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H Ekiert

Publications and source records attributed to H Ekiert.

At least 19 recordsLinked to original sources
PubMed2005

Accumulation of biologically active furanocoumarins in Ruta graveolens ssp. divaricata (Tenore) Gams in vitro culture.

The study was designed to investigate dynamics of accumulation of five linear furanocoumarins and umbelliferone in stationary liquid cultures of Ruta graveolens ssp. divaricata (Tenore) Gams during 6-week growth cycles. The contents of individual metabolites in biomass increased 1.8-3.5 times while their total content rose 2.3 times. Maximum contents of xanthotoxin, bergapten and isopimpinellin (112.3, 76.2 and 84.0mg/100g d.w., respectively) and maximum total content of all metabolites (283.4 mg/100 g d.w.), obtained on 35th culture day, are interesting from practical point of view.

Biomass↗
PubMed2005

Accumulation of biologically active furanocoumarins in agitated cultures of Ruta graveolens L. and Ruta graveolens ssp. divaricata (Tenore) Gams.

This study was designed to investigate the dynamics of accumulation of linear furanocoumarins (psoralen, bergapten, xanthotoxin, isopimpinellin, imperatorin) and their biogenetic precursor, umbelliferone, in agitated cultures of Ruta graveolens L. and Ruta graveolens ssp. divaricata (Tenore) Gams during 6-week growth cycles. The metabolites under study were almost exclusively accumulated in the cultured biomass. The total content of all metabolites increased 4.8- and 2.0-fold, in R. graveolens and R. graveolens ssp. divaricata cultures, respectively. Xanthotoxin and bergapten, which are the most important therapeutic compounds, were the dominating metabolites in cultures of both plants. The maximum content of xanthotoxin (25.0 mg/100 g dry wt.) and bergapten (18.4 mg/100 g dry wt) and the maximum content of all metabolites (64.0 mg/100 g dry wt) in R. graveolens ssp. divaricata callus obtained on the 35th culture day were relatively low. However, maximum contents of xanthotoxin (136.8 mg/100 g dry wt), bergapten (210.4 mg/100 g dry wt.) and isopimpinellin (96.7 mg/100 g dry wt), and total content of all metabolites in R. graveolens shoots (520.8 mg/100 g dry wt) obtained on the 42nd culture day are interesting from a practical point of view.

Biomass↗
PubMed2000

Medicinal plant biotechnology: the Apiaceae family as the example of rapid development.

This article reviews the results of research representative of different trends in biotechnological studies of the Apiaceae species. These species are a well-known source of many important herbal products. A number of investigations focus on the biosynthesis of secondary metabolites in plant in vitro cultures. There are also numerous reports concerning the methods of plant micropropagation, especially using somatic embryogenesis. The papers dealing with the usage of the enzymatic potential of plant cells cultured in vitro, in biotransformation processes are less copious. Several studies are related to genetic engineering, exploring mainly the possibility of plant transformation with Agrobacterium rhizogenes to obtain hairy root cultures. The present review demonstrates the significance of biotechnological methods in the studies of medicinal plants taking species of the Apiaceae family as an example.

Apiaceae↗
PubMed2000

Furanocoumarins in Pastinaca sativa L. in vitro culture.

Callus cultures of Pastinaca sativa L. (parsnip), Apiaceae, were cultivated on variants of Linsmaier-Skoog's medium, containing varying quantities (0.1-10.0 mg/l) of phytohormones: NAA-BAP and IBA-BAP which allowed to obtain 1.5-3-fold fresh biomass growth during 6-week subcultures. HPLC analyses showed that tissues cultured in vitro produced psoralen, bergapten, xanthotoxin, isopimpinellin and umbelliferone which are well known metabolites in plants growing under natural conditions. Total content of coumarins depended on the nature and quantity of phytohormones present in the medium, and ranged from 115.7 to 408.5 mg/100 g of the dry weight, isopimpinellin being the metabolite which dominated quantitatively (maximum content of 238.9 mg/100 g). Psoralen was also accumulated in callus tissues at considerable amounts (maximum content of 108.8 mg/100 g). This metabolite dominated in vegetative plant parts that have been analysed in our study (leaves, stems, roots) but its contents were lower than in the material from in vitro culture (48.9 mg/100 g 10.6 mg/100 g and 14.9 mg/100 g, respectively). Imperatorin was not detected in callus tissues although it dominated in the analysed fruits of the studied plant (200.0 mg/100 g). The best of the tested media in respect of promoting tissue biosynthetic capabilities was that which contained 3 mg/l NAA and 1 mg/l BAP. The studies showed that in vitro cultures of Pastinaca sativa L. can be a convenient model to study the biosynthesis of furanocoumarins and also a potential rich source of these compounds, particularly isopimpinellin.

