Influence of extraction methods on the composition of essential oils

The aim of this work is to demonstrate our results on comparison of composition of essential oil fractions obtained by traditional steam distillation and supercritical fluid extraction. The plant materials for the various extraction methods were selected from the Lamiaceae, Apiaceae and Asteraceae families. For the supercritical fluid extraction (SFE) carbon dioxide was used as supercritical solvent. The extracts were collected by stage wise precipitation in two separators. The waxy product and extract rich in essential oil were collected in the 1st and in the 2nd separator respectively. The traditional water steam distillation (SD) was carried out in the special apparatus of the Hungarian Pharmacopoea (7th ed.). GC analysis was carried out on capillary silica fused columns coated with DB-1701 and the specific chiral columns coated with Rt-beta DEX m or Rt-beta DEX sm. Comparing the composition of steam distilled oils with that of volatile SFE fractions the following general characteristics were established. The SFE fractions were richer in monoterpene-esters and poorer in alcohols than the traditional essential oils (clary sage, lavander, moldavian dragonhead). Regarding the distribution of the monoterpene and sesquiterpene compounds, the SFE fractions contained sesquiterpenes in higher percentage than the distilled oils (Salvia fruticosa). Furthermore, the proportion of sesquiterpenes increased in SFE fractions collected successively with time (Salvia officinalis) similar to the ratio of oxygenated monoterpenes to monoterpene hydrocarbons (Rosmarinus officinalis). The phtalides of lovage (Satureja hortensis) did not show regular change during the supercritical extraction. In other cases it was verified that part of the mono- and sesquiterpenes were present originally in bound form (glycosides) in plants. Thus they appeared only in essential oil fractions after previous acidic treatment (Thymus, Origanum, Satureja species). During the super-critical extraction the azulenogene sesquiterpene lactones did not transform to azulenes (chamomile, yarrow), but SFE fractions of some Asteraceae plants contained sesquiterpene-gamma-lactones of unchanged structure.     

Pharmaceutical applications of supercritical carbon dioxide.

The appearance of a supercritical state was already observed at the beginning of the 19th century. Nevertheless, the industrial extraction of plant and other natural materials started about twenty years ago with the decaffeination of coffee. Today carbon dioxide is the most common gas for supercritical fluid extraction in food and pharmaceutical industry. Since pure supercritical carbon dioxide is a lipophilic solvent, mixtures with organic solvents, especially alcohols, are used to increase the polarity of the extraction fluid; more polar compounds can be extracted in this way. The main fields of interest are the extraction of vegetable oils from plant material in analytical and preparative scale, the preparation of essential oils for food and cosmetic industry and the isolation of substances of pharmaceutical relevance. Progress in research was made by the precise measurement of phase equilibria data by means of different methods. Apart from extraction, supercritical fluid chromatography was introduced in the field of analytics, as well as micro- and nanoparticle formation using supercritical fluids as solvent or antisolvent. This review presents pharmaceutical relevant literature of the last twenty years with special emphasis on extraction of natural materials.     

超临界流体萃取技术与中药现代化

本文介绍了超临界流体萃取技术的基本原理和工艺流程、该技术在中草药有效成分提取分离中的应用以及超临界流体色谱技术。     

Pharmaceutical applications of supercritical carbon dioxide

The supercritical state of a fluid is intermediate between that of gases and liquids. Supercritical fluids exhibit some solvent power which is tunable in function of pressure and temperature. In the pharmaceutical field, supercritical carbon dioxide is by far the most commonly used fluid; of course, the first applications of supercritical fluids were the replacement of organic solvents in extraction processes; other applications appeared during the last twenty years: supercritical fluids are also used as eluents in chromatography, as solvents in organic synthesis or for the processing of solid dosage forms by drug micronization, by the production of nanospheres, of solid dispersions, of porous polymeric matrices containing different active substances. Supercritical carbon dioxide has been proposed for encapsulating both hydrophilic and hydrophobic drug substances into liposomes as well as for including different active substances into cyclodextrins. There are also future prospects for the use of pressurized carbon dioxide as a sterilizing agent.     

