七子花不同时期叶片提取物的体外抑菌活性

为调查七子花Heptacodium miconioides生长过程中叶片提取物抑菌活性的变化规律,采集不同时期七子花叶片,以乙醇为溶剂提取活性物质,以金黄色葡萄球菌Staphylococcus aureus和大肠杆菌Escherichia coli为检定菌株,以琼脂扩散法检测不同时期七子花叶片提取物的抑菌活性。结果表明,与煮沸法和索氏提取法相比,超声波提取简单易行,不影响叶片的体外抑菌活性,1 g提取物稀释80倍后对大肠杆菌的抑制率仍超过60%,适用于大量样本的快速分析。在整个叶片生长期,七子花叶片均表现较高的抑菌活性,抑制率超过50%,且对金黄色葡萄球菌抑杀作用强于对大肠杆菌的抑杀作用,但以4月上旬、7月中旬和9月下旬的抑菌活性最强。图1表1参7

Anti-bacterial activity of leaf extracts from Heptacodium miconioides

The anti-bacterial activity of Heptacodium miconioides(sevenseedflower tree)on Staphylococcus aureus and Escherichia coli were studied by a disc diffusion test with leaves picked at different dates(4th Apr,18th Apr,2nd May,16th May,30th May,30th Jun,27th Jun,11th Jul,25th Jul,8th Aug,22nd Aug,5th Sep,19thSep).Compared with boiling or Soxhlet's extraction methods,ultrasound was suitable for analysis of larger quantities of samples.When diluted 80 times.1 g ultrasound extraction still had a strong anti-bacterial rate(>60%).Furthernore,a strong anti-bacterial rate(>50%) was observed during the entire leaf growing period with S.aureus having a higher susceptivity than E.coli.Although it fluctuated with time,leaves of H.miconioides displayed the highest anti-bacterial activity the first 10 d of April,the middle 10 d of July,and the last 10 d of September.[Ch,1 tab.1 fig.7 ref.]