【摘要】 采用甲醇冷浸提取法提取和制备了5种桉叶提取物,并通过TLC-MTT-生物自显影法测定不同桉叶提取物对6种供试细菌的抑制活性;采用菌丝生长速率法测定不同桉叶提取物对油茶炭疽病菌（Colletotrichum gloeosporioides）的抑制活性;采用多孔板-DPPH法测定不同桉叶提取物的抗氧化活性;进一步通过HPLC对不同桉叶提取物进行分析.结果表明,5种桉叶提取物对不同供试细菌的抑制活性差异较大,其中W5提取物的抑制细菌活性最强,对桉树青枯病菌（Ralstonia solanacearum）、枯草芽孢杆菌（Bacillus subtilis）、大肠杆菌（Escherichia coli）和黄瓜角斑病菌（Pseudomonas lachrymans）抑菌斑直径均大于10 mm,在0.00～1.00的R_f值范围内均具有抑菌活性;W5和雷林1提取物对油茶炭疽病菌（C.gloeosporioides）表现出一定的抑制活性,EC₅₀值分别为（16.82±0.20）mg/mL和（22.21±0.57）mg/mL;不同桉叶提取物均表现出一定的抗氧化活性,除广林9外,其他4种桉叶提取物的抗氧化活性均强于阳性对照BHT;不同桉叶提取物中主要化合物的种类和数量差异不大,但同一化合物的相对含量存在较大差异.总之,W5提取物表现出较好的抗细菌、抗真菌和抗氧化活性,可作为候选植物资源,进一步分离、纯化和鉴定其中的活性成分.更多还原

【Abstract】 Five Eucalyptus spp. leaf extracts were prepared by methanol soaking extraction at room temperature. The antibacterial activities of the leaf extracts were determined by TLC-MTT-bioautography method. The antifungal activities of the leaf extracts on Colletotrichum gloeosporioides were determined by mycelium growth rate method. The antioxidant activities of the leaf extracts were determined using the multi-orifice plate-DPPH coloration method. And HPLC was employed to analyze the different Eucalyptus leaf extracts. Five Eucalyptus spp. leaf extracts showed certain inhibitory activities against the tested bacteria, but the differences were obvious. W5 leaf extract performed strongest antibacterial activities against Ralstonia solanacearum, Bacillus subtilis, Escherichia coli and Pseudomonas lachrymans, and diameters of the inhibition spot were more than 10 mm. R_f values felling into the range between 0.00 and 1.00 displayed antibacterial activities. W5 and Leilin 1 leaf extracts showed certain inhibitory activities against C. gloeosporioides, whose EC₅₀ values were（16.82±0.20）mg/mL and（22.21±0.57）mg/mL, respectively. The result about antioxidant activity indicated different Eucalyptus spp. leaf extracts performed certain antioxidant activities. Apart from Guanglin 9, the antioxidant activities of the remaining four Eucalyptus spp. leaf extracts were stronger than the positive control BHT. The HPLC analysis showed that the difference about type and amount of the major compounds from the different Eucalyptus leaf extracts was not obvious, but the relative contents of the same compound are significant different. W5 leaf extract exhibits the strong antibacterial, antifungal and antioxidant activities, which can be used as candidate plant resources for further isolation, purification and identification of active component.更多还原