龙眼果皮不同方法提取物对自由基的清除作用

Free Radical Scavenging Activities of Extracts from Peel of Dimocarpus Longan by Different Methods

用超声波、微波、冷凝回流及常温浸泡4种方法,用φ(C2H5OH)=95%的乙醇提取龙眼果皮,分别得到超声波提取物(UE)、微波提取物(ME)、热提物(RE)和浸提物(DE)。然后采用二苯代苦味酰肼自由基(DPPH)法对不同质量浓度的各提取物进行了自由基清除实验。结果表明,龙眼果皮乙醇提取物对自由基有很强的清除作用,清除能力远远优于3,5-二叔丁基-4-羟基甲苯(BHT);不同的提取方法所得提取物对自由基的清除作用有显著差别,其中以ME的效果最佳,当其质量浓度为1.2 mg/mL时,最大清除率高达83.11%。

Peel of Dimocarpus longan was extracted with ethanol by four methods：uhrasonic method, microwave method, refluxing and condensation, and dipping at normal temperature, to get ultrasonic extract （ UE ）, microwave extract （ ME）, refluxing extract （ RE ）, and dipping extract （ DE ） respectively. Then their free radical scavenging activities were measured with 1,1-diphenyl-2-picrylhydrazyl（DPPH） method. The results showed that the ethanol extracts of the peel of Dimocarpus longan had stronger free radical scavenging activities than butylated bydroxytoluene（BHT）. With different extraction methods, the free radical scavenging activities of the extracts were also different. ME was the best. The highest free radical scavenging rate was 83.11% when mass concentration of ME was 1.2 mg/mL.