Research About Antibacterial Activity Of Extractive And Effective Compositions From Korean Medicine Castanea Molissma Leaf

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.Castanea mollissima Leaf,belongs to Ulmaceae.It is the lunar of Korean C hinese folk medicine.The chemical components of Castanea mollissima Leaf h as good antioxidant activity,antibacterial activity and cell protective effects.The chemical component of this experiment was tracked by Streptococcus mutans,Staphylococcus aureus and Escherichia coli.The herb was were extracte d with 60%ethanol for two successive periods of 72 hours at room temperatur e,with daily agitation.partitioned with petroleum ether and ethyl acetate,respec tively.And then measure the antibacterial activity of each component.The extr act were separated by silica gelcolumn chromatography,MPLC and high perfor mance liquid chromatography,respectively.Eventually,50 compounds were isol ated from Castanea mollissima Leaf and identified the chemical structure by n uclear magnetic resonance such as 1H-NMR,13C-NMR,HMQC,HMBC and H R-ESI-MS.Then measured the minimum inhibitory concentration(MIC)and mini mal bactericidal concentration(MBC)of the nine compounds.In vitro antibacteri al activity of the target compounds was determined by using the tube dilution method.19 compounds were identified as ?-sitosterol(1),daucosterol(2),7a-hydroxy-sitosterol(3a),7?-hydroxysitosterol(3b),a-tocopherol(5),y-(6Z,92,12Z)Linoleni c acid ethyl ester(6),glyceroyl monopalmitate(7),(7S,7'S,8R,8'S)-4,4'-dihydr oxy-3,3'-dimethoxy-7,7' epoxylignan(8),friedelin(9),canophyllal(10),Pomoli c acid(11),hederagenin(12),3?,23-dihydroxy-l-oxo-olean-12-en-28-oic(13),urs olic acid lactone(14),euscaphic acid(15),2a-hydroxy-betulinic acid(16),1?,3?-dihydroxyl-olean-12-en-28-oic acid(17),maslinic acid(18),fouquierol(19),a fter the structural analysis.All of the compounds are firstly isolated from this plant,and 2?11?13?17?19 are firstly isolated from this species.According to the results of the antibacterial experiment,Compound 6,7,11,12,13,15,17 and 18 have antibacterial activity,in addition follow the result of MIC,Compo and 11,12,17 and 18 have obvious antibacterial activity.Among them compo und 12 against some Gram-positive bacteria like Candida albicans(7535)and S.aureus(503),the minimum inhibitory concentration is 64?g/mL and 16?g/mL,r espectively.The compound 18 have antibacterial activity against Staphylococcus aureus(3505),QRSA CCARM(3519)and E.coli KCTC(1924),the minimum inhibitory concentration is 32 ?g/mL,64 ?g/mL,32 ?g/mL,respectively.Comp ound 17 has inhibitory effects on some Gram-positive bacteria,Gram-negativeb acteria,and drug-resistant bacteria,and the MIC value of Gram-positive bacteri a S.aureus RN(4220)is 64 ?g/mL.The MBC value is generally less than 4MI C,which shows that Compound 6,7,11,12,13,15,17 and 18 have antibact erial effect and not easy to make bacteria produce drug resistance.The antibact erial activity of compounds 7,12,13,18 are reported for the first time.