Research About Antibacterial Activity Of Extractive And Chemical Compositions From Korean Medicine Rhizoma Alimatis

Rhizoma Alismatis,belongs to Alismaceae.It is shao yang medicine in Korean medicine.We found Alisma methanol extract has good antibacterial activity by measured 100 kinds of Korean herbal medicine.The main objective of this experiment is to find monomer compounds guided by each phase of the antimicrobial activity data and do some primary work for the development of national medicine in China.The herb was soaked in methanol for 24 hours at 25 ℃ and then extracted by petroleum ether and ethyl acetate in turn and measure the antibacterial activity of each component.Eventually,nine compounds were isolated from Alisma and identified the chemical structure by nuclear magnetic resonance such as 1H-NMR,13C-NMR and time of flight mass spectrometer(TOF).Then measured the minimum inhibitory concentration(MIC)and minimal bactericidal concentration(MBC)of the nine compounds.In vitro antibacterial activity of the target compounds was determined by using the tube dilution method.Nine compounds were identified as Compound I(dibutyl phthalate),Compound II(23-Acetyl Alisma B),Compound III(23-Acetyl Alisma C),Compound IV(β －sitosterol),compound Ⅴ(Alisma B),compound VI(oleic acid)and compound VII(alismol),compound Ⅷ(sixteen alkyl acid)compound Ⅸ(alismoxide),after the structural analysis.According to the results of the antibacterial experiment,compounds Ⅱ,Ⅲ,Ⅴ,Ⅶ and Ⅸ have antibacterial activity.Compound Ⅱ,Ⅲ,Ⅴ,Ⅶand IX all have antibacterial activity against Gram-positive like Streptococcus mutans(3289),and the minimum inhibitory concentration is 2～64 μg/mL.Among them,compound V and VII have antibacterial activity against Staphylococcus aureus(3505),and minimum inhibitory concentration is 128 μg/mL.Compound VII also has antibacterial activity against methicillin-resistant Staphylococcus aureus(3506)and quinolone-resistant Staphylococcus aureus(3519),Gram-positive bacteria like Staphylococcus aureus(209)and Gram-negative bacteria like Escherichia coli(1924),and minimum inhibitory concentration is 128 μg/mL.The antibacterial activity of compound Ⅱ,Ⅲ,Ⅴ,Ⅶ and Ⅸ is reported for the first time.MBC experiment results show that the MBC of the compound Ⅱ,Ⅲ,Ⅴ,Ⅶ and Ⅸ is equal to the MIC,which shows that compound Ⅱ,Ⅲ,Ⅴ,Ⅶ and Ⅸ have antibacterial effect and not easy to make bacteria produce drug resistance.The anticancer experiment results showed that compound Ⅱ,Ⅲ,Ⅴ,Ⅸ all have some anticancer properties,but also have some cytotoxicities.compound VII has good antitumor activity and small cytotoxicity.