Use of advanced techniques for the extraction of phenolic compounds from Tunisian olive leaves: Phenolic composition and cytotoxicity against human breast cancer cells

A comparison among different advanced extraction techniques such as microwave-assisted extraction (MAE), supercritical fluid extraction (SFE) and pressurized liquid extraction (PLE), together with traditional solid–liquid extraction, was performed to test their efficiency towards the extraction of phenolic compounds from leaves of six Tunisian olive varieties. Extractions were carried out at the best selected conditions for each technique; the obtained extracts were chemically characterized using high-performance liquid chromatography (HPLC) coupled to electrospray time-of-flight mass spectrometry (ESI-TOF-MS) and electrospray ion trap tandem mass spectrometry (ESI-IT-MS²). As expected, higher extraction yields were obtained for PLE while phenolic profiles were mainly influenced by the solvent used as optimum in the different extraction methods. A larger number of phenolic compounds, mostly of a polar character, were found in the extracts obtained by using MAE. Best extraction yields do not correlate with highest cytotoxic activity against breast cancer cells, indicating that cytotoxicity is highly dependent on the presence of certain compounds in the extracts, although not exclusively on a single compound. Therefore, a multifactorial behavior is proposed for the anticancer activity of olive leaf compounds.     

Anti-HIV activity of Indian medicinal plants

Acquired immunodeficiency syndrome patients face great socio-economic difficulties in obtaining treatment. There is an urgent need for new, safe, and cheap anti-HIV agents. Traditional medicinal plants are a valuable source of novel anti-HIV agents and may offer alternatives to expensive medicines in future. Various medicinal plants or plant-derived natural products have shown strong anti-HIV activity and are under various stages of clinical development in different parts of the world. The present study was directed towards assessment of anti-HIV activity of various extracts prepared from Indian medicinal plants. The plants were chosen on the basis of similarity of chemical constituents with reported anti-HIV compounds or on the basis of their traditional usage as immunomodulators. Different extracts were prepared by Soxhlet extraction and liquid-liquid partitioning. Ninety-two extracts were prepared from 23 plants. Anti-HIV activity was measured in a human CD4+ T-cell line, CEM-GFP cells infected with HIV-1NL4.3. Nine extracts of 8 different plants significantly reduced viral production in CEM-GFP cells infected with HIV-1NL4.3. Aegle marmelos, Argemone mexicana, Asparagus racemosus, Coleus forskohlii, and Rubia cordifolia demonstrated promising anti-HIV potential and were investigated for their active principles.     

Identification and isolation of the cyclooxygenase-2 inhibitory principle in Isatis tinctoria

Various extracts prepared from the traditional dye and medicinal plant Isatis tinctoria L. were submitted to a broad in vitro screening against 16 anti-inflammatory targets. Dichloromethane (DCM) extracts from dried leaves showed a marked cyclooxygenase (COX) inhibitory activity with a preferential effect on COX-2 catalysed prostaglandin synthesis. A supercritical fluid extraction (SFE) procedure employing CO2-modifier mixtures was developed by which the bioactivity profile and chromatographic fingerprint of the DCM extract could be reproduced. High-resolution activity directed on-line identification of the COX-2 inhibitory principle, using a combination of LC-DAD-MS with a microtitre-based bioassay, led to the identification of tryptanthrin (1) as the constituent responsible for essentially all COX-2 inhibitory activity in the crude extract. Following on-line identification, 1 was isolated at preparative scale and its structure confirmed by comparison with synthetic tryptanthrin. In an assay with lipopolysaccharide stimulated Mono Mac 6 cells, tryptanthrin (1) was of comparable potency (IC50 = 64 nM) than the preferential COX-2 inhibitors nimesulide (IC50 = 39 nM) and NS 398 (IC50 = 2 nM). The SFE extract and 1 showed no cytotoxicity in Mono Mac 6 and RAW 264.7 cells when tested at 100 microg/ml and 10 microM, respectively.     

川芎挥发油提取工艺的研究进展

川芎是一种重要的药用植物,其主要成分是挥发油。本文综述了川芎挥发油的各种提取方法,包括水蒸气蒸馏法、溶液萃取法、提取-共沸精馏耦合新工艺、超临界流体萃取法和超声强化超临界CO2萃取法,从得率、提取得到的成分及含量等方面对各种方法的优缺点进行了比较和分析,并对其发展方向提出展望。     

广东海风藤超临界流体萃取物的气相色谱-质谱联用分析

目的 分析广东海风藤超临界萃取物的化学成分.方法 采用CO2超临界流体萃取广东海风藤的脂溶性部位,以气相色谱-质谱联用(GC-MS)法鉴定化学成分,面积归一化法测定各成分相对含量.结果 从广东海风藤超临界萃取物中共分离出28个组分,鉴定了其中25个化合物,占萃取物总量的78.33%,主要为T-杜松醇(18.195%)、8-杜松烯(11.485%)、α-没药醇(8.304%)和瓦伦烯(6.672%).结论 广东海风藤的挥发油提取物中主要含有萜烯和萜醇.     

