Quantitative analysis of polyphenols and antioxidant activity in four Daphne L. species

Abstract

The content of biologically active phenolic compounds (total polyphenols, tannins, flavonoids, and phenolic acids) were determined using spectrophotometry in four wild Croatian species of Daphne L. in the family Thymelaeaceae (Daphne alpina, D. cneorum, D. laureola, and D. mezereum). The concentration of total flavonoids (TF) was highest in the leaves of these Daphne species (0. 12-0. 51% dry herb weight, DW) whereas the content of other phenolic compounds analyzed were highest in the roots, including total polyphenols (TP; 2. 71-19. 03% DW), tannins (T; 1. 14-7. 39% DW), and total phenolic acids (TPA; 0. 12-0. 87% DW). D. alpina contained the highest amount of polyphenols, with the exception of flavonoids, where maximum concentrations were found in D. laureola. We also examined the antioxidant activity of leaf, stem, and root extracts. All extracts analyzed demonstrated high free radical scavenging activity with the highest concentration in the leaf extracts of D. alpina. Leaf extracts of D. cneorum showed the highest antioxidant activity in a β-carotene bleaching assay. © 2012 Versita Warsaw and Springer-Verlag Wien.