Variability of the essential oil from three sorts of Echinacea MOENCH genus during ontogenesis.

Variability of the essential oil from three sorts of Echinacea MOENCH genus during ontogenesis The content and quality of the essential oil in relation to the main ontogenetic stages of plants were studied in three various sorts of Echinacea genus. The comparison included Echinacea purpurea, Echinacea atrorubens, and Echinacea pallida. The differences in the content of the oil in different parts of plants and the abundance of individual oil constituents in oils from the sorts under study at the optimum stage of ripeness for harvest were evaluated as well.

[Qualitative characteristics of selected species of the genus Echinacea Moench]. / Stúdium kvalitatívnych vlastností vybraných druhov rodu Echinacea Moench.

The paper examined the effect of production-technological conditions in relation to the ontogenetic stage of plants in three different species of the genus Echinacea Moench., comparing the species Echinacea purpurea, Echinacea atrorubens, and Echinacea pallida. It also examined the differences in the content of essential oil in different plant organs and evaluated the representation of individual components in the essential oils of the species under study at the stage of the optimal maturity for collection.

[Determination of residual trifluralin in the herbal drug Mentha piperita L]. / Stanovenie rezíduí trifluralinu v droge Mentha piperita L.

A HPLC/UV method was worked out to determine the residues of the herbicide trifluralin in the vegetable drug of the peppermint (M. piperita L.). The yield of the method, determined in model samples, was at least 70%, the determination limit of the method being 0.07 mg.kg-1. The content of trifluralin residues in the vegetable drug of the peppermint plant after application of the preparation Treflan 48 EC (in a dose of administration of 2 kg.ha-1) for the treatment of the growth in a small-plot experiment was below the detection limit of the analytical method.

Determination of the hop-derived phytoestrogen, 8-prenylnaringenin, in beer by gas chromatography/mass spectrometry.

A method was developed to determine 8-prenylnaringenin, a novel hop-derived phytoestrogen, in beer. Matrix purification involved solid-phase extraction on octadecyl silica followed by liquid/liquid extraction on a ChemElut 1010 column connected to a Florisil adsorption/desorption cartridge. 8-Prenylnaringenin was eluted from the tandem columns using a 1:1 mixture of diethyl ether and ethyl acetate and subsequently determined as tris(trimethylsilyl) ether by GC/MS-SIM. The recovery of 8-prenylnaringenin in beer samples was between 61.1 +/- 6.6 and 82.2 +/- 8.8% for levels of 37 and 92.5 microg L(-1), respectively, and the detection limit was approximately 5 microg L(-1). Although most beers do not contain 8-prenylnaringenin in detectable quantities, the highest concentration found was 19.8 microg L(-1). The concentration of 8-prenylnaringenin in beers and, possibly, its absence depend on the selection of particular hop varieties, the hopping rate, or the type of hop product used in brewing. The efficiency of transfer of 8-prenylnaringenin from hops to beer is between 10 and 20%.

The effect of herbicides on the qualitative properties of healing plants. Part 2: Content and composition of the essential oil from Salvia officinal is L. after application of Afalon 50 WP.

The aim of our work was to study the changes of the content and quality of volatile oil in Salvia officinalis L. being treated with Afalon 50 WP (the active substance linuron) in the major ontogenetic phases of the plant growth. The plants treatment with a herbicide in pre-emergence did not cause a dramatic change in the essential oil content or in the proportional representation of its individual components. During the investigation of the changes in quality of the essential oil after an application of Afalon during various plant growth phases there was found the same relationship when compared with those being untreated.