High anti-inflammatory activity of harpagoside-enriched extracts obtained from solvent-modified super- and subcritical carbon dioxide extractions of the roots of Harpagophytum procumbens

Solvent-modified carbon dioxide extractions of the roots of Harpagophytum procumbens have been investigated with respect to extraction efficiency and content of harpagoside, and compared with a conventional extract. The effects of pressure, temperature, type and concentration of the modifier have been examined. Two extraction steps were necessary in order to achievehigh anti-inflammatory harpagoside-enriched extracts. The first extraction step was carried out in the supercritical state using carbon dioxide modified with n-propanol to remove undesired lipophilic substances. The main extraction was performed either in the supercritical or in the subcritical state with carbon dioxide modified with ethanol. The supercritical fluid extraction resulted in extracts containing up to 30% harpagoside. The subcritical extracts showed a harpagoside content of ca. 20%, but the extraction yield was nearly three times greater compared with supercritical conditions. The total harpagoside recovery resulting from the sum of the extract and the crude drug residue was greater than 99% in all experiments. The conventional extract and two carbon dioxide extracts were tested for in-vitro inhibition of 5-lipoxygenase or cyclooxygenase-2 biosynthesis. Both carbon dioxide extracts showed total inhibition on 5-lipoxygenase biosynthesis at a concentration of 51.8 mg/L. In contrast, the conventional extract failed to show any inhibition of 5-lipoxygenase biosynthesis.     

Supercritical fluid extraction of naringin from the peel of Citrus paradisi

The highest yield (14.4 g/kg) of naringin, the major flavonoid from the peel of Citrus paradisi L., that could be achieved by supercritical fluid extraction was obtained using supercritical carbon dioxide modified with 15% ethanol and fresh (rather than dried) peels at 95 bar and 58.6 degrees C. This yield is higher than that attained by the conventional technique of maceration, and close to those obtained by reflux and Soxhlet methods. Furthermore, supercritical fluid extraction consumes less solvent and provides a shorter extraction time than conventional extraction methods.     

Extraction of squalene from yeast by supercritical carbon dioxide

Squalene produced under anaerobic conditions, by a strain of Torulaspora delbrueckii was extracted from the biomass using supercritical carbon dioxide. Minimum use of solvent, lower time of isolation and a higher selectivity of extraction merit use of supercritical fluid extraction (SFE) technique over solvent extraction of squalene, as optimized and reported previously. A maximum squalene yield of 11.12 g g^–1 (dry weight) of yeast cells was obtained at a temperature of 60 °C and pressure of 250–255 bar at a constant flow rate of 0.2l min^–1 of carbon dioxide. Lyophilization prior to SFE increased the squalene yield to 430.52 g g^–1 dry weight of yeast cells, an amount that is far greater than that obtained by (2:1) chloroform–methanol solvent extraction.     

秋橄榄果实中番茄红素的超临界萃取技术研究

秋橄榄果实中番茄红素含量丰富。利用超临界二氧化碳技术萃取秋橄榄中的番茄红素,对影响萃取的诸因素,如萃取压力、萃取温度、萃取时间、夹带剂等进行研究,并进一步用响应曲面法优化萃取工艺条件。结果表明：丙酮作为夹带剂效果最佳,优化后的最佳萃取工艺条件是萃取压力37MPa,萃取温度52℃,萃取时间3．8h。     

Extraction and fractionation of complex lipid mixtures with dense carbon dioxide on a micro scale

The effects of pressure, temperature and some organic solvents on the recovery of various lipid classes from plant and animal tissues can be assessed by fractional extraction with dense carbon dioxide and consecutive analysis by thin-layer chromatography.     

