三种热带水果多酚物质的检测及其体外抗菌活性测定

Determination and in vitro antibacterial activity of three kinds of polyphenols in tropical fruits

目的检测珍珠番石榴、鸡心柿和番荔枝中多酚物质的种类和含量,了解对常见致病菌的抗菌活性。方法用高效液相色谱法测定水果提取液中多酚物质的成份,用微量稀释法测定对蜡样芽胞杆菌、金黄色葡萄球菌、白色念珠菌、表皮葡萄球菌、鼠伤寒沙门菌、福氏志贺菌、大肠埃希菌、铜绿假单胞菌等8种常见致病菌的最小抑菌浓度(minimal inhibitory concentration,MIC)和最小杀菌浓度(minimum bactericidal concentration,MBC)。结果三种热带水果提取液中均检出儿茶素、没食子酸、槲皮素、木犀草素等多酚物质,珍珠番石榴含儿茶素为391.93 mg/kg,鸡心柿和番荔枝含没食子酸分别为377.11 mg/kg和256.52 mg/kg。珍珠番石榴提取液对表皮葡萄球菌的抗菌活性最强,MIC为0.0781 g/m L;鸡心柿提取液对金黄色葡萄球菌的MIC为0.312 5 g/m L;提取液对受试菌具有明显的杀菌或抑菌作用,抗菌活性强弱为:G+>G-,球菌>杆菌>真菌,条件致病菌>致病菌。结论珍珠番石榴、鸡心柿和番荔枝所含的多酚物质具有较高的抗菌活性,其中含量最高的是儿茶素和没食子酸。

Objective To understand antibacterial activity of pearl guava,heart-shaped persimmon and sweetsop againstcommon pathogens, and clear the varieties and contents of polyphenols in them. Methods The contents of polyphenols infruit extracts were determined by high performance liquid chromatography. Minimal inhibitory concentration（MIC） andminimum bactericidal concentration（MBC） of 8 common pathogens, including Bacillus cereus,Staphylococcus aureus,Monillia albican,Staphylococcus epidermidis,Salmonella typhimurium,Shigella flexneri,Escherichia coli,and Pseudomonas aeruginosa,were determined by micro dilution method. Results Polyphenols,including catechin, gallic acid, quercetin,and luteolin,were detected in extracts. Pearl guava contained catechin up to 391.93 mg/kg. Heart- shaped persimmon and sweetsopcontained gallic acid up to 377.11 mg/kg and 256.52 mg/kg respectively. The antibacterial activity of the extract of pearl guavaagainst Staphylococcus epidermidis was the highest, and the MIC was 0.078 1 g/m L. Heart- shaped persimmon extract of Staphylococcus aureus MIC was 0.312 5 g/m L. Extracts had sterilization and antibacterial action of different degree to the testedstrains. The antibacterial activity of extracts was G＋〉G-, staphylococcus 〉bacillus 〉fungi, opportunistic pathogen pathogen. Conclusion Polyphenols in pearl guava, heart-shaped persimmon and sweetsop had higher antibacterial activity.The highest content in the polyphenols was the catechin and gallic acid.