The problems to improve the standardisation of yarrow herb

Relevance. It is known the method of quantitative determination of the total flavonoids in the herb of common yarrow (Achillea millefolium L.) included in the State Pharmacopoeia of the Russian Federation XIV edition, according to which at the stage of extraction of these raw materials should be acid hydrolysis with ethyl alcohol 96% containing 1% hydrochloric acid concentrated, followed by determination of the amount of flavonoids in recalculation on luteolin. The flavonoid glycosides, including 7-O-glucosides luteolin (cynaroside) and apigenin (cosmosiin), difficult to acid hydrolysis, which does not allow for complete hydrolysis and exhaustive extraction of the target substances. Determination of the main groups of biologically active substances by thin-layer chromatography (TLC) involves the use of a standard sample of sudan III, not contained in the raw material.

The purpose of this study is the improvement of methods of qualitative and quantitative analysis of herb of Achillea millefolium L.

Material and methods. Yarrow herb harvested in 2021 was used as study materials. Extraction of individual substances from yarrow herbs was carried out using column chromatography on silica gel KSC 50/100 under conditions of gradient elution with chloroform-ethanol solvent mixture in different ratios. Along with the isolated individual flavonoids, we used working standard samples of flavonoids obtained by the authors in previous studies of herbal plants containing flavonoids, characterized using UV and NMR spectroscopy: rutin, quercetin, kaempferol, cynaroside, luteolin. Flavonoid content was determined by thin-layer chromatography and by differential spectrophotometry.

Results. TLC analysis revealed the presence of three dominant and diagnostically significant flavonoids: cosmosiin, cynaroside and apigenin. Analysis of UV spectra also confirmed that the spectral characteristics of the water-alcoholic extracts from common yarrow herbs, especially under the conditions of differential spectrophotometry, are mainly determined by the dominant flavones (cosmosiin, cynaroside and apigenin).

Conclusions. The obtained results of studies on the flavonoid composition and spectral characteristics of the isolated dominant flavonoids suggest the feasibility of conducting of the qualitative and quantitative analysis of common yarrow herbs using cynaroside as a standard sample.