Comparative analysis of the oil and supercritical CO(2) extract of Schinus molle L. growing in Yemen

In this study, we report the preliminary data on the chemical composition of Yemeni Schinus molle L. volatile oil obtained by supercritical extraction with carbon dioxide (40°C and 90?bar), SFE, and by hydrodistillation (HD). The composition of the volatile oil has been analysed by GC and GC-MS. The content of the major constituents in the oils from leaves varied in the following ranges: germacrene D 3.7% in SFE and 16.7% in HD; β-caryophyllene 19.1% in SFE and 13.5% in HD. The amount of monoterpenes constituted 4%, in all the analysed samples, while the number of sesquiterpenes was 44% in supercritical and 67% in HD oil. Some compounds were not identified by GC-MS and it will require further analysis using other analytical techniques.     

Chemical composition and biological activity of the volatile extracts of Achillea millefolium

In this study, flowering aerial parts of wild Achillea millefolium growing on the Mediterranean coast (Sardinia Island, Italy) and on the Atlantic coast (Portugal- Serra de Montemuro) were used as a matrix for supercritical extraction of volatile oil with CO2 (SFE). The collected extracts were analyzed by GC-FID and GC-MS methods and their composition were compared with that of the essential oil isolated by hydrodistillation. A strong chemical variability in essential oils depending on the origin of the samples was observed. The results showed the presence of two type oils. The Italian volatile extracts (SFE and essential oil) are predominantly composed by alpha-asarone (25.6-33.3%, in the SFE extract and in the HD oil, respectively), beta-bisabolene (27.3-16.6%) and alpha-pinene (10.0-17.0%); whereas the main components of the Portuguese extracts are trans-thujone (31.4-29.0%), trans-crhysanthenyl acetate (19.8-15.8%) and beta-pinene (1.2-11.1%). The minimal inhibitory concentration (MIC) and the minimal lethal concentration (MLC) were used to evaluate the antifungal activity of the oils against Candida albicans, C. tropicalis, C. krusei, C. guillermondii, C. parapsilosis, Cryptococcus neoformans, Trichophyton rubrum, T. mentagrophytes, T. mentagrophytes var. interdigitale, T. verrucosum, Microsporum canis, M. gypseum, Epidermophyton floccosum, Aspergillus niger, A. fumigatus and A. flavus. The oils showed the highest activity against dermatophyte strains, with MIC values ranging from 0.32-1.25 microL mL(-1).     

Composition of seed essential oils of Rhododendron tomentosum

For the first time, the chemical composition of the seed essential oil of Rhododendron tomentosum was determined. Forty-seven compounds were identified, comprising 91.7% of the total oil. Palustrol (38.3%) and ledol (27.0%) were the predominant constituents. Some constituents, such as beta-pinene oxide, iso-menthyl acetate, nerolidyl acetate, cadalene and guaiazulene were characteristic only for the seeds and were identified for the first time in Rh. tomentosum oils. For comparison purposes, the essential oil isolated from the shoots of the same plant were analyzed [GC(FID) in combination with RIs, GC-MS and 13C NMR]. More than a half of the oil was comprised of ledol (36.5%) and palustrol (21.0%). Quantitative analysis of ascaridol, a heat-sensitive compound, was carried out by 13C NMR spectroscopy. Indeed, ascaridol undergoes partial thermal isomerization to iso-ascaridol during GC analyses.     

Supercritical fluid extraction of vapor-deposited pyrene from carbonaceous coal stack ash

The efficiencies of extraction of vapor-deposited pyrene from a high-carbon coal stack ash by Soxhlet extraction with methanol, ultrasonic extraction with toluene, acid pretreatment and subsequent ultrasonic extraction with toluene, batch extraction with toluene, and supercritical fluid extraction (SFE) are compared. SFE using CO(2) or isobutane yielded extraction recoveries virtually identical with those obtained using ultrasonic or Soxhlet extraction processes. Collection of the SFE extract was performed by expansion into a solvent or onto the head of a gas chromatography (GC) column. No loss of extracted pyrene was observed upon collection of methanol-modified CO(2) SFE by expansion into methanol. Also, no loss of pure CO(2) SFE extract was observed upon collection on the head of a GC column. However, use of a methanol or toluene modifier for CO(2) SFE directly coupled to GC effected complete loss of extracted pyrene.     

