甘薯茎叶多酚类物质的组分构成及抑菌活性

Individual Phenolic Composition and Antimicrobial Activity of Sweet Potato Leaf Polyphenols

【目的】研究甘薯茎叶多酚的组分构成及其抑菌活性。【方法】采用反相高效液相色谱法,分析甘薯茎叶多酚组分构成;采用牛津杯法和最小抑菌浓度法,测定甘薯茎叶多酚及其组分对常见细菌(金黄色葡萄球菌、枯草芽孢杆菌、大肠杆菌、普通变形杆菌)及霉菌(米曲霉、米根霉)的抑菌活性。【结果】甘薯茎叶多酚主要由7种多酚类物质组成,其中4,5-O-二咖啡酰奎宁酸的含量最高(占总酚的40.18%)。甘薯茎叶多酚及其组分抑菌活性强弱顺序均为革兰氏阳性菌>革兰氏阴性菌>霉菌。多酚各单一组分中咖啡酸的抑菌活性最强,对革兰氏阳性菌的最小抑菌浓度为47μg/mL,与阳性对照(头孢曲松钠)相同。【结论】甘薯茎叶多酚有潜质成为一种应用于食品和医药等领域的新型天然抑菌剂。

【Objective】To identify the individual phenolic composition and antimicrobial activity of sweet potato leaf polyphenols.【Methods】HPLC was used to identify the individual phenolic composition of sweet potato leaf polyphenols.Furthermore,oxford cup method and minimum inhibitory concentration method were used to determine the inhibitory activity of sweet potato leaf polyphenols on bacteria(Staphylococcus aureus,Bacillus subtilis,Escherichia coli,Proteus vulgaris)and mould(Aspergillus oryzae,Rhizopus oryzae).【Results】Sweet potato leaf polyphenols were mainly composed by 7 individual phenolic compounds.The order of inhibitory activity of sweet potato leaf polyphenols against bacteria and mould was:Gram-positive bacteria>Gram-negative bacteria>mould.Caffeic acid showed the highest antibacterial activity,with the minimum inhibitory concentration on Staphylococcus aureus and Bacillus subtilis 47μg/mL,and it was true of that of ceftriaxone sodium.【Conclusion】Sweet potato leaf polyphenols have the potential to be used as a novel source of antimicrobial agent in the fields of food and medication.