Concept: Supercritical fluid
Abstract Ethnobotanical surveys indicated that in the traditional medicines worldwide, several Juniperus species are utilized as antihelmintic, diuretic, stimulant, antiseptic, carminative, stomachic, antirheumatic, antifungal, and for wound healing. In the present study, essential oils obtained from heartwood samples of Juniperus virginiana L., Juniperus occidentalis Hook. and Juniperus ashei J. Buchholz were evaluated for wound healing and anti-inflammatory activities by using in vivo experimental methods. The essential oils were obtained by the supercritical carbon dioxide extraction method. Linear incision and circular excision wound models were performed for the wound-healing activity assessment. The tissues were also evaluated for the hydroxyproline content as well as histopathologically. To evaluate the anti-inflammatory activity of the essential oils, the test used was an acetic acid-induced increase in capillary permeability. The essential oil of J. occidentalis showed the highest activity on the in vivo biological activity models. Additionaly, the oil of J. virginiana was found highly effective in the anti-inflammatory activity method. The experimental data demonstrated that essential oil of J. occidentalis displayed significant wound-healing and anti-inflammatory activities.
The volatile oil parts of frankincense (Boswellia carterii Birdw.) were extracted with supercritical carbon dioxide under constant pressure (15, 20, or 25 MPa) and fixed temperature (40, 50, or 60°C), given time (60, 90, or 120 min) aiming at the acquisition of enriched fractions containing octyl acetate, compounds of pharmaceutical interest. A mathematical model was created by Box-Behnken design, a popular template for response surface methodology, for the extraction process. The response value was characterized by synthetical score, which comprised yields accounting for 20% and content of octyl acetate for 80%. The content of octyl acetate was determined by GC. The supercritical fluid extraction showed higher selectivity than conventional steam distillation. Supercritical fluid-CO(2) for extracting frankincense under optimum condition was of great validity, which was also successfully verified by the pharmacological experiments.
Combination techniques such as gas chromatography/mass spectrometry (GC/MS) and liquid chromatography/mass spectrometry (LC/MS) are commonly used for pesticide residue analysis, but there is no reported method for the simultaneous analysis of multiple pesticides in a sample using a single instrument. Supercritical fluid chromatography (SFC) offers high resolution at high flow rates and various separation modes and hence may aid the rapid simultaneous analysis of pesticide. We developed an SFC/MS/MS method and analyzed 17 pesticides with a wide range of polarities (logP(ow)=-4.6 to 7.05) and molecular weights (112.1-888.6) within 11min using a polar-embedded reversed-phase column. To the best of our knowledge, there is no previous report on the SFC analysis of a wide variety of compounds, including highly hydrophilic ones. By SFC, diquat dibromide (logP(ow)=-4.6), together with cypermethrin (logP(ow)=6.6) and tralomethrin (logP(ow)=5.05), could be detected in the presence of various other pesticides using a single mobile phase. SFC/MS allows for the rapid and simultaneous analysis of low concentrations (ng/L levels) of pesticides that typically need to be analyzed by GC/MS and LC/MS separately.
In this study, supercritical fluid extraction (SFE) with CO(2) and hydrodistillation (HD) were compared as methods to isolate the essential oil from Cupressus sempervirens. The odour of the oil obtained by SFE at 90 bar and 40°C was very close to the odour of the leaves of C. sempervirens before the extraction. Compounds extracted by both SFE and HD were identified by GC-FID and GC-MS. Moreover, the difference in the chemical composition obtained by SFE and HD was quite noticeable qualitatively and quantitatively. Phenolic composition and antioxidant activity were also determined. Compared to HD, the SFE method presents some advantages: the extraction was completed after 1 h in SFE, although 4 h is necessary for HD, and the yield was improved by 34%. Finally, it has also been shown that SFE is very selective towards some specific components such as manoyl oxide, trans-totarol and α-acoradiene.
Oil and xanthorrhizol extraction from Curcuma xanthorrhiza Roxb. rhizome by supercritical carbon dioxide was optimized using Taguchi method. The factors considered were pressure, temperature, carbon dioxide flowrate and time at levels ranging between 10-25 MPa, 35-60 °C, 10-25 g/min and 60-240 min respectively. The highest oil yield (8.0 %) was achieved at factor combination of 15 MPa, 50 °C, 20 g/min and 180 min whereas the highest xanthorrhizol content (128.3 mg/g oil) in Curcuma xanthorrhiza oil was achieved at a factor combination of 25 MPa, 50 °C, 15 g/min and 60 min. Soxhlet extraction with n-hexane and percolation with ethanol gave oil yield of 5.88 %, 11.73 % and xanthorrhizol content of 42.6 mg/g oil, 75.5 mg/g oil, respectively. The experimental oil yield and xanthorrhizol content at optimum conditions agreed favourably with values predicted by computational process. The xanthorrizol content extracted using supercritical carbon dioxide was higher than extracted using Soxhlet extraction and percolation process.