超临界CO2流体萃取法与水蒸气蒸馏法提取荆芥穗挥发油化学成分的研究

采用超临界CO2萃取法(SFE)与水蒸气蒸馏法(SD)从荆芥穗中提取挥发油。采用SE-54毛细管柱进行分析,用气相色谱-质谱法对挥发油中各种化学成分进行鉴定,用归一化法测定各组分的含量。色谱条件:SE-54毛细管柱 (30 m×0.25 mm i.d.,0.25 μm),柱温50 ℃(3 min)5 ℃/min180 ℃(2 min)10 ℃/min260 ℃(50 min);分流进样,分流比1∶50;进样口温度280 ℃。在采用超临界CO2萃取法提取的挥发油中共鉴定出54种成分,其主要成分为长叶薄荷酮、薄荷酮、亚油酸氯化物等;在水蒸气蒸馏法提取的挥发油中共鉴定出39种成分,其主要成分为长叶薄荷酮、薄荷酮、柠檬烯等。超临界法较水蒸气法更加稳定可靠,重现性好,适用于中药挥发油的化学成分分析。     

Supercritical fluid extraction of aurentiamide acetate from Patrinia villosa Juss and subsequent isolation by silica gel and high-speed counter-current chromatography

Supercritical fluid extraction (SFE) of aurentiamide acetate from Patrinia villosa Juss was performed. The optimization of parameters was carried out using an analytical-scale supercritical fluid extraction (SFE) system. Then the extraction was scaled up by 100 times using a preparative SFE system under the optimized conditions of 55 degrees C, 35 MPa and modified CO2 with 10% methanol. Then, the crude extract I obtained by SFE was chromatographed on silica gel and the solvent system composed of petroleum ether-ethyl acetate (5:1, v/v) was used to produce the crude extract II, which was further isolated and purified by high-speed counter-current chromatography (HSCCC) with a two-phase solvent system composed of n-hexane-ethyl acetate-methanol-water (1:1.2:1.2:1, v/v/v/v). One hundred fifty-five milligrams of aurentiamide acetate was obtained from 400 mg crude extract II (contained 42% target) with a purity of 99.3% determined by HPLC and 92.3% recovery in one-step elution, and identification was performed by UV, MS, 1H NMR and 13C NMR. As far as we know, this is the first report of discovering aurentiamide acetate from the plant of Patrinia genius.     

Supercritical fluid extraction for identification and determination of volatile metabolites from Angelica dahurica by GC-MS

The volatile components of Angelica dahurica were obtained by supercritical fluid extraction (SFE) method. These oils obtained were analyzed by GC-MS (identification and determination of metabolites). The compounds were identified according to their retention indices and mass spectra (electron impact (EI), 70 eV). The effects of different parameters, such as pressure, temperature, flow rate of CO(2), and the amount of modifier, on the SFE of A. dahurica oil were investigated. A total of 50 compounds of SFE extracts were identified. Phellopterin (PO), isoimperatorin (IO), imperatorin (IM), alloimperatorin (AM), byakangelicin, isooxypeucedanin, and pimpinellin were the major coumarin compounds identified in A. dahurica SFE extracts. The quantitations of PO, IO, IM, and AM were then accomplished. The calibration curves showed good linearity (R(2) >0.99) in the concentration ranges tested. The recoveries were higher than 85%, with RSDs less than 10%. The GC-MS method was successfully validated and applied to the quantitation of A. dahurica.     

An efficient new method for extraction, separation and purification of psoralen and isopsoralen from Fructus Psoraleae by supercritical fluid extraction and high-speed counter-current chromatography

Psoralen and isopsoralen were extracted from Fructus Psoraleae (Psoralea corylitolia L.) by supercritical CO2. The effect of various parameters, i.e., pressure, temperature and sample particle size on yield was investigated with an analytical-scale supercritical fluid extraction (SFE) system to find the optimal conditions. The process was then scaled up by 50 times with a preparative SFE system under the optimized conditions of pressure (26 MPa), temperature (60 degrees C) and a sample particle size of 40-60 mesh. The yield of the preparative SFE was 9.1% and the combined yield of psoralen and isopsoralen was 2.5 mg/g of dry seeds. Psoralen and isopsoralen in the extract were separated and purified by high-speed counter-current chromatography with a two-phase solvent system composed of n-hexane-ethyl acetate-methanol-water (1:0.7:1:0.8, v/v), and the fractions were analyzed by HPLC, MS, 1HNMR and 13C NMR. The structures of the products were further confirmed by comparison with authentic samples (National Institute of the Control of Pharmaceutical and Biological Products, Beijing, China).     

