title: Unusual sesquiterpene lactones from Ligularia virgaurea spp. oligocephala.
abstract: [structure: see text] [structure: see text] Sesquiterpene lactones, ligulolide A (1) and 6beta,8alpha-dihydroxy-1-oxoeremophila-7(11),9(10)-diene-12,8-olide (2), were isolated from Ligularia virgaurea spp. oligocephala. Their structures were established by analysis of one- and two-dimensional NMR data. The relative stereostructures were determined on the basis of NOESY and single-crystal X-ray experiments. 1 represents a novel sesquiterpene carbon framework, and a possible biosynthetic process is proposed. 2 is a novel eremophilane-type sesquiterpene.
authors.affiliation: State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou 730000, P. R. China.
authors.forename: Quan-Xiang
authors.initials: QX
authors.lastname: Wu
authors.forename: Yan-Ping
authors.initials: YP
authors.lastname: Shi
authors.forename: Li
authors.initials: L
authors.lastname: Yang
mesh_terms: D000970:Antineoplastic Agents / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D019659:Asteraceae / Q000737:chemistry*; D018360:Crystallography, X-Ray; D004354:Drug Screening Assays, Antitumor; D018922:HL-60 Cells; D006801:Humans; D020128:Inhibitory Concentration 50; D007783:Lactones / Q000737:chemistry* / Q000302:isolation & purification*; D008968:Molecular Conformation; D015394:Molecular Structure; D009281:Naphthalenes / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D019906:Nuclear Magnetic Resonance, Biomolecular; D000081223:Polycyclic Sesquiterpenes; D012717:Sesquiterpenes / Q000737:chemistry* / Q000302:isolation & purification* / Q000494:pharmacology; D014407:Tumor Cells, Cultured
chemical_list: C495526:6beta,8alpha-dihydroxy-1-oxoeremophila-7(11),9(10)-diene-12,8-olide; D000970:Antineoplastic Agents; D007783:Lactones; D009281:Naphthalenes; D000081223:Polycyclic Sesquiterpenes; D012717:Sesquiterpenes; C018286:eremophilane compounds; C495527:ligulolide A