番石榴叶提取物的鉴定及其抑菌活性

Study on Antibacterial Activity and Idenfication of Extract from Guava Leaf

采用索氏抽提法利用甲醇、乙醇、正丁醇,乙酸乙酯对番石榴叶进行提取,确定最佳提取条件:甲醇,乙醇,正丁醇分别在料液比为1:16,提取时间5h时最佳;乙酸乙酯在料液比为1:18,提取时间5h时最佳。用RP-HPLC于波长280nm鉴定了番石榴叶提取物中的6种酚类物质:没食子酸、4-羟基酸、绿原酸、咖啡酸、阿魏酸、槲皮素。采用纸片扩散法对枯草芽孢杆菌、大肠杆菌、四联球菌和金黄色葡萄球菌分别在4、28、37℃进行抑菌实验,结果表明:28℃时乙醇提取物分别对枯草芽孢杆菌和四联球菌,产生了良好的抑菌效果,抑菌圈直径分别为15.3mm和12.4mm;乙酸乙酯提取物对大肠杆菌和金黄色葡萄球菌产生了良好的抑菌效果,抑菌圈直径分别为15.5mm和16.8mm。对番石榴叶提取液进行稀释后在28℃做抑菌实验,结果表明25%浓度的提取液仍有一定的抑菌效果,说明番石榴叶提取物具有较强的抑菌作用。

The soxhlet extraction method was used for guava leaf by methanol,ethanol,butanol and ethyl acetate.Through the single factor experiment determined the effects on the extraction rate of the guava leaf extract,such as the solid-liquid ratio and extraction time.The optimum extraction technological conditions are as follows：The solid-liquid ratio of methanol,ethanol and ethyl acetate is 1：16 while the extraction time is 5 h;and the solid-liquid ratio of butanol is 1：18 while the extraction time is also 5 h.6 compounds （gallic acid,4hydroxy acid,chlorogenic acid,caffeic acid,ferulic acid,quercetin） were identified in the guava leaf extract by RP-HPLC analysis at 280 nm.Disc diffusion method was used to assay the bacteriostatic effects of the extract from the guava leaf on 4 strains of common bacteria （Bacillus subtilis,Escherichia coli,Tetracoccus,staphylococcus aureus）.The effects were compared to 4 ℃,28 ℃,37 ℃.The extract on 28 ℃ have the most strong bacteriostatic effects,and the ethanol extract have the best antibacterial effect to Bacillus subtilis and Tetracoccus,on which the antibacterial circle diameter were 15.3 mm and 12.4 mm.The ethyl acetate extract has the best antibacterial effect to Escherichia coli and staphylococcus aureus,on which the antibacterial circle diameter were 15.5 mm and 16.8 mm.The concentration of guava leaf extract were divided into 100 %,50 % and 25 %,Tetracoccus and staphylococcus aureus were selected to comparative on 28 ℃.The results showed that 25 % of the extract concentration still inhibits bacteria,which was shown to have fairly strong antibacterial effects.