Study On Antitumor Active Constituents In Trigonostemon Howii Merr.et Chun

Trigonostemon howii Merr.et Chun belongs to the genus Euphorbiaceae.There are about 89 species of Trigonostemon in the world,9 of which are native to China,mainly distributed in hainan and other tropical and subtropical areas of China,As a common folk medicine in China’s southern ethnic areas and Thailand,it has the functions of antisepsis,sterilization,diarrhea,phlegm and so on.More than 400 compounds,including terpenoids,alkaloids and ellagic tannins,have been reported from this genus since 1990.Many of these compounds have a variety of biological activities,such as anti-tumor,anti-HIV-1 and anti-inflammatory activities,showing a very broad prospect of patent medicine value.In this paper,the chemical constituents of T.howii were studied carefully.Some novel compounds were isolated and purified,and their structures were analyzed.In these compounds a new chromogenic dimer was contained.Petroleum ether,ethyl acetate and n-butanol were successively used to extract the total extract of medicinal materials with 95%ethanol solution.Through preliminary screening of pharmacological activity,it was found that dichloromethane extract had certain cytotoxic activity against human cervical cancer HeLa cell line,and its IC50 value was 20.52±8.39 μg/mL.This experiment is mainly to fine separation of parts dichloromethane extract,preliminary separation by silica gel column chromatography,guided by TLC uv and HPLC method as the instruction,after repeated silica gel column chromatography,gel column chromatography,column chromatography,ODS column chromatography and MCI half preparative high performance liquid chromatography and other separation methods for separation and purification extract.A total of 16 monomer compounds were obtained,and their structures were determined by spectral analysis and literature comparison,including one chromogenic dimer trigochromene A（1）;one chromogenic ketone:Isoevodionol methyl ether（2）;three terpenoids:friedelin（3）,friedelan-3-one-25-al（4）,lupenone（5）;one chromone:calofolic acid E（13）;7 aromatic compounds:p-hydroxybenzaldehyde（6）,isovanillin（7）,p-hydroxyacetophenone（8）,syringaldehyde（9）,4-ethoxy-2-hydroxy-6-methylbenzoic acid（10）,ethyl syringate（11）,ethyl ferulate（12）;three other compounds:isoimperatorin（14）,stearic acid（15）,stigmasterol（16）.Among them,compound 1 was a new compound,compound 10 was a new natural product,compounds 2,3,4,6,7,11,13,14 were isolated from the genus T.for the first time,and compounds 5,9,15,16 were isolated from T.howii Merr.et Chun for the first time.In this study,a new chromene dimer（1）and its corresponding monomer（2）were identified.The possible biogenic pathway of compound 1 was also given according to the structure of the two compounds.In this study,the in vitro antiproliferative activities of 16 compounds against human colon cancer HCT116 cells,human cervical cancer HeLa cells and human liver cancer HepG2 cells were determined by CCK-8 method.The results showed that compound 1 and 12 had certain anti-proliferation activities against some tumor cells,compound 13 had significant anti-proliferation activities against HeLa cells、HepG2 cells and HCT116 cells with IC50 values of 9.34±1.04 μM、13.85±0.75 μM and 25.87±0.61 μM,respectively.Compounds 1,12 and 13 showed significant concentration-dependent inhibitory activities on the proliferation of the three tumor cells.For compound 13 with relatively significant anti-tumor activity,the research group selected two tumor-related proteins for molecular docking by using network pharmacology research method.It was found that the binding force to TP53 was 5.67.The binding force for CASP-3 was 4.48.In order to study the composition of the small polar oil in the dichloromethane section,the small polar oil in the dichloromethane section,which was integrated in the process of plant chemical separation,was identified and analyzed by gas chromatography-mass spectrometry（GC-MS）.Fifty-three compounds were identified and analyzed.In this study,we expanded the compounds in T.howii and analyzed the components in small polar oil.The in vitro antiproliferative activities of the isolated compounds and crude extracts were determined by CCK-8 method which evaluated the druggability of T.howii.