Extraction of volatile compounds from Juniperus communis L. leaves with supercritical fluid carbon dioxide: comparison with hydrodistillation

Supercritical fluid extraction of volatile components from Bunium persicum Boiss. (black cumin) and Mespilus germanica L. (medlar) seeds

Essential oil of Eucalyptus oleosa, cultivated in Iran, was obtained by hydrodistillation and supercritical (carbon dioxide) extraction methods. The effects of supercritical carbon dioxide extraction parameters such as pressure, temperature, dynamic extraction time and modifier volume on the extraction efficiency were investigated by the three-level orthogonal array design. Regarding the percentages of α-pinene and 1,8- cineole, the optimum supercritical fluid extraction (SFE) results were obtained at the following experimental conditions: pressure = 100 atm, T = 45°C, dynamic time = 25 min, and Vmodifier = 2 mL. The composition of the extracts obtained from E. oleosa using supercritical fluid extraction was compared with the essential oil obtained by hydrodistillation. The composition of the SFE products was markedly different from the corresponding hydrodistillated oil.

Comparison of essential oils compositions of Ferula assa-foetida obtained by supercritical carbon dioxide extraction and hydrodistillation methods

Comparison of essential oil compositions of Salvia mirzayanii obtained by supercritical carbon dioxide extraction and hydrodistillation methods

The volatiles of Achillea millefolium L., cultivated in Iran, were obtained by hydrodistillation and supercritical (carbon dioxide) extraction methods. The volatiles were analyzed by capillary gas chromatography using fame ionization and mass spectrometric detections. The effects of different parameters, such as pressure, temperature, modifier volume and extraction time, on the supercritical fluid extraction (SFE) of A. millefolium volatiles were investigated. The results showed that, under a pressure of 300 atm, temperature 35°C, 5% methanol and dynamic extraction time of 20 min, extraction was more selective for germacrene D. Fifty compounds were identified in the hydrodistilled oil. The major volatile components of A. millefollium were 1,8-cineole (15.2%) and germacrene D (14.1%). However, by using supercritical carbon dioxide under optimum conditions, only two components constituted more than (60%) of the volatile concentrate.

Essential oil of Nepeta ucrainica L. ssp. kopetdaghensis was obtained using hydrodistillation and supercritical fluid extraction (SFE) methods. The oils were identified by GC-MS and determined by GC-FID. The results revealed that under the pressure of 35.5 MPa, temperature of 35°C, 4.5 %methanol, dynamic extraction time of 50 min. and static extraction time of 25 min. extraction was more selective for the Germacrene-D. Eighteen compounds were identified in the hydrodistilled oil. The major components were Germacrene-D (20.0 %), Spathulenol (5.6 %) and Bourboene (5.8 %). However, by using SFE under optimum conditions, only four components contained more than 95 % of the oil. The extraction yield based on hydrodistillation was 0.04 (v/w). On the other hand, using SFE extraction yields in the range of 0.08 - 1.32 % (w/w) were obtained at different conditions.

Supercritical fluid extraction (SFE) of essential oil from Pimpinella anisum, using carbon dioxide as a solvent is presented in this work. An orthogonal array design OA9 (34) was applied to select the optimum extraction condition. The effects of pressure, temperature, dynamic extraction time and methanol volume on the extraction efficiency were investigated by the three-level orthogonal array design. Results show that pressure has a significant effect on the extraction efficiency. The extract obtained from P. anisum by using supercritical fluid extraction was compared with the essential oil obtained by hydrodistillation, considering both quantity and quality of the product. SFE products were found to be of markedly different composition, compared with the corresponding hydrodistilated oil. The total amount of extractable substances obtained in SFE (7.5%) is higher than that obtained by hydrodistillation (3.1%) and SFE is faster than hydrodistillation method.

