Abstract:Flavonoids from Rosa davurica Pall. were extracted with ethanol assisted by negative pressure ultrasonic technology. On the basis of single factor experiment, a three-level Box-Behnken experiment design was applied with ultrasonic time, ultrasonic temperature, ultrasonic power and material-liquid ratio as influencing factors. Using the yield of flavonoids from Rosa davurica Pall. as the response value, the extraction process was optimized by response surface methodology as follows: the ratio of material to liquid 1:30, the ultrasonic power 400 W, the ultrasonic time 33 min, and the ultrasonic temperature 56 ℃. Under these conditions, the yield of flavonoids reached (3.342±0.027) mg/g. In addition, a predictive quadratic mathematical model was established for extraction of flavonoids from Rosa davurica Pall. by ethanol solution. Antioxidant evaluation showed that Rosa davurica Pall. flavonoids had good reducibility and radical scavenging abilities towards OH·,DPPH·, and O2-·,with the IC50 values being of 0.021 mg/mL, 0.182 g/mL and 0.013 mg/mL, respectively. Their reducibility and radical scavenging abilities were higher than those of Vc at the same concentrations. The results showed that the flavonoids with good antioxidant activity could be extracted from Rosa davurica Pall. by negative pressure ultrasonic method.
