杂交鹅掌楸总黄酮检测及DPPH自由基清除作用

Determination of Total Flavonoids and Their Scavenging Activity on DPPH Free Radicals in Liriodendron Hybrid Leaves

本研究通过Al Cl3-Na Ac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/m L。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 Al Cl3-Na Ac 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 flavonoids in Liriodendron hybrid leaves. The optimal determination time was in 30 - 80 minutes after color development. The relative standard deviation（ RSD） of precision test was 0. 56%（ n = 5）,and the average recovery 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 obviously 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 / m L respectively. In conclusion,the content of total flavonoids in Liriodendron hybrid leaves was significantly higher with stronger antioxidant activity,so it had potential value of development and utilization.