Study On The Chemical Constituents In The Flowers And Antibacterial Activity In The Different Parts Of Tujia Medicine Eupatorium Japonicum

Eupatorium japonicum Thunb.is a perennial herb of the Eupatorium genus in the Asteraceae family.It is distributed in many provinces in the east and south of China.Many ethnic minorities in China use it as a medicinal plant.It is mainly used to treat colds,fevers,bruises,snake bites,and sore throat,stomatitis,and bronchitis.It is reported in the literature that E.japonicum has various biological activities such as antibacterial,anti-inflammatory,antitumor,and inhibition of larval growth.However,the material basis of plants is not clear,and there are few reports on the chemical constituents of E.japonicum.Therefore,based on the research of the predecessors and our research group,this paper systematically isolated and purified the flowers of E.japonicum,providing a theoretical basis for its development and utilization.In order to study the chemical constituents of the flowers of E.japonicum,70% ethanol extracts from E.japonicum were separated and purified by silica gel,gel and high performance liquid chromatography.Thirty five compounds were isolated and twenty-two compounds were identified by NMR and other spectroscopic methods.They are coumarin(1),2-hydroxy-2,6-dimethylbenzofuran-3(2H)-one(2),1-(2-Hydroxy-4-methylphenyl)propan-1,2-dione(3),subamone(4),(7R*)-opposit-4(15)-ene-1β,7-diol(5),gentisic acid(6),caffeic acid(7),9-hydroxythymol(8),protocatechuic acid(9),trans-o-hydroxycinnamic acid(10),umbelliferone(11),quercetin(12),traxasterol(13),9-acetoxythymol 3-O-tiglate(14),taraxasterol acetate(15),linoleic acid(16),9-angeloyloxythymol(17),stigmasterol(18),dipentyl phthalate(19),palmitic acid(20),eugenyl-O-β-D-glucopyranoside(21).Compounds 2-9,11-13,16,19-22 were isolated from E.Japonicum for the first time,and compounds 4-6,16,19,21 were isolated from the genus of Eupatorium for the first time.And there are several sesquiterpenes need to be confirmed chemical structure by 2D NMR.Secondly,the volatile constituents in different parts of E.Japonicum were extracted by steam distillation,and analyzed and identified by GC-MS combined with retention index.There were 132 volatile components identified in whole plant.A total of 41 chemical components were identified from roots,40 from stems,76 from leaves,and 55 from flowers,representing the relative contents of 90.08%、86.8%、87.3% and 94.09% of the total composition.There are large differences in the constituents and contents of volatile components in various parts of E.japonicum.In addition,the antibacterial activity of 70% ethanol extracts from the roots,stems,leaves,and flowers of E.japonicum was studied.The results showed that petroleum ether extracts of the stems had better bacteriostatic effect before flowering;the petroleum ether extracts of the flowers had a better bacteriostatic effect at the flowering stage;the ethyl acetate extracts of the fruits had the best bacteriostatic effect and the widest range in the fruiting period.To sum up,this thesis complements the research on the chemical composition of E.japonicum;the best antibacterial effect part was screened out.The results of this study can provide a new scientific basis for the development and utilization of E.japonicum.