Supercritical carbon dioxide extraction of colchicine and related alkaloids from seeds of Colchicum autumnale L

A method for the extraction of the alkaloids colchicine, 3-demethylcolchicine and colchicoside from seeds of Colchicum autumnale by supercritical carbon dioxide has been established. Several parameters such as pressure, temperature, percentage of modifier and extraction time have been examined. Two extraction steps with constant carbon dioxide density (0.90 g/mL) and flux (1.5 mL/min) were required to extract the alkaloids in 110 min using 3% methanol as modifier. The quantitative determination of the alkaloids was performed by HPLC; the percentages of recovery were higher than 98% for the three alkaloids. This extraction procedure was compared with a conventional method involving maceration and sonication, and the same levels of alkaloids were obtained in each case. The supercritical carbon dioxide method is, however, very efficient, more rapid and more environmentally friendly than conventional methods.     

地鳖虫活性物质的超临界CO_2萃取及其药效

应用超临界流体萃取技术萃取地鳖虫Eupolyphaga sinensisWalker活性物质,采用三因素三水平正交试验方案,考察压力、温度、时间等参数对萃取地鳖虫活性物质萃取量的影响。同时,对萃取产物与水提物进行药效比较。结果表明,在试验设计范围内,萃取压力18 MPa、温度55℃、时间90 min为最佳工艺参数组合,地鳖虫活性物质萃取量最大能达到62.50 mg/g,影响萃取量三因素主次关系为压力>温度>时间。地鳖虫超临界萃取产物对镇痛、消炎和抗凝血有较好的效果,相对于水提物有更好的发展潜力。     

HPLC comparison of supercritical fluid extraction and solvent extraction of coumarins from the peel of Citrus maxima fruit

The efficiency of carbon dioxide supercritical fluid extraction (SFE) of the biologically active compounds imperatorin, meranzin and meranzin hydrate from the fruit peel of Citrus maxima Merr. has been compared with that of solvent extraction with acetone. Under the best SFE conditions tested for the three coumarins, which involved extraction at 50 degrees C and 27.6 MPa, the extractive efficiencies were 84, 76 and 18% for imperatorin, meranzin and meranzin hydrate, respectively. The presence of modifiers significantly affected the extraction efficiency: the highest extraction efficiency of the three coumarins was obtained with ethanol as modifier.     

Application of supercritical CO2 for extraction of polyisoprenoid alcohols and their esters from plant tissues

In this study, a method of supercritical fluid extraction (SFE) with carbon dioxide of polyisoprenoids from plant photosynthetic tissues is described. SFE was an effective extraction method for short- and medium-chain compounds with even higher yield than that observed for the “classical extraction” method with organic solvents. Moreover, SFE-derived extracts contained lower amounts of impurities (e.g., chlorophylls) than those obtained by extraction of the same tissue with organic solvents. Elevated temperature and extended extraction time of SFE resulted in a higher rate of extraction of long-chain polyisoprenoids. Ethanol cofeeding did not increase the extraction efficiency of polyisoprenoids; instead, it increased the content of impurities in the lipid extract. Optimization of SFE time and temperature gives the opportunity of prefractionation of complex polyisoprenoid mixtures accumulated in plant tissues. Extracts obtained with application of SFE are very stable and free from organic solvents and can further be used directly in experimental diet supplementation or as starting material for preparation of semisynthetic polyisoprenoid derivatives, e.g., polyisoprenoid phosphates.     

超临界流体萃取——高效液相色谱法测定百合中秋水仙碱

分别用超临界二氧化碳流体和有机溶剂萃取百合中的秋水仙碱,然后用高效液相色谱法直接测定萃取物中秋水仙碱的含量,从而测得百合中秋水仙碱的含量。超临界流体萃取的条件是：用乙醇作提携剂,萃取压力为18MPa,萃取温度为40℃,高效液相色谱测定条件为：ODS柱,甲醇：磷酸二氢钾溶液作流动相,检测波长为220nm,此法快速,简便,准确,可应用于秋水仙碱原料,制剂及其它植物中秋水仙碱含量的测定。     

