Functional Activity of the Antioxidant System of Artemisia Genus Plants in the Republic of Buryatia (Russia) and Its Significance in Plant Adaptation.

Plants are sessile organisms and any changes in environmental factors activate various responses and defense mechanisms. Artemisia plants widely inhabit harsh conditions of arid and semiarid ecosystems. Using two species-a subshrub, Artemisia frigida, and an annual-biennial herb, Artemisia scoparia-the functioning of the antioxidant system of plants in semiarid territories have been examined. The activity of enzymatic antioxidants and the content of non-enzymatic antioxidants in both species as well as the antiradical activity of their extracts have been shown. Although the plants were collected in areas differing in moisture supply, the activity of enzymatic antioxidants and the content of non-enzymatic antioxidants corresponds to their physiological level, within the range of the norm of reaction, in wormwood. Consequently, conditions of differing moisture deficiency do not cause a specific biochemical response at the level of the antioxidant system in the studied species, which confirms their adaptability to these conditions. Meanwhile, A. frigida plants show greater morphological and biochemical plasticity than A. scoparia under changing growth conditions. Both species contain tissue monoterpenoids and sesquiterpenoids, the emission of which provides additional protection against high temperatures and drought. Their composition and contents of phenolic components illustrates the differences in adaptation between perennial and annual plants.

Essential Oils of Artemisia frigida Plants (Asteraceae): Conservatism and Lability of the Composition.

Plants of arid regions have adapted to harsh environments during the long span of their evolution and have developed a set of features necessary for their survival in water-limited conditions. Artemisia frigida Willd. (Asteraceae) is a widely distributed species possessing significant cenotic value in steppe ecosystems due to its high frequency and abundance. This study examines different patterns of formation of essential oil composition in A. frigida plants under the influence of heterogeneous factors, including climate and its integral characteristics (HTC, Cextr, SPEI and others). The work is based on the results of our research conducted in Russia (Republic of Buryatia, Irkutsk region), Mongolia, and China, from 1998 to 2021. A total of 32 constant compounds have been identified in the essential oil of A. frigida throughout its habitat range in Eurasia, from Kazakhstan to Qinghai Province, China. Among them, camphor, 1,8-cineol and bornyl acetate are the dominant components, contained in 93-95% of the samples. Among the sesquiterpenoids, germacrene D is the dominant component in 67% of the samples. The largest variability within the composition of the essential oils of A. frigida is associated with significant differences in the climatic parameters when plants grow in high-altitude and extrazonal conditions.

Chemical Diversity of Artemisia rutifolia Essential Oil, Antimicrobial and Antiradical Activity.

This paper presents the results of the study of the composition of the essential oil (EO) of Artemisia rutifolia by the GC/MS method as well as its antimicrobial and antiradical activities. According to the PCA-analysis, these EOs can be conditionally divided into "Tajik" and "Buryat-Mongol" chemotypes. The first chemotype is characterized by the prevalence of α- and ß-thujone, and the second chemotype by the prevalence of 4-phenyl-2-butanone, camphor. The greatest antimicrobial activity of A. rutifolia EO was observed against Gram-positive bacteria and fungi. The EO showed high antiradical activity with an IC50 value of 17.55 µL/mL. The presented first data on the composition and activity of the EO of A. rutifolia of the Russian flora indicate the prospects of the species as a raw material for the pharmaceutical and cosmetic industry.

Composition and antioxidant activity of the essential oil of Artemisia annua L.

Artemisia annua L. is an annual Eurasian desert-steppe plant. The composition of essential oils found in Artemisia annua from Russian (Buryatian) flora was analyzed in this work using gas chromatography mass-spectrometry method. Artemisia ketone, ß-selinene, caryophyllene, caryophyllene oxide, germacrene D were the main components of the analyzed essential oils. The comparison of own and literature data showed that the essential oils of A. annua conditionally could be divided into "Asian" and "European" groups. Our samples, referring to "Asian" profile, exhibited higher antiradical activity in comparison with data from previously published studies.