Study On The Composition And Activity Of Sesquiterpene In Inula Britannica

Inula britannica.is a perennial herbal plant of the genus Inula L.,which mainly distributes in Europe and Asia regions such as China,South Korea and Japan.The drug is collected in the 2015 edition of the Chinese Pharmacopoeia and is mainly used to treat cold cough,phlegm retention,chest distress,vomiting.Relevant chemical studies have found that the genus is rich in sesquiterpenes.In view of the fact that the sesquiterpenes are rich in content,diverse in structure,difficult in total synthesis and remarkable in cell activity of the genus Inula L.,the purpose of this study is to optimize the extraction process of total terpenes from Inula L.,and more new sesquiterpenes were isolated and their activities were studied.In this study,the dried inflorescence of Inula britannica.was selected as the research object.The crude extract of inflorescence was obtained by ultrasonic-assisted extraction.The content of total terpenoids in Inula britannica.was determined and the optimum extraction technology of total terpenoids was determined.The ethyl acetate extract with the highest sesquiterpene content was isolated and purified,and four sesquiterpene monomers were obtained.Compounds 2 and 3 were not reported in the literature,which were new compounds.The antitumor activities of four sesquiterpene monomers were evaluated by MTT method.The main results were as follows:?1?The optimum extraction conditions of total terpenoids from Inula britannica.were as follow:the concentration of ethanol is 60%,the ratio of material to liquid was 1:20 and extraction time was 50 min.According to this process,the average content of total terpenoids from Inula britannica.was 19.328 mg/g.?2?The chemical constituents of the ethyl acetate fraction rich in sesquiterpenoids in Inula britannica.were separated,and the structures of the monomer compounds were identified by modern analytical methods(ESI-MS,¹H-NMR,¹³C-NMR).Four sesquiterpenoids were identified,of which compounds 2?3-oxo-6?-acetoxy-eudesma-4?5?,11?13?-olide?and compounds 3?6?-hydro-Isoalantolactone?were new compounds.Compounds1?Tomentosin?and 4?1?-hydroxyalantolactone?were known compounds.?3?The MTT results showed that there was good cytotoxicity to HepG2 cancer cells of the four compounds,and of which IC₅₀ were 23.74 ug/mL,10.44 ug/mL,15.35 ug/mL and 28.05ug/mL,respectively.The cytotoxicity of two of the new compounds is more pronounced.