Total polyphenol, flavonoid contents and antioxidant capacities of different polarity parts in extracts from Premna microphylla Turcz in vitro

Objective: The antioxidant capacities of different polarity parts in extracts from Premna microphylla Turcz leaves were studied. Methods: Different polarities of extracts were classified by different polarity solvents, such as petroleum ether, chloroform, ethyl acetate, N-butyl alcohol and water, the content of total flavonoids was determined and the antioxidant activity was compared by FRAP, DPPH and ABTS+. Results: The contents of total phenolics and total flavonoids in the ethylacetate phase were the highest ( 635.935 ± 6.529 mg GAE-1and 953.018 ± 21.774 mg QE·g^-1) , all polarity parts were promoted to have a certain antioxidant activity and there was a significant dose-effect relationship, the antioxidant capacity of ethyl acetate phase and petroleum ether phase was different ( p < 0.01) . Conclusion: The different polarity fractions of extracts from Premna microphylla Turcz had certain antioxidant abilities which were related to contents of total phenolics and total flavonoids.The free radical scavenging capacity of ethyl acetate was stronger than that of VC, it can be further separated and purified.