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Background. Linden flowers (Tilia cordata Mill) in the form of various medicinal forms is used as a diaphoretic and expectorant. The pharmacological properties of Linden flower preparations are mainly due to the essential oil (farnesol) and polysaccharides. However, according to literature data, the raw materials of Linden contain flavonoids, which are represented by tilianin, quercetin, hyperoside, and rutin. One of the most important properties of flavonoids is the ability to increase the strength of capillary walls (P-vitamin activity) due to the antioxidant effect, which is important in the treatment of chronic venous insufficiency, hypertension and other cardiovascular diseases associated with increased permeability of blood capillaries [1, 2]. The most striking representative in this group of substances is rutin, which belongs to the group of vitamin R. In this case, Linden flowers are of great interest. The problem of chemical standardization of raw materials of this plant is not fully solved, it is important to develop methods of standardization for the quantitative content of the amount of flavonoids. In our opinion, despite the complex chemical composition of Linden flowers, represented by such groups of biologically active compounds as essential oil, polysaccharides, flavonoids, it is advisable to standardize this plant according to the content of flavonoids. Objective – research on the development of a method for quantifying the content of flavonoids in Linden raw materials. Materials and methods. The object of the study was used 3 samples of dried Linden flowers grown in the Penza, Samara and Moscow regions. Quantitative determination of flavonoids was performed by the method of differential spectrophotometry. Results. In methods of quantitative determination of flavonoids of plant raw materials, water-alcohol solutions of different concentrations are used for extraction. It was found that in comparison with 70 % alcohol extracts, the intensity of peaks in 40 and 95 % alcohol extracts is less. Therefore, for the extraction of flavonoids from Linden flowers, it is advisable to use 70 % ethanol. It is shown that the UV spectra of Linden flower extracts have one clear maximum absorption at 279 nm, regardless of the concentration of ethanol-extractant. In the development of quantitative determination of flavonoids in Linden flowers, UV spectra of their complex compounds with aluminum chloride were studied. It was found that in the presence of aluminum chloride, the maximum absorption of the complex compound of Linden flavonoids is in the region of 408 ± 2 nm. As a result of the study, it was revealed that the best concentration of alcohol is 70 %, the best ratio of raw materials and extractant is 1:100, the best time for extraction is 60 minutes. Conclusions. Samples of Linden grown in different regions of Russia were analyzed using the developed technique for determining flavonoids. It was found that the content of flavonoids in Linden flowers varies from 1,5–2,0 %. |
