三种红树植物醇提取物抗菌及抗氧化活性研究

Comparision on antibacterial and antioxidant activities of ethanol extracts from three mangrove species

比较3种红树植物黄槿、白骨壤、桐花树不同溶剂萃取物体外对5种常见细菌的抑菌作用与清除自由基作用。利用乙醇浸提法和溶剂萃取法提取分离,得到4种不同溶剂萃取物。以5种常见的细菌作为供试菌,采用纸片扩散法、微孔板2倍稀释法比较3种红树植物萃取物的抑菌活性。采用硫酸亚铁一水杨酸法氧化法、DPPH反应法和邻苯三酚自氧化法比较体外清除自由基作用。结果显示：3种红树植物萃取物对5种供试细菌的抑菌活性的强弱顺序为黄槿〉白骨壤〉桐花树。水萃取物的抑菌效果较其他显著。3种红树植物水萃取物对金黄色葡萄球菌的MIC在11.2~15.6 mg/m L之间。清除自由基的强弱依次为DPPH自由基〉超氧阴离子自由基〉羟基自由基。桐花树具有较强的DPPH自由基清除作用,且乙酸乙酯萃取物〉正丁醇萃取物〉石油醚萃取物、水萃取物。结果表明黄槿水萃取物具有极强的抑菌作用,极性很强;而桐花树乙酸乙酯萃取物具有较强的清除DPPH自由基作用。

To investigate the antibacterial and antioxidant activities in vitro of extracts from 3 mangroves including Hibiscus tiliaceus, Avicennia marina, Aegiceras corniculatum. Four kinds of different solvent extracts were extracted by ethanol extraction and then solvent separation. The inhibition zone and minimal inhibitory concentration（MIC）,were used to detect the antibacterial activities,and determined by disk diffusion method and broth microdilution method. The scavenging effect to the hydroxyl radical,superoxide radical and DPPH was detected with the oxidation of ferrous sulfate-salicylic acid,self-oxidation of pyrogallic acid system and DPPH system,respectively. The results showed that the antibacterial effect on 5 species of common pathogens were H. tiliaceusA. marinaA. corniculatum. Inhibitory effect of water extracts was higher than other extracts significantly. All of water extracts from 3 kinds of mangroves had good bacteriostatic effect on Staphlococcus aureus（for the MIC ranging in 11.2~15.6 mg/m L）. The free radical scavenging effect was DPPHsuperoxide free radicalhydroxyl radical. A. corniculatum had more stronger effect on DPPH free radical scavenging,four kinds of solvent extracts of A. corniculatum had strong scavenging effects,and the ethyl acetate extract n-butanol extract petroleum ether extract,water extract. The results showed that the antibacterial activity of extract from H. tiliaceus was mainly in the water extract,and the ethyl acetate extract from A. corniculatum had strong scavenging effect of DPPH free radical.