野龙竹竹叶黄酮含量及其抗氧化活性测定实验

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

以芦丁为对照样品,用NaNO2-Al(NO3)3比色法在510 nm处测定野龙竹80%乙醇提取物的石油醚相、氯仿相、乙酸乙酯相、水相4部分的黄酮含量,建立了芦丁标准曲线的回归方程:A=10.735C+0.010 9(R2=0.999 5),并用DPPH.对氯仿相和乙酸乙酯相的抗氧化活性进行了测定。实验结果表明,野龙竹竹叶的石油醚相黄酮含量为6.95%,氯仿相的黄酮含量为11.72%,乙酸乙酯相的黄酮含量为12.72%,水相的黄酮含量为5.35%。抗氧化实验显示,氯仿相清除DPPH.的IC50值为0.15 mg/mL,乙酸乙酯相清除DPPH.的IC50值为0.09 mg/mL,野龙竹醇提物的氯仿相和乙酸乙酯相黄酮含量较高,乙酸乙酯相具有较强的抗氧化作用。

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 e- quation of rutin standard working curve： A = 10. 735C ＋ 0. 010 9 （Rz = 0. 999 5 ） was established; then free radi- cal 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 ICs0 are 0. 15 mg/mL and that ethyl acetate extract ICs0 are 0. 09 mg/mL. The research indi- cates 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.