雪莲果叶提取物的抗氧化活性研究

Study on the anti-oxidant activities of extract of Smallanthus sonchifolius leaves

目的对雪莲果叶进行提取分离,并对提取物及萃取各部位进行抗氧化活性测试,将雪莲果叶发展成为抗氧化植物源。方法以70%的乙醇溶剂对雪莲果叶进行提取,提取液减压浓缩后依次用石油醚、乙酸乙酯、正丁醇进行分步萃取,获得雪莲果叶总提取物及石油醚萃取物、乙酸乙酯萃取物、正丁醇萃取物、水留层5个极性不同的部位。分别测定5个部位的总酚酸含量、DPPH自由基消除活性、ABTS^+自由基消除活性、羟基自由基消除活性。结果雪莲果叶乙酸乙酯部位的总酚酸含量最高,达(29.93±0.31)mg/g,对自由基清除活性最强,清除DPPH、ABTS^+及羟基自由基的SC50值分别为(37.96±0.43、29.46±1.05、1.67±0.03)μg/mL,活性高于(P<0.05)常用人工合成抗氧化试剂2,6-二叔丁基-4-甲基苯酚(butylated hydroxytoluene,BHT)。结论雪莲果叶具有抗氧化活性的成分主要集中于乙酸乙酯部分,酚酸是其具有抗氧化活性的主要原因。

Objective Extraction and separation of Smallanthus sonchifolius leaves,and the anti-oxidant activity of crude extract and fractions of different polarity were tested,to make the leave of S. sonchifolius as a promising natural antioxidant source. Methods The S. sonchifolius was extracted by 70% ethanol,then extracted with petroleum ether,ethyl acetate,n-butanol to get five fractions,including petroleum ether fraction（ PE fra.）,ethyl acetate fraction（ EA fra.）,n-butanol fraction（ NB fra.）,Water fraction（ WT fra.） and crude extact（ CE） Then,the total phenolic content and the anti-oxidant activities,including DPPH,ABTS^＋,OH radicals scavenging activity of the crude extract and fractions were tested. Results The leaves of S. sonchifolius possessed strong radical scavenging activities,especially the ethyl acetate fraction,possessing the highest total phenolic content reaching（ 29. 93 ± 0. 31） mg/g,and the strongest anti-oxidant activities toward DPPH,ABTS^＋,OH radicals with SC50of（ 37. 96 ± 0. 43,29. 46 ± 1. 05,1. 67 ± 0. 03） μg/ml,respectively. The anti-oxidant activity of extract of S.sonchifolius leaves were higher than frequently-used antioxidant butylated hydroxytoluene（ BHT）（ P 0. 05）.Conclusion The anti-oxidant active components of S. sonchifolius leaves concentrated in ethyl acetate fraction,polyphenol acids could be major ingredients for the anti-oxidant activities of S. sonchifolius leaves.