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1.
葡萄籽中原花青素提取方法优化处理   总被引:7,自引:0,他引:7  
吕国红  傅星 《生态学杂志》2004,23(5):241-244
溶剂提取法是提取葡萄籽原花青素的常用方法 ,然而 ,在不同提取条件下 ,提取效果并不一致。利用水、甲醇、乙醇、丙酮及它们的水溶液提取葡萄籽中的原花青素 ,而后用铁盐催化比色法测原花青素含量 ,考察了提取剂的浓度、粉碎度对提取的影响。在优化处理的基础上 ,获得了有效的提取条件 :葡萄籽粉碎度 10 0目 ,提取剂 70 %甲醇水溶液。  相似文献   

2.
紫芝中三萜化合物标准化提取方法研究   总被引:6,自引:0,他引:6  
为了更好地发挥紫芝的药用功效,本文优选了紫芝子实体三萜类化合物的提取条件。采用L9(34)正交实验设计,以提取溶媒、提取方法、提取时间和提取次数四因素三水平的提取工艺优选。各因素重要性依次为提取溶媒>提取次数>提取方法>提取时间。本文确定了以氯仿或丙酮为提取溶剂提取紫芝中三萜类物质的标准化方法。在提取过程中如果采用甲醇、乙醇或水作为提取溶媒,虽然提取效率高,但含糖、氨基酸等其它非三萜成分多,三萜类物质提取不全。  相似文献   

3.
Cyclopentyl methyl ether (CPME) was evaluated for extracting oil or triacylglycerol (TAG) from wet cells of the oleaginous yeast Lipomyces starkeyi. CPME is a greener alternative to chloroform as a potential solvent for oil recovery. A monophasic system of CPME and biphasic system of CPME:water (1:0.7) performed poorly having the lowest TAG extraction efficiency and TAG selectivity compared to other monophasic systems of hexane and chloroform and the biphasic Bligh and Dyer method (chloroform:methanol:water). Biphasic systems of CPME:water:alcohol (methanol/ethanol/1‐propanol) were tested and methanol achieved the best oil extraction efficiency compared to ethanol and 1‐propanol. Different biphasic systems of CPME:methanol:water were tested, the best TAG extraction efficiency and TAG selectivity achieved was 9.9 mg/mL and 64.6%, respectively, using a starting ratio of 1:1.7:0.6 and a final ratio of 1:1:0.8 (CPME:methanol:water). Similar results were achieved for the Bligh and Dyer method (TAG extraction efficiency of 10.2 mg/mL and TAG selectivity of 66.0%) indicating that the biphasic CPME system was comparable. The fatty acid profile remained constant across all the solvent systems tested indicating that choice of solvent was not specific for any certain fatty acid. This study was able to demonstrate that CPME could be used as an alternative solvent for the extraction of oil from the wet biomass of oleaginous yeast. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 33:1096–1103, 2017  相似文献   

4.
As chloroform has proved to be carcinogenic we were looking for an alternative solvent system for chloroform:methanol widely used in plant lipid investigations. The lipids from leaves of wheat ( Triticum aestivum L. cv. Vakka) and from protonemata of the moss Ceratodon purpureus (Hedw.) Brid. were extracted with two petroleum ether:methanol solvent systems. The polar lipids were separated by two-dimensional thin-layer chromatography and the amounts of each lipid class were compared with those obtained from chloroform:methanol (2:1, v/v) extractions. The significantly higher amounts of phosphatidylinositol observed in petroleum ether:methanol (1:1, v/v) extraction suggest that the small amounts reported earlier in plants may be an artefact relating to the solvent system used. As petroleum ether:methanol (1:1, v/v) proved to be at least as good a solvent system as chloroform:methanol (2:1, v/v) we propose it as an alternative extractant for plant polar lipids.  相似文献   

