Isolation of Crithmum maritimum L. volatile oil by supercritical carbon dioxide extraction and biological assays

The chemical composition of the volatile concentrate obtained by supercritical CO2 extraction of aerial parts of Crithmum maritimum L. growing spontaneously in one area of Mediterranean coast (Buggerru, Sardinia Island, Italy) and in two areas of the Atlantic coast (Figueira da Foz and S. Pedro de Moel, Portugal) was investigated by GC and GC-MS. The major oil components identified were p-cymene, beta-phellandrene, gamma-terpinene, thymol methyl ether and dillapiole. The results showed the presence of two chemotypes of C. maritimum with different dillapiole contents, ranging from 0.2 to 64.2% in Portuguese and Italian plants, respectively. The minimal inhibitory concentration (MIC) and the minimal lethal concentration (MLC) were used to evaluate the antifungal activity of the oils against yeasts and dermatophyte strains. All the oils exhibited significant antifungal activity against dermatophyte strains. The oil with the higher amount of dillapiole (64.2%) was the most active with MIC values ranging from 0.08-0.32 microL mL(-1).     

Enrichment of the thymoquinone content in volatile oil from Satureja montana using supercritical fluid extraction

Supercritical fluid extraction (SFE) of the volatile oil from Satureja montana L. was performed under different conditions of pressure (90 and 100 bar), temperature (40 and 50°C), mean particle sizes (0.4, 0.6 and 0.8 mm) and CO₂ flow rate (0.8, 1.1 and 1.3 kg/h) to understand the influence of these parameters on the composition and yield of this oil. The results were compared with those obtained for the essential oil isolated by hydrodistillation (HD). The volatile and the essential oil were analysed by GC and GC‐MS. The main compounds are carvacrol (52.2–62.0% for HD vs. 41.7–64.5% for SFE), thymol (8.6–11.0% for HD vs. 6.0–11.3% for SFE), p‐cymene (6.9–12.8% for HD vs. 6.0–17.8% for SFE), γ‐terpinene (6.4–9.4% for HD vs. 2.3–6.0% for SFE) and β‐bisabolene (2.0–2.7% for HD vs. 2.2–3.5% for SFE). The major difference between SFE and HD was the relative amount of thymoquinone, an oxygenated monoterpene with important biological activities, which can be ten‐fold higher in volatile oil (1.6–3.0 for SFE vs. 0.2% for HD). The morphology of the glandular trichomes of S. montana and the effect of the grinding process on them was also evaluated by SEM.     

Comparative studies of volatile oil composition of Rhododendron anthopogon by hydrodistillation, supercritical carbon dioxide extraction and head space analysis

Volatile oil composition of the leaves of Rhododendron anthopogon (Ericaceae) growing wild in alpine Western Himalaya was studied using different extraction techniques including SC-CO(2) extraction and hydrodistillation (HD). Results from different extraction methodologies were compared with headspace analysis (HS) and evaluated for the effectiveness of techniques in characterisation of various terpene categories and to assess their influence on the yield and composition of volatiles. Variability in constituents and in quantitative yields was observed. The results varied with different extraction methods. A total of 27 constituents in SC-CO(2) extraction, 31 in HD and 17 in HS analysis were identified. Constituents in SC-CO(2) and HD oils were identified by gas chromatography mass spectrometry analysis. SC-CO(2) extraction was carried out at 40°C and 140 bar pressure and the oil represented by major constituents as β-caryophyllene (5.96%), α-humulene (4.06%) and p-menthadiene-2,9-diol (7.28%); in HD, oil limonene (11.26%), β-caryophyllene (11.62%), α-humulene (7.22%), and E-nerolidol (5.83%) dominated the oil and in HS analysis, limonene (24.14%), γ-terpinene (40.73%), α-terpinene (4.92%), β-phellandrene (3.44%) and β-ocimene (7.15%) were present as major constituents.     