超临界流体萃取在天然药物分析中的应用

按物质的不同性质综述了１９９５年以来超临界流体萃取技术在天然药物分析中的一些进展情况,常见的分析主要包括萜类、生物碱、黄酮类、挥发油及苯丙素类。超临界流体萃取作为一门新型的样品前处理技术,在天然药物的分离分析中展示了其特有的优点。该技术操作温度低,不会引起热敏性的分解变质;使用的有毒溶剂少,从而减少化学药品对药物的污染。     

Composition and antioxidant activity of Thymus vulgaris volatiles: Comparison between supercritical fluid extraction and hydrodistillation

Supercritical fluid extraction (SFE) of the volatile oil from Thymus vulgaris L. aerial flowering parts was performed under different conditions of pressure, temperature, mean particle size and CO₂ flow rate and the correspondent yield and composition were compared with those of the essential oil isolated by hydrodistillation (HD). Both the oils were analyzed by GC and GC‐MS and 52 components were identified. The main volatile components obtained were p‐cymene (10.0–42.6% for SFE and 28.9–34.8% for HD), γ‐terpinene (0.8–6.9% for SFE and 5.1–7.0% for HD), linalool (2.3–5.3% for SFE and 2.8–3.1% for HD), thymol (19.5–40.8% for SFE and 35.4–41.6% for HD), and carvacrol (1.4–3.1% for SFE and 2.6–3.1% for HD). The main difference was found to be the relative percentage of thymoquinone (not found in the essential oil) and carvacryl methyl ether (1.0–1.2% for HD versus t?0.4 for SFE) which can explain the higher antioxidant activity, assessed by Rancimat test, of the SFE volatiles when compared with HD. Thymoquinone is considered a strong antioxidant compound.     

Supercritical CO2 extract from needles of Pinus nigra ssp. laricio: combined analysis by GC, GC-MS and 13C NMR

The chemical composition of the volatile concentrate prepared by supercritical CO(2) extraction of the needles of Pinus nigra Arnold ssp. laricio Poiret from Corsica was investigated using GC (RI), GC-MS and (13)C NMR spectroscopy. The major component was by far manoyl oxide (63%), a compound of potential interest for the perfumery and pharmaceutical industries. Consequently, the supercritical fluid extract of P. nigra ssp. laricio (yield 1.60%) could be considered as a source of this diterpene.     

A two-step supercritical fluid extraction of polycyclic aromatic hydrocarbons from roadside soil samples

A two-step procedure for the supercritical fluid extraction (SFE) of polycyclic aromatic hydrocarbons from soil samples was developed. The procedure consists of a static supercritical fluid treatment in a closed extraction cell at a high temperature (T=250 or 340degreesC for 20 min) and an SFE with a solvent trapping. During the static phase, the sample is exposed to a supercritical organic solvent (methanol, toluene, dichloromethane, ACN, acetone, and hexane). The solvent penetrates particles of the matrix to substitute strongly bonded molecules and dissolves the analytes in the supercritical phase. At ambient temperature, supercritical fluids became liquid and lost their solvation abilities. Most of the analytes condense on the surface of the particles or on the extraction cell walls without forming strong bonds or penetrating deep into the matrix. Thus, the pretreatment liberates the analytes and they behave similar to those in freshly spiked samples. The common SFE with toluene-modified CO2 as an extraction fluid follows the static phase. With the use of the most suitable extraction phases (toluene, ACN), the extraction efficiency of the combined procedure is much higher (approximately100%). The results of the combined procedure are compared to the SFE procedure of the same untreated sample (difference less than 5%) and to the Soxhlet extraction. The extracts were analyzed using a GC with the flame ionization detection.     

Essential oil composition of Valeriana officinalis L. roots cultivated in Iran. Comparative analysis between supercritical CO2 extraction and hydrodistillation

The composition of essential oil extracted from Valeriana officinalis L. roots growing wild in Iran was studied by hydrodistillation and supercritical CO2 extraction. Forty-seven components representing 89.3% and 35 constituents varying from 86.1% to 95.1% of the oil obtained by hydrodistillation and supercritical CO2 were identified, respectively. The major components in the extracted oil from supercritical CO2 were isovaleric acid (18.7-41.8%), valerenic acid (8.2-11.8%), acetoxyvaleranone (5.6-9.6%), (Z)-valernyl acetate (4.5-6.5%), bornyl acetate (2.3-7.7%) and valerenol (3.7-5.2%), whereas by hydrodistillation were bornyl acetate (11.6%), valerenic acid (8.0%), (Z)-valernyl acetate (7.9%) and acetoxyvaleranone (7.6%). The analysis of the extracts was performed by capillary GC and GC/MS.     

Identification and quantification of the volatile constituents in Cnidium monnieri using supercritical fluid extraction followed by GC‐MS

The volatile components of Cnidium monnieri were obtained by supercritical fluid extraction (SFE) and analyzed by GC‐MS (identification and determination of metabolites). The compounds were identified according to their retention times and mass spectra. The effects of different parameters, such as extraction pressure, temperature, dynamic extraction time, flow rate of CO₂, on the SFE of C. monnieri extracts were investigated. A total of 14 compounds of SFE extracts were identified. Osthole (69.52%), bornyl acetate (10.03%), α‐pinene (4.71%), and imperatorin (2.42%) were the major compounds identified in C. monnieri SFE extracts. The quantitation of osthole and imperatorin were then accomplished. The linear calibration ranges were all 5–1000 μg/mL for osthole and imperatorin by GC‐MS analysis. The recovery of osthole and imperatorin were in the range 96.5–101.8%. The LODs for osthole and imperatorin were 1.0 and 0.6 μg/mL, respectively.     