Phytosterols provide important health benefits especially lowering of cholesterol. From environmental and commercial point of views, the most appropriate technique has been searched to extract the phytosterols from plant matrices. As a green technology, supercritical fluid extraction (SFE) using carbon dioxide (CO2 ) is widely used to extract bioactive compounds from different plant matrices. Several studies have been performed to extract phytosterols using supercritical CO2 (SC-CO2 ) and this technology has clearly offered a potential advantages over conventional extraction methods. However, the efficiency of SFE technology fully relies on the processing parameters, chemistry of interest compounds, nature of the plant matrices and expertise of handling. This review covers the SFE technology with particular reference to phytosterols extraction using SC-CO2 . Moreover, chemistry of phytosterols, properties of supercritical fluids (SFs) and the applied experimental designs have been discussed for better understanding of phytosterol solubility in SC-CO2 .
The aim of this study was to optimize the antioxidant activity of Piper nigrum L. essential oil extracted using the supercritical carbon dioxide (SC-CO2) technique. Response surface methodology was applied using a three-factor central composite design to evaluate the effects of three independent extraction variables: pressure of 15-30MPa, temperature of 40-50°C and dynamic extraction time of 40-80min. The DPPH radical scavenging method was used to evaluate the antioxidant activity of the extracts. The results showed that the best antioxidant activity was achieved at 30MPa, 40°C and 40min. The extracts were analyzed by GC-FID and GC-MS. The main components extracted using SC-CO2 extraction in optimum conditions were β-caryophyllene (25.38±0.62%), limonene (15.64±0.15%), sabinene (13.63±0.21%), 3-carene (9.34±0.04%), β-pinene (7.27±0.05%), and α-pinene (4.25±0.06%). The essential oil obtained through this technique was compared with the essential oil obtained using hydro-distillation. For the essential oil obtained by hydro-distillation, the most abundant compounds were β-caryophyllene (18.64±0.84%), limonene (14.95±0.13%), sabinene (13.19±0.17%), 3-carene (8.56±0.11%), β-pinene (9.71±0.12%), and α-pinene (7.96±0.14%). Radical scavenging activity of the extracts obtained by SC-CO2 and hydro-distillation showed an EC50 of 103.28 and 316.27µgmL(-1) respectively.
Grape by-products are a rich source of bioactive compounds having broad medicinal properties, but are usually wasted from juice/wine processing industries. The present study investigates the use of supercritical fluid extraction (SFE) for obtaining an extract rich in bioactive compounds. First, some variables involved in the extraction were applied. SFE conditions were selected based on the oil mass yield, fatty acid profile and total phenolic composition. As a result, 40 °C and 300 bar were selected as operational conditions. The phenolic composition of the grape seed oil was determined using LC-DAD. The antioxidant activity was determined by ABTS and DPPH assays. For the anti-inflammatory activity the inhibition of nitrite production was assessed. The grape seed oil extracted was rich in phenolic compounds and fatty acids with significant antioxidant and anti-inflammatory activities. From these results, added economic value to this agroindustrial residue is proposed using environmentally friendly techniques.
Stainless steel (SS) particles were demonstrated as a novel useful support for a water stationary phase in packed column supercritical fluid chromatography using a CO2 mobile phase. Separations employed flame ionization detection and the system was operated over a range of temperatures and pressures. Retention times reproduced well with RSD values of 2.6% or less. Compared to analogous separations employing a water stationary phase coated onto a SS capillary column, the packed column method provided separations that were about 10 times faster, with nearly 8 fold larger analyte retention factors, while maintaining good peak shape and comparable column efficiency. Under normal operating conditions, the packed column contains about 131 ± 4 μL/m of water phase (around a 5% w/w coating), which is over 25 times greater than the capillary column and also affords it a 20 fold larger sample capacity. Several applications of the packed column system are examined and the results indicate that it is a useful alternative to the capillary column mode, particularly where analyte loads or sample matrix interference is a concern. Given its high sample capacity, this packed column method may also be useful to explore on a more preparative scale in the future.
Black pepper (Piper nigrum L.), the King of Spices is the most popular spice globally and its active ingredient, piperine, is reportedly known for its therapeutic potency. In this work, enzyme-assisted supercritical carbon dioxide (SC-CO2) extraction of black pepper oleoresin was investigated using α-amylase (from Bacillus licheniformis) for enhanced yield of piperine-rich extract possessing good combination of phytochemical properties. Optimization of the extraction parameters (without enzyme), mainly temperature and pressure, was conducted in both batch and continuous modes and the optimized conditions that provided the maximum yield of piperine was in the batch mode, with a sample size of 20 g of black pepper powder (particle diameter 0.42 ± 0.02 mm) at 60°C and 300 bar at 2 L/min of CO2 flow. Studies on activity of α-amylase were conducted under these optimized conditions in both batch and continuous modes, with varying amounts of lyophilized enzyme (2 mg, 5 mg and 10 mg) and time of exposure of the enzyme to SC-CO2 (2.25 h and 4.25 h). The specific activity of the enzyme increased by 2.13 times when treated in the continuous mode than in the batch mode (1.25 times increase). The structural changes of the treated enzymes were studied by (1)H NMR analyses. In case of α-amylase assisted extractions of black pepper, both batch and continuous modes significantly increased the yields and phytochemical properties of piperine-rich extracts; with higher increase in batch mode than in continuous.