The Antioxidant Activity of the Russian Far East Representatives of the Spiraea L. (Rosaceae Juss.) Genus

Abstract

Biologically active substances and antioxidant activity of extracts from leaves and inflorescences of nine representatives of the genus Spiraea L. growing on the territory of the Far East of Russia were investigated. Widespread species of the genus Spiraea (S. salicifolia, S. media var. media, S. betulifolia and S. ussuriensis subsp. ussuriensis) have the highest levels of biologically active substances. The inflorescences of spiraeas there contain more flavonols (up to 3.9%), oxycinnamic acids (up to 1.2%), catechins (up to 5.7%) and saponins (up to 5.1%) compared to their leaves, and there are more tannins (up to 11.6%) in the leaves. Among the Far Eastern representatives of the genus Spiraea, S. betulifolia and S. beauverdiana (section Calospira), S. humilis and S. salicifolia (section Spiraria), S. pubescens and S. media var. media (section Chamaedryon) are promising antioxidants. Plants of the genus Spiraea probably contain water-soluble antioxidant compounds of phenolic type, because the antioxidant activity of aqueous extracts in the leaves and inflorescences of spiraeas is higher (0.16–2.79 mg/g) than that of water-alcoholic compounds (0.06–2.54 mg/g). The antioxidant activity in the leaves of spiraeas is generally higher than that in the inflorescence. A reliable positive correlation is observed between the antioxidant activity of aqueous extracts from the organs of spiraeas and a content of oxycinnamic acids.