Optimisation of supercritical fluid extraction of essential oil components of Diplotaenia cachrydifolia: Box-Behnken design

Essential oil of Diplotaenia cachrydifolia cultivated in Iran was obtained by supercritical fluid extraction (SFE) method. The oils were analysed by capillary gas chromatography using flame ionisation and mass spectrometric detections. The compounds were identified according to their retention indices and mass spectra (EI, 70?eV). The effects of different parameters, such as pressure, temperature, modifier volume and extraction times (dynamic and static), on the SFE were inspected by a fractional factorial design (2(5-2)) to identify the significant parameters and their interaction. It showed that static and dynamic times had no effect on the extraction. Finally, a Box-Behnken design was applied to obtain the optimum condition of the significant parameters. The optimal condition was obtained as 30.2?MPa for pressure, 65.6°C for temperature and 258.4?μL for modifier volume. The main components that were extracted with SFE were dillapiole (35.1%), limonene (33.5%) and α-calacorene (25.5%).     

离线超临界流体萃取和气相色谱-红外-质谱联用测定水中有机污染物

利用吸附剂ＧＤＸ－３０１对黄河水中的有机污染物富集并以超临界ＣＯ２脱附后,通过气相色谱、色谱－红外－质谱联用技术对各目标分析物逐一定性,并比较了超临界ＣＯ２萃取和溶剂洗脱的结果。实验表明,在２０ＭＰａ,６０℃,４０ｍｉｎ条件下进行超临界ＣＯ２萃取时的萃取效率和溶剂萃取效率相当或略高。     

Supercritical fluid extraction of the volatile oil from Santolina chamaecyparissus

Supercritical fluid extraction (SFE) of the volatile oil from Santolina chamaecyparissus L. flower heads was performed under different conditions of pressure, temperature, mean particle size and CO₂ flow rate. This oil was compared with the essential oil isolated by hydrodistillation (HD). The SFE volatile and essential oils were analysed by GC and GC‐MS. The range of the main volatile components obtained with HD and SFE were, respectively: 1,8‐cineole (25–30% and 7–48%), camphor (7–9% and 8–14%), borneol (7–8% and 2–11%), terpinen‐4‐ol (6–7% and 1–4%), terpinolene (1–4% and 1–7%) and isobornyl acetate (1–2% and 1–11%). The chemical composition of the extracts was greatly influenced by the conditions of pressure and temperature used. In fact, it was possible to enrich the sesquiterpene fraction by increasing the pressure from 8 to 9 MPa, while changing the temperature from 40 to 50°C at 90 bar enriched of the volatiles in n‐alkanes.     

Fat content for nutritional labeling by supercritical fluid extraction and an on-line lipase catalyzed reaction

A method using sequential supercritical fluid extraction (SFE) and enzymatic transesterification has been developed for the rapid determination of total nutritional fat content in meat samples. SFE conditions of 12.16 MPa and 50°C were utilized to extract lipid species from the sample matrix. The enzymatic transesterification of the lipids by methanol was catalyzed by an immobilized lipase isolated from Candida antarctica. Conversion of the triglycerides to fatty acid methyl esters was monitored by supercritical fluid chromatography, while the fatty acid content of the extract was determined by capillary gas chromatography (GC). Total fat, saturated fat and monounsaturated fat contents were calculated from the GC data and compared to values from traditional extraction and lipid determination methods. Both off-line SFE and automated SFE followed by on-line GC analysis using two different instruments were utilized in this study. The enzymatic-based SFE method gave comparable results to the organic solvent extraction-based method followed by conventional BF₃-catalyzed esterification.     

Enantiomeric composition studies in Lavandula species using supercritical fluids

Characteristic aroma compounds in plants and essential oils of Lavandula from different varieties were examined. The study of the qualitative and quantitative composition of the major volatile components was faced by developing a method based on the use of supercritical fluid extraction-GC-MS (SFE-GC-MS). The optimization of a variety of parameters affecting SFE extraction enabled RSDs from three replicates lower than 2% to be achieved. Equally, recoveries of up to 59% were obtained by applying the proposed method. The use of multidimensional GC was necessary to enantiomerically resolve the target compounds. The obtained results showed enantiomeric purities >90% for all studied compounds in all varieties considered, proving the natural invariability of the enantiomeric composition of the compounds of interest. This information can be useful in authenticity studies as well as in selecting natural sources of enantiomerically pure compounds.     

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).