[Study on extraction and purification techniques and free radical scavenging activity of total flavonoids from Fissistigma oldhamii].

Objective: To optimize the extraction and purification techniques of total flavonoids in Fissistigma oldhamii. The scavenging activity to DPPH of the total flavonoids and the extraction were studied in vitro.
Methods: By orthogonal design, we investigated the effects of concentration of ethanol, temperature, ratio of solid to liquid and time of extraction on the total flavonoids extraction rate. The total flavonoids was separated and purified by AB-8 macroporous resin absorption.
Results: The optimum extraction condition was that at extraction time of 3 h, concentration of alcohol 90%, solid/liquid ratio of 1:10 and temperature of 70 degrees C. The content of total flavonoids in the refined product was above 55%. The GFM-2 fraction showed antioxidant capacity in vitro.
Conclusion: The optimum extraction condition and purification experiment are very useful for further development of industrial process. Meantime, the result may be helpful for further development of Fissistigma oldhamii as health protection foods.