The component composition of the Achillea. nobilis essential oil, which grows in Azerbaijan, was studied for the first time by the gas-chromato-mass spectrometry method. In the essential oil, 35 components are identified, of which the predominant are artemisia ketone (23.706%), thujone 22.400%), 2-bornanone (6,367%), eudesm-7(11)-en-4-ol (6.321%), eucalyptol (4.507%), cubenol (3.317%), lavandulol (2.975%), β-thujone (2.933%), β-eudesmol (2.702%), methyl hinokiate (2.108%), terpinen-4-ol (1.715%), 1,2-longidione (1.313%), limonene-6-ol, pivalate (1.188%), neryl (S)-2-methylbutanoate (1.120%), caryophyllene oxide (1.014%). The effect of A. nobilis essential oil on the ultrastructural organization of bacteria (S. aureus) was studied using transmission electron microscopy. It was revealed that under the influence of essential oil, a violation of the plasma permeability of the plasma membrane is observed, accompanied by diffusion of the fine-grained osmiophilic precipitate of the destroyed cytoplasmic structures, which leads to the loss of the layered structure of the wall elements and to a significant compaction of the matrix in comparison with the control preparations. The death of bacterial cells was observed with complete destruction of the integrity of all structures that make up their wall. Along with this, on ultrathin sections, focal accumulations of dead bacterial cells are found, surrounded by structurally changed elements of their walls. The remains of destructively altered fragments of CP are found on various parts of unseparated bacterial cells. All of the above shows that the essential oil of A. nobilis has a pronounced antibacterial activity.

About 500 species of wormwood are known in the world. In the flora of Azerbaijan, this genus is represented by 42 taxa. The main chemicals in wormwood are shown to be sesquiterpene lactones, coumarins, steroids, and essential oils. From the aerial parts of Artemisia campestris (var. Marschalliana) Spreng., collected during the phenological phase of budding, an acetone extract was obtained, which, after removal of the solvent, was subjected to the column chromatography in neutral alumina oxide (II degree of activity) and eluted graduality with hexane, benzene, chloroform and their mixtures of increasing polarity. As a result of chromatographic separation, two sesquiterpene lactones of the eudesmann type were isolated - α-santonin (substance I) with m.p. 170–172 °С and artemisin (substance II) m.p. 201–203 °С. Moreover, an acetyl derivative of artemisin (substance III) with m.p. 196–198°C, the identification of which was carried out on the basis of physicochemical and spectral data (UV, IR, and 1H, 13C, 13C Dept 45, 13C Dept 90, 13C Dept 135 NMR spectra was obtained. Substances I and II are isolated from Artemisia campestris (var. Marschalliana) Spreng. for the first time.