Preparative isolation and purification of sinomenine from Sinomenium acutum by centrifugal partition chromatography

Preparative centrifugal partition chromatography (CPC) was successfully carried out for the separation of sinomenine from the methanolic extract of Sinomenium acutum stems and rhizomes. The optimum two-phase solvent system of CPC was composed of n-hexane/ethyl acetate/methanol/water at a volume ratio of 1:6:2:8 (v/v/v/v) with 0.1% triethylamine (TEA). Preparative CPC yielded 44.3 mg of sinomenine from 400 mg of MeOH extract with a purity of 96.9%.     

Determination of sinomenine in Sinomenium acutum by capillary electrophoresis with electrochemiluminescence detection

A Ru(bpy)₃²⁺-based electrochemiluminescence (ECL) detection coupled with capillary electrophoresis (CE) has been established for the determination of sinomenine for the first time. Optimum separation was achieved with a fused-silica capillary column (50 cm × 25 μm i.d.) and a background electrolyte of 50 mM sodium phosphate (pH 5.0) at a separation voltage of 15 kV. The content of sinomenine was detected by ECL at the detection voltage of 1.15 V (versus Ag/AgCl) with 5 mM Ru(bpy)₃²⁺ in 75 mM phosphate solution (pH 8.0) when a chemically modified platinum electrode by europium(III)-doped prussian blue analogue (Eu-PB) was used as a working electrode. Under the optimized conditions, the ECL intensity was in proportion to sinomenine concentration in the range from 0.01 to 1.0 μg mL⁻¹ with a detection limit of 2.0 ng mL⁻¹ (3σ). The relative standard derivations of migration time and ECL intensity were 0.93 and 1.11%, respectively. The level of sinomenine in Sinomenium acutum Rehd. et Wils was easily determined with recoveries between 98.6 and 102.7%.     

LC Analysis of Lignans from Schisandra sphenanthera Rehd. et Wils.

Schisandra sphenanthera Rehd. et Wils. is widely used in traditional Chinese medicine. A rapid and convenient method to separate and quantify four lignans (schisandrin, schisantherin A, deoxyschizandrin, and γ-schizandrin) was established by reversed-phase liquid chromatographic. On a Shimadzu C₁₈ column (Phenomenex, 150 × 4.6 mm; 5 μm particle size), an isocratic flow elution program and a simplified sample pretreatment approach were used in the experiment. Samples from different parts of S. sphenanthera were extracted by chloroform and then separated with methanol and deionized water (70:30 v/v) at a flow rate of 0.8 mL min^?1. The detection wavelength was set at 280 nm. The content of lignans in fruits is the highest, and the quantities of schisantherin A, deoxyschizandrin, and γ-schizandrin from fruits are 0.56, 0.54 and 0.30%, respectively. Schisandrin is not detected in all the plant extracts. This research forms a basic framework for the better use of S. sphenanthera in medicine.     

LC Analysis of Lignans from Schisandra sphenanthera Rehd. et Wils.

Schisandra sphenanthera Rehd. et Wils. is widely used in traditional Chinese medicine. A rapid and convenient method to separate and quantify four lignans (schisandrin, schisantherin A, deoxyschizandrin, and γ-schizandrin) was established by reversed-phase liquid chromatographic. On a Shimadzu C₁₈ column (Phenomenex, 150 × 4.6 mm; 5 μm particle size), an isocratic flow elution program and a simplified sample pretreatment approach were used in the experiment. Samples from different parts of S. sphenanthera were extracted by chloroform and then separated with methanol and deionized water (70:30 v/v) at a flow rate of 0.8 mL min⁻¹. The detection wavelength was set at 280 nm. The content of lignans in fruits is the highest, and the quantities of schisantherin A, deoxyschizandrin, and γ-schizandrin from fruits are 0.56, 0.54 and 0.30%, respectively. Schisandrin is not detected in all the plant extracts. This research forms a basic framework for the better use of S. sphenanthera in medicine.

     

Supercritical fluid extraction of aflatoxin B(1) from soil

This research describes the development of a supercritical fluid extraction (SFE) method to recover aflatoxin B(1) from fortified soil. The effects of temperature, pressure, modifier (identity and percentage), and extraction type were assessed. Using the optimized SFE conditions, the mean recovery from air dried soil was 72%. The variables associated with changes in recovery of aflatoxin were co-solvents, static extraction, and temperature. Acetonitrile-2% acetic acid, used both in-cell and on-line, provided the most efficient recovery. The results indicate that desorption from the soil was the limiting factor in recovery and that the static phase was more important than the dynamic.     

