title: Sesquiterpenoids and tirucallane triterpenoids from the roots of Scorzonera divaricata.
abstract: A sulfated guaiane sesquiterpene lactone, an unusual pyridinium alkaloid with a sulfated guaiane sesquiterpene lactone nucleus, an amino conjugate of a sulfated guaiane sesquiterpene lactone, a bisabolane sesquiterpene, three tirucallane triterpenes, and six known compounds, were isolated from roots of Scorzonera divaricata. Their structures and absolute configurations were established based on chemical and spectroscopic methods, X-ray single crystal crystallography, and also by comparison with experimental and calculated ECD spectra. One of the tirucallane triterpenes exhibited significant cytotoxic activities against four human cancer cell lines (HL60, HeLa, HepG2, and SMMC-7721) in vitro. Two of sulfated guaiane sesquiterpenoids also exhibited antioxidant activities by scavenging ABTS cation free radicals. Tirucallane-type and dammarane-type triterpenes were not previously known in the genus Scorzonera. The study suggests that sulfated guaiane-type sesquiterpenoids are a valuable marker for systematic chemical studies in the Lactuceae tribe of the Asteraceae.
authors.affiliation: State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Tianshui South Road 222, Lanzhou 730000, Gansu, People's Republic of China.
authors.forename: Yong-Jin
authors.initials: YJ
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Tianshui South Road 222, Lanzhou 730000, Gansu, People's Republic of China.
authors.forename: Juan
authors.initials: J
authors.lastname: Yao
authors.affiliation: State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Tianshui South Road 222, Lanzhou 730000, Gansu, People's Republic of China.
authors.forename: Xiao-Jie
authors.initials: XJ
authors.lastname: Jin
authors.affiliation: State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Tianshui South Road 222, Lanzhou 730000, Gansu, People's Republic of China.
authors.forename: Zhuan-Ning
authors.initials: ZN
authors.lastname: Shi
authors.affiliation: State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Tianshui South Road 222, Lanzhou 730000, Gansu, People's Republic of China.
authors.forename: Tian-Fei
authors.initials: TF
authors.lastname: Shen
authors.affiliation: State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Tianshui South Road 222, Lanzhou 730000, Gansu, People's Republic of China.
authors.forename: Jian-Guo
authors.initials: JG
authors.lastname: Fang
authors.affiliation: State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Tianshui South Road 222, Lanzhou 730000, Gansu, People's Republic of China.
authors.forename: Xiao-Jun
authors.initials: XJ
authors.lastname: Yao
authors.affiliation: State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Tianshui South Road 222, Lanzhou 730000, Gansu, People's Republic of China. Electronic address: zhuy@lzu.edu.cn.
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhu
mesh_terms: D000972:Antineoplastic Agents, Phytogenic / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D018360:Crystallography, X-Ray; D004354:Drug Screening Assays, Antitumor; D018922:HL-60 Cells; D006367:HeLa Cells; D056945:Hep G2 Cells; D006801:Humans; D008968:Molecular Conformation; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D018517:Plant Roots / Q000737:chemistry; D031186:Scorzonera / Q000737:chemistry*; D012717:Sesquiterpenes / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D045789:Sesquiterpenes, Guaiane; D014315:Triterpenes / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D000097669:Dammaranes
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D012717:Sesquiterpenes; D045789:Sesquiterpenes, Guaiane; D014315:Triterpenes; D000097669:Dammaranes; C421026:guaiane; C514393:tirucallane
keywords: ABTS radical scavenging capacity; Asteraceae; Circular dichroism; Cytotoxicity; Scorzonera divaricata; Sesquiterpenoid; Structure elucidation; Triterpenoids; X-ray single crystal diffraction