Isolation of Seseli bocconi Guss., subsp. praecox Gamisans (Apiaceae) volatile oil by supercritical carbon dioxide extraction

Isolation of the volatile concentrate from dried leaves of Seseli bocconi Guss. subsp. praecox Gamisans were obtained by supercritical fluid extraction (SFE) with carbon dioxide. Leaves from different zones of Sardinia (Italy) were collected and treated. Compositions of samples were analyzed by GC-MS. The volatile concentrate of S. bocconi from Buggerru was found to contain: himachalol (16.4%), sabinene (14.8%), beta-phellandrene (8.1%), cis-sabinene hydrate (4.5%). beta-Phellandrene (29.2%), undecane (9.6%), alpha-pinene (6.1%) and beta-guaiene (5.7%) were the main constituents of the volatile extract of S. bocconi from Carloforte. The volatile concentrate of S. bocconi of Ogliastra inland, was composed chiefly by alpha-humulene (17.7%), gamma-himachalene (9.3%), beta-phellandrene (8.0) and bicyclogermacrene (7.7%). The yields of extraction were in the range (0.13-0.60%). A comparison with the hydrodistilled oil revealed in each case a remarkable difference in composition.     

薤白挥发油成分的超临界CO2萃取及GC-MS分析

采取超临界CO2萃取和水蒸气蒸馏两种方法提取薤白中的挥发油,比较了两种提取方法得到的挥发油的理化性质,并利用GC-MS对它们进行了定性、定量分析。两种方法的主要提取物均为含硫化合物,但超临界CO2萃取法得到的含硫化合物的数量和质量都高于水蒸气蒸馏法得到的提取物。采用水蒸气蒸馏法提取8 h得到的萃取率为1.72%。通过设计的超临界CO2萃取的正交实验,得到了最佳萃取工艺条件为:压力25 MPa,温度40℃,CO2流量为25L/h。最佳萃取时间为120 min,萃取率为4.41%,是水蒸气蒸馏法萃取率的2.8倍。实验结果表明,超临界CO2萃取法简单易行,可以较快速、有效地提取薤白中的挥发油。     

Extraction of Lantana camara essential oil by supercritical carbon dioxide: influence of the grinding and biological activity

The aim of this study was to produce Lantana camara essential oil by SFE and to study the effect of matrix grinding on the yield and/or composition of the extract. Experiments were carried out on grinding matrices (G) and on not grinding matrices (NG). The extracts were analyzed by GC-MS. A comparison with the oil obtained by hydrodistillation is also given. Finally, the antibacterial and antifungal activity of the various extracts has been assayed.     

Extraction of volatile oil from aromatic plants with supercritical carbon dioxide: experiments and modeling

An overview of the studies carried out in our laboratories on supercritical fluid extraction (SFE) of volatile oils from seven aromatic plants: pennyroyal (Mentha pulegium L.), fennel seeds (Foeniculum vulgare Mill.), coriander (Coriandrum sativum L.), savory (Satureja fruticosa Béguinot), winter savory (Satureja montana L.), cotton lavender (Santolina chamaecyparisus) and thyme (Thymus vulgaris), is presented. A flow apparatus with a 1 L extractor and two 0.27 L separators was built to perform studies at temperatures ranging from 298 to 353 K and pressures up to 30.0 MPa. The best compromise between yield and composition compared with hydrodistillation (HD) was achieved selecting the optimum experimental conditions of extraction and fractionation. The major differences between HD and SFE oils is the presence of a small percentage of cuticular waxes and the relative amount of thymoquinone, an oxygenated monoterpene with important biological properties, which is present in the oils from thyme and winter savory. On the other hand, the modeling of our data on supercritical extraction of volatile oil from pennyroyal is discussed using Sovová's models. These models have been applied successfully to the other volatile oil extractions. Furthermore, other experimental studies involving supercritical CO₂ carried out in our laboratories are also mentioned.     

液态及超临界CO_2萃取八角茴香油的研究

本文用液态及超临界CO_2对八角茴香油进行了萃取研究，在萃取压力为20．0～25．0MPa的条件下，详细地考察了临界温度上下萃取温度和解析温度对出油率和油的表观相态的影响，结果表明，萃取温度越高和／或解析温度越低出油率越低；用液体CO_2萃取比用超临界CO_2萃取的出油率要高得多；萃取温度大约在318K以下或解析温度在临界温度以下时，萃取所得八角茴香油都有明显分层现象．     

Seed oil extraction with supercritical carbon dioxide modified with pentane

Chromatographia - Soybean, wheat germ, sunflower and peanut oils were extracted with supercritical carbon dioxide modified with pentane. The extractions were optimized by chemometric methods using...     