Apiaceae↗
PubMed2000

Coumarin compounds in Ammi majus L. callus cultures.

Callus cultures of Ammi majus L. (bishop's weed), Apiaceae, were maintained on variants of Linsmaier-Skoog's (L-S) medium differing in the content of the phytohormones, alpha-naphthaleneacetic acid (NAA) and 6-benzylaminopurine (BAP) (0.1-10.0 mg/l). The increments of callus tissue fresh weight showed considerable differences (1.4 bis 4.4-fold) during 4-week subcultures on the media tested. HPLC analysis revealed the presence of six compounds in the extracts of callus tissues, which are known metabolites in plants growing under natural conditions: the linear furanocoumarins psoralen, bergapten, xanthotoxin, isopimpinellin, imperatorin and their precursor umbelliferone. The total contents of coumarin compounds under examination showed marked differences dependent on the phytohormone concentrations in the medium. They ranged from 40.95 to 871.05 mg/100 g of dry weight. Imperatorin was the metabolite dominating among the furanocoumarins in calli from almost all tested variants of L-S medium (maximum content of 169.27 mg/100 g). Callus tissue cultured on one of the variants (0.1 mg/l NAA, 0.1 mg/l BAP) yielded in high content of xanthotoxin (145.33 mg/100 g). On the majority of media, umbelliferone was also accumulated at high quantities (maximum content of 536.29 mg/100 g). The medium containing 0.1 mg/l NAA and 0.1 mg/l BAP was the best for the accumulation of analysed coumarins. This medium favoured the formation of embryogenic callus. Xanthotoxin also dominated quantitatively among the furanocoumarins in the tested vegetative organs and fruits of the plant grown under natural conditions (leaves: 26.10 mg, roots: 5.55 mg, fruits: 3010.41 mg/100 g). Maximum contents of this metabolite in in vitro culture were many times higher than those found in vegetative plant organs but manifold lower than in fruits. On the other hand, maximum contents of imperatorin obtained in in vitro culture were many times higher in comparison with those detected in vegetative organs and fruits (leaves: 14.10 mg, roots: 3.30 mg, fruits: 94.70 mg/100 g of dry weight.). The A. majus L. callus culture, established in the course of the present experiments, can be considered a valuable model for studies of the biosynthesis of coumarin compounds, and a potential source of the psoralen 8-alkoxy derivatives imperatorin and xanthotoxin and their precursor umbelliferone.

Apiaceae↗
PubMed2000

In vitro cultures of higher plants and fungi as a potential source of bioactive metabolites.

The review presents the results of investigations conducted at the Chair of Pharmaceutical Botany, Collegium Medicum, Jagiellonian University, which demonstrated a prospects to obtain biologically active metabolites representative of many chemical groups (furanocoumarins, polysaccharides and lectins, indole compounds, carotenoids) in in vitro cultures of both higher plants and higher fungi (Macromycetes) (mycelial cultures). These cultures can be a potential, rich, new source of metabolites.

Fungi↗
PubMed1981

EEG data reduction by means of autoregressive representation and discriminant analysis procedures.

A program for automatic evaluation of EEG spectra, providing considerable reduction of data, was devised. Artefacts were eliminated in two steps: first, the longer duration eye movement artefacts were removed by a fast and simple 'moving integral' methods, then occasional spikes were identified by means of a detection function defined in the formalism of the autoregressive (AR) model. The evaluation of power spectra was performed by means of an FFT and autoregressive representation, which made possible the comparison of both methods. The spectra obtained by means of the AR model had much smaller statistical fluctuations and better resolution, enabling us to follow the time changes of the EEG pattern. Another advantage of the autoregressive approach was the parametric description of the signal. This last property appeared to be essential in distinguishing the changes in the EEG pattern. In a drug study the application of the coefficients of the AR model as input parameters in the discriminant analysis, instead of arbitrary chosen frequency bands, brought a significant improvement in distinguishing the effects of the medication. The favourable properties of the AR model are connected with the fact that the above approach fulfils the maximum entropy principle. This means that the method describes in a maximally consistent way the available information and is free from additional assumptions, which is not the case for the FFT estimate.

Brain↗