5.
In the work described here, a set of screening factorial design experiments was carried out in order to study the extraction process of anthocyanins from red grape pomace with carbon dioxide, along with either methanol or water as cosolvent, at high pressure. The variables studied were pressure, temperature, solvent flow‐rate, cosolvent percentage, cosolvent type (methanol or water) and extraction time. The quantification of the total amount of anthocyanins was performed by a colorimetric method. The results of the ANOVA study show a strong influence of the type and percentage of cosolvent. The best results were obtained with 20 mol‐% of methanol, 100 bar, 60 °C and a flow‐rate of 22 mmol/min after two hours of extraction.  相似文献   

6.
本研究使用单因素方法考察了无花果(Ficus carica L.)果皮中花青素的最佳提取条件,并考察了7种参数对花青素提取率的影响。参数设置如下:溶剂性质(水,甲醇,乙醇和丙酮)、提取次数(1~3次)、固液比(1/50,1/100,1/150和1/200)、提取时间(60 min,120 min,180 min和240 min)、甲醇浓度(0,20%,40%,60%,80%和100%)、酸类型(盐酸,乙酸,柠檬酸和酒石酸)和酸浓度(0,1%,2%,5%和10%)。使用pH-示差法测量无花果果皮中单体花色素的含量。研究显示,无花果果皮中花青素的最佳提取条件为:溶剂为甲醇溶剂,提取次数为2次,固液比为1/100,提取时间为180 min,甲醇浓度为80%,酸类型为柠檬酸,柠檬酸浓度为5%。该最佳提取条件下的花青素的提取率达到最高(345.62 mg/100g DS)。  相似文献   

7.
Lipid extraction is a critical step in the downstream processing of biodiesel production from microalgae. Solvent extraction using mixtures of non-polar and polar solvents is one of the most well-known processes for this purpose. Hexane is the most common solvent of choice for large-scale lipid extractions due to its technical and economic advantages, especially its high selectivity toward lipids and low cost. In this study, extractions using mixtures of hexane and polar solvents were evaluated for their performance in order to develop a more efficient method for large-scale lipid extraction from microalgae. The combination of hexane and methanol resulted in the highest fatty acid methyl ester (FAME) yield for lipids from Tetraselmis sp. The effects of extraction conditions, including proportions of methanol to hexane, ratios of total solvent volume to dry biomass, and extraction time, on extraction yields were evaluated to determine optimum conditions providing higher lipid and FAME yields. The optimal conditions were as follows: proportion of hexane to methanol of 1:1, ratio of total solvent volume to dry biomass of 10 mL/g, and extraction time of 120 min. Finally, the selected solvent mixture and optimal conditions were applied to larger scale extraction experiments with scale-up factors of 10, 50, and 100. FAME yields of large-scale extractions were almost completely consistent with increasing scale-up factors. The results of this study suggest that a hexane and methanol mixture is a promising solvent for large-scale lipid extraction from microalgae.  相似文献   

8.
An open microwave-assisted extraction system was used to extract gallic acid, protocatechuic acid, chlorogenic acid and caffeic acid from Eucommia ulmodies. The effect of extraction variables, especially solvent, on the recoveries of these polyphenolic compounds was investigated using factorial design. As extracting solvent for these compounds, methanol produced a higher recovery than pure water. For straight chain alcohol solvents, the lower the carbon number, the higher the recoveries of the polyphenolic acids. The optimal ratio of methanol:water:glacial acetic acid in the solvent mixture used in microwave-assisted extraction was 2:8:0.3 (v/v) and this solvent could be directly used as the mobile phase in HPLC separation without additional intermittent treatment as reported in literature. The extraction under the condition of 50% microwave power and 30 s irradiation at a solvent:sample ratio of 10 (mL/g) was found to be the most advantageous. The repeatability test of extraction and chromatographic analysis was satisfactory for the analysis of these polyphenolic compounds.  相似文献   

