Interpopulation Variability of Polyphenol Concentration in the Leaves of <i>Spiraea aquilegifolia</i> (Rosaceae) from the Republic of Buryatia

Abstract

Abstract—Composition and content of flavonoids and phenol carboxylic acids in the leaves of Spiraea aquilegifolia Pall. from natural populations of the Republic of Buryatia (Western Transbaikalia) are given in the article. Aqueous ethanol (40%) extracts from raw materials were used for chromatographic study of phenolic compounds. The analysis of phenolic compounds was carried out on an analytical High-Performance Liquid Chromatography (HPLC) system consisting of an Agilent 1200 liquid chromatograph (USA) with a diode array detector, an autosampler, and a system for collecting and processing chromatographic data ChemStation. At least 24 phenolic compounds were identified in aqueous ethanol extracts from Spiraea aquilegifolia Pall. leaves by HPLC. Three acids (chlorogenic, p-coumaric and p-hydroxybenzoic) and six flavonols (hyperoside, isoquercitrin, avicularin, astragalin, quercitrin and kaempferol) were identified among them. Flavonols hyperoside (2.9–8.2 mg/g), avicularin (3.0–5.8 mg/g) and isoquercitrin (0.8–2.5 mg/g) are the main substances in aqueous ethanol extracts from leaves. Plants from populations located at the northern distribution limit in the Western Transbaikalia have a higher content of phenol carboxylic acids (near the village Koma) and flavonols (near the village Klyuchi). Plants from populations located to the eastern limit (near villages Kusoty and Zagan) have the lowest concentration of identified phenolic compounds. A high and very high level of interpopulation variability of the studied biochemical parameters has been established. This can be explained by the functional significance of the identified compounds and their active participation in general metabolic processes in the plant. The content of identified free phenolic acids and flavonols in S. aquilegifolia was characterized by medium and high levels, compared to other studied Spiraea species. This confirms the prospects for further study of the composition of phenolic compounds of S. aquilegifolia.