核桃仁皮不同极性提取物的体外抗氧化活性分析

采用乙酸乙酯、正丁醇、氯仿、石油醚对核桃仁皮多酚进行提取,通过清除DPPH自由基、OH自由基、ABTS自由基法与铁离子还原能力初步评价其体外抗氧化活性。结果表明,不同极性溶剂对核桃仁皮多酚提取能力为乙酸乙酯>正丁醇>氯仿>石油醚;乙酸乙酯提取物具有最强的DPPH自由基清除能力和ABTS自由基清除能力,其IC₅₀值分别为5.004和29.654 μg/mL,其次为正丁醇(9.596、23.681 μg/mL)、氯仿提取物(62.719、144.475 μg/mL)以及石油醚提取物(48.316、146.424 μg/mL);正丁醇提取物具有最强的OH自由基清除能力,其IC₅₀值为393.578 μg/mL,其次为乙酸乙酯(510.186 μg/mL)、氯仿提取物(627.003 μg/mL)与石油醚提取物(840.315 μg/mL);在铁离子还原能力实验中,当样品浓度均为100 μg/mL时,各提取物的吸光度为乙酸乙酯(0.821)>正丁醇(0.509)>氯仿(0.406)>石油醚(0.142)。总之,不同极性提取物其抗氧化能力有差异,依次为乙酸乙酯>正丁醇>氯仿>石油醚,且与质量浓度呈正相关。

Study on antioxidant activity of different polar extracts from walnut kernel pellicle in vitro

Using ethyl acetate,n-butanol,chloroform,petroleum ether extracted polyphenols from walnut kernel pellicle. Preliminary evaluation the antioxidant activities of different polarity extract from walnut kernel pellicle by DPPH free radical scavening assay,OH free radical scavenging assay,ABTS free radical scavening assay and iron ion reduction capacity. The results showed that the extraction capacity of polyphenols from walnut kernel pellicle was ethyl acetate>n-butanol>chloroform>petroleum ether. The ethyl acetate extract has the strongest DPPH free radical and ABTS free radical scavenging ability,the IC₅₀ values were 5.004 μg/mL and 29.654 μg/mL,followed by the n-butanol(9.596,23.681 μg/mL),chloroform extract(62.719,144.475 μg/mL)and petroleum ether extract(48.316,146.424 μg/mL). The n-butanol extract has the strongest OH free radical scavenging capacity,the IC₅₀ value was 393.578 μg/mL,followed by ethyl acetate(510.186 μg/mL),chloroform extract(627.003 μg/mL)and petroleum ether extract(840.315 μg/mL). When the sample concentration was 100 μg/mL,the absorbance of the different polarity extracts were ethyl acetate extracts(0.821)>n-butanol extracts(0.509)>chloroform extracts(0.406)>petroleum ether extracts(0.142)in the iron ion reduction reaction. In conclusion,the antioxidant activity of different polar extracts was different,followed by acetic ether>n-butanol>chloroform>petroleum ether,and positively correlated with the mass concentration.