Studies On The Chemical Constituents And Bioactivities From The Roots Of Scorzonera Divaricata

The Scorzonera genus (family Compositae) is distributed in the temperate zone of Eurasia, about 175 species in the world. There are 23 species and 3 varieties in China, mainly distributed in northwest areas. Some species of the genus have been widely utilized as food, medicinal supplements and forage for livestock. S. divaricata Turcz is used in folk medicine and treat skin wounds of livestock in China.We made systemic phytochemical studies on S. divaricata, which were collected from Lanzhou, Gansu province. Consequently,46 compounds were isolated from 95% ethanol extraction of the roots of S. divaricata by means of silica gel column chromatography (CC), preparative thin layer chromatography (PTLC), Sephadex LH-20, MCI chromatography and medium pressure column chromatography. The structures of 45 compounds were elucidated by spectroscopic methods, such as (HRESIMS, EIMS, 1H NMR,13C NMR, DEPT,1D-NOE, 1H-1H COSY, HSQC, HMBC, IR, UV, and CD) and in combination with comparison to the literature data or authentic samples. Among them, nine compounds are news. 45 compounds include of eight triterpenes, five quinic acid derivatives, five sesquiterpenes, eight sterols, eleven benzene derivatives, one lignanoid, two cumarin, and others.The bioactivities of selected isolates obtained in this investigation were studied, using ABTS and DPPH methods to evaluate their antioxidation activities, Trolox and BHA as a positive control. Sd9, Sd10, Sd11 exhibited strong radicla scavenging activity against ABTS+, IC50 28.29,31.22 and 41.40μM, respectively, and Sd10, Sd11 exhibited strong radicla scavenging activity against DPPH, IC50 34.68 and 49.70μM, respectively.Finally, this thesis reviewed on the structure and bioactivities of tirucallane-type triterpene from 1990 to 2010. Results of the photochemistry and biological activity in the thesis provide scientific basis for chemotaxonomy, Chinese traditional medicines as well as the screen of new medicines. This study is expected to provide benefits for utilizing and developing the natural plant resources of our country.