engleski

Content of polyphenolic constituents and antioxidant activity of some Stachys taxa

Seven Croatian Stachys taxa (S. alpina, S. officinalis, S. palustris, S. recta subsp. recta, S. recta subsp. subcrenata, S. salviifolia and S. 12 sylvatica) have been investigated in order to determine their content of biologically active compounds (polyphenols, tannins, phenolic 13 acids and flavonoids) as well as their antioxidant activity. All taxa tested had a high content of total polyphenols, medium content of 14 total phenolic acids, and a rather low content of tannins and flavonoids. The total phenolic acids content correlated significantly with 15 total polyphenols content and the content of polyphenols unadsorbed on hide powder. A low correlation between plant phenolic acids 16 and tannins was observed. Methanolic, ethanolic and dichloromethane extracts were investigated using DPPH, lipid peroxidase and xan- 17 thine oxidase assays. The extracts showed no inhibitory effects against lipid peroxidation and xanthine oxidase, but they had the ability to 18 scavenge DPPH. The most effective in the DPPH assay were methanolic extracts of S. recta sub. recta and S. palustris whose radical 19 scavenging activity was higher then that of the reference rutin. A low correlation between radical scavenging capacities of extracts with 20 total flavonoids content was observed. The results indicate that investigated Stachys taxa exhibit potent antiradical activity and therefore 21 could be a potential material for extracting free radical scavengers

Stachys ; polyphenols ; tannins ; phenolic acids ; flavonoids ; DPPH ; lipid peroxidase ; xanthine oxidase

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