Kitagawia baicalensis (Redow. ex Willd.) Pimenov (Umbelliferae) is a perennial monocarpic plant with Siberian-Mongolian type of habitats. Decoction of flowers and roots has been used in Tibetan medicine for intoxication and as diuretic agent to treat edema. The essential oils of the aerial part of K. baicalensis growing within the territory of the Republic of Buryatia were obtained by steam distillation method. The isolated essential oils were yellow oily liquids, lighter than water, with characteristic pleasant odour. The qualitative composition and quantitative content of the components of essential oils were determined by GC/MS. 26 compounds with aromatic, mono- and sesquiterpenoid structures were identified in the composition of essential oils. The main components of the essential oils of the aerial part of the Kitagawia baicalensis from Buryatia were limonene (34.40%), β-myrcene (21.10%), γ-terpinene (12.60%), β-elemen (5.70%), sabinene (5.30%), germacren B (3.20%) and germacrene D (3.10%). Monoterpenoids (83.00%) predominated in general composition of essential oils. The content of compounds with sesquiterpenoid structure was 14.70%. The group of aromatic compounds was represented only by p-cymene (2.30%). Bactericidal and bacteriostatic activities of essential oils against Bacillus cereus, Staphylococcus aureus, Streptococcus pyogenes, Escherichia coli, Pseudomonas aeruginosa, Salmonella enterica, Aspergillus niger, Candida albicans were determined in this paper. The most pronounced antibacterial effect of essential oils was found against Streptococcus pyogenes (1 : 64 dilution).

The article is devoted to investigate the changes in the composition of biologically active substances (essential oils, lipid fraction, phenolic compounds) of the aerial part of the Bupleurum scorzonerifolium Willd. in depending on the phase of plant development. The greatest variety of compounds included in the composition of essential oils is characterized by a flowering phase. Fifteen terpene compounds – p-cymol, β-myrcene, trans-β-ocymene, limonene, (E,E)-α-farnesene, α-copaene, β-elemene, humulene, germacrene D, caryophyllene, γ-muurolene, bicyclogermacrene, Δ-cadinene, t-muurolol, spatulenol – are constant components of essential oils, regardless of phenophase. The quantitative content of these components varies from trace to major at different phenological phases. The coincidence of the main components of the lipid fraction was established. The main saturated acid is 16:0. Its content changes depending on the phase of vegetation – it is approximately at the same level determined in the phases of vegetation and flowering phases (26.78% and 27.26%, respectively) and there is a decrease in the fruit phase (18.17%). The main monounsaturated fatty acid is 18:1n9. Its greatest content was found in the fruiting phase, the smallest – flowering. The predominant polyunsaturated fatty acid is 18:2n9,12. Its greatest content was found in the vegetation phase (26.78%), the lowest - flowering (24.23%). However, the total content of unsaturated fatty acids exceeds the total content of saturated fatty acids in all phases of plant development. Although, their ratio varies from phenophase. There is a general pattern of highest content of phenolic compounds in the flowering phase for all studied samples. It was shown that during the flowering phase, the maximum accumulation of essential oils, lipids and phenolic compounds is observed.

The component composition of pine buds essential oil, growing in the area of active economic activity in Tomsk region, has been studied. Essential oil from pine buds obtained by the method of distillation with the water steam. The component composition of the essential oil was studied by gas-liquid-chromatography-mass spectrometry on the gas chromatograph Agilent 6890 with quadrupole mass spectrometer (HP MSD 5973N). Chromatography conditions: 30-meter long quartz column HP-5MS with internal diameter 0.25 mm, film thickness of 0.25 µm (copolymer 5% diphenyl 95% dimethylsiloxane), carrier gas – helium (constant flow 1 ml/min), column temperature – 50 °С (2 min isotherm), 50–200 °С (40 °C, min), 200–280 °С (20 °С/min), 280 °С (5 min isotherm), the temperature of the ion source 170 °С, the interface between the gas chromatograph and mass selective detector 280 °С. The energy of ionizing electrons is 70 eV. The volume of injected sample of 1 µl. The component composition was determined by comparing the times and linear retention indices, mass spectra values, the database of the chromatographic-mass spectrometric library of volatile substances of plant origin. About 163 individual components were found. It is established that with the increase of technogenic pollution, the amount of essential oil decreases, the component composition changes, which can serve as an indicator of the quality of raw materials, the state of the forest stand of pine and the environment as a whole. Data on the dominant content of 3-caren in the composition of essential oils of the pine buds, growing in the Tomsk region, suggests a limited use of this raw material and essential oil on its basis in medical practice.