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Comparison of Extraction Methods for Isolation of 20-Hydroxyecdysone from Leuzea carthamoides
Machalová, Zdeňka ; Sajfrtová, Marie ; Sovová, Helena ; Bártlová, Milena
This work is focused on the extraction of 20-HE from roots and seeds of Leuzea carthamoides using SFE, PLE and Soxhlet extraction. The SFE and PLE conditions (pressure, temperature, type and concentration of solvent, extraction time) were optimized to improve extraction yields and concentrations of 20-HE in extracts. These methods were compared with a conventional Soxhlet-type extraction. The SFE experiments were carried out at temperatures from 40°C to 60°C, pressures from 30 to 65 MPa and with addition of 5-20% of co-solvent (ethanol, methanol and acetone). PLE with ethanol, methanol and acetone was made at temperatures from 70°C to 100°C, pressures from 7 to 20 MPa and extraction time from 5-15 min. Soxhlet extraction with ethanol was used to evaluate the total content of 20-HE in roots and seeds. The concentration of 20-HE in extracts was determined by HPLC.
Fulltext: content.csg -  PDF
Plný tet: SKMBT_C22014082908303 - PDF
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Extraction Kinetics and Insecticidal Activity of Volatile Components Isolatedfrom rue by Supercritical CO2.
Sajfrtová, Marie ; Karban, Jindřich ; Sovová, Helena ; Pavela, R.
The aim of the work was to describe the SFE of volatile components from rue and to analyse their insecticidal effects. The objectives consisted in: (a) optimizing the SFE condition (pressure, temperature, extraction time, use of additional separator and concentration of modifier in CO2),investigating their effect on the yield, concentration volatiles in extract and the insecticidal activity, determination of the SFE kinetics of major components in the rue extracts and comparing the SFE with hydrodistillation and maceration.
Fulltext: content.csg - PDF
Plný tet: SKMBT_C22014090110391 - PDF
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Extraction of beta-Sitosterol from the Stinging Nettle Root with Supercritical CO2
Sajfrtová, Marie ; Bártlová, Milena ; Sovová, Helena
The stinging nettle root contains both polar and non-polar biologically active substances. beta-Sitosterol (BS), the most important component of its neutral lipids, is active in the root extracts used for various alternative medicine treatments, including the reduction of enlarged prostate. Dry roots contaning 0.28 g/kg BS were extracted with CO2 at pressure 12-60 MPa and temperature 40-80 C. Though the maximum yield of BS was only 89 %, its concentration in extract was increased by 13 % compared to the extraction with hexane. Changing vials where the CO2 extract was collected, fractions with double and higher BS concentration could be obtained. The fractionation was simulated using a mathematical kinetic model of multicomponent extraction.
Fulltext: content.csg - PDF
Plný tet: SKMBT_C22013110513041 - PDF
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Optimization and Mathematical Modelling of Hydrodistillation from Eucalyptus grandis and Lippia javanica
Topiař, Martin ; Sajfrtová, Marie ; Sovová, Helena ; Karban, Jindřich
K získání silice z rostlin Eucalyptus grandis a Lippia javanica sloužila hydrodestilace s použitím Clevengerova nástavce. Proměnnými parametry procesu byla doba varu, velikost částic a hydromodul. K vyhodnocení kinetických konstant hydrodestilace obou rostlin byl použit vhodný matematický model1, který počítá s rozdělením destilátu na dva podíly, kdy jeden je extrahován rychleji a druhý pomaleji, přičemž každému podílu přísluší vlastní kinetická konstanta. Mezi hlavní analyzované složky silice z eukalyptu patřil 1,8 cineol, alfa-pinen (8,2 hm. %), aromadenrden a spathulenol. Majoritní složky získané z výtažku lipie byly perillaldehyd, limonen a germacren. Bylo zjištěno, že optimálními parametry z hlediska maximalizace výtěžku jsou doba varu 5 h s poměrem navážka k objemu vody 1:5. Velikost částic nemá u zkoumaných rostlin zásadní vliv na velikost výtěžku. Maximální výtěžek eukalyptové silice dosahoval 26,7 mg/g, zatímco u lipie byl maximální výtěžek poloviční, a to 12,8 mg/g.
Fulltext: content.csg - PDF
Plný tet: SKMBT_C22013102510210 - PDF
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Photocatalytic Degradation of Bisphenol A
Spáčilová, Lucie ; Maléterová, Ywetta ; Cajthaml, Tomáš ; Šolcová, Olga
Bisphenol A belongs to the group of the environmental estrogens that act as the hormonal system of the body. It is one of the most representative endocrine disruptors in wastewater. Bisphenol A gets into rivers from the production of polycarbonate, respectively, from the processing thereof. More than 75% of the Czech polycarbonate consumption is concentrated in three key economic sectors: automotive, construction, electronics and electrical industry.
Fulltext: content.csg - PDF
Plný tet: SKMBT_C22013102415320 - PDF
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