不同成熟度桑葚果实和叶片的多酚、黄酮和抗氧化性研究(英文)

Total polyphenols, flavonoids and antioxidant activities in mulberry(Morus alba) leaves and fruit at different maturities

【目的】明确桑葚果实和叶片的抗氧化活性。【方法】以不同成熟度的红桑葚(Morus rubra)果实和叶子为材料,研究其提取物的多酚、黄酮和抗氧化活性差异。【结果】成熟叶片中的多酚和黄酮含量最高,接下来依次是嫩叶、黑色果和红色果。通过DPPH、FRAP和SRSA方法,测定的抗氧化能力从低到高的顺序依次是黑色果、红色果、嫩叶和成熟叶。清除ABTS自由基的能力从高到低依次是成熟叶、嫩叶、黑色果和红色果。表明在DPPH、FRAP和SRSA分析体系里,提取物中花青素的含量起着主要的抗氧化作用,而在ABTS体系里,抗氧化活性主要与多酚和黄酮含量和种类有关。【结论】桑葚的果实和叶片是很好的天然抗氧化物质,尤其是果实。

【Objective】 Mulberry is widely distributed in China. In additional to its usage as forage plant for silkworms, it is also used as a herbal medicine. 【Method】 This study investigated the total polyphenols and total flavonoid contents, and antioxidant activities in the extracts from mulberry fruits and leaves at different development stages. 【Result】 The highest total polyphenol and flavonoid contents were found in the mature leaves followed in descending order by the premature leaves, black colored fruit, and red colored fruit.. The antioxidant capacities of the extracts determined by 2,2-Diphenyl-l-picrylhydrazyl(DPPH),ferric reducing antioxidant power(FRAP), and superoxide anion scavenging ability(SRSA) methods followed a descending order of black colored fruit > red colored fruit > premature leaves > mature leaves,while The order of the antioxidant activity determined by 2,2 ethyl-benzothiazoline-6-sulfonic acid(ABTS)method was mature leaves > premature leaves > black colored fruit > red colored fruit. The results indicated that anthocyanins in the extracts might be the main contributor to DPPH scavenging capacity,FRAP, and superoxide anion scavenging capacity, while the ABTS scavenging potential was correlated with the polyphenol and flavonoid content and composition. 【Conclusion】 In general, mulberry leaves and fruit, especially fully mature fruit, are good sources of natural antioxidants.