茯神挥发性成分及其生物活性研究

为研究茯神挥发性成分含量、构成及其生物活性,本实验采用二氧化碳超临界的方法提取茯神低极性成分,以提取率作为响应值,在单因素试验的基础上采用响应曲面法考察提取压力、温度、二氧化碳流速对提取效果的影响,优化提取工艺。运用气相色谱-质谱联用仪(GC-MS)对其主要化学成分进行鉴定,并采用生长速率法测定了挥发油对5种真菌的生物活性。得到提取模型极值点,即提取压力27.26MPa、提取温度55.97℃、提取流速10.68L/min时,提取率达到最大,提取率预测值为1.66mg/g。通过NIST14质谱库检索,鉴定了其中17个主要化合物,运用峰面积归一法确定各个组分的含量,占挥发油总量的84.5%。抗菌实验表明茯神挥发油对采绒革盖菌菌株有低浓度促进高浓度抑制的活性。     

杜香挥发油的超临界CO2萃取实验条件优化

采用正交实验法对超临界CO₂萃取杜香挥发油的条件进行了优化。研究了萃取温度、萃取压力、CO₂流量等因素在不同水平下对杜香挥发油提取率的影响。得到了超临界CO₂萃取杜香挥发油的最佳实验条件：萃取压力为20 Mpa、萃取温度为35℃、CO₂的流量为60 kg·h^-1。     

芹菜子的超临界CO2流体萃取物的化学成分研究

本文采用ＧＣ和ＧＣ－ＭＳ技术,就芹菜子的超临界ＣＯ２流体萃取法（ＳＦＥ－ＣＯ２）精油和水汽蒸馏法（ＳＤ）精油的化学组成作了对比研究。结果表明,ＳＤ法精油的主要成分为单萜烯烃类物质,而ＳＦＥ－ＣＯ２法精油为苯并呋喃酮类化合物。共有３２种化合物被鉴定,其中两种为首次在芹子油中被发现。     

Supercritical carbon dioxide extraction of hydrocarbons from the microalgaBotryococcus braunii

Samples of the microalgaBotryococcus braunii were submitted to supercritical fluid extraction with carbon dioxide at 40 °C and pressures of 12.5, 20.0 and 30.0 MPa. The extraction yield and the fraction of the hydrocarbons in the extracts both increased with pressure and at 30 MPa these compounds were obtained rapidly. This behaviour is associated with the localization of the hydrocarbons outside the cell wall. In the extracts, which are fluid, golden and limpid, chlorophyll and phospholipids were not detected.Author for correspondence     

猴头菌子实体超临界流体技术萃取活性物质初探

以猴头菌子实体为原料,萃取物得率作为指标,采用CO₂超临界流体萃取技术,以萃取压力和CO₂流量等参数为考察因素,结合正交试验获得优化的萃取工艺：萃取压力为30MPa,温度为45℃,时间为1.5h,CO₂流量为20g/min,夹带剂（乙醇）与猴头菌子实体的物料比为5:1（mL:g）,在此条件下,萃取物得率为2.78%。与猴头菌子实体的醇提物相比,猴头菌子实体超临界萃取物具有更好的体外抗氧化能力和抗肿瘤活性,本研究结果为合理地开发和利用猴头菌子实体超临界萃取物产品提供科学的数据。     

Mathematical modeling and study of mass transfer parameters in supercritical fluid extraction of fatty acids from Trout powder

Mathematical modeling of fatty acids (FAs) extraction from Trout powder by supercritical carbon dioxide was performed in the present work. Trout powder with its low cost contains high amount of essential FAs and it is commonly available as a proper source of FAs. The effect of process parameters, such as pressure (25, 28, 31, 34 and 37 MPa) and temperature (310, 318 and 326 K) of extraction and void fraction of the bed (0.25, 0.35 and 0.45, v/v) on the yield of FAs extraction was examined in a series of experiments conducted in a laboratory scale apparatus. The results indicated a significant increase of extraction yield with an increase of pressure from 25 to 34 MPa, but working at the higher pressure (37 MPa) caused reduction of the extract. Increasing the temperature higher than 318 K revealed significant reduction of the FAs yield and increasing the bed void fraction from 0.25 to 0.45 showed enhancement of the extraction.

