Studies On The Chemical Constituents And Antibacterial Activity Of Eupatorium Chinense L. Root

Eupatorium chinense L.is one of species of the genus Eupatorium,which belongs to the family compositae.It was widely used in Chinese folk medicine for the treatment of laryngeal disease,such as diphtheria,moth throat,sore throat for the Detoxification,anti-inflammatory and analgesic properties,which known as "almighty medicine".To better take advantage of the medicinal plants,the aim of this work was to study the chemical composition and antibacterial activity of Eupatorium chinense L.Various chromatography technique such as column chromatography on silica gel,Sephadex LH-20 and preparative HPLC were used to isolate and purify the compounds and their structures were identified by the spectral data and physicochemical properties.Nine compounds were isolated,comprising one triterpenoid,five benzofurans,one sterol,one glycoside and one ester,and they were identified as 3?-acetoxy-lup-12,20(29)-diene(1),5-acetyl-6-hydroxy-2-isopropenyl-3-ethoxy-benzodihydrofuran(2),stigmasterol(3),phthalic acid dibutyl ester(4),12,13-dihydroxyeuparin(5),5-acetyl-6-hydroxy-2-isopropenyl benzofuran(6),2,5-diacetyl-6-hydroxy benzofuran(7),ruscodibenzofuran(8),2-acetyl-5-(prop-1-ynyl)-thiophen-3-O-?-D-glucopyranoside(9),among them,Compounds 1,2,4 and 8 were isolated from the plants in genus Eupatorium for the first time.,The antibacterial activity against Several kinds of pathogenic bacteria,such as Streptococcus pyogenes(Spy),streptococcus pneumoniae(Spn),Staphylococcus aureus(Sau),pseudomonas aeruginosa(Pae),klebsiella pneumoniae(Kpn),Escherichia coli(E.coli)and Candida albicans(Cal)was also investigated by the Oxford cup method,MIC was measured by broth dilution method.The petroleum ether extract and ethyl acetate extract showed similar bacteriostatic activity as crude extract,all of them were against Spy,Spn and Sau,however,They didn't show obvious antibacterial activity against Pae,Kpn,E.coli and Cal.Compounds 2,6,7 and 8 showed antibacterial activities at varying degree on five kinds of testing pathogenic bacteria,among them,Compound 6 and 8 showed the strongest inhibitory efect on Kpn with the MIC 0.98 ?g/mL and 0.49 ?g/mL,and compound 7 showed the strongest inhibitory effect on E.coli with MIC 3.91?g/mL,therefore,petroleum ether extract and ethyl acetate extract were the main antibacterial activity extract and benzofurans may be the main antibacterial activity ingredients.