Abstract

This paper, applied the central composite design combined with response surface methodology to optimize the parameter of ultrasonic-assisted extraction the total flavonoids from Selaginella doederleinii Hieron (SD). The results indicate that themaximum extract of total flavonoids was 4.414 mg/g by using 70% ethanol as solvent, extract 50 min at 65°C. Antioxidant activity of extracts, determined by 2,2-diphenyl-1-picryl-hydrazyl (DPPH) assay, ranged from 20.22 to 46.64 mg/ml of raw SD. The optimization condition for antioxidant activity was similar to extract of total flavonoids. Yield increase of the total flavonoids depends on the cooperative effect of three selected parameters in the process of ultrasonic-assisted extract.Antioxidant activity more reckon on the ethanol concentration. Moreover, it was also found that there was not significant correlation between the bioactivities andcontent of total flavonoids.

Key words: Selaginella doederleinii hieron, response surface methodology, flavonoi, antioxidant activity.