Home – Home – Jornals – Chemistry for Sustainable Development 2023 number 4

The content of phenolic compounds (flavonols, flavans (catechins), tannins), polysaccharides (pectins, protopectins), tetraterpenes (carotenoids) and the antioxidant activity have been studied in Inula helenium L., Antennaria dioica (L.) Graertn., Ligularia macrophylla (Ledeb.) DC Echinacea purpurea (L.) Moench. cultivated in Western Siberia. Flavonol content in the leaves and inflorescences of the studied species of the Asteraceae family was determined to be 0.75-1.98 wt. %, the maximum amount was detected in the inflorescences of I. helenium. Tannins are present in the amount of 9.62-14.86 wt. %, the maximum content is observed in the leaves of A. dioica and inflorescences of E. purpurea. The amount of catechins ranges from 0.02 ( A. dioica, L. macrophylla ) to 0.13 wt. % ( E. purpurea, I. helenium ). Pectins are present at the level of 1.20 %, somewhat lower content is detected in the leaves of I. helenium and inflorescences of L. macrophylla (0.43 and 0.59 wt. %, respectively), a fairly high content of protopectins (7.89-11.88 %) in the leaves and inflorescences of the studied species exhibits no significant differences. The concentration of carotenoids in the leaves and inflorescences of L. macrophylla is almost at the same level, while in I. helenium and E. purpurea it is significantly higher in leaves, in A. dioica - in inflorescences. The indicators of the total content of phenolic antioxidants in the leaves and inflorescences of I. helenium, A. dioica, and L. macrophylla have no significant differences. According to the results of a comparison of the antioxidant capacity of the studied extracts by means of DPPH, the highest radical-binding activity is exhibited by the extracts from the leaves of I. helenium (0.46 mg/mL) and inflorescences of A. dioica (0.47 mg/mL), somewhat lower activity is exhibited by the extracts of E. purpurea (0.70-0.92 mg/mL) and L. macrophylla (1.00-1.25 mg/mL).