicates that the extract likely exerted a synergistic effect, showing that the extract had better neuroprotective activity than the single component (chlorophyll a) alone. This work also confirmed the neuroprotective mechanism of the extract mainly due to its high antioxidant activity, allowing it to greatly decrease accumulation of ROS and Ca²⁺ within HT22 cells. The results of this work will have implications for expanding the use of a nonthermal ultrasonic process to extract heat-sensitive bioactive substances from natural resources.     

Analysis of fatty acids in A. szechenyianum Gay. by microwave‐assisted extraction and gas chromatography‐mass spectrometry

Introduction – Aconitum szechenyianum Gay. is a traditional Chinese medicinal herb with the detumescent and styptic effects and antitumor activity. There have been only a few researches on its chemical components, but no detailed report has appeared on its fatty acids. Objective – To develop a simple and effective method for the extraction of fatty acids from A. zechenyianum Gay. and then to investigate the fatty acid components. Methodology – Microwave‐assisted extraction (MAE) was optimized with response surface methodology, and the fatty acid compositions of extract were determined by GC–MS with previous derivatisation to fatty acid methyl esters (FAMEs). The results were compared with that obtained by classical Soxhlet extraction (SE). Results – Compared with SE, MAE showed significantly higher fatty acid yields, shorter extraction time, and lower energy and solvent consumption. The major fatty acids in A. szechenyianum Gay. are linoleic acid, palmitic acid, linolenic acid, oleic acid and stearic acid, and the unsaturated fatty acids occupy 66.4% of the total fatty acids. Copyright © 2010 John Wiley & Sons, Ltd.     

余甘子总黄酮超声波辅助提取工艺的优化

以余甘子干粉为材料,利用超声波辅助提取余甘子总黄酮。单因素试验分析液料比、乙醇浓度、超声时间、超声功率对余甘子总黄酮提取率的影响,在此基础上,利用响应面分析法对提取工艺进行优化。结果表明,余甘子总黄酮最佳提取条件为：液料比82:1(V/W)、乙醇浓度45%、超声时间41 min、超声功率210 W,在此条件下余甘子总黄酮的实际提取率为6.12%。