Study on Flavonoids Purification by Macroporous Resin and Antioxidant Activity of Flavonoids in Purple Sweet Potato

OBJECTIVE To study the flavonoids purification by macroporous resin and antioxidant activity of flavonoids in purple sweet potato.METHODS Four types of macroporous resins including D101,NKA-9,AB-8,NKA-Ⅱwere used to purify flavonoids with static adsorption capacity and elution ratio as evaluation factors.The optimum purification conditions were investigated with L9(34) orthogonal experimental design.The antioxidant activity of the extract was tested by using methods of pyrogallol autoxidation and phenanthroline with VC as reference.RESULTS AB-8 was the most suitable type of macroporous resin and the optimum conditions were as follows:the concentration of sample was 0.81 mg·mL-1,the washing pH value was 2,the flow rate of 70% ethanol was at 2 mL·min-1.The IC50 of antioxidant activity were 0.037 4 and 0.105 mg·mL-1 respectively.CONCLUSION The macroporous resin showed significant effect on the purification of flavonoids and flavonoids from purple sweet potato has strong antioxidant activity.