Screening of phenolic compounds (flavonoids and phenolpropanoids) of Centaurea cyanus L. flowers by planar chromatography

Introduction. Centaurea cyanus L. is an annual herbaceous plant whose funnel-shaped flowers are used as medicinal plant raw materials in official medicine. The biological activity (diuretic, choleretic, anti-inflammatory) of Centaurea cyanus flowers is associated with a complex of biologically active substances of phenolic nature. Anthocyanins act as the leading group used for the standardization of raw materials, according to the requirements of the State Pharmacopoeia of the Russian Federation, XV edition. Studies of the composition of flavonoids and phenolpropanoids of Centaurea cyanus flowers are relevant in terms of the value of their pharmacological properties. Aim. To conduct TLC screening of phenolic compounds (flavonoids and phenolpropanoids) of Centaurea cyanus L. flowers. Materials and methods. The objects of the study were dried whole flowers of Centaurea cyanus manufactured by the following companies: LLC «Lekra-SET», «Russkie Korni», Fito Way, LLC «HORST Company», LLC «Travy Gornogo Kryma» and LLC «Travy Bashkirii». Macro- and microscopic analysis was performed using a Mikromed MS-1 stereomicroscope (China), a Primo Star (Carl Zeiss, Germany) equipped with a Levenhuk M1400 PLUS digital camera, and microphotography editing was performed in Photoscape 3.7 according to the requirements of the State Pharmacopoeia of the Russian Federation, 15th edition. Screening of phenolic compounds was performed on plates with a silica gel layer on an aluminum substrate (Silica gel 60 F 254 , Merck KGaA, Германия). Detection was carried out with a 10 g/l solution of aminoethyl ester of diphenylboronic acid in ethyl alcohol and a 50 g/l solution of macrogol 400 in ethyl alcohol. After detection, the chromatograms were viewed in daylight and UV light at wavelengths of 254 and 365 nm using a UFS-254/365 chromatographic irradiator (IMID LLC, Russia). The comparison solutions were the following: rutin, quercetin, isoquercitrin, hyperoside, and caffeic acid. Results and discussion. As a result of the studies, the macro- and microscopic characteristics of the analyzed samples of Centaurea cyanus flowers corresponded to FS.2.5.0064.18 « Centaurea cyanus flowers». An adsorption zone with yellow-green fluorescence was found on the chromatogram of all the studied extracts, which, according to the Rf value, corresponds to the isoquercitrin RS. Chromatographic profiles of four of the six analyzed objects had 4 chromatographic adsorption zones related to flavonoids and phenolpropanoids. The samples of «Russkie Korni» and LLC «HORST Company» had only 3 zones, which is probably due to the low concentration of phenolic compounds in the plant material. Conclusion. The screening of phenolic compounds (flavonoids and phenolpropanoids) of Centaurea cyanus flowers was carried out using the planar chromatography method. The chromatograms of water-alcohol extracts showed an adsorption zone corresponding to isoquercitrin RS, and there were also other adsorption zones with fluorescence in UV light.