Flavonoid Contents and Antioxidant Activities of Extracts from Leaves of Dendrocalamus semiscandens

The 80 % ethanol extract from leaves of Dendrocalamus semiscandens were divided into four fractions of petroleum ether extract,chloroform extract,ethyl acetate extract and water extract.They were used to determine flavonoid content with rutin and investigated by colorimetry of NaNO2-Al(NO3)3 at 510 nm.The regression equation of rutin standard working curve: A=10.735C+0.010 9(R2=0.999 5)was established;then free radical scavenging activities of chloroform extract and ethyl acetate extract were measured with DPPH· method.The experimental results showed that the flavonoid contents of petroleum ether extract,chloroform extract,ethyl acetate extract and water extract were 6.95 %,11.72 %,12.72 %,5.35 % respectively.The DPPH·scavenging value of chloroform extract IC50 are 0.15 mg/mL and that ethyl acetate extract IC50 are 0.09 mg/mL.The research indicates that the flavonoid content of chloroform extract and ethyl acetate extract is higher than that of petroleum ether extract and water extract;the DPPH· free radical scavenging activities of ethyl acetate extract is better than that of chloroform extract.