厚朴籽不同溶剂萃取物抗氧化活性比较分析

Comparative Analysis of Antioxidant Activity of Different Solvent Extracts of Magnolia offcinalis Seed

为研究厚朴籽抗氧化成分,测定厚朴籽90%乙醇粗提物及其石油醚、乙酸乙酯、正丁醇和水萃取物的1,1-二苯基-2-三硝基苯肼(1,1-diphenyl-2-picrylhydrazyl,DPPH)自由基清除活性,2,2-联氮基-双-(3-乙基苯并噻唑啉-6-磺酸)二铵盐(2,2-azino-bis(3-ethylbenzthiazoline-6-sulonic acid),ABTS)自由基清除活性和铁离子还原能力(ferric reducing antioxidant power,FRAP),同时测定其总酚及总黄酮含量。结果发现,乙酸乙酯萃取物的总酚和总黄酮的含量最高,含量依次为(253.64±7.25)和(179.11±0.61)mg/g。厚朴籽乙醇粗提物和萃取物具有一定抗氧化活性,其中乙酸乙酯萃取物的抗氧化活性最强,DPPH自由基清除活性显著(P<0.05)高于阳性对照BHT,其IC50仅为(29.33±2.31)μg/mL;乙酸乙酯萃取物ABTS自由基清除活性与VC相当,IC50分别(30.33±1.53)和(31.67±3.06)μg/mL;厚朴籽乙醇粗提物和萃取物对铁离子的还原能力较低,均显著(P<0.05)低于阳性对照VC和BHT。相关性显示,厚朴籽三种体外抗氧化活性均与总酚和总黄酮极显著相关(P<0.01)。以上结果表明,乙酸乙酯可以富集厚朴籽酚类物质,为下一步厚朴籽抗氧化物质分离奠定了理论依据。

The purpose of the study was to investigate antioxidant constituents in Magnolia offcinalis seed.The 90%ethanol extracts was fractionated by successive extraction with petroleum ether,ethyl acetate,n-butanol and water.The abilities of the extracts and these four fractions on scavenging DPPH,ABTS free radicals and FRAP were measured.Along with this,their total phenolics and total flavonoids contents were determined.The results showed that Magnolia offcinalis seed were rich in total phenolics and total flavonoids.The contents of ethyl acetate fractions were(253.64±7.25)and(179.11±0.61)mg/g,which were the highest in the solvent fractions.Moreover,the ethyl acetate fractions had the strongest antioxidant activity,when compared with enthanol extracts and other three fractions.The IC50 of DPPH free radical scavenging activity to ethyl acetate fractions was only(29.33±2.31)μg/mL,which was significantly(P<0.05)higher than the BHT.The ABTS free radical scavenging activity of ethyl acetate fractions was similar to VC,and the IC50 were(30.33±1.53)and(31.67±3.06)μg/mL,respectively.The ethanol extracts of Magnolia offcinalis seed and fractions,exhibited low FRAP activity,which were lower than VC and BHT significantly(P<0.05).The correlation analysis showed that these three antioxidant activities were significantly correlated with total phenolics and total flavonoids(P<0.01).The above results indicated that ethyl acetate could enrich the phenolic constituents of Magnolia officinalis seed,which laid a theoretical foundation for the separation of antioxidant constituents in Magnolia officinalis seed.