The mathematical model was developed considering diffusion-controlled regime in the particle and film mass transfer resistance around the particle with axial dispersion of the bulk phase at dynamic conditions. Henry law was used to describe the equilibrium state of solid and fluid phases. The proposed mass balance equations were numerically solved using implicit finite difference method and the model parameters were correlated using the experimental results of the outlet FAs concentration in the oil extracted at dynamic conditions. Well-known Nelder–Mead method was applied to estimate the four parameters of the model, namely, mass transfer coefficient (k_f), axial dispersion coefficient (D_ax) in the bulk phase, effective diffusivity (D_eff) into the pores and Henry coefficient (H). In the range of studied conditions, the higher extraction efficiency with higher pressure resulted lower correlated H, although the temperature increasing which showed a retrograde phenomena in the FAs yield, revealed H passing though a minimum.     

北五味子果实超临界CO2萃取工艺的研究

通过正交设计的试验方法,探讨了超临界CO₂法萃取五味子果实中木脂素的工艺条件,确定了最佳工艺条件为萃取压力30 Mpa,萃取温度50℃,萃取时间120 min。     

Supercritical carbon dioxide extraction of chamomile flowers: extraction efficiency, stability, and in-line inclusion of chamomile-carbon dioxide extract in beta-cyclodextrin

The extraction of chamomile flowers using supercritical carbon dioxide was investigated with respect to extraction efficiency and compared with solvent extraction. The stability of matricine, a sensitive constituent of the essential oil of chamomile, in these extracts was studied during storage at different temperatures over 6 months. Matricine was stable at -30 degrees C. A slight decrease (80-90% recovery) occurred at +5 degrees C, whereas complete decomposition of matricine took place within 3-4 months at room temperature and at +30 degrees C, respectively. An in-line inclusion of chamomile constituents in beta-cyclodextrin (beta-CD) during the extraction process was assessed and inclusion rates between 40 and 95% were obtained depending on the amount of beta-CD and the type of chamomile constituent. No further stabilization of matricine in the carbon dioxide extract/beta-CD complexes was achieved. High residual water contents in the complexes even after freeze-drying were identified as accelerating the decomposition. In addition, the extractability of flavonoids, such as apigenin and apigenin-7-glucoside, was determined. Apigenin-7-glucoside, the more hydrophilic substance, was not extractable with pure carbon dioxide and showed a recovery of 11% using methanol modified carbon dioxide (18%, w/w) at 60 degrees C and 380 bar. Extraction conditions in the two-phase region of the binary mixture carbon dioxide-methanol (70 degrees C, 100 bar) led to a drastic change in fluid polarity and hence extractability increased to 92-95%.     

Distribution of aflatoxins between extract and extraction residue of paprika using supercritical carbon dioxide

Paprika powder, naturally contaminated with aflatoxins, was extracted by supercritical carbon dioxide at standard conditions (300 bar and 50 degrees C). A lipophilic top phase and an aqueous base phase were obtained. These and the extraction residue were analysed by HPLC for aflatoxins. The main quantity of aflatoxins, about 60% of aflatoxin B1 and about 70% of aflatoxin B2 related to the original paprika powder, was found to be located in the extraction residue. This confirms the results of previous studies with other spices and demonstrates that the use for flavouring purposes of supercritical carbon dioxide extracts, rather than natural spice, offers potential application in reducing aflatoxin levels in spiced foods.     

Optical resolution of 6-fluoro-2-methyl-1,2,3,4-tetrahydroquinoline by supercritical fluid extraction

6-Fluoro-2-methyl-1,2,3,4-tetrahydroquinoline (FTHQ) enantiomers were separated by supercritical fluid extraction using carbon dioxide. Diastereoisomeric salts were formed from the racemic base with less than one equivalent of O,O'-di-(4-toluoyl)-(2R,3R)-tartaric acid (DPTTA). Further purification was achieved by partial salt formation of the enantiomeric mixture with an achiral acid (HCl) followed by the supercritical fluid extraction of the free enantiomers.