Optimization and comparison of three methods for extraction of volatile compounds from Cyperus rotundus evaluated by gas chromatography-mass spectrometry

The essential oil of Cyperus rotundus has multiple pharmacological activities. Therefore, the extraction with high yield and quality is very important for preparation of essential oil of C. rotundus. In this paper, three methods, namely hydrodistillation (HD), pressurized liquid extraction (PLE) and supercritical fluid extraction (SFE), for extraction of volatile compounds from C. rotundus were optimized and compared by gas chromatography-mass spectrometry. Among eight identified compounds in C. rotundus, five components including alpha-copaene, cyperene, beta-selinene, beta-cyperone and alpha-cyperone were quantitatively determined or estimated using alpha-cyperone as standard, which showed that PLE had the highest extraction efficiency, while SFE had the best selectivity for extraction of beta-cyperone and alpha-cyperone. The contents of ingredients from C. rotundus extracted with HD, PLE and SFE are significantly different, which suggest that comparison of chemical components and pharmacological activities of different extracts is helpful to elucidate the active components in C. rotundus and control its quality.     

超临界CO_2-分子蒸馏对螺旋藻有效成分的萃取与分离

目的　研究螺旋藻的化学成分并建立提取方法。方法　采用超临界CO2 分子蒸馏对螺旋藻化学成分进行萃取与分离 ,并对其提取物和蒸出物进行GC MS分析。结果　从超临界CO2 萃取物和蒸出物分别得到 2 0种和 13种化学成分。结论　超临界CO2 分子蒸馏技术对螺旋藻的提取分离是一种先进合理的提取方法     

超临界流体萃取法在中药材质量控制中的应用

用超临界流体萃取法(supercriticalfluidextraction,SFE)代替传统的溶剂萃取法对中药材马蓝(Strobilanthescusia)、菘蓝(Isatistinctoria)和蓼蓝(Polygonumtinctorium)中有效成分靛玉红(indirubin)的萃取条件进行了研究,并用微孔高效液相色谱法做了含量监测。结果证明:SFE省时、省力、经济、选择性可调的性能很强,与传统的溶剂萃取法相比,有独特的优点。     

气-质联用分析比较麻黄及其炮制品中挥发性成分(英文)

采用气质联用法分析麻黄生品及其炮制品种的挥发油成分。采取水蒸汽蒸馏法和超临界流体萃取技术提取麻黄各品种中的挥发油, 其中通过水蒸汽蒸馏法提取得到的麻黄生品、蜜麻黄和清炒麻黄挥发油中, 鉴定的成分分别为48, 57和48种, 蜜炙和清炒后分别产生14 和 9种新成分通过超临界流体萃取法提取得到的麻黄生品、蜜麻黄和清炒麻黄挥发油中, 鉴定的成分分别为22, 36和28 种, 蜜炙和清炒后分别产生15 和23种新成分。麻黄经炮制后挥发油成分和相对含量均发生了明显变化, 这可能是导致麻黄炮制品功效的改变原因之一。     

Coupling SFE to uterotonic bioassay: an on-line approach to analysing medicinal plants

Supercritical fluid extraction has been directly coupled on-line to a uterotonic bioassay, using guinea pig uterine smooth muscle in vitro. This technique was developed for the detection of uterotonic compounds present in medicinal plants used during pregnancy to induce or augment labour. The direct passage of CO2 into the muscle chamber led to adiabatic cooling of the physiological fluid and inhibition of muscle contraction. This was alleviated by the construction of a CO2 reduction interface together with the passage of carbogen which aided in the rapid displacement of excess CO2. The on-line system was evaluated with four plants (Clivia miniata (Lindl.) Regel, Ekebergia capensis Sparrm., Grewia occidentalis L. and Asclepias fruticosa L.) that are currently used during pregnancy by some black South African women. Extractions were performed with water modified supercritical CO2. Fractions of supercritical fluid extracts, obtained by sequentially increasing the pressure from 200 to 300 and 400 atm at constant temperature were transferred directly to the muscle chamber to identify the active fractions. The 400 atm extracts of C. miniata, A. fruticosa and E. capensis displayed maximum uterotonic activity while only the 300 atm extract of G. occidentalis induced uterine muscle contraction. This technique proved to be a safe and sensitive method for analyzing medicinal plants that contain uterotonic substances hence assisting in rapidly validating the uterotonic properties and detecting any toxic effects of these extracts.     

