Extraction of chalcones from the dry vegetable raw materials by extraction

Purpose . The main problem of the synthesis of α,β-unsaturated carbonyl compounds is their high reactivity due to the presence of active electrophilic centers. At the same time, chalcones with a wide range of pharmacological activity are included in the composition of available plant raw materials, such as flowers of sand Helichrysum arenarium, bark of white willow (Salix alba) and roots of licorice (Glycyrrhiza glabra). The purpose of this work was to consider the possibility of extracting chalcones from dry plant raw materials using an aqueous solution of ethyl alcohol. Methods . The following methods were used in the study extraction of organic compounds; qualitative determination of compounds and spectrophotometric determination of the quantitative content of the sum of chalcones; physical and chemical methods for determining moisture content, viscosity, density, and other characteristics. Results . The paper considers known variants of chalcon synthesis and problems in their implementation. As an alternative, the extraction of chalcones from dry vegetable matter with an aqueous solution of ethyl alcohol under conditions of continuous extraction at the boiling point of a solvent in a Soxlet apparatus and maceration at room temperature is proposed. The selected objects (sandy immortelle (Helichrysum arenarium), white willow (Salix alba), and smooth licorice (Glycyrrhiza glabra)) have a wide distribution area and are considered as affordable raw materials. The effect of the initial raw material moisture on the amount of extracted chalcones and the ratio of raw material and solvent was evaluated. Conclusion . It has been established that both continuous extraction in a Soxhlet apparatus and maceration in the absence of stirring are suitable for extracting chalcones from dry plant raw materials. For all the types of raw materials studied in this work (flowers, roots, and bark), continuous extraction at the boiling point of the solvent proved to be more effective. The maximum amount of chalcones was extracted from the flowers of Helichrysum arenarium under conditions of continuous extraction. Based on the extraction of chalcones from the flowers of Helichrysum arenarium, it was found that the maximum yield of flavonoids is observed when the ratio of raw material to extractant is 1:10.