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Supercritical Fluid Fractionation for 20-Hydroxyecdysone Enrichment in Leuzea carthamoides Extract
Sajfrtová, Marie ; Maščeník, J. ; Sovová, Helena ; Bártlová, Milena
Supercritical fluid extraction of 20-hydroxyecdysone (20-HE) using pure and modified carbon dioxide from seeds of Leuzea carthamoides was studied. The effect of operation conditions on the yields of whole extract and its minor component 20-HE was analysed in a series of experiments at pressures from 30 MPa to 60 MPa, temperatures from 40 °C to 80 °C and modifier (ethanol, methanol and acetone) concentrations in CO2 0-19 wt. %. The consecutively collected extract fractions were analysed using HPLC. The efficiency of SFE in terms of 20-HE concentration in extract and yield was compared with the efficiency of Soxhlet extraction with ethanol.
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Enrichment of Supercritical Extracts in beta-Sitosterol by Fractionation Process
Rochová, Kristina ; Sovová, Helena ; Sajfrtová, Marie ; Bártlová, Milena
The aim of this contribution was to use the extraction with supercritical CO2 coupled with fractionation of extract for preparation of extracts rich in beta-sitosterol. Phytosterols have been proved to lower serum cholesterol levels in humans and to have other benefit for human health. Supercritical extraction is a green method to separate such compounds from plants. Sea buckthorn seeds and sunflower seeds were extracted and a mathematical model was applied to determine separation factor of beta-sitosterol as minor component of extract. According to the obtained results, conditions of fractionation were set up. The most important enrichment of a part of extract from seeds with beta-sitosterol was achieved with fractionation in two separators (first separator kept at 15MPa and 50°C) and subsequent fractionation in time at the output of the second separator.
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Supercritical Fluid Extraction and Insecticidal Activity of Lamiaceae Plants
Sajfrtová, Marie ; Pavela, R. ; Karban, Jindřich ; Sovová, Helena
Natural insecticides based on bioactive extracts from plants represent a new trend in plant protection. Supercritical extraction (SFE) using CO2 is a modern extraction technique able to isolate high-added value compounds from plant without any thermal degradation, which allows to obtain extracts with high biological activity. In this work, insecticidal activity of SFE extracts from plant of mint family (Lamiaceae) has been studied and compared to activity of isolates obtained by conventional extraction techniques (hydrodistillation, organic solvent extraction). As a result of variation in extraction pressure, three types of extract were obtained: extract rich in volatile compounds (at 12 MPa), extract rich in oleoresins (at 28 MPa) and in polar compounds (5% of acetone used as modifier). Chemical composition and biological activity (LD50, antifeedant activity) of all isolates were evaluated and compared.
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