Study On The Chemical Constituents From The Roots Of Euphorbia Sikkikensis And Their Bioactivities

Euphorbia sikkimensis is a dicotyledonous plant belonging to genus Euphorbia of the family Euphorbiaceae.It is widely distributed in Guangxi,Guizhou,Hubei,Sichuan,Yunnan proviences,as well as in the district of the Tibetan region of mainland China.Its root has been used as the folklore and Chinese tradition medicine due to significant effects of purging water,clearing heat and detoxifying.Crude preparations of Euphorbia sikkimensis have been widely used as Tibetan folk medicine for the treatment of nephritis edema,bloating,and constipation.Previous phytochemical investigation indicated that the compounds isolated from this genus have wide range of promising bioactivities,includin anticancer,improved multi-drug resistance,antibacterial and anti-inflammatory.Recently,due to unique structural skeleton and their diversity,the genus Euphorbia has raised extensive research interesting in the area of natural products community.In this thesis,the chemical constituents from the roots of Euphorbia sikkimensis collected from the town of Baisha,Yulong county of Yunnan province were investigated,through various of techniques,including normal phase silic gel chromatography,Sephadex LH-20 column and HPLC.As a reuslt,a new ent-atisane type diterpene,10-epi-ent-(13S)-hydroxyatis-16-ene-3,14-dione(1)and six known compounds scopoletin(2),quercetin(3),luteolin(4),d-pinoresinol(5),p-hydroxybenzaldehyde(6),ethyl gallate(7)were isolated.Their structures were elucidated based on the extensive spectroscopic analysis,including 1D,2D NMR,high resolution mass spectrum(HRMS),IR,and in comparison with the literatures.Compound 1 is the C-10 epimer of ent-(13S)-hydroxyatis-16-ene-3,14-dione.,Compound 5 is a lignan firstly isolated from Euphorbia sikkimensis.In addition,the anticancer activity against the human colon cancer cell line of HT29 for compounds 1-4 and 7 has been carried out through CTG luminescence method.The experimental results indicated that none of these compounds presented significant inhibital activity for HT29 cells.Furthermore,the PPAR γ agonistic activites for compounds 1-4,and 7 were also investiaged by cell-based luciferase reporter gene assays and GW9662 block experiements.The results indicated compound 1 ehxited moderate agonistic activity for_PPARγ receptor with relative fluorescence intensity of 14.95 at 100 μM.Therefore,further investigation is warranted for Euphorbia sikkimensis to exploring potential new natural antidibetic leads.