本研究通过 AlCl3－NaAc 显色体系，采用分光光度法测定杂交鹅掌楸树叶中总黄酮含量，并与其它部位含量及其 DPPH 自由基清除能力进行比较分析。结果表明，该方法的最佳测定波长为272 nm，最佳测定时间范围为显色后30～80 min 内，精密度 RSD ＝0．56％（n ＝5），回收率为103．64％（RSD ＝2．05％），该测定方法准确可靠，利用该法测得杂交鹅掌楸树叶总黄酮含量为4．67％（RSD ＝2．01％，n ＝5），明显高于其它部位；不同部位提取的黄酮类化合物对 DPPH 自由基的清除能力由高到低为：树根＞树叶＞树皮＞花＞叶柄＞树枝，IC50值依次为：6．65、9．88、10．25、15．55、19．71、24．15μg／mL。杂交鹅掌楸树叶中总黄酮含量较高，抗氧化性较强，具有开发利用的潜在价值。%The total flavonoids in Liriodendron hybrid leaves were determined by spectrophotometry using AlCl3 -NaAc chromogenic system.Their contents and DPPH radical scavenging ability were compared with those in other parts.The results showed that the optimum wavelength was 272 nm for determination of total fla-vonoids in Liriodendron hybrid leaves.The optimal determination time was in 30 ~80 minutes after color de-velopment.The relative standard deviation (RSD)of precision test was 0.56% (n =5),and the average re-covery rate was 103.64% (RSD =2.05%),so this method was accurity and reliable.Using this method,the contents of total flavonoids in Liriodendron hybrid leaves was 4.67% (RSD =2.01%,n =5),which was ob-viously higher than those of any other parts.The ability of scavenging DPPH radical of total flavonoids from different parts was in the order of root >leaf >bark >flower >petiole >branches with the IC50 as 6.65,9.88, 10.25,15.55,19.71 and 24.15 μg/mL respectively.In conclusion,the content of total flavonoids in Lirio-dendron hybrid leaves was significantly higher with stronger antioxidant activity,so it had potential value of de-velopment and utilization.
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