9.
A solvent system that extracts a maximum number of metabolites belonging to diverse chemical classes from complex biofluids, such as plasma, may offer useful inputs to understand the metabolic and physiological state of an individual. The present study compared seven solvent systems for extraction of metabolites from plasma. The extracts were analyzed by mass spectrometry (MS) and MS/MS (MS2) using a quadrupole time-of-flight liquid chromatography/MS system in positive and negative modes of ionization. Metabolites with molecular mass below 400 were identified using Human Metabolome Database MS2 and MS search interfaces. The acetone/isopropanol (2:1) system yielded promising results in positive ionization mode, as the maximum number of MS and MS2 features was detected in the extract. It was found to be superior in extraction of various classes of metabolites, especially organic acids, nucleosides and nucleoside derivatives, and heterocyclic molecules. Glycerophosphocholines in the mass range of 400–700 were found to be efficiently extracted by the methanol/chloroform/water (8:1:1) system. In negative mode as well, the maximum number of MS2 features was detected in methanol/chloroform/water and acetone/isopropanol extracts. The fingerprints of molecular features obtained in the negative and positive modes differed from each other to a significant extent.  相似文献   

10.
Metabolomic analysis of tissue samples can be applied across multiple fields including medicine, toxicology, and environmental sciences. A thorough evaluation of several metabolite extraction procedures from tissues is therefore warranted. This has been achieved at two research laboratories using muscle and liver tissues from fish. Multiple replicates of homogenous tissues were extracted using the following solvent systems of varying polarities: perchloric acid, acetonitrile/water, methanol/water, and methanol/chloroform/water. Extraction of metabolites from ground wet tissue, ground dry tissue, and homogenized wet tissue was also compared. The hydrophilic metabolites were analyzed using 1-dimensional (1D) 1H nuclear magnetic resonance (NMR) spectroscopy and projections of 2-dimensional J-resolved (p-JRES) NMR, and the spectra evaluated using principal components analysis. Yield, reproducibility, ease, and speed were the criteria for assessing the quality of an extraction protocol for metabolomics. Both laboratories observed that the yields of low molecular weight metabolites were similar among the solvent extractions; however, acetonitrile-based extractions provided poorer fractionation and extracted lipids and macromolecules into the polar solvent. Extraction using perchloric acid produced the greatest variation between replicates due to peak shifts in the spectra, while acetonitrile-based extraction produced highest reproducibility. Spectra from extraction of ground wet tissues generated more macromolecules and lower reproducibility compared with other tissue disruption methods. The p-JRES NMR approach reduced peak congestion and yielded flatter baselines, and subsequently separated the metabolic fingerprints of different samples more clearly than by 1D NMR. Overall, single organic solvent extractions are quick and easy and produce reasonable results. However, considering both yield and reproducibility of the hydrophilic metabolites as well as recovery of the hydrophobic metabolites, we conclude that the methanol/chloroform/water extraction is the preferred method. C. Y. Lin and H. Wu contributed equally.  相似文献   

11.
葡萄籽油的提取研究   总被引:10,自引:2,他引:8  
利用葡萄饮料厂生产加工的废料葡萄籽提取葡萄籽油,并对影响葡萄籽油提取率的因素,如提取溶剂的选择、提取温度、提取时间及提取料液比等条件进行研究,初步确定了获得最大提取收率的条件。即:以石油醚(60~90)作为提取剂;提取温度65℃;提取时间为3h;提取料液比为17。并对提取的葡萄籽粗油进行精制。得到具有透明黄色,核桃仁味道的葡萄籽油。  相似文献   

