微波辅助法从黎蒿中提取黄酮类化合物的研究

本文介绍了一种有效利用微波辅助从藜蒿(Artemisia selengnesisTurcz)中提取黄酮类化合物的方法。通过考察了微波辐射时间、功率、料液比及提取溶剂等因素对提取率的影响,得出的结论为:以75%乙醇做提取溶剂,密封条件下,功率200 W,料液比1 g∶25 mL,辐射时间20 s/次×3次,提取率最高。与传统提取方法相比,该方法不仅工艺简单,而且可以提高产率,缩短提取时间。     

响应面法优化微波辅助提取枇杷叶中黄酮类化合物

为充分利用枇杷叶,研究微波辅助乙醇浸提法从枇杷叶中提取黄酮类化合物的工艺。首先研究了影响提取效果的因素:不同体积分数的乙醇溶液、料液比、时间及微波功率。在单因素试验基础上利用响应面分析法,确定了各因素与总黄酮得率之间的关系,并以总黄酮得率为响应值做响应面和等高线图。研究表明,枇杷叶中黄酮类化合物提取最佳工艺为乙醇体积分数50%,料液比1∶30,提取时间3 min,微波功率500 W,最佳条件下总黄酮得率为2.04%,与理论推导值2.07%相比,误差为1.4%,黄酮类化合物响应方程的回归分析表明此方法合理可行。本研究对枇杷叶总黄酮提取优化的研究为进一步探讨枇杷叶的深度开发提供了理论参考依据,并为枇杷叶总黄酮的生物活性研究提供材料。     

微波辅助提取补阳还五汤多糖的研究

采用单因素实验和正交实验法,进行了微波辐射萃取补阳还五汤多糖的最佳工艺条件研究。探讨了不同微波辐射时间、微波功率及料液比等条件对多糖提取率的影响。结果表明,在微波辐射时间20min,微波功率325W,料液比为1：7,补阳还五汤中多糖的提取率为7．75％。微波辅助萃取大大缩短了提取时间,节省了溶剂,提高了收率。     

麻栎叶黄酮的提取及其抗氧化活性研究

在单因素试验的基础上,对麻栎叶黄酮提取工艺进行优化,并研究了麻栎叶黄酮类化合物的抗氧化活性.结果显示,麻栎叶黄酮提取的最佳工艺是以60％乙醇为提取剂,提取物固液比1∶20,提取温度60℃,提取次数2次,微波功率640W、微波时间2 min,提取时间60 min,黄酮提取率为6.06 mg/g,回收率为96.5％.麻栎叶黄酮类化合物对自由基DPPH·、·OH以及亚硝酸盐的清除率分别达到97.7％、97.6％和94.4％.试验结果表明提取工艺合理,黄酮提取率高,麻栎叶黄酮提取液具有很好的抗氧化活性.     

苹果渣中原花青素的提取分离条件的优化

采用单因素和正交试验优化了溶剂直接提取及微波辅助提取苹果渣中原花青素的提取条件。结果表明:溶剂直接提取苹果渣中原花青素的最佳提取条件为乙醇体积分数30%,料液比(g/mL)1∶12,浸提温度90℃,提取时间0.5h;微波辅助提取法提取苹果渣中原花青素的最佳提取条件为乙醇体积分数50%,料液比(g/mL)1∶9,微波功率为700W,提取时间3min。与溶剂直接提取法相比,微波辅助提取法能更省时、高效地提取苹果渣中的原花青素。     

密闭微波辅助间歇提取RP-HPLC测定三七中三种皂苷类化合物

本文建立了采用微波辅助间歇提取三七样品中的皂苷类化合物,并以反相高效液相色谱（RP—HPLC）测定其中三七皂苷R1、人参皂苷Rg1和人参皂苷Rb1含量的实验方法。分别通过单因素实验和正交实验设计,优化了萃取溶剂浓度、溶剂用量、微波功率和微波辐射时间等提取条件。与传统的索氏提取法、冷浸法和超声波提取法比较,微波辅助萃取法具有快速、提取率高、溶剂消耗少等优点,间歇萃取较连续萃取更是大大节省了微波能耗。     

