The changes in the composition and content of phenolic compounds in the leaves and inflorescences of
Hedysarum alpinum
L. and
H. flavescens
Regel et Schmalh., introduced into the forest-steppe zone ...of Western Siberia, were studied. Using the example of
H. alpinum
, the variation in the content of phenolic compounds depending on the year of harvest and on the plant organ (leaves, inflorescences) was investigated. The contents of individual substances (gallic acid, chlorogenic acid, mangiferin, hyperoside, rutin, avicularin, and 17 phenolic components) and of phenolic compounds by groups (hydroxycinnamic acids, hydroxybenzoic acids, xanthones, and flavonols) were determined. Differences in the content of phenolic compounds by groups (in mg/100 g) were found between the two species of the genus
Hedysarum
L. Specifically, the leaves of
H. alpinum
accumulated more xanthones and flavonols (up to 4614.9 ± 63.7 and 1280.0 ± 6.7, respectively) and the inflorescences, more xanthones (up to 847.9 ± 29.8) compared to the leaves (2911.6 ± 79.0 and 976.2 ± 0.5, respectively) and the inflorescences (76.2 ± 2.5) of
H. flavescens
. In the leaves of
H. flavescens
, compared to the leaves of
H. alpinum
, the content of hydroxybenzoic acids and hydroxycinnamic acids prevailed. The leaves of the studied species accumulated mostly hydroxycinnamic acids and xanthones, and the inflorescences, mostly flavonols. The contents of hydroxybenzoic acids, xanthones, and flavonols in
H. alpinum
varied significantly depending on the year of observation.
The analytical task of determining the phenolic compound content of water-ethanol extracts of
Populus
tremula
L. (common aspen) leaves is complicated by the heterogeneity of compound groups having ...different polarities and appearing in varying concentrations. The purpose of the present work is to study the conditions of solid-phase extraction and high-performance liquid chromatography used to analyse the content of different groups of phenolic compounds in water-ethanol extracts of leaves from the
P
.
tremula
plant. In order to facilitate the derivation of phenolic compounds, an exhaustive extraction process was carried out using ethanol. Solid-phase extraction was carried out using a Diapak C16 cartridge, after which the eluates were passed through a membrane filter having a pore diameter of 0.45 μm. The high-performance liquid chromatography method was used to determine the content of phenolic acids and flavonoid glycosides, as well as salicin and individual flavonoid glycoside components: hyperoside, rutin, astragalin and two unidentified flavonoid glycosides in aqueous (analyte 1) and aqueous-alcoholic fractions (analyte 2) in two systems along the gradient elution. The requirement of analysing the primary aqueous eluate together or in parallel with the main aqueous-alcoholic fraction in the preparation of
P. tremula
leaf extracts for high-performance liquid chromatography using solid-phase extraction cartridges was substantiated. For separating the extract to determine the hydroxycinnamic and hydroxybenzoic acid content, it is preferable to use system 2; for determining the phenologlycoside (salicin) content, system 1 is more effective. Flavonoid glycosides (hyperoside, rutin, astragalin and two unidentified flavonoids) make the most significant contribution to the difference between the aqueous and aqueous-alcoholic fractions.
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