Flavonoids and phenolic acids isolated from the herbs of Melampyrum pretense (MP) and M. nemorosum (MN) (Scrophulariaceae) growing in the Ural region have been studied by two-dimensional paper chromatography. The phenolic complex of MP contains 23 compounds including 17 flavonoids and 6 phenolcarboxylic acids. The MN herb contains 9 flavonoids and 5 phenolcarboxylic acids. A comparison with reference samples showed the presence of cinaroside, luteolin, quercetin, hyperoside, and chlorogenic, caffeic, and ferulic acids. Differential UV spectra of the extracts of MP and MN herbs in the presence of aluminum chloride showed peaks at 395.6 and 398.7 nm, respectively, which have been used for quantitative determination of the flavonoids (recalculated for cinaroside). The maximum flavonoid content was found in the generative organs; the minimum, in the roots. It is established that the flavonoid content in various organs varies within 0.08 -3.17% for MP and 0.04 -2.29% for MN.

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Introduction. Natural biologically active substances (BAS) are distinguished by different polarity, which determines their physicochemical properties, including solubility. When using solvents of different polarity, it is possible to influence the spectrum of BAS extracted from plants, achieving their division into groups, and further achieving isolation in an individual form. Тhe aerial part of Linaria vulgaris Mill. (common toadflax) contains both lipophilic and hydrophilic substances. The herb L. vulgaris is widely used in folk medicine for treatment of angina, conjunctivitis, dermatomycosis, periodontitis and other diseases. Bacterial factors play an important role in the pathogenesis of these diseases.Aim. To study the effect of solvents of different polarity on the component composition of extracted BAS and to study the antimicrobial activity of fractions from the herb L. vulgaris.Materials and methods. The aerial part of L. vulgaris was collected at the flowering stage – at the beginning of fruiting stage in July 2021 in the Perm region. The fractions were obtained by sequential exhaustive liquid-liquid extraction of an alcoholic extract from the herb L. vulgaris with hexane, dichloromethane, and n-butanol. Detection of BAS was carried out by HPLC and planar chromatography on paper. Antimicrobial activity was studied against Escherichia coli, Staphylococcus aureus and Candida albicans.Results and discussion. Using solvents of different polarity four fractions were obtained from the alcohol extract of L. vulgaris: hexane, dichloromethane, n-butanol and water. These fractions have differences in the composition of BAS. The number of polyphenolic substances in the fractions increases with increasing of solvent polarity: hexane (14), dichloromethane (55), butanol (61). The dichloromethane and n-butanol fractions have a similar composition, represented by polyphenolic compounds and iridoids. The main groups of compounds in these fractions are phenolic acids and flavonoids. Iridoids are found in trace amounts. In the hexane fraction, the smallest number of substances was found, iridoids are completely absent, and phenolic acids were found in trace amounts. The water fraction is characterized by the content of the entire BAS complex. The highest antibacterial activity against Escherichia coli and Staphylococcus aureus was found for the aqueous fraction, while the highest antifungal activity was found for the hexane and dichloromethane fractions.Conclusion. Using solvents of different polarity, fractions containing a diverse set of BAS were obtained from the alcoholic extract of L. vulgaris. Fractions exhibiting different polarities from L. vulgaris have antimicrobial activity against Staphylococcus aureus and Escherichia coli, as well as against pathogenic fungi from the genus Candida.

The content of moisture, ash, extractive substances, impurities, and the main biologically active substances in the above-ground parts of blue cow wheat (Melampyrum pratense) has been studied. The average content of the main components, flavonoids and iridoids, has been estimated at 0.18 -0.64 and 1.35 -5.90%, respectively. The optimum extraction conditions are provided by the repercolation of a raw material comminuted to a particle size within 0.25 -2.0 mm with a 50% ethanol solution in a battery of four percolators. Liquid (1:1) extracts, dry alcohol extract, and dry aqueous extract have been obtained and their anticonvulsant activity has been determined in tests on mice. The maximum activity was observed for the dry aqueous extract in a dose of 100 and 200 mg/kg, which is explained by the consistent action of the entire complex of biologically active substances. The acute toxicity (LD 50 ) is 2930 mg/kg for the dry extracts and 30.8 ml/kg for the liquid extracts. 2070091-150X/05/3904-0207