Supercritical carbon dioxide extraction of podophyllotoxin from Dysosma pleiantha roots

Supercritical fluid extraction (SFE) was utilized to extract podophyllotoxin from the roots of Dysosma pleiantha. The extraction was carried out in the temperature range of 40-80 degrees C and the pressure range of 13.6-34.0 MPa with supercritical carbon dioxide. However, podophyllotoxin was not sufficiently extracted by pure supercritical carbon dioxide. Methanol was used as modifier to enhance the extraction yield of podophyllotoxin. As a result, SFE produced a higher recovery of podophyllotoxin than conventional 95% ethanol extraction.     

Bioanalytical applications using supercritical fluid techniques

The bioanalytical applications of supercritical fluid techniques, such as supercritical fluid extraction (SFE) and supercritical fluid chromatography (SFC), are of increasing interest. The main role of these techniques is in the sample preparation and separation of biologically active compounds, particularly drugs and their metabolites, as well as endogenous compounds. An insight is given into the different types of extracting fluids and modifiers, detectors, stationary phases, mobile phases and collection strategies. A critical discussion is presented on the existing state of the art concerning the applications of SFC and SFE with a specific focus on its advantages and limitations in the bioanalytical field. New developments and the possibilities for routine work in the near future are also covered.     

Supercritical fluid extraction-liquid chromatography method development for a polymeric controlled-release drug formulation

We have recently been involved in the development of a method for assaying the active component in a controlled-release drug formulation, which is composed of a drug substance covalently bonded to polymer matrix. The drug substance in the formulation is the active enantiomer of misoprostol, a synthetic analog of natural prostaglandins and the active ingredient in Cytotec^®. Our method development consisted of a systematic evaluation of dynamic, off-line supercritical fluid extraction (SFE) as sample preparation for the formulation assay. Extracts were analyzed with normal phase and reversed-phase HPLC methods. The reversed-phase system utilized postcolumn reaction to provide selective detection of the extracted prostaglandin sample components. Several SFE parameters were investigated to optimize the recovery of the drug substance from the formulation, including sample quantity, extraction cell volume, extraction duration, supercritical carbon dioxide modifier, temperature, pressure, and collection solvent. The SFE experiments were completed with a commercially available multicell extractor. Preliminary validation studies utilized a formulation made with radiolabeled drug to determine the recovery achieved under the optimized SFE conditions and assessed the precision of replicate determinations. Analysis was completed under the optimized conditions to quantitate levels of the active component and related compounds in lots of the experimental polymeric formulation and to determine the total weight per cent extracted.     

超临界CO_2萃取与水蒸气蒸馏法提取太子参挥发油化学成分气质联用研究

目的:分析比较采用超临界CO2流体萃取法与水蒸气蒸馏法提取的太子参提取物中挥发性化学成分的异同。方法:使用水蒸馏提取法和超临界CO2萃取技术从太子参中提取挥发性成分,用归一化法测定其百分含量。用气相色谱-质谱(GC-MS)计算机联用技术分离鉴定其中的化学组成。结果:太子参超临界CO2流体萃取物中初步鉴定了33种成分,主要成分为:亚油酸乙酯(28.70%)、n-十六酸(23.12%)、3-糠醇(5.51%)等;水蒸气蒸馏法提取挥发油初步鉴定了17种成分,主要成分为2-丙基呋喃(22.45%)、3-糠醇(19.78%)、3-乙基-3-甲基戊烷(19.47%)。结论:2种方法提取的挥发油化学成分差异较大,超临界CO2流体萃取法提取的挥发油能更真实、全面地反映太子参药材中的化学成分。     

超临界流体萃取法测定川芎中藁本内酯含量的研究

系统研究了压力、温度、静态萃取时间、动态萃取量、改性剂加入量等因素对超临界流体萃取(SFE)中药川芎中藁本内酯的影响,确定最佳萃取条件为:压力27.6MPa,温度40℃,静态萃取时间3min,动态萃取量7ml,改性剂加入量0.1ml。并对超临界流体萃取的收集方法作了研究,发现固液收集法在收集效率和精密度方面比溶剂收集法效果好。并用离线的SFE RPHPLC对川芎药材中藁本内酯的含量进行了测定。     

Comparison of solid-phase extraction and supercritical fluid extraction for the analysis of morphine in whole blood.

A comparative study of the quantitative determination of morphine in whole blood using solid-phase extraction (SPE) and supercritical fluid extraction (SFE) is described. Comparative studies were made of the two techniques for the extraction of morphine from authentic forensic blood specimens. Quantitative results indicate that morphine levels measured using SPE correspond well to morphine levels produced using SFE. The two techniques are therefore comparable, although SFE is faster and cleaner and extracts may be produced with higher analyte recoveries than with SPE. This paper presents a comparison of the two techniques and the morphine concentrations determined in blood.