Morphological and biochemical diversity of Spiraea hypericifolia (Rosaceae) growing under natural conditions in Novosibirsk Oblast

A study on some morphological characteristics and the set and levels of phenolic compounds was performed for the first time on Spiraea hypericifolia L. (Rosaceae Juss.) growing under natural conditions in the Novosibirsk region (four sites). Two phenotypic varieties of S. hypericifolia were identified. Twenty-three phenolic compounds were found in aqueous-ethanol extracts from S. hypericifolia leaves by high-performance liquid chromatography. Chlorogenic, p-hydroxybenzoic, and p-coumaric acids and quercetin, hyperoside, isoquercitrin, avicularin, rutin, and astragalin were identified among them. Hyperoside (6.7–20.5 mg/g) is the main phenolic compound in S. hypericifolia leaves. Flavonoid aglycones were prepared from the leaves by hydrochloric-acid hydrolysis of the aqueous-ethanol extracts (1:1). Three flavonol aglycones (quercetin, kaempferol, and isorhamnetin) were identified in the extract hydrolysates from S. hypericifolia leaves by chromatographic analysis. Quercetin glycosides proved to be predominant phenolic compounds in all the extract hydrolysates. A comparative analysis was performed on the levels of phenolic compounds in leaves among S. hypericifolia from the different sites and between the two varieties of S. hypericifolia. It was revealed that an increase in plant size by approximately twofold correlates with a decrease in concentrations of the identified flavonoids and phenolcarboxylic acids in S. hypericifolia leaves