Studies On The Chemical Constituents From Senecio Densiserratus Chang Of Compositae

The genus Senecio (Asteraceae) contains more than1500species widely distributed throughout the world. Over200species of the genus are found mainly distributed in the northwest and southwest of China, such as Senecio cannabifolius Less, S. liangshanensis, S. dubitabilis, S. krascheninnikovii, S. lijiangensis Senecionemorensis Linn, S. arachnanthus Franch, S. densiserratus Chang, The stems, roots, leaves and flowers of them have long been used in Chinese folk medicine for their liver eyesight, detumescence, anti-inflammatory, vermifuge properties.In this thesis, the chemical constituents of S. densiserratus Chang. were studied. Firstly, the chemical constituents of33compounds were isolated by means of high performance liquid chromatography (HPLC), silica gel column chromatography (CC), thin layer chromatography (TLC), and recrystallization etc. Then various spectroscopic methods including IR, UV, CD, EIMS, FABMS, HRESIMS,1H NMR,13C NMR, DEPT, NOED,1H-1H COSY, HSQC, HMBC, and single-crystal X-ray crystallography were used to elucidate the structures of33compounds, including twenty sesquiterpenoids, three lignans, six steroids, one triterpene, one cyclic peptide and one benzene derivatives, among which there were nine new compounds. Eight of these new compounds represent a rare type of sesquiterpenoid glucoside with the angeloyloxy group connected with the glycosyl moiety. Furthermore SRB method was used to evaluate the cytotoxicity against selected HL60, SMMC-7721, and HeLa cancer cell lines of nine new compounds with mitomycin taken as positive control. The results revealed that compounds2,3,4,5,6,13,14showed modest cytotoxicity with IC50≈40μg/mL.Finally, some published methods for construction of eduemane type bicyclic Sesquiterpenes were revied.