亚麻木酚素的微波辅助提取工艺研究

采用微波辅助提取法从脱脂亚麻籽壳中提取亚麻木酚素,以磷钼酸显色的方法定量测定亚麻木酚素,通过单因素试验、中心组合试验及响应面分析,确定微波辅助提取的最优工艺条件为:乙醇浓度40.9%(v/v)、液固比21.9:1(mL/g)、超声处理5 min进行预浸、辐照时间90.5 s、微波功率为130 W。与常规溶剂提取法和索氏提取方法相比,微波辅助提取法显著提高了亚麻木酚素的得率,大大缩短了提取时间,并节省了能耗。     

微波法从黄连中提取黄连素的工艺研究

为了研究微波法从黄连中提取黄连素的效果,分别考察不同微波功率、原料浸泡时间、料液比(g/mL,下同)、提取次数、微波辐射时间对黄连素提取率的影响。结果微波法从黄连中提取黄连素的最佳工艺条件为:提取功率500W,原料浸泡时间24 h,料液比1∶120,提取次数2次,微波辐射时间3 min,提取率达5.61%,提取效果较好。与硫酸法、石灰法、乙醇浸取法相比,不仅提高了提取速度,并且更加环保。     

九种药用植物花黄酮类物质提取及对羟自由基清除能力的研究

微波辅助法提取九种药用植物花中黄酮类化合物,研究其提取物清除羟基自由基(·OH)的能力.九种药用植物花提取物对羟基自由基有不同程度的清除作用,且生态环境对该作用有较大影响,其中旋覆花中总黄酮含量最高,夏至草花总黄酮含量最低;荷兰菊、旋覆花、玫瑰花清除羟基自由基能力较强,清除率在一定浓度范围内与提取物浓度呈正相关.     

辣蓼总黄酮超声波辅助提取条件优化研究

目的:优化超声波辅助法提取辣蓼黄酮类化合物的工艺条件。方法:实验从超声温度、料液比、乙醇浓度和超声时间四个方面对黄酮类化合物的提取效果进行了探讨,通过单因素试验确定提取黄酮类化合物的较优水平,再结合正交试验确定辣蓼全草中黄酮类化合物的最优提取工艺。结果和结论:经研究所得工艺的最佳参数为:乙醇浓度60%,料液比1∶45,超声温度50℃,提取时间50 min。在此工艺条件下得到黄酮类化合物含量为55.8mg/g。由此证明辣蓼中黄酮类化合物能够利用超声波辅助法来方便有效地提取。     

Microwave-assisted extraction of embelin from <Emphasis Type="Italic">Embelia ribes</Emphasis>

A rapid and efficient microwave-assisted extraction (MAE) process for the selective extraction of embelin from Embelia ribes was developed. Solvent selection, microwave energy input and solid loading were optimized. The rate of extraction and purity of embelin depended upon the solvent used and exposure time to microwaves. Maximum MAE was achieved in acetone with total yield of 92% (w/w) embelin with 90% (w/w) purity with 1% (w/v) raw material loading at 150 W power level in 80 s. Non-polar solvents, such as hexane and dichloromethane, were not effective for the selective extraction of embelin.     

油菜花粉总黄酮的微波辅助提取及其抗氧化活性研究

采用微波辅助提取法提取油菜花粉总黄酮,通过单因素和正交试验,得到最佳提取条件：80％的乙醇、1：20的料液比、提取时间140s、微波功率242W、提取3次,总黄酮质量分数为（2．64±0．05）％。同时还研究提取物对羟自由基、DPPH自由基的清除作用,以及对小鼠肝组织脂质过氧化的抑制作用,自由基半清除质量浓度和脂质过氧化丰抑制盾奄浓度分剐为0．115、0．325和0．065mg／mL。     

Microwave assisted extraction of ursolic acid and oleanolic acid from Ocimum sanctum

Present study deals with the microwave assisted extraction (MAE) of ursolic acid (UA) and oleanolic acid (OA) from Ocimum sanctum leaves. UA and OA have been reported to possess significant medicinal properties. Various experimental parameters such as selection of solvent, solvent composition, irradiation time, microwave power, solid to solvent ratio, preleaching time and number of cycles were investigated to optimize the extraction process. Under optimum conditions of irradiation time (3 min), microwave power (272 W), solid to solvent ratio (1:30), preleaching time (10 min), maximum UA and OA has been extracted in one extraction cycle with ethanol: water (80:20) as a solvent. Maximum 86.76 and 89.64% of UA and OA was extracted under above mentioned optimized experimental conditions. MAE was also compared with the batch and ultrasound assisted extraction (UAE) method. As compared to batch and UAE, higher extraction yield of these important phytochemicals have been obtained through MAE in only 3 min.     

