准噶尔山楂叶总黄酮提取、测定及抗氧化活性研究

Extraction,Determination and Antioxidant Activity of Total Flavonoids from Crataegus songorica Leaves

研究常温浸提、索氏提取、超声提取等方法提取准噶尔山楂叶总黄酮及提取液清除DPPH自由基能力,采用亚硝酸钠-硝酸铝法和氯化铝法对不同提取液中总黄酮含量进行测定和分析比较.结果表明:超声提取法较其他两种提取法操作简单,耗时少,提取效率高.两种比色法经比较发现:氯化铝法可消除干扰,重现性好,准确度高,更适合于准噶尔山楂叶总黄酮含量测定.6月至10月采摘的准噶尔山楂叶中所含总黄酮没有显著性差异.不同提取物均具有一定的清除DPPH自由基能力,与对照品相比强弱顺序为:槲皮素>VC>超声提取液>浸泡提取液>索氏提取液,各待测液抗氧化活性与浓度呈正相关性,清除DPPH自由基IC50分别为0.047 mg/m L、0.059mg/m L、0.36 mg/m L、0.55 mg/m L、0.69 mg/m L.

The total flavonoids and antioxidant activity of different extracts from Crataegus songorica leaves were investigated using normal temperature extraction, soxhlet extraction and ultrasonic-assisted extraction, respec- tively. The contents of the flavonoids in leaves extract that disposed through different conditions were measured and compared with NaNO：Al（NO3）3 method and AlCl3 method. The results showed that the ultrasonic-assisted extrac- tion was more convenient, less time, higher extraction efficiency. AlCl3 method can eliminate the interference, it was the most appropriate for the determination of total flavonoids in Crataegus songorica leaves. Concentration of total flavonoids from Crataegus songorica leaves was no significant differences between June to October. Different extracts all had certain capacity to scavenge DPPH free radicals, and the antioxidant activities was quercetin 〉 VC 〉 ultrasonic-assisted extract 〉 normal temperature extract 〉 soxhlet extract, which was positively correlation with concentration. Their hemi-inhibitory concentration（ICs0） to DPPH free radical was 0.047 mg/mL,0.059 mghnL, 0.36 mg/mL,0.55 mg/mL,0.69 mg/mL, respectively.