Essential oil of fennel cultivated in Iran was obtained by hydrodistillation and supercritical (CO2) extraction (SFE) methods. The oils were analysed by capillary gas chromatography using flame ionization and mass spectrometric detection. 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 time, on the supercritical fluid extraction of fennel oil were investigated. The results showed that, under pressure of 350 atm, temperature 55 °C, methanol 5% and dynamic extraction time of 45 min, extraction was more selective for the extraction of (E)‐anethol. Sixteen compounds were identified in the hydrodistilled oil. However, by using supercritical carbon dioxide in optimum conditions, only nine components represented more than 99% of the oil. The results showed that, in Iranian fennel oil, (E)‐anethol is a major component. Copyright © 2002 John Wiley & Sons, Ltd.

Comparison of essential oil composition of Carum copticum obtained by supercritical carbon dioxide extraction and hydrodistillation methods

Comparison of volatile components of Marchantia convoluta obtained by supercritical carbon dioxide extraction and petrol ether extraction

Optimization of ethanol modified supercritical carbon dioxide on the extract yield and antioxidant activity from Biebersteinia multifida DC

ABSTRACTThe findings of this study suggests that chemical composition, essential oil yield, antioxidant and antimicrobial activity of Boswellia serrata oleo gum resin essential oils extracted by hydro distillation, steam distillation and supercritical fluid carbon dioxide methods vary greatly from each other. The optimum essential oil yield was obtained using hydro distillation method (8.18 ± 0.15 %). The essential oils isolated through different extraction methods contained remarkable amounts of total phenolics and total flavonoids. Essential oil isolated through supercritical fluid carbon dioxide extraction exhibited better antioxidant activity with highest free radical scavenging potential (96.16 ± 1.57 %), inhibition of linoleic acid oxidation (94.18 ± 1.47 %) and hydrogen peroxide free radical scavenging potential (68.25 ± 1.02 %). Moreover, the antimicrobial activity of essential oils was performed through well diffusion, resazurin microtiter plate and micro dilution broth assay assays. The essential oil isolated through steam distillation method revealed highest antimicrobial activity with maximum inhibition zone (24.21 ± 0.34 to12.08 ± 0.30 mm) and least MIC values (35.18 ± 0.77 to 281.46 ± 7.03 µg/mL). The comparison of chemical composition of essential oils isolated at different extraction methods have shown that the concentration of α-thujene, camphene, β-pinene, myrcene, limonene, m-cymene and cis-verbenol was higher in steam distilled essential oil as compared to hydro and supercritical fluid carbon dioxide extracted essential oils. These compounds may be responsible for the higher antimicrobial activity of Boswellia serrata oleo gum resin steam distilled essential oil.

Application of response surface methodology and central composite design for the optimisation of supercritical fluid extraction of essential oils from Myrtus communis L. leaves

