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Utilization of Supercritical Fluid Extraction for Botanical Insecticide Isolation
Sajfrtová, Marie ; Sovová, Helena ; Karban, Jindřich ; Pavela, R.
The aim of this study was to compare the insecticidal activity of extracts obtained by SFE and traditional extraction methods from 20 plants. Three types of extracts were prepared using the benefit of variable solvent power of supercritical carbon dioxide. The extracts rich in essential oil or oleoresin were obtained at 50 °C and 12 or 28 MPa, respectively. The extract enriched with polar components was extracted at pressure of 28 MPa with ethanol added to CO2 as modifier. Essential oils were isolated from the herbs by hydrodistillation and oleoresins were obtained using Soxhlet extraction with liquid solvents. The biological activity of extracts was measured on different kinds of insect by means of contact toxicity test (LD50, LD90) and antifeedant activity. The insecticidal activity of the SFE products was compared with conventional extracts.
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Alternative Plant Utilization for Obtaining of Significant Nature Substances: Can Weed Find a Utilization?
Wimmer, Zdeněk ; Sajfrtová, Marie ; Sovová, Helena ; Pavlík, Milan ; Svobodová, Hana ; Jurček, Ondřej ; Wimmerová, Martina
Numbers of compounds and their mixtures, which are produced by plants, can be obtained by extracting plant materials by supercritical fluids. Phytosterols and phytoecdysterotds represent an important family of these plant products. They can be used in a synthesis of supramolecular structures with possible importance for targeted effect of drugs or other biological(y active compounds. Target organisms for the compounds investigated are: (a) insects - pests and human food competitors, also important as model system in investigation of convenient application forms of biologically active compounds; (b) cell cultures used during basic pharmacological research. Supramolecular structures may form convenient matrices for practical application of the biologically active compounds. It has already been proved that numbers of medicinal or cultural plants produce important natural compounds. The present question has appeared to be answered, if so far inutile weeds may be turned into important sources of pro-drugs for disease treatments.
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Extrakty z rostlin jako směsi a jejich předběžné dělení superkritickým CO2
Sovová, Helena ; Sajfrtová, Marie ; Rochová, Kristina
This work concerns supercritical extraction from plants, a semi-continuous process where solutes are extracted from a fixed bed of plant particles to a stream of supercritical CO2. Though the efficiency of control of extract composition in this one-equilibrium-stage process is lower than in the counter-current column, the composition of extract is affected substantially by extraction conditions. Further equilibrium stages are represented by the following separation of extract from solute in two or more separators adjusted to different pressures and temperatures, where the least soluble components precipitate first.
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Superkritická extrakce beta-sitosterolu ze slupek a listů rakytníku řešetlákového
Sajfrtová, Marie ; Sovová, Helena ; Bártlová, Milena
Extraction of beta-sitosterol with supercritical carbon dioxide from sea buckthorn pulp and leaves, a by-product of production of sea buckthorn juice, was studied. The effect of operation conditions on the yields and solubility of whole extract and its minor component beta-sitosterol was analysed in a series of experiments at pressures from 15 MPa to 28 MPa and temperatures 40 °C and 60 °C. The consecutively collected extract samples were analysed using HPLC. The selectivity of beta-sitosterol to major component was determined. The content of beta-sitosterol in both plant materials was obtained using Soxhlet extraction with hexane.
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Insekticidní aktivita rostlinných extraktů izolovaných různými metodami
Sajfrtová, Marie ; Sovová, Helena ; Karban, Jindřich ; Pavela, R.
The aim of this study was to compare the insecticidal activity of extracts obtained by SFE and traditional extraction method. Three types of extracts were prepared using the benefit of variable solvent power of supercritical carbon dioxide under different experimental conditions. Composition and product activities of the CO2 extracts were compared with hydrodistillation (HD) and Soxhlet extraction. The composition of volatile compounds in the isolates was determined by gas chromatography, and the toxicity and antifeedant effects of the extracts on larvae of Colorado potato beetle were evaluated.
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Supercritical Fluid Extraction and Characterisation of Urtica Dioica L. Leaves Pigments
Sajfrtová, Marie ; Sovová, Helena ; Bártlová, Milena ; Opletal, L.
Extraction and fractionation of green and yellow pigments from stinging nettle leaves was studied using ethanol-modified carbon dioxide as a solvent. The extracts were analysed by means of HPLC and RP-HPLC systems. The effect of operation conditions was analysed in a series of experiments at pressures from 20 MPa to 28 MPa, temperatures between 25 °C and 60 °C, and ethanol concentration in CO2 between 0 and 7.4 wt.%. The main result was that the best conditions for the supercritical fluid extraction of pigments were ethanol concentration in CO2 4.5 - 7.4 wt.%, temperature 40°C and pressure 28MPa and that degradation of pigments was eliminated with decrease of temperature of micrometer valve and addition of small amount of antioxidant to ethanol.
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