【作者】 林烽；

【导师】 陈清西；

【作者基本信息】 福建农林大学 ， 果树学， 2008， 硕士

【摘要】 本文对橄榄叶总黄酮的测定方法、提取工艺和抗氧化能力进行了研究;同时以檀香、长营和惠圆3个橄榄品种的叶片为试材,在不同的时期分析了总黄酮、花青苷、简单酚类的含量和PAL、C4H、4CL活性的变化情况。研究结果如下:1.通过各种定性颜色反应,初步确定橄榄叶中存在黄酮类化合物,其类型可能为黄酮及黄酮醇。采用分光光度法定量分析橄榄叶总黄酮,方法具有较好的重现性和准确性。2.实验采用乙醇加热回流提取,应用石油醚预处理,通过单因素试验、正交试验及方差分析,确定了总黄酮热回流提取最佳条件:乙醇浓度为60%,提取温度为80℃,提取时间为1.5 h,液固比为20:1。3.对檀香、长营和惠圆3个橄榄品种叶片中总黄酮、花青苷和简单酚类含量不同时期的测定结果表明:花青苷可能不是影响总黄酮合成的主要因素,简单酚类和总黄酮存在一定的依存关系。对檀香、长营和惠圆3个橄榄品种叶片中PAL、C4H和4CL活性不同时期的测定结果表明:PAL、C4H、4CL三者间呈同步变化;总黄酮含量与PAL、C4H及4CL活性呈显著正相关,相关系数分别为0.9132～0.9389、0.7518～0.788和0.801～0.806;PAL在总黄酮合成过程中可能起到重要作用。4.与其他植物叶片比较,橄榄叶片总黄酮含量为3.09%～5.63%,处于中上水平。檀香叶片的总黄酮含量明显高于长营和惠圆,三个品种均以5月叶龄的叶片总黄酮含量最高。如果作为提取黄酮的原料,宜在12月到1月间采摘约5月～9月左右叶龄的叶片。5.对橄榄叶总黄酮提取物进行了抗氧化能力的测定,结果表明橄榄叶总黄酮提取物还原能力和清除·OH的能力低于BHT,但强于V_c;清除O₂^-的能力高于BHT和V_c;清除DPPH的能力远高于BHT,在低浓度时,低于V_c,高浓度时,则相反。从橄榄叶黄总酮清除各种自由基的IC₅₀来看,清除超氧阴离子的能力最强,其次是羟自由基,最后是DPPH。这表明橄榄叶总黄酮提取物具有良好的抗氧化能力。更多还原

【Abstract】 Taking the leaves of Chinese white olive as material,the paper studied the methods of analyzing and determination of total flavonoids,the optimum extraction techniques of total flavonoids and the antioxidant activities of total flavonoids.PAL activity,C4H activity,4CL activity,the contents of flavonoids,anthocyanin and simple phenols in Tanxiang,Huiyuan and Changying were also determined during different stages,and the dynamic changes of those were analyzed.The results were as follows:1.The qualitative analysis of total flavonoids by color reaction showed that the extraction solution from Chinese white olive leaves contains flavones and flavonols. Spectrophotometry was applied to detect the content of total flavonoids in the experiment,the method presented good reproducibility and accuracy.2.The extraction process of the total fiavonoids from the leaves of Chinese white olive by single factor and orthogonaltest was studied.The optimum extraction condition was established as follows:solvent 60%（v/v）ethanol,extraction temperature（water bath）80℃,extraction time 1.5h,and ratio of liquid to material（mL /g）20:1.3.Taking the leaves of Tanxiang,Huiyuan and Changying as raw material,the experiment results showed that antioxidant might not be the main factor of influencing total flavonoids to synthesize.There was certain dependency relation between total flavonoids and simple phenols.There were synchronous trends of change among PAL activity,C4H activity and 4CL activity.The content of total flavonoids was correlated positively with PAL activity,C4H activity and 4CL activity. The correlation coefficient between flavonoids and PAL ranged from 0.9132 to 0.9389. The correlation coefficient between flavonoids and C4H ranged from 0.7518 to 0.788. The correlation coefficient between flavonoids and 4CL ranged from 0.801 to 0.806. PAL might play an important role in flavonoids synthesized.4.Compared with leaves of other plants,the content of total flavonoids in leaves of Chinese white olive was a little higher than middling which ranged from 3.09%to 5.63%The content of total flavonoids in Tanxiang was higher than Huiyuan and Changying,and leaves which had about five months of leaf age had the highest content of total flavonoids among three varieties.If we used the leaves of Chinese white olive as material to extract flavonoids,the best time for picking leaves were from December to January,and the best leaf age was between five months and nine months.5.The oxidationresistant experiments were studied by total flavonoids extracted from leaves of Chinese white olive,its ability of reducing power and scavenging.OH were stronger than that of V_C,but lower than that of BHT,its ability of scavenging O₂^-was stronger than that of BHT and V_C,its activity of scavenging DPPH was stronger than that of BHT,and when its concentration is lower,its activity of scavenging DPPH was lower than that of V_C,,however,when its concentration was higher,its activity of scavenging DPPH was stronger than that of V_C,.Base on the 50%effective dose of scavenging free radicals for total flavonoids,its scavenging effect on O₂^- was the strongest,the second on scavenging·OH,and the weakest on scavenging DPPH.The results showed total flavonoids of Chinese white olive leaves had well oxidationresistant ability.更多还原