甘薯叶片中多酚成分及其抗菌活性研究

Study on the constituents and antibacterial activities of polyphenols from sweetpotato leaves (Ipomoea batatas L.)

中文关键词:  甘薯叶  多酚  成分  抗菌活性

英文关键词:sweetpotato leaf  polyphenols  constituent  antibacterial activity

中文摘要:

      目的 提取分离纯化甘薯叶片中多酚的成分, 并研究其抗菌活性。方法 采用Sephadex LH-20羟丙基葡聚糖凝胶柱色谱、液相色谱等方法, 分离纯化甘薯叶片乙酸乙酯和正丁醇部位的多酚成分, 根据波谱数据和文献对其结构进行鉴定; 采用平板稀释法测定不同化合物对3种病原菌最小抗菌浓度; 采用肉汤二倍稀释法测量不同化合物对3种病原菌的抑制率, 并计算半数抗菌浓度。结果 从甘薯叶提取物中分离并鉴定出3个酚酸类单体化合物、2个黄酮类单体化合物, 分别为咖啡酸、3,5-二咖啡酰奎宁酸甲酯、3,4-二咖啡酰奎宁酸甲酯、槲皮素3-O-β-D-葡萄糖苷和山奈酚-3-O-β-D-葡萄糖苷。5种化合物均具有不同程度的抗菌活性, 其中咖啡酸对肺炎克雷伯菌抑制作用明显; 山奈酚-3-O-β-D-吡喃葡萄糖苷对金黄色葡萄球菌抑制作用明显; 3,4-二咖啡酰奎宁酸甲酯和槲皮素-3-O-β-吡喃葡萄糖苷对鲍曼不动杆菌抑制作用明显。结论 多酚成分是甘薯叶片抗菌作用的有效成分之一, 具有作为天然抗菌剂应用于食品和医药领域的潜力。

英文摘要:

      Objective To extract and purify polyphenols from sweetpotato leaves and study their antibacterial activity. Methods The polyphenols compounds in the ethyl acetate fraction and N-butanol fraction were isolated and purified by Sephadex LH-20 hydroxypropyl glucan gel column chromatography and liquid chromatography. The structures were identified by various spectroscopic data and references. The minimal inhibitory concentrations of different compounds to three pathogens were determined by plate dilution method. The inhibitory rates of different compounds to three pathogens were measured by broth double dilution method, and the half inhibitory concentration was calculated. Results Three kinds of phenolic acids and 2 kinds of flavonoids were isolated from the extracts of sweetpotato leaves and identified as caffeic acid, 3,5-dicaffeoylquinic acid methyl ester, 3,4-dicaffeoylquinic acid methyl ester, quercetin-3-O-β-glucopyranoside and kaempferol-3-O-β-D-glucopyranoside. All the 5 kinds of compounds showed different degree of antibacterial activity: Caffeic acid had obvious inhibitory effect on Klebsiella pneumonia; Kaempferol-3-O-β-D-glucopyranoside had obvious inhibitory effect on Staphylococcus aureus; 3,4-dicaffeoylquinic acid methyl ester and quercetin-3-O-β-glucopyranoside had obvious inhibitory effect on Acinetobacter baumannii. Conclusion Polyphenols are one of the main antibacterial constituents from sweetpotato leaves, and have the potential to be used as natural antimicrobial agents in the field of food and medicine.