Abstract
The total content of phenolic compounds, including catechins, flavonols, phenolcarboxylic acids, and the antioxidant activity of aqueous-ethanol extracts from the above-ground organs of Spiraea humilis Pojark. from two Far Eastern populations were studied. It has been established that plant leaves contain more phenolcarboxylic acids and flavonols (population from the environs of Selikhino village, Khabarovsk Territory). Plant inflorescences contain more catechins, phenolic compounds, flavonols (population from the environs of Komsomolsk-on-Amur, Khabarovsk Territory). Plant stems were inferior in content of the studied compounds to leaves and inflorescences. Studies have shown that the antioxidant activity of water-ethanol extracts from leaves and stems of S. humilis is significantly lower than from inflorescences. From the correlation analysis, it was found that antioxidant activity is significantly positively related to the total content of phenolic compounds, mainly flavonols and catechins, in Spiraea organs. Phenolcarboxylic acids have the least effect on neutralizing 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radicals. Fifteen phenolic compounds with high biological activity were identified in aqueous-ethanol extracts from aerial organs of S. humilis by high-performance liquid chromatography. Differences in the profiles of phenolic compounds of plants from two Far Eastern populations were established. Of the identified phenolic compounds, the flavonols, quercitrin, rutin and quercetin make the greatest contribution to the antioxidant activity of the extracts. A preliminary assessment of plant materials showed that S. humilis accumulates a sufficient amount of biologically active substances in above-ground vegetative and generative organs and can be recommended as a promising source of antioxidants and other biologically active substances.