12.
The naphthoquinone plumbagin has a broad spectrum of biological activities. The aim of this study was to investigate the efficiency of two extraction methods (Soxhlet and ultrasound-assisted extraction) and three solvents (methanol, chloroform and hexane) to recover plumbagin from fresh and dried tissues of field specimens of Drosophyllum lusitanicum (L.) Link. The highest extraction yields were obtained with methanol as solvent and using fresh plant material. The obtained extracts were analysed by gas chromatography with mass spectrometric detection and plumbagin was the major compound present. Plumbagin was quantified in the extracts using the external standard methodology. The results obtained showed that the best recoveries of plumbagin were attained using fresh plant material and there were no significant differences between Soxhlet and ultrasound-assisted extraction. Moreover, hexane proved to be the more appropriate solvent for the extraction of plumbagin, providing high recoveries and the most concentrated extracts, yielding 2.42 mg of plumbagin per gram of plant material with the highest degree of purity. This method is a simple and efficient one to extract large amounts of plumbagin from D. lusitanicum field specimens.  相似文献   

13.
采用单因素实验,分别研究提取试剂、发酵液放置时间、pH值和温度对发酵液中多拉菌素提取效果的影响;然后以乙酸乙酯为萃取试剂,研究萃取次数及萃取体积对多拉菌素萃取效果的影响。结果显示,甲醇为最佳提取试剂;发酵液在pH为3~11、温度为20~80℃的条件下放置144 h,多拉菌素均能稳定存在,提取得到的多拉菌素的质量浓度没有显著变化;浓缩提取液液经2倍体积乙酸乙酯萃取2次即可。该条件下多拉菌素的质量浓度和萃取率分别为151.78μg/mL和98.00%。  相似文献   

14.
A two-choice bioassay was developed to evaluate the role of host-plant berry compounds on the oviposition site acceptance of the generalist moth Lobesia botrana (Denis & Shiffermüller). A key feature was the lining of the bioassay arena with felt which focused oviposition on the test substrates. Initial experiments comparing substrates with different physical features indicated that smooth textures and spherical shapes with interstices favour oviposition. Artificial oviposition substrates were thus constructed with glass spheres in order to test the behavioural activity of grapevine berry extracts. Only polar extracts obtained by soaking berries in methanol or water stimulated oviposition (more eggs were laid on the extract-treated substrate than on the control substrate), whereas more apolar ones obtained with chloroform or hexane had no significant effect. The prior removal of epicuticular waxes from grape berries before extraction did not enhance the stimulatory activity of the methanol extract. The oviposition response to this extract was dose-dependent. It is concluded that polar compounds present on grape berries act as oviposition stimulants for L. botrana.  相似文献   

15.
Fusarium, graminearum KF 370 isolate is able to simultaneous biosynthesis of three toxic metabolites, namely: fusarenone-X (FUS), nivalenol (NIV) and zearalenone (F-2). After metabolites extraction with methanol — water (3:1) and defatting with n-heptane toxins were partitioned into chloroform layer. Purification of the? compounds was performed on Celite 545 — charcoal — Aluminiumoxid 90 column then metabolites were separated on Kieselgel 60 (200–300 mesh) column with developing solvent chloroform — methanol. This way FUS, NIV and F-2 were obtained as crystalline or high purity standards.  相似文献   

16.
A method has been developed for the determination of vitamins A and E in food using supercritical fluid extraction (SFE), applying liquid or solid trapping, with an accuracy equal to conventional solvent extraction methods. Under optimal conditions, using methanol modified carbon dioxide as a supercritical fluid, Hydromatrix as a water adsorbent, and with a small amount of ascorbic acid and methanol added to the sample, the extraction time is reduced to 80 min. This time is considerably shorter than in conventional methods. Other advantages are the reduction of manual manipulations leading to lower labour costs and reduced consumption of organic solvents in the sample preparation step.  相似文献   

