Studies On Chemical Constituents Of Euphorbia Pekinensis Rupr

"Jing Daji", a well-known traditional Chinese drug recorded in Chinese pharmacopoeia, is the radix of Euphorbia pekinensis Rupr. Its property and flavor is cold and bitter. It is widely used for treatment of edema, removing the full bilge, pleurisy, schizophrenia, and so on. Up to now, there was little report about the chemical constituents and bioactivities of Euphorbia pekinensis. According to the literatures, some diterpenes and triterpenes were isolated from the roots of Euphorbia pekinensis. In addition, there haven't had suitable analytical methods for quality control of Euphorbia pekinensis.In order to elucidate the constituents and find novel bioactive products from this plant, eight compounds were isolated from the 95% EtOH extract of Euphorbia pekinensis by means of the repeated column chromatography on silica gel, recrystallizing and preparative TLC. Their chemical structures were elucidated on the basis of physico-chemical properties and spectroscopic analysis, including IR, EI-MS, HR-ESI-MS,'H-NMR,13C-NMR,1H-1H COSY, HSQC, HMBC, NOESY, X-ray, etc. These compounds were isoeuphpekinensin(Ⅰ), octadecanol(Ⅱ), octadecanyl-3-methoxy-4-hydroxybenzeneacrylate(Ⅲ), triacontanoic acid(Ⅳ), (2,2'-dimethoxy-3,3'-dihydroxy-5,5'-oxo-6,6'-biphenyl-formican-hydrid(Ⅴ), euphol(Ⅵ), tirucallol(Ⅶ),β-sitosterol(Ⅷ). Among them, compoundⅠwas a new compound, andⅡ,Ⅳ,Ⅵ,Ⅵwere isolated from this plant for the first time.The cytotoxicity in vitro of isoeuphpekinensin on 6 human cancer cell lines was tested by Alamar Blue assay. The new compound showed significant cytotoxic activities against KB, NCI-H1299, NCI-H460, SGC-7901, and HO-8910. Their IC50(μg/ml) were 8.52,10.52,10.05, 13.82, and 14.16, respectively. And it also showed moderate activity towards SF-268.Moreover, the method of quantitative analysis has been established for determining the contents of euphol in Euphorbia pekinensis with HPLC. A series of methodical experiments proved that this method has the advantages of simple, rapid, accuracy, sensitivity, reproducible, etc. This method could be used as the quality control standard for Euphorbia pekinensis.In conclusion, this paper provided valuable experimental data for further development of Euphorbia pekinensis.