Regeneration of cobalt-contaminated activated carbon by supercritical carbon dioxide extraction

A mixture of Di-(2-ethylhexyl) phosphoric acid (D2EPHA) and n-hexane or methanol is used as the extractant solution for extracting cobalt from activated carbon using supercritical carbon dioxide extraction technology. In this work, a semi-continuous pilot unit of SFE is employed to conduct the extraction. In order to feed the viscous extractant by HPLC pump, n-hexane or methanol is added as a diluent to reduce the viscosity of the extractant. The amount of cobalt removed along the time course of the extraction is recorded and plotted as an extraction curve. A kinetic model is also established and fit to the extraction curve, and the obtained parameters of the model are used to explain the regeneration mechanism. The effects of temperature ranged from?40 to?80?°C and the effect of the concentration of diluents on the extraction are investigated and discussed based on the established model. It is also found that the removal of cobalt ions reaches a maximum; this varies with the operational conditions and is known as maximum removal efficiency. It is presumed that the maximum removal efficiency is affected by the adsorption kinetics of the extractant and the rate of ion exchange between the extractant and metal ions on the surface of the activated carbon. After increasing the extraction temperature from?60 to?80?°C it is observed that the maximum removal efficiency is greatly increased, presumably resulting from the diminishing competitive adsorption between the extractant and diluents. The established model can help to reveal the extraction mechanism and to promote maximum removal efficiency for regenerating activated carbon without secondary pollution.     

Mathematical modelling for extraction of oil from Dracocephalum kotschyi seeds in supercritical carbon dioxide

Extraction of oil from Dracocephalum kotschyi Boiss seeds using supercritical carbon dioxide was designed using central composite design to evaluate the effect of various operating parameters including pressure, temperature, particle size and extraction time on the oil yield. Maximum extraction yield predicted from response surface method was 71.53% under the process conditions with pressure of 220 bar, temperature of 35 °C, particle diameter of 0.61 mm and extraction time of 130 min. Furthermore, broken and intact cells model was utilised to consider mass transfer kinetics of extracted natural materials. The results revealed that the model had a good agreement with the experimental data. The oil samples obtained via supercritical and solvent extraction methods were analysed by gas chromatography. The most abundant acid was linolenic acid. The results analysis showed that there was no significant difference between the fatty acid contents of the oils obtained by the supercritical and solvent extraction techniques.     

超临界CO2萃取柚子叶挥发油的研究及GC-MS分析

采用超临界CO2萃取技术提取柚子叶的挥发性成分,以挥发油得率为衡量工艺参数的指标,通过正交试验法考察超临界CO2萃取过程中萃取温度、萃取压力、CO2的流量及萃取时间4个因素对柚子叶挥发油得率的影响。结果表明20MPa、萃取温度45℃、CO2流量7kg·h-1、萃取时间120min为最佳工艺。通过GC-MS对挥发油进行分析,从柚子叶挥发油中分离出144个组分,鉴定了61种成分,占化合物检出总量的90.4%。     

Selective extraction of astaxanthin from crustaceans by use of supercritical carbon dioxide

An on-line supercritical fluid extraction (SFE) system coupled to a continuous flow manifold including a UV detector was used as a screening system to extract astaxanthin from crayfish, which was found to be the major carotenoid present in the samples. This compound constitutes the principal additive used to dye salmon flesh. The flow manifold was used to confirm the presence of astaxanthin in the crustacean samples. Also, an HPLC/UV-vis method was used to ascertain that this compound was the major carotenoid extracted under the optimum SFE conditions employed. The influence of SFE operating variables such as pressure, temperature, equilibration time, extraction time, trap temperature, and volume of CO₂ modifier was examined in order to maximize the efficiency of analyte extraction. The use of supercritical CO₂ enables the expeditious, selective, quantitative extraction of astaxanthin from crustaceans.     

