In Vitro Antibacterial Activity of Different Polar Solvent Extracts from Oxalis

The Oxalis extract was obtained by soaking with ethanol, then mixed with distilled water and successively extracted using chloroform, ethyl acetate and n-butanol. The four different polar solvent (chloroform, ethyl acetate, n-butanol, aqueous) extracts were evaporated under reduced pressure to obtain four kinds of crude extractum. Antibacterial activity on Staphylococcus aureus, Escherichia coli, Albicans Saccharomyces and Pseudomonas aeruginosa of the four fractions were studied by minimal inhibitory concentration method (MIC). The results indicated that the chloroform extract and n-butanol extract from red Oxalis have no antimicrobial activity to the above 4 bacteria; the ethyl acetate extract showed significant inhibitory activities to the above 4 bacteria, the minimal inhibitory concentration (MIC) were 2560ug/ml, 1280ug/ml, 2560ug/ml, 2560ug/ml respectively; the aqueous extract have inhibitory activity to Escherichia coli and Albicans Saccharomyces, the minimal inhibitory concentration (MIC) were 2560ug/ml, 2560ug/ml respectively, but it has no antimicrobial effect on the other two kinds of bacteria. The chloroform extract and ethyl acetate extract from yellow Oxalis have no antimicrobial activity to the above 4 bacteria; the n-butanol extract has inhibitory activity to Escherichia coli, Albicans Saccharomyces and Pseudomonas aeruginosa, the minimal inhibitory concentration (MIC) were 5120ug/ml, 5120ug/ml, 5120ug/ml respectively, but it has no antimicrobial effect on Staphylococcus aureus; the aqueous extract have inhibitory activity to Escherichia coli and Albicans Saccharomyces, the minimal inhibitory concentration (MIC) were 2560ug/ml, 5120ug/ml respectively, but it has no antimicrobial effect on the other two kinds of bacteria.