小叶丁香皮不同溶剂提取物的抗氧化活性

Antioxidant Activities of Different Solvent Extracts from Syringa pubescens Turcz Bark

目的:研究小叶丁香皮中不同溶剂提取物的抗氧化活性。方法:采用ABTS+.、DPPH自由基及还原性反应体系,利用分光光度法测定小叶丁香皮的总提液、乙酸乙酯层、正丁醇层和石油醚层在不同质量浓度下的抗氧化能力及总酚含量。结果:小叶丁香皮的不同溶剂提取物对DPPH自由基均具有较强的清除能力及还原能力,其清除率与质量浓度呈良好的量效关系。其中正丁醇层抗氧化能力最强,在质量浓度0.62mg/mL时,对ABTS+.的最大清除率为96.28%,对DPPH自由基的最大清除率为96.16%,与同质量浓度VC的清除率接近,且其IC50分别为0.074、0.012mg/mL;测得的正丁醇层总酚含量最高,为120.1μg/20mg。结论:小叶丁香具有较好的抗氧化能力,其正丁醇层抗氧化能力显著,这与总酚含量有较大的相关性。

Objective：To explore the antioxidant activities of different solvent extracts from Syringa pubescens Turcz bark.Methods：ABTS＋· and DPPH free radical scavenging and ferric reducing assay were used for antioxidant activity evaluation.The content of total phenols in 75% ethanol extract and its different solvent fractions（ethyl acetate,n-butanol and petroleum ether） were determined spectrometrically.Results：All the investigated samples had strong ability to scavenge DPPH free radicals and reduce ferric ions in a dose-dependent fashion.Among them,the strongest antioxidant activity was observed in n-butanol fraction.The maximum scavenging rate of n-butanol fraction against ABTS＋· was 96.28% at the concentration of 0.62 mg/mL.However,its maximum scavenging rate of against DPPH radicals was 96.16%,which was close to that of vitamin C.The IC50 of the fraction against ABTS＋· and DPPH radicals were 0.074 mg/mL and 0.012 mg/mL,respectively.In addition,it had the strongest antioxidant activity,which might be largely associated with its high level of total phenols,120.1μg/20 mg.Conclusion：Syringa pubescens Turcz bark has good antioxidant capacity,in which components soluble in both 75% ethanol and n-butanol reveal the strongest antioxidant capacity.