华中五味子挥发性成份的研究

华中五味子有收敛、止咳、止汗、止泻、活血和健胃等作用。近年来已分离到约15种非挥发性成份,但关于它的挥发性成份迄今未见报道。我们用毛细管气相色谱法分离出     

Supercritical fluid extraction of kava lactones from Piper methysticum (kava) herb

Supercritical fluid extraction of kava lactones from Piper methysticum Forst. herb is described here. The extraction was performed with supercritical carbon dioxide alone and supercritical carbon dioxide modified with 15% ethanol, and the extracts were analyzed by gas chromatography/mass spectrometry. Seven lactones including: 7,8-dihydrokavain; kavain; 5,6-dehydrokavain; 5, 6, 7, 8-tetrahydroyangonin; dihydromethysticin; yangonin; and methysticin were the major constituents in the SFE extract.     

Supercritical fluid extraction of Beauvericin from maize

Beauvericin (BEA), a supercritical fluid extraction with supercritical carbon dioxide from maize was investigated. Extraction efficiencies under several different extraction conditions were examined. Pressure, temperature, extraction time, organic modifier and water matrix content (10%) were investigated. The best extraction conditions were at a temperature of 60 °C, 3200 psi, for 30 min static extraction time and methanol as modifier solvent. Extraction recovery of 36% without modifier by adding water to the matrix in the extraction vessel (reproducibility relative standard deviations (R.S.D.)=3-5%) were recorded. Extraction recovery of 76.9% with methanol as co-solvent (reproducibility R.S.D.=3-5%) was obtained. Data shows that SFE gives a lower BEA recovery compared to conventional extraction protocol with organic solvents while SFE with modifier and conventional extraction yields are comparable. BEA extract contents were determined by high pressure liquid chromatography (HPLC) with a diode array detector (DAD) at 205 nm and BEA peak confirmed by LC-MS. Acetonitrile-water as mobile phase and column C-18 were both tested. Instrumental and analytical parameters were optimized in the range linear interval from 1 to 500 mg kg⁻¹ and reached a detection limit of 2 ng.     

南五味子中五味子甲素的薄层扫描色谱定量分析

南五味子是2000年中国药典开始收录的中药材。南五味子与北五味子的性状完全不同,所含化学成分亦不同,功能主治各有侧重。南五味子为木兰科植物华中五味子的干燥成熟果实,性味酸、甘、温,具有收敛固涩,益气生津,补肾宁心之功效。现代研究表明,南五味子的活性成分主要包括五味子甲素和五味子酯甲等木脂素成分。五味子甲素具有显著的功效,但药典仅有五味子酯甲的含量测定,未有五味子甲素的含量测定,相关研究报道也很少,因此有必要研究建立南五味子中五味子甲素含量测定方法。     

Supercritical fluid extraction of flavonoids from Scutellariae Radix

An optimal condition of supercritical fluid extraction (SFE) for flavonoids of Scutellaria baicalensis was developed. In this study, various temperatures, pressures and modifiers were studied. The conventional extraction methods were conducted in parallel for comparison. The crude extracts were qualitatively compared by TLC and GC–MS, and the contents of flavonoids were determined by HPLC. The amounts of baicalin, baicalein and wogonin in the Scutellariae Radix obtained by supercritical fluid extraction and a conventional sonic shaking method were 137.6 mg/g, 8.6 mg/g and 2.2 mg/g, 113.5 mg/g, 5.7 mg/g and 2.3 mg/g, respectively. Application of SFE for extraction of the flavonoids from Scutellariae Radix was preferable. The optimal conditions of SFE was as follows: supercritical carbon dioxide–MeOH–water (20:2.1:0.9), 50°C and 200 bar.     

Supercritical fluid extraction of oxadixyl from food crops

Summary This work describes the study of a degradation curve of Oxadixyl in field-treated potato and tomato samples. The residues were extracted using classical and supercritical fluid (SFE) extraction methods and analyzed by HRGC/ECD. The extraction techniques were compared and the results indicate the advantages of using SFE as an alternative method for pesticide analyses in these samples.     

