The project is focused on: (a) Designing a new approach for effective working-up of cultural plants by non-traditional ways with focusing on extraction of phytosteroids and phytosterols from model plant material by using supercritical carbon dioxide; (b) Designing a synthesis of several types of supramolecules on the basis of naturally occurring (biodegradable) phytosteroids for application in biology, through which approach an added value will be given to the plant material in consequence with using extracted natural products in new types of supramolecular materials for application in biology and medicine; (c) Designing a synthesis of model supramolecular biologically active compounds (juvenogens), in which selected compounds displaying biological activity on insect will be used as model system; (d) Performing biological screening tests of model supramolecular juvenogens on selected insect species, namely on aphids (Acyrthosiphon pisum), bugs (Pyrrhocoris apterus), and two types of termites.
(joint project with Institute of Experimental Botany AS CR, Chemispol, s.r.o., Institute of Chemical Technology Prague)
The aim of the project is to apply supercritical fluid extraction, an advanced "green" technology, to isolate biologically active substances that are simultaneously efficient against insects and nontoxic for vertebrates from selected plants. The project includes plant screening, research on the methods enhancing production of biologically active substances in plants, extensive biological tests of extract effects on insects, and optimisation of extraction conditions in a wide range with the aim to concentrate the biologically active substances in the extracts. The results of the project will be applied to develop safe, highly efficient, and stable natural crop protectants and/or insecticides enabling planting crops for high-quality health foods. As medicinal and spice plants are among the examined botanical materials, the results of the project may be utilised also in the production of pharmaceuticals and nutraceuticals.
(joint project with Research Institute of Plant Production, Agra Group, a.s.)
The crude extracts and essential oils obtained from species of Ranunculaceae family selected according to the phytochemical and ethnobotanical data are examined on various biological in vitro assays to evaluate their potential antimicrobial, anti-inflammatory and antioxidative effects in frame of this project. Specific active fractions or pure compounds are isolated and purified using bioassay-guided approach. Traditional analytical (e.g. HPLC, HPLC-MS, GC, GC-MS, NMR) and separation/purification methods (e.g. TLC, CC, MPLC) as well as some modern analytical and separation techniques (e.g. SFE, GCxGC-TOF-MS) are used to obtain and characterize active fractions or pure compounds.The supposed results of this project could be used by food or pharmaceutical industry for development of new herbal-based nutraceuticals, functional foods, food additives and pharmaceutical or veterinary preparations.
(joint project with Czech University of Life Sciences Prague, Institute of Organic Chemistry and Biochemistry AS CR)
The main objective of the present project is to study the phase equilibria and solubility of natural substances of high industrial potential extracted from vegetable matrices with pure and modified supercritical carbon dioxide. The objective is realised through a judicious and inter-related combination of experiments and high-pressure phase equilibrium modelling and calculations. The project is aimed to analyse the possibilities to extract from plants and concentrate high added value phytochemicals. This sustainable use of renewable resources, complying with consumer health and environmental requirements, outlines the importance of the project not only for Bulgaria and the Czech Republic, but gives it a European dimension as well.
Joint project with Institute of Chemical Engineering, BAN, Sofia, Bulgaria - Assoc. Prof. Dr. Roumiana P. Stateva
The objectives are: the supercritical fluid extraction of volatile oils from Thymus vulgaris L. (French and Spanish ecotypes) and from Satureja montana L. with the aim of analyse their chemical composition and to assess the effect of process parameters; the separation of other compounds from the plant matrix, after volatile oil extraction, to assess their potentialities as antioxidants; modelling the supercritical fluid extraction of volatile oils from aromatic plants.
Joint project with Instituto Superior Técnico, Lisbon, Portugal – Prof. António Manuel de Figueiredo Palavra
The aim of the project was based on the state of research in two high-pressure processes, supercritical fluid extraction from plants and catalyzed reactions in supercritical carbon dioxide medium in continuous-flow reactor. Both processes require two tasks to be solved: 1. To examine flow patterns in extraction bed and in the bed of immobilized catalyst particles under different conditions. Both experimental results and results of mathematical modelling indicate process rate dependence on deviations from plug flow, related to the tendency of supercritical fluids to natural convection. The method of response to the pulse input of tracer simultaneously with extraction or reaction was applied. 2. To test different methods of mixture fractionation as a downstream step and recommend to each process the optimum conditions of extract/reaction mixture separation from the solvent.
Institute of Chemical Process Fundamentals CAS
The aims of the project were: 1. Development of an integrated production and product recovery process for the extraction of oil from blackcurrant seeds and its lipase catalysis in SC-CO2 medium. 2. Screening of subspecies of Geotrichum candidum from the point of view of their ability to activate lipase with specificity to unsaturated compounds containing 9Z double bond. 3. Enzymic modifications of blackcurrant seed oil in SC-CO2.
