不同品种嘉宝果叶片提取物的抗氧化活性

Antioxidant capacities of different leaf extracts of Jaboticaba cultivars

【目的】探讨4个嘉宝果品种叶片不同溶剂提取物的抗氧化活性,分析其与总多酚、总黄酮含量的相关性,为嘉宝果叶片的开发提供理论依据。【方法】以沙巴、四季早生、福冈、阿根廷等4个品种嘉宝果嫩/老叶片为研究对象,分别用水、50%乙醇(体积分数,下同)、70%乙醇和无水乙醇进行提取,检测提取物中的总黄酮、总多酚含量,分析提取物对DPPH·、·OH、ABTS+自由基的清除能力,以及总多酚、总黄酮含量与3种自由基清除能力的相关性。【结果】各嘉宝果品种均表现为嫩叶的总黄酮、总多酚含量高于老叶,其中以沙巴嫩叶70%乙醇提取物总多酚含量最高(273.70mg/g),阿根廷嫩叶70%乙醇提取物总黄酮含量最高(213.45mg/g)。各嘉宝果品种嫩叶的抗氧化活性均高于老叶,沙巴嫩叶各提取物抗氧化活性在同溶剂提取物中最强,其次为四季早生嫩叶、阿根廷嫩叶和福冈嫩叶。不同溶剂提取物抗氧化活性差异明显,表现为70%和50%乙醇提取物抗氧化活性优于无水乙醇及水提取物。相关性分析表明,醇提取物抗氧化活性与叶片总多酚含量极显著正相关(P<0.01)。【结论】沙巴嫩叶70%乙醇提取物总多酚含量最高、抗氧化活性最强,是天然抗氧化剂的良好来源。

【Objective】The antioxidant capacity of different extracts from leaves of four Jaboticaba cultivars was investigated.The correlation between the contents of total polyphenols,total flavonoids and the antioxidant capacity was analyzed to provide a theoretical basis for the development of Jaboticaba leaves.【Method】Four cultivars of Jaboticaba including Sabah,Sijizaosheng,Fukuoka and Argentina were used to determine the contents of total polyphenols,total flavonoids and scavenging ability on DPPH,·OH and ABTS+radicals.The correlations between the contents of total flavonoids and total polyphenols and scavenging capacity were also analyzed.【Result】The contents of total polyphenols,total flavonoids and antioxidant capacity in extracts of tender leaves were higher than those of aged leaves of all cultivars.The 70%ethanol extract of tender leaves of Sabah showed the highest content of total polyphenols(273.70 mg/g),and the 70%ethanol extract of tender leaves of Argentina had the highest content of total flavonoids(213.45 mg/g).The tender leaves of Sabah had the highest antioxidant activity,followed by tender leaves of Sijizaosheng,Argentina and Fukuoka.The difference in antioxidant activity was significant among different solvent extracts.The antioxidant abilities of 70%and 50%ethanol extracts were better than absolute ethanol and water extracts.Correlation analysis revealed that the scavenging activities of free radicals were significantly and positively correlated with the content of total polyphenols(P<0.01)for all ethanol extracts.【Conclusion】The 70%ethanol extract of tender leaves of Sabah exhibited the highest content of total polyphenols and antioxidant activity,indicating that it was a good source of natural antioxidants.