Research On Antibacterial Effect Of Extractive Chemical Compositions Of Plantago Asiatica

Plantago belongs to Planttago asiatica L. In the folk, the dry whole plant of Plantago is made to medicines which is used to cure cool blood, expectorant effect and so on. In recent years, with the deepening of the study on plantain, people isolated more effective ingredients from Plantago. But less research of antibacterial activity, and most of the pharmacological studies are based on plantain extracts. Therefore, isolation of monomer compounds having antimicrobial active for the purpose, in order to find lead compounds with antibacterial development value.In this study, whole plant of Plantago was extracted in methanol soaking, and was extracted successively with Petroleum ether, Ethyl acetate and Butyl alcohol. The activity was screened by antibacterial experiment on three groups extracted. In final, petroleum ether and ethyl acetate layer of plantain was determined to have good inhibition on S. aureus and S. Mutans. Therefore, according to the principle of active tracking method, I separated Petroleum ether and Ethyl acetate layer.Using silicagel column chromatography, TLC thin-layer chromatography, reversed-phase silicagel chromatography, recrystallization, Preparative thin-layer chromatography and hydroxypropyl Sephadex chromatography method, isolated eight compounds from plantagin.They are compound Ⅰ (oleic acid), the compound Ⅱ (linolenic acid methyl ester), compound Ⅲ (linoeic acid), a compound Ⅳ (sixteen alkyl acid), the compound V(maslinic acid), the compound Ⅵ(β-sitosterol), the compound Ⅶ(oleanolic acid) and the compound Ⅷ (ursolic acid).First of all, the preliminary activity screening of eight compounds, finding that Compound Ⅰ, compound Ⅲ, compound Ⅴ, compound Ⅶ and compound Ⅷ have antimicrobial activity. They have good inhibition on S. Mutans、S. aureus、B. Cereus and B.subtilis of gram positive bacteria. The minimum bacteriostatic concentration (MIC) values 16～128μg/mL.They have good inhibition on E. Coli and P. Aeruginosa of gram negative bacteria.The MIC values 64～256μg/mL.Compound V and compound Ⅷ of activity for E. coli is particularly prominent, better than the control drug streptomycin,The MIC values 64μg/mL. They have good inhibition on drug resistant bacteria,The MIC values 16～128μg/mL. Finally, I found that the five compounds in the same concentration of antibacterial of cells without toxic injury in the cell toxicity experiment, and compounds Ⅶ and Ⅷ have some antioxidant activity in the antioxidant experiments, and compound Ⅷ is not easy to produce drug resistance in the bacterial resistance test. At the same time, The minimum bactericidal concentration (MBC) value and the MIC value is almost equal.Therefore, the compound Ⅷ not only has the characteristics of excellent antibacterial activity and difficult to generate resistance, and no toxicity on cell injury, and also has certain antioxidant properties, can be used as one of the good antibacterial activity of the lead compounds.