Institute of Organic Chemistry and Biochemistry CAS
Institute of Chemical Process Fundamentals CAS
Institute of Chemical Technology Prague
Enzymatic reactions in supercritical carbon dioxide combine the advantages of biocatalysts (substrate specificity under mild reaction conditions) and supercritical fluids (high mass-transfer rate, easy separation of reaction products from the solvent, environmental benefits). The project was focused on obtaining alfa- and gamma-linolenic acids from blackcurrant seed via a new procedure where enzymatic hydrolysis of blackcurrant oil follows after its supercritical fluid extraction from the seed. Two types of lipases were isolated from Geotrichum candidum 4013 exhibiting sn-1 and sn-3 regioselectivity. A special attention was paid to stability of the lipases in SCCO2. Plant oil contains saturated fatty acids in triacylglycerols mainly in sn-1 and sn-3 positions. Remaining acylglycerols were enriched by polyunsaturated fatty acids. Effects of operating conditions (pressure, temperature, water content, enzyme load and velocity of CO2 in the reactor) on the process were investigated. The experiments showed great potential for new large-scale extraction-reaction process, which could be applied to obtain products from agricultural commodities for use as ingredients in food and other industries. The products of the hydrolytic reaction were analysed by GC and LC-NMR (fatty acids), LC-MS and HPLC (triacylglycerols), PTLC and colorimetric method (conversion of the hydrolysis). The analytical methods were optimized.
Institute of Organic Chemistry and Biochemistry CAS
Institute of Chemical Process Fundamentals CAS
Institute of Chemical Technology Prague
The interdisciplinary Research Centre for "Behaviour of multiphase systems under super-ambient conditions" integrated physical chemists and chemical engineers to study and develop new processes based on gas-liquid-solid contacting. Such processes are very frequent in chemical industry, as well as in the pharmaceutical, food, oil, gas, and steel industry. In order to achieve savings and/or preservation of the environment, they are often run under super-ambient conditions that are not covered by the present technological knowledge. This gives rise to the need for their fundamental research.
The Centre was established in view of significant reorientation and transformation of the R&D potential towards the advanced fields of multiphase systems under extreme conditions, namely to thermodynamic systems at high pressures and temperatures, to bubble processes in metallurgy and to hydrodynamics of rheologically complex systems. The reorientation demands further intensification and integration of all the existing contacts and links of the Centre with academia and industry in Europe..
Institute of Chemical Process Fundamentals CAS – Dr. J. Drahoš
Major part of the project concerned the experimental determination of data on phase equlibria at high pressures in model fluid systems. Phase equilibria at extreme conditions were measured particularly for the systems containing CO2 as extractans, then, so far unknown group contributions were evaluated from experimental data. In parallel, the methods of quantitative thermodynamic description based on equations of state were developed. Project involves necessary chemical engineering studies (kinetics, mass transfer, etc.), too. The information obtained was immediately applicable to the design of separation units exploiting supercritical fluid extraction as an environmentally clean process suitable e.g. for low-volume production of high-value materials.
Institute of Chemical Process Fundamentals AS CR E. - Hala Laboratory of Thermodynamics - Dr. I. Wichterle
Phytochemical research of Schizandra chinensis cauloma and leaves was carried out. Under extraction pressures of 20-28 MPa, temperatures of 25-60 C, and ethanol concentration in supercritical carbon dioxide 0-10 wt.%, optimal conditions for effective isolation of biologically active substances from dry plants were determined. Lignans were extracted from cauloma and leaves and (E)-cinnamic acid from leaves of Schizandra chinensis, beta-carotene, lutein and chlorophylls a and b from leaves and beta-sitosterol and scopoletin from roots of stinging nettle (Urtica dioica), and bilobalide and ginkgolide A from Ginkgo biloba leaves. Condition for extractive separation of 20-hydroxyecdysone and cynaropicrin from Leuzea carthamoides leaves were found. Further examined phenomena were (i) degradation of labile chlorophylls to pheophytins and how to suppress it, (ii) gradual loss of substances from the stored milled plants, (iii) gradual strengthening of solute-matrix interaction during the storage, and, particularly, (iv) solute-matrix interaction for all examined solutes and (v) difference in the extraction of low-polar and polar solutes. The extraction of minor low-polar components (beta-carotene and beta-sitosterol) and major extract components was synchronous. The consequence is that the content of minor low-polar components in the extract depends only on the quality of extracted material, not on extraction conditions.
(joint project with Faculty of Pharmacy, Charles University in Prague)
The isomeric gama-linolenic (GLA) and alfa-linolenic (ALA) acids are the precursors of eicosanoids and vital components of mammalian cells, providing an important store of energy and playing a leading role in the membrane structures and functions. They represent two different families (n-6 vs. n-3) of polyunsaturated fatty acids, and display different nutritional and metabolic significance in the human body. The project was focused on a production of GLA and ALA esters from blackcurrant seeds that are know to contain uniquely both acids as triglycerides in amounts extending 10% of each acid. A hypothesis that purified esters can be prepared via lipase catalyzed hydrolysis/transesterification reactions in supercritical carbon dioxide was verified.
Institute of Organic Chemistry and Biochemistry CAS
Institute of Chemical Process Fundamentals CAS
Institute of Chemical Technology Prague
Solubility in supercritical fluids strongly depends on temperature and pressure. Knowledge of the dependency is necessary to determine optimum conditions of supercritical fluid extraction, a method increasingly utilised in large-scale equipment where plant materials are extracted, as well as in laboratory extractors where analytes are separated from matrix, instead of Soxhlet extraction. Dense carbon dioxide is used as a solvent, if necessary, with addition of an entrainer. In the project, solubilities in supercritical CO2 were established in the presence of a third component, representing either the entrainer or a susbstance retarding the extraction. A new approach combining measurement of solubility with thermodynamic calculation of phase equilibrium was applied. The composition of solvent-rich phase was measured in a selected range of pressure, temperature and concentration, using dynamic method.
A mathematical model for supercritical extraction of oils from vegetable materials was developed and verified. The model distingishes the oil closed in intact cells and the oil in broken cells close to particle surface, which is extracted in the first extraction period.
