Method of quantitative determination of the total flavonoids in the leaves of Populus alba L.

Introduction. White poplar (Populus alba L.) as a promising source of raw materials containing phenolic compounds is of interest for expanding the raw material base of medicinal plant materials with antimicrobial activity. It is known that the leaves of the white poplar contain flavonoids, for example, rutin, phenylpropanoids (p-coumaric acid, caffeic acid), simple phenols (salicin) and other compounds. From the point of view of standardization of this raw material, flavonoids are of interest. The aim of the present study is to develop a technique for quantifying of the total flavonoids in the leaves of white poplar (Populus alba L.). Material and methods. The research material was the leaves of the white poplar harvested in 2022 in the Samara region (near the village of Alekseevka). Differential spectrophotometry was used as a method of investigation, held according with Pharmacopoeial monograph 1.2.1.1.0003.15 «Spectrophotometry in ultraviolet and visible spectrum». Spectral characteristics of water-ethanolic extraction was marked on spectrophotometer Specord 40 (Analytik Jena AG, Germany) in cuvette with layer thickness 10 mm. Results. There was developed the methods for the quantitative determination of the total flavonoids in leaves of white poplar. We used the differential spectrophotometry method with the state standard sample of rutin at an analytical wavelength of 410 nm. The content of total flavonoids in the plant raw material is varied from of 1,30±0,04 % to 2,19±0,05 % (calculated on rutin). The error of a single determination with a confidence level of 95% is ±5,22%. Conclusion. As a result of the conducted research, the expediency of assessing the quality of raw materials Populus alba leaves by the content of the total flavonoids in canculated on rutin was justified. The validation evaluation of the developed methodology was carried out according to the indicators of specificity, linearity in accordance with the State Pharm of the Russian Federation of the XIV edition. Based on the results of the validation evaluation of the experimental results, we can conclude about the suitability of using this technique for quantifying of the total flavonoids calculated on rutin. The obtained research results can be used in the development of regulatory documentation for a promising type of raw material Populus alba leaves for introduction into the State Pharmacopoeia of the Russian Federation.