The genus Xanthium (Compositae) is represented by 25 species in the world and 3 species and 1 variety in China [1]. These are X. sibiricum Patr. (X. strumarium L.), X. mongolicum Kitag., X. inaequilaterum DC., and X. sibiricum var. subinerme (Winkl.) Widder. Xanthium species have been used as traditional herbal medicines for the treatment of nasal sinusitis, headache caused by wind-cold, urticaria, and arthritis for a long time in oriental countries [2]. The chemical composition of ent-kaurane diterpenoids, sesquiterpene lactones, caffeoylquinic acids, and thiazinediones from this genus (leaves or fruits) has been reported [3–8]. Chemical examination of the essential oil from the leaves of Xanthium strumarium showed that the main components of the essential oil were d-limonene and d-carveol, with a relative content of 35% and 25% (w/w), respectively [9]. The composition of the fruit essential oil of Xanthium sibiricum Patr. was reported in 1994 [10], and showed that saturated paraffin hydrocarbons such as eicosane and nonadecane were the major components. The fruit oil of Xanthium obtained by crushing were reported to have anti-thrombus effects and to decrease blood-fat in civil use [11], which were referred to the lipophylic extracts of Xanthium fruits. The purpose of this research was to conduct a comparative analysis on the fatty oil composition from samples belonging to three Xanthium species growing in China: X. sibiricum, X. sibiricum var. subinerme, and X. mongolicum. The collected location and date of the three Xanthium species used for supercritical fluid extraction (SFE) and GC-MS analysis are listed in Table 1. This is the first report on the lipophylic extracts prepared by SFE of the three Xanthium species. The results of the fatty acid analysis by GC-MS and the oil yield of the taxa are presented in Table 1. The extraction of essential oil components using solvents at high pressure, or supercritical fluids, has received much attention in the past several years, especially in the food, pharmaceutical, and cosmetic industries, because it presents an alternative to conventional processes such as organic solvent extraction and steam distillation [12, 13]. By comparing the composition of the product with hydrodistilled oil [14], higher levels of the volatile components such as d-limonene and d-carveol were found by using the hydrodistillation method [9]. However, these compounds were not found in the SFE products. In contrast, the fatty acids linoleic acid, palmitic acid, stearic acid, and some sterols were found in the SFE products, whereas negligible amounts were present in the distilled oils. In this study, a total of 37 compounds of three Xanthium species in China was determined, of which aromadendrene, α-phellandrene, globulol, norphytane, tomentosin, etc. were identified from Xanthium genus for the first time. The fatty oil composition of the studied Xanthium genus was not uniform but overlap. A considerable content of linoleic acid and palmitic acid was noted in all samples, but small quantitative differences were also found. Linoleic acid was the predominant constituent of the studied fruit oil and had the relative content of 80.24% (X. sibiricum), 70.75% (X. sibiricum var. subinerme) and 77.71% (X. mongolicum), respectively. The amount of linoleic acid is important with respect to the quality of the oils consumed as a food resource [15]. Therefore, the fruits of the three studied Xanthium species can all be regarded as a new resource for linoleic acid production. Stearic acid, linolenyl alcohol, n-tetracosane, n-pentacosane, and n-nonacosane, were present in both X. sibiricum var. subinerme and X. mongolicum fruit oil. The X. sibiricum var. subinerme oil composition was characterized by a large variation of the long-chain diolefins, including n-heptadecane, n-docosane, and all the linear-chain diolefin froms n-tetracosane to n-nonacosane. Only nine compounds of X. mongolicum fruit oil were determined, of which diisooctyl phthalate was the special component.

Volatile oils from the leaves of E. spathulata and E. microtheca, cultivated in Iran, were obtained by hydro-distillation and supercritical (carbon dioxide) Extraction methods. The oils were analyzed by capillary gas Chromatography using flame ionization and mass spectrometric detections. The compounds were identified according to their retention indices and mass spectra (EI, 70eV). The effects of different parameters, such as pressure, temperature, modifier volume and Extraction time, on the supercritical fluid Extraction (SFE) of E. spathulata and E. microtheca oils were investigated. The results showed that for E. spathulata under a pressure of 100 atm, temperature 450C, 250 μl methanol and dynamic Extraction time of 25 min, Extraction was more selective for the 1,8-cineole, while for E. microtheca the pressure of 300 atm, temperature 550C, 0 μl methanol and dynamic Extraction time of 25 min, resulted more selectivity for 1,8-cineole. Thirty-two compounds were identified in the hydro-distilled oils of E. spathulata and E. microtheca. The major components of these oils were 1,8-cineole (44.5% and 14.4%) and α-pinene (20.2% and 10.3%), respectively. However, by using supercritical carbon dioxide under optimum conditions, only 1,8-cineole constituted 73.8% of the oil of E. spathulata and 39.3% of the oil of E. microtheca. The Extraction yield, based on hydro-distillation, was 3.77% and 0.79% (w/w) for E. spathulata and E. microtheca, respectively. Extraction yield, based on the SFE, varied in the range of 1.27–8.37% for E. spathulata and 1.23–5.90% (w/w) for E. microtheca, under different conditions.