Optimization of extraction technology by response surface methodology and inoxidizability of total flavonoids from Tricyrtis maculata Machride

The response surface methodology was used to optimize ultrasound-assisted extraction of total flavonoids from Tricyrtis maculata Machride.Based on single factor experiment and the extraction rate of total flavonoids for evaluation index, an ultrasonic procedure for the extraction of total flavonoids from T. maculata Machride was established by Box-Benhnken center-united experiment design and response surface analysis method. The main ultrasonic extraction factors including extraction ultrasonic power, ultrasonic time, extraction temperature, solid-liquid ratio which effect on the extraction yield of total flavonoids from T.maculata Machride were analyzed. The results showed that the optimum extraction conditions of total flavonoids from T.maculata Machride as follows:Material liquid ratio of 1:40 (g:mL), extraction temperature of 45℃, ultrasonic time of 60 min, extraction ultrasonic power of 210 W. The extraction rate of total flavonoids was (12.966±0.045) mg/g under the optimal extraction conditions and closing to predicted extraction rate of 13.035 mg/g. The results showed that the extractive of T.maculata Machride had a scavenging effect on DPPH free radical and hydroxyl radical. It had been revealed from result that the antioxidant activity of 50% ethanol extractive was the greatest, which of the methanol extractive was inferior and of the water extractive was the least.