Extraction of Lepidium apetalum seed oil using supercritical carbon dioxide and anti-oxidant activity of the extracted oil

The supercritical fluid extraction (SFE) of Lepidium apetalum seed oil and its anti-oxidant activity were studied. The SFE process was optimized using response surface methodology (RSM) with a central composite design (CCD). Independent variables, namely operating pressure, temperature, time and flow rate were evaluated. The maximum extraction of Lepidium apetalum seed oil by SFE-CO? (about 36.3%) was obtained when SFE-CO? extraction was carried out under the optimal conditions of 30.0 MPa of pressure, 70 °C of temperature, 120 min of extraction time and 25.95 L/h of flow rate. GC-MS analysis showed the presence of four fatty acids in Lepidium apetalum seed oil, with a high content (91.0%) of unsaturated fatty acid. The anti-oxidant activity of the oil was assessed by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging assay and 2,2'-azino- bis(3-ethylbenzthiazoline-6-sulphonic acid) diammonium salt (ABTS) test. Lepidium apetalum seed oil possessed a notable concentration-dependent antioxidant activity, with IC?? values of 1.00 and 3.75 mg/mL, respectively.     

Chemical composition and bioactivity of Citrus medica L. cv. Diamante essential oil obtained by hydrodistillation, cold-pressing and supercritical carbon dioxide extraction

The chemical composition of the essential oil of Citrus medica L. cv. Diamante peel obtained by hydrodistillation, cold-pressing and supercritical carbon dioxide extraction techniques was determined by GC/MS analysis. Forty-six components were fully characterised. Limonene and γ-terpinene were the major components of the oils obtained by hydrodistillation (HD) and cold-pressing (CP), while citropten was the major constituent in the oil obtained by supercritical carbon dioxide extraction (SFE). Acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activities were evaluated. The essential oil obtained by hydrodistillation exerted the highest inhibitory activity against BChE (IC?? value of 154.6 μg mL?1) and AChE (IC?? value of 171.3 μg mL?1. Interestingly, the oil obtained by cold-pressing exhibited a selective inhibitory activity against AChE. The essential oils have also been evaluated for the inhibition of NO production in LPS induced RAW 264.7 macrophages. The oil obtained by hydrodistillation exerted a significant inhibition of NO production with an IC?? value of 17 μg mL?1 (IC?? of positive control 53 μg mL?1).     

Nanosized paclitaxel particles from supercritical carbon dioxide processing and their biological evaluation

The rapid expansion of a supercritical solution into a liquid solvent (RESOLV) technique with benign supercritical carbon dioxide was applied to obtain aqueous suspended nanoparticles of the highly potent anticancer drug paclitaxel. The paclitaxel nanoparticles were protected from agglomeration by using a known nontoxic stabilization agent. The aqueous suspended paclitaxel nanoparticles of different average particle sizes were evaluated in vitro against human breast cancer cells. The results suggest that the nanosized paclitaxel particles are effective, with an antineoplastic activity comparable to that of the commercial paclitaxel formulation. The technique should be generally applicable to the processing of nanoparticles from other important drugs with aqueous solubility problems.     

Selective extraction of strontium with supercritical fluid carbon dioxide

Strontium (Sr(2+)) can be selectively extracted from aqueous solutions into supercritical fluid CO(2) at 60 °C and 100 atm with dicyclohexano-18-crown-6 (DC18C6) using CF(3)(CF(2))(6)CO(2) (-) (PFOA(-)) or CF(3)(CF(2))(6)CF(2)SO(3) (-) (PFOSA(-)) as a counter anion; at a mole ratio of Sr(2+) : DC18C6 : PFOA(-) = 1:10:50, the extraction of Sr (5.6 × 10(-5) M) from water at pH 3 is near quantitative whereas Ca(2+) and Mg(2+) at equal concentration are only extracted to a level of 7 and 1%, respectively; PFOSA(-) is an effective counter anion for selective extraction of Sr(2+) from 1.3 M HNO(3) with DC18C6 in supercritical CO(2).     

Analysis of essential oil of Satureja thymbra by hydrodistillation, thermal desorber, and headspace GC/MS techniques and its antimicrobial activity

The essential oil composition of Satureja thymbra was analyzed by direct thermal desorber and Headspace GC/MS analysis methods. Its constituents were determined to be mainly carvacrol (40.15%), gamma-terpinene (26.56%), p-cymene (16.39%), and thymol (13.16%). The other techniques, thermal desorber and Headspace GC/MS, were used for the plant leaves at three different temperature, which showed similar results. The thermal desorber GC/MS gave better and more sensitive results than Headspace GC/MS. The essential oil was found to be active against the bacteria Escherichia coli, Pseudomonas aeruginosa, Salmonella typhimurium, Shigella sonnei, and Staphylococcus aureus and the yeast Candida albicans.