Supercritical fluid extraction of pesticides

Summary The extraction behaviour of 10 g samples of five pesticides and some related compounds from glass wool with supercritical CO₂ has been investigated under several conditions (10 MPa, 20 MPa extraction pressure, 313 K, dry and water saturated CO₂). The extraction fluid was decompressed over a line of little columns, filled with 3 Si₆0 or RP18, and the amount of deposited material was analyzed by HPLC for each of these columns. Due to the progressive pressure/density reduction along the line, the solubility diminishes and hence the compounds are deposited according to their polarity/vapor pressure earlier or later on the line. Thus extraction and prefractionation of compounds of different polarity take place in one sample preparation step.

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Extraktion von Pesticiden mit überkritischen fluiden PhasenI. Extraktionseigenschaften von ausgewählten Pesticiden in CO₂

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Herrn Prof. Dr. R. Neeb zum 60. Geburtstag gewidmet     

Supercritical fluid extraction of Moroccan (Timahdit) oil shale with water

Timahdit oil shale was subjected to supercritical water extraction. The results reveal significant difference in oil yields and composition when compared with those obtained from conventional pyrolysis. In addition, the effect of temperature and residence time on the supercritical water extraction of oil was investigated in a set of three experiments. The results revealed that the yield and the fraction of paraffins and aromatics increase while the percentage of asphaltenes decreases as the temperature is increased from 380 to 400°C. The residence time was found to affect the yield and the fraction of asphaltenes and polar compounds.     

Supercritical fluid extraction of 2,3,7,8-tetrachlorodibenzo-p-dioxin from sediment samples

Supercritical fluid extraction (SFE) is a promising technique for the extraction of 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD) from environmental matrices such as contaminated sediments. The ability of SFE to solubilize many organic contaminants is well documented in industrial processes but its analytical applications were exploited just recently. In this study supercritical carbon dioxide and nitrous oxide and their mixtures with 2% methanol were used to extract 2,3,7,8-TCDD from aquatic sediments. An attractive feature of this process is that the carbon dioxide, being a virtually inert fluid, leaves no solvent residue on the processed sediment. Almost 100% of the 2,3,7,8-TCDD can be extracted from a sediment spiked with 200 μg/kg 2,3,7,8-TCDD in 30 minutes by using supercritical carbon dioxide + 2% methanol. Cleanup procedure is compared with the Soxhlet extraction procedure currently used as a standard method for extracting dioxins from sediment samples.     

Supercritical fluid extraction of triazine herbicides from solid matrices

Summary Several investigations were performed to optimise the extraction of polar triazine herbicides using supercritical fluid extraction from two different solid matrices: C₁₈-silica and soil samples. Supercritical CO₂ modified with methanol [10% (VV)] at 250 bars and 50°C was required to quantitatively extract Atrazine and 2-Hydroxyatrazine from spiked C₁₈-silica. Extraction of Desisopropyl-desethyl-2-hydroxyatrazine (MET) attained only 52%, even following addition of water to the polar modifier. Extractions of spiked soil samples (20 ppm of each pesticide) were successful at 300 bars and 65°C. A non polar wash improved the recoveries of the three target analytes [i.e. atrazine: 88%; 2-hydroxyatrazine: 96%; MET: 41%]. The extraction parameters employed are discussed in this paper.     

Supercritical fluid extraction of phenol compounds from olive leaves

A clean, highly selective supercritical fluid extraction (SFE) method for the isolation of phenols from olive leaf samples was examined. Total phenol extracts were determined using the Folin-Ciocalteu reagent. Dried, ground, sieved olive leaf samples (30 mg) are subjected to SFE, using carbon dioxide modified with 10% methanol at 334 bar, 100 degrees C (CO(2) density 0.70 g ml(-1)) at a liquid flow-rate of 2 ml min(-1) for 140 min. Diatomaceous earth is used to reduce the void volume of the extraction vessel. The influence of extraction variables such as modifier content, pressure, temperature, flow-rate, extraction time, and collection/elution variables, were studied. Supercritical fluid extracts were screened for acid compounds such as carboxylic acids and phenols using Electrospray-MS (in the negative ionization mode). SFE was found to produce higher phenol recoveries than sonication in liquid solvents such as n-hexane, diethyl ether and ethyl acetate. However, the extraction yield obtained was only 45%, using liquid methanol.     

Supercritical fluid extraction of oxindole alkaloids from Uncaria tormentosa

Supercritical fluid extraction of oxindole alkaloids from Uncaria Tormentosa is described. The extraction was performed with supercritical carbon dioxide alone and with supercritical carbon dioxide modified with 10% metanol, and the extracts were analyzed by GC/MS and HPLC/MS.