Abstract:

Purpose: To explore the antioxidant activity of different solvent extracts from the flowers of Trollius ledebouri
Reichb. Methods: The dried flowers were extracted sequentially with petroleum ether, ethyl acetate, 95% ethanol, 60%
ethanol, 30% ethanol and deionized water. Each extract obtained was analyzed by ultraviolet-visible spectrophotometry for
the contents of yellow pigment, total flavonoids and total polyphenols, and their radical scavenging activity against hydroxyl
and DPPH free radicals were tested. Results: Petroleum ether extract had the highest content of yellow pigment (11.37 ±
0.07) mg/g; 60% ethanol extract from the flowers of Trollius ledebouri had the highest content of total flavonoids (213.21 ±
1.12) mg/g and total polyphenols (121.75 ± 0.58) mg/g, 95% ethanol extract had slightly lower contents of total flavonoids
(200.47 ± 6.49) mg/g and total polyphenols (105.19 ± 0.61) mg/g. Petroleum ether extract had the strongest hydroxyl
radical scavenging ability with IC50 of 92.77 mg/L, while 95% ethanol extract had the strongest DPPH radical scavenging
ability with IC50 of 10.14 mg/L and 60% ethanol extract had slightly lower DPPH radical scavenging ability with IC50 of
10.70 mg/L. Conclusion: The hydroxyl radical scavenging capacity presented a positive correlation with the concentration
of yellow pigment, and the DPPH radical scavenging capacity presented a positive correlation with the concentration of
total flavonoids and total polyphenols; petroleum ether and 95% ethanol extracts from the flowers of Trollius ledebouri have
potent antioxidant activity.

Key words: flowers of Trollius ledebouri, antioxidant extracts, yellow pigment, total flavonoids, total polyphenols, hydroxyl radical, DPPH radical