| Autor: |
Wolniak M; Medical University of Warsaw, Faculty of Pharmacy, Department of Physical Chemistry, 02-097 Warsaw, 1 Banacha str., Poland., Tomczykowa M, Tomczyk M, Gudej J, Wawer I |
| Jazyk: |
angličtina |
| Zdroj: |
Acta poloniae pharmaceutica [Acta Pol Pharm] 2007 Sep-Oct; Vol. 64 (5), pp. 441-7. |
| Abstrakt: |
Extracts from herb and flowers of Bidens tripartita L. (Asteraceae), obtained using solvents of different polarity, were studied for their radical scavenging effects. Antioxidant activities of pure flavonoids: flavanomarein (isookanin 7-O-glucoside), cynaroside (luteolin 7-O-glucoside) and luteolin, which had been isolated from this plant, were also evaluated. Radical-scavenging activity was measured by electron paramagnetic resonance (EPR) spectroscopy using stable 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical. The content of flavonoids in flower heads is half of that found in the herb; however, the extract from flowers showed that the antioxidant activity was almost two times higher there. Some extracts (n-BuOH fraction) showed long lasting radical scavenging activity and the EPR spectra were recorded in time to follow the reaction kinetics. Scavenging of DPPH showed second-order kinetics at the beginning of the assay period and later the first-order one. Different kinetics suggested the presence of polymerized and/or less active antioxidants with different scavenging mechanisms for particular polyphenolic compounds. Bur-marigold extracts are a potential source of natural antioxidants that may be used in pharmaceutical or food industry. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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