Extraction Process Optimization and Anti-oxidant Activity of Total Flavonoids in Dendrobium nobile Lindl.

摘要

[Objectives]To improve the yield of flavonoids from Dendrobium nobile Lindl.[Methods]On the basis of four single-factor experiments of solid/liquid ratio,extraction temperature,extraction time and ethanol volume fraction,the ultrasonic-assisted extraction process of total flavonoids from D.nobile Lindl.was optimized using quadratic general rotary unitized design,and the in-vitro anti-oxidant activity of the flavonoids extracted was evaluated preliminarily.[Results]The optimized extraction process for flavonoids in D.nobile Lindl.was as follows:extraction time 10 min,solid/liquid ratio 1∶15(g∶mL),extraction temperature 75℃and ethanol volume fraction 90%.According to the revised optimal process,6 repeated experiments were carried out,and the average yield of flavonoids was(0.5515±0.0004)mg/g,consistent with the predicted value of the model.The results of anti-oxidation experiment show that the flavonoids extracted from D.nobile Lindl.have better scavenging effect on ABTS and DPPH free radicals,and the scavenging activity is proportional to the mass concentration of the extract.[Conclusions]The optimized extraction process for flavonoids from D.nobile Lindl.is reasonable and feasible,and the flavonoids in D.nobile Lindl.have strong antioxidant activity.