Abstract:

The orthogonal experimental design method was employed to study the ultrasonic-assisted extraction process of total flavonoids from the leaves of Ficus carica Linn. and their scavenging activities against hydroxyl and superoxide anion free radicals were evaluated. The optimum conditions for extracting total flavonoids from the leaves of Ficus carica Linn. were found to be: ethanol concentration 40%, material-to-liquid ratio 1:60 (g/mL), extraction temperature 60 ℃ and length of ultrasonic treatment of 50 min. Under these optimum conditions, the extraction efficiency of total flavonoids reached as high as 25.04 mg/g. Extraction temperature had the most important effect on the extraction of total flavnoids from the leaves of Ficus carica Linn., followed by length of ultrasonic treatment, material-to-liquid ratio and ethanol concentration. The total flavonoids extract from the leaves of Ficus carica Linn. had marked scavenging effects on both hydroxyl and superoxide anion free radicals in a concentration-dependent fashion.

Key words: the leaves of Ficus carica L., ultrasonic-assisted extraction, total flavonoids, antioxidant activity