The steam distillation method was used to obtain samples of essential oil of some species of genus Agastache L. introduced in Belarus. More than 20 components have been identified and determined in the essential oils of Agastache pallidiflora ssp.neomexicana L., Agastache aurantiaca L., Agastache mexicana L., Agastache foeniculum L. by gas liquid chromatography.The quantitative composition of the samples of essential oils depends on the type of plant material. The main its components are limonene, 1.8-cineol, mentone, isomentone, methyl chavicol, methyeugenol. The main component of essential oils Agastache pallidiflora ssp. neomexicana L. и Agastache aurantiaca L is mentone (40–65 %). Essential oil Agastache foeniculum L. is enriched with pulegone and isomentone. Methyl chavicol and methyleugenol dominate in Agastache mexicana essential oil. Distribution of the enantiomers of limonene, menthone and pulegone are shown. Regardless of the plant species, the samples are optically pure in the (+)-pulegone. The nature of the distribution of the enantiomers of limonene and menthone is an individual characteristic of the studied Agastache L. essential oils.

The essential oil obtained by hydrodistillation method from plants of three varieties Agastache aurantiaca, cultivated on the Republic of Belarus were investigated. Some morphobiometric parameters of plants 'Tango', 'Apricot Sprite' and 'Fragrant Delight' and oil yields were determined. Using the technique of gas-liquid chromatography essential oil components were identified and determined. The main components of the essential oil from 'Tango' and 'Fragrant Delight' plants were menton (~ 53 and ~ 65 v/v % respectively) and pulegon (~ 36 and ~ 25 v/v % respectively). The samples of 'Apricot' Sprite' essential oil were rich in isomentone (~ 46 v/v %) and pulegon (~ 41 v/v %). All tested essential oils contained (+)-menton and (+)-pulegon enantiomeric forms only. The antibacterial activity of dimethylsulfoxide and ethanolic essential oil solutions against Staphylococcus aureus, Salmonella alony, Bacillus subtilis, Clostridium sp., Escherichia coli Hfr H, Pseudomonas aeruginosa was proved. Ethanol solutions of essential oils at the concentrations 0.001–0.1 v/v % had significant bactericidal activity. A correlation between the composition of the essential oil and their antibacterial properties was established.

Aim. The aim of this work was the possibility of using the composition of essential oils enantiomers as chemomarkers for the genus Pinus. Methods. The plant materials were subjected to hydrodistillation in a Ginsburg type apparatus (0.2 kg each loading) for 1 h. The collected samples of essential oils were dried with anhydrous Na2SO4 and stored at 4.8℃ until analyzed. The enantioselective capillary GC analysis was conducted on a Cyclosil B capillary column (30 m x 0.32 mm, film thickness 0.25 μm, 30 % hepatkis (2,3-di-O-methyl-6-O-t-butyldimethylsilyl)-β-cyclodextrin in DB-1701). The relative amounts of individual components (in %) were calculated on the basis of GC peak areas without using correction factors. Results. The composition and enantiomeric terpene distribution of essential oils from the Pinus plants cultivated in the Central Botanical Gardens of Belarus is reported. Conclusions. The obtained experimental data indicate the presence of individual enantiomer composition features of essential oils of various representatives of the pine trees that can be used in chemosystematics of the genus Pinus. A common feature for the studied species of the genus Pinus is a significant predominance of (+)-Δ3-carene over (-)-form, the levorotatory isomer of β-pinene over (+)-form. As chemomarker for the section Cembra can be used enantiomeres excess (-)-limonene. Keywords: Pinus, essential oil, enantiomer, chemomarker.

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