New antioxidant flavonoid isolated from Leuzea carthamoides

Abstract

A new natural flavonoid patuletin 3′-β-xylofuranoside was isolated from Leuzea carthamoides leaves. The antioxidant activity of this compound was evaluated by the DPPH radical assay and ferric reducing antioxidant power (FRAP) assay, and the results were compared with those for trolox and quercetin. DPPH radical scavenging activity of the tested compounds was expressed by the parameter EC₅₀: patuletin 3′-β-xylofuranoside (56.0 μM), trolox (27.8 μM), and quercetin (25.3 μM). The ferric reducing activity of the compounds was demonstrated as FRAP values at 4 and 60 min: patuletin 3′-β-xylofuranoside (28.4 μM, 35.8 μM), trolox (19.3 μM, 20.2 μM), and quercetin (54.3 μM, 79.9 μM). The structure/activity relationship of the flavonoid is also discussed. The results indicate significant antioxidant potency of patuletin 3′-β-xylofuranoside.

Keywords::

• Leuzea carthamoides
• flavonoid
• patuletin
• antioxidant
• FRAP
• DPPH

Acknowledgements

This work was supported by a grant from the Charles University (Czech Republic), GAUK 124/2005/B-BIO/FaF, and a research project of the Ministry of Education of the Czech Republic (MSM 0021620822).

Declaration of interest: The authors report no conflicts of interest.