Microwave-assisted extraction of homoharringtonine from <Emphasis Type="Italic">Cephalotaxus koreana</Emphasis>

An efficient method using microwave energy was developed to extract homoharringtonine (HHT), an alkaloid component effective in the treatment of leukemia, from Cephalotaxus koreana. The effects of major process parameters on extraction efficiency were also investigated. Using a fixed biomass-to-methanol ratio of 1:8 (w/v), an extraction temperature of 30°C, an extraction time of 20 min, and a stirrer velocity of 250 rpm, a 25% higher yield of HHT was achieved using microwave-assisted extraction (MAE) than using conventional solvent extraction. It was possible to recover more than 95% of the HHT by extracting twice using MAE. In addition, the HHT yield increased as the extraction temperature increased, but the content of plant-derived tar and waxy compounds increased as well. Removal of these impurities and of the pigments from extracts was most effectively accomplished at a mixing ratio of biomass-to-sylopute of 1:1.5 (w/w). The effects of using different organic solvents (acetone, chloroform, ethanol, or methanol) for MAE were also assessed; the highest extraction efficiency was obtained using methanol. When the agitation speed was altered, most of the HHT (> 99%) was recovered at 250 rpm. A mixing ratio of biomass-to-methanol of 1:6 (w/v) at an extraction temperature of 40°C and an extraction time of 10 min proved to be the most effective for reducing processing time and organic solvent usage while enabling nearly all of the HHT (> 99%) to be recovered.     

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.     

响应面法优化芦荟中抗氧化活性成分的提取工艺

对芦荟中抗氧化活性物质提取工艺及其成分进行研究,通过单因素实验和响应面优化,以提取物对DPPH自由基的清除率为抗氧化的考察指标,得到芦荟中抗氧化活性成分的提取工艺条件:提取温度29 ℃、料液比(g/mL)1:33、提取时间107 s、微波功率500 W,微波辅助水提,此条件下得到的提取物对DPPH自由基的清除率达91.414%.提取物活性成分分析表明:提取物中芦荟甙含量为1.5 mg/g、黄酮为1.13 mg/g、多酚为4.33 mg/g、多糖为126.36 mg/g.     

Microwave hydrodiffusion and gravity processing of Sargassum muticum

An aqueous based extraction process was developed to obtain soluble fractions from Sargassum muticum. Microwave hydrodiffusion and gravity (MHG) and subsequent rehydration and extraction stages (MHG-W) in an open system, hot pressurized water extraction or autohydrolysis (A) and enzyme aided extraction (E) were selected on the basis of their simplicity and the possibility of using water as solvent. The performance of these combined technologies using biorenewable solvents to extract antioxidants was compared. A preliminary selection of MHG extraction conditions suggested that 600 W was the optimal irradiation power. A multistage process based on an initial solvent free MHG stage followed by a sequence of water extraction stages (MHG-W) proved suited to selectively obtain phenolic compounds in shorter times than conventional processes. The yield of total solubles was lower than with conventional solvent extraction, but the phenolic content of the extracts and their ABTS radical scavenging properties were enhanced. The microscopic observations of extracted tissues confirmed the impact of the microwave and hot pressurized water processes on the algal cell wall integrity.     

正交设计优选贯叶连翘中总黄酮提取工艺

本文采用正交设计实验,对影响贯叶连翘总黄酮提取工艺的因素进行了系统考察。结果发现,以总黄酮得率作为考察指标,影响贯叶连翘总黄酮提取的主次因素为:溶媒种类>提取时间>提取次数>溶剂用量,其中溶媒种类、提取时间、提取次数均对总黄酮的提取有显著性影响;贯叶连翘中总黄酮的最佳提取工艺条件为:用10倍量80%乙醇提取3次,每次1h。建立了以UV法测定贯叶连翘中总黄酮的含量方法。