Phytochemical characteristics of some plants of Northern Mongolia

The article presents the results of determining the content of pectin substances, organic acids and freesugars in 7 species (8 samples) of plants collected in the steppe regions of Northern Mongolia. These are: Armeniaca sibirica(L.) Lam. – siberian apricot, leaves; Artemisia adamsii Bess. – Adams wormwood, aboveground part; Betula fusca Pallasex Georgi - brown birch, leaves; Iris lactea Pallas, milky white iris, leaves; Polygonatum (Aconogonon) divaricatum L. –spreading knotweed (battering ram), leaves and flowers; Thermopsis dahurica Czefr. – Daurian thermopsis, abovegroundpart; Veronica incana L. – gray-haired Veronica, aboveground part. The studied species comprise a significant amountof pectin substances, citric, acetic, lactic and other organic acids, as well as free sugars: glucose, fructose, sucrose. Thequantitative content of these substances has been determined.

Germination characteristics and phytotoxic inhibition of germination in Artemisia adamsii, a low-palatability weed in the Mongolian steppe

Artemisia adamsii is a weed with low palatability to livestock and is thus recognized as an indicator of rangeland degradation in Mongolia. We investigated the germination characteristics of this species, phytotoxic suppression of its germination by its own residue, and the applicability of such germination behaviour to the control of this species. We also discussed the ecological consequence of these factors regarding the vegetation dynamics of the Mongolian steppe. Germination of A. adamsii was tested at different light and temperature conditions. Germination was also tested for A. adamsii and four native grassland species in the presence or absence of A. adamsii residue. Germination of A. adamsii was light-demanding and temperature-dependent. Artemisia adamsii residue showed autotoxic but sub-fatal suppression of germination, and the chemicals causing that suppression were shown to be aqueous and volatile. Phytotoxicity of A. adamsii residue on the germination of grassland species was low, except for in Artemisia frigida. The applicability of the observed sub-fatal autotoxicity for controlling this species was likely to be low, but the elucidated germination characteristics could contribute to developing a strategy for controlling this species. The autotoxicity in A. adamsii germination was suggested to have an ecological consequence that mediates species transition from A. adamsii to other species in degraded land occupied by A. adamsii. As low-palatability A. adamsii can act as a nurse plant of palatable species under grazing conditions, the invasion of A. adamsii into disturbed grasslands may facilitate the recovery of such grasslands in terms of improving pasture quality.

TLC-Direct Bioautography for Determination of Antibacterial Activity of Artemisia adamsii Essential Oil

The aim of the present study was the chemical characterization of the essential oil of a Mongolian medicinal plant, Artemisia adamsii Besser, and the investigation of the antibacterial effect of its oil on different human pathogenic bacteria (Staphylococcus aureus, methicillin-resistant S. aureus, and S. epidermidis). The chemical composition of the oil was established by GC and GC/MS. Direct bioautography was used for detecting the antibacterial activity of the essential oil. The result of GC experiments showed that α-thujone was the main component (64.4%) of the oil, while the amount of β-thujone was 7.1%. 1,8-Cineole seemed to be the other relevant component (15.2%). The antibacterial activity of the A. adamsii essential oil against all three investigated bacteria was observed in the bioautographic system, but this effect was not proportional to the concentrations of α- or β-thujone; therefore, from a microbiological aspect, thujone content does not determine the medicinal value of this oil. On the whole, the combination of TLC separation with biological detection is an appropriate method for evaluating multicomponent and hydrophobic plant extracts, for instance, essential oils, and it provides more reliable results than traditional microbiological methods (e. g., disc diffusion and agar plate techniques).