17.
The sediment-dwelling polychaete, Hediste diversicolor, is commonly found in Northern temperate estuaries. Its limited mobility and tolerance to polluted conditions makes it a good candidate for biological monitoring. Moreover, its importance in the functioning of the sediment ecosystem has caused it to be described as a keystone species. Here we present the development of analytical methodology that will enable the use of H. diversicolor in environmental metabolomics studies for the biomonitoring of estuarine ecosystems. Polar and non-polar extraction solvents have been used to solubilise a wide range of metabolites. Extraction solvents assessed include: aqueous phosphate buffer solution, methanol:chloroform:water (1:1:0.9), methanol:water (1:1 and 2:1) and chloroform. The metabolites were analysed using 1-dimensional (1D) 1H nuclear magnetic resonance (NMR) spectroscopy. Using the methanol:water (1:1) method, previous freezing to aid cell rupture did not result in an enhanced extraction. Removal of methanol with a speed vacuum resulted in reduction in yield. Methanol:water (1:1) and chloroform extractions proved to be the most appropriate techniques based on the sample yield and repeatability. NMR-based metabolomics in the ragworm can now be used to understand the ecophysiology of this important estuarine organism and has applications in biomonitoring, biomarker development and ecotoxicological studies.  相似文献   

18.
An extraction technique, dynamic pressurized liquid extraction (DPLE), was proposed to extract the taxanes; including 10-DAB III, Baccatin III, 9-DHB III and paclitaxel, from powdered Taxus canadensis needles. A dual-solvent approach was adopted in which the impurities were firstly removed by extraction with hexane, and the taxanes were subsequently extracted with an appropriate solvent. The performance of chloroform, dichloromethane, and mixtures of methanol/dichloromethane was compared for use as the taxane-extracting solvent, and it was found that solvents containing a higher proportion of methanol had higher extraction capabilities. The effect of temperature on DPLE extraction of the taxanes was also studied, and it was found that higher extraction efficiencies could be realized with increasing temperature up to a threshold of 90°C. Based on a progressive conversion model, a kinetic equation for the extraction process was proposed. This model successfully confirmed that smaller needle powder particle sizes would result in higher extraction rates, which is consistent with the data obtained by experimentation.  相似文献   

19.
Leaf extracts of the walnut, Juglans regia L., were evaluated under laboratory conditions to determine their acaricidal activity on the mites Tetranychus cinnabarinus (Boisduval) and Tetranychus viennensis Zacher (Acari: Tetranychidae). Extracts had both contact and systemic toxicity to these mites. The four solvents tested for preparing crude extracts were petroleum ether, chloroform, ethyl acetate, and methanol. Methanol was the most efficient solvent, with an extraction rate from 17.06 + 0.80 to 20.27 +/- 0.28%. Petroleum ether was the least effective solvent, with extraction rates from 2.30 +/- 0.13 to 2.71 +/- 0.13%. However, the crude extracts with petroleum ether resulted in the highest mite mortality (79.04 +/- 0.52%) in a slide dip bioassay. Mites mortalities from the concentrated extracts prepared by chloroform, ethyl acetate, methanol, or distilled water were significantly lower than petroleum ether. The mean lethal concentrations (LC50) of the extracts from petroleum ether, chloroform, ethyl acetate, methanol, and distilled water to the two mite species were 0.73 +/- 0.04, 1.66 +/- 0.28, 4.96 +/- 0.35, 7.45 +/- 0.67, and 9.91 +/- 0.32 mg/ml, respectively. After liquid chromatography and thin-layer chromatography, the concentrated extracts of petroleum ether were separated into eight fractions and tested for acaricidal activity. Fraction 6 produced significantly higher mite mortality rates than the other groups, killing approximately 90% of both species.  相似文献   

20.
A method for the extraction of acyl-CoA esters from tissue, and their subsequent analysis by HPLC is described. The lipids are removed by a two-phase extraction in a chloroform/methanol/water system. The long-chain acyl-CoA esters are extracted using methanol and a high salt concentration (2 M ammonium acetate). Reextraction of the dry residue after evaporation of extraction solvent results in low overall recoveries (20%). By adding 1 mg/ml acyl-CoA-binding protein to the extraction solvent the overall recovery was increased to 55%. The method is easy and fast to perform and is thereby suitable for analysis of a large number of samples. The advantages of the method over previously published methods are discussed.  相似文献   

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