title: Eremophilane-type sesquiterpenoids with diverse skeletons from Ligularia sagitta.
abstract: Five new highly oxygenated eremophilane-type sesquiterpenoids, possessing C19 (1 and 2), C15 (3 and 4), and C14 (8) skeletons, along with eight known eremophilenolides were obtained from the aerial parts of Ligularia sagitta. The absolute configuration of 1 was assigned by X-ray diffraction analysis and that of 3 by ECD spectroscopy. Compounds 1-10 were evaluated for their antibacterial activities against Staphyloccocus aureus, Bacillus subtilis, Escherichia coli, Bacillus cereus, and Erwinia carotovora. Compounds 4 and 5 displayed broad-spectrum inhibitory activity against these bacteria with MIC values of approximately 7.25 μg/mL, followed by 3 and 6 with MIC values in the range of 23.0-125.0 μg/mL. Compounds 3 and 8 showed mild activity against three human tumor cell lines (IC50 ≈ 13 μM). Preliminary structure-activity relationships for these eremophilenolides are reported.
authors.affiliation: State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University , Tian-shui Road 222, Lanzhou 730000, People's Republic of China.
authors.forename: Jian-Jun
authors.initials: JJ
authors.lastname: Chen
authors.forename: Chao-Jun
authors.initials: CJ
authors.lastname: Chen
authors.forename: Xiao-Jun
authors.initials: XJ
authors.lastname: Yao
authors.forename: Xiao-Jie
authors.initials: XJ
authors.lastname: Jin
authors.forename: Kun
authors.initials: K
authors.lastname: Gao
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D019659:Asteraceae / Q000737:chemistry*; D001412:Bacillus subtilis / Q000187:drug effects; D018360:Crystallography, X-Ray; D004354:Drug Screening Assays, Antitumor; D004365:Drugs, Chinese Herbal / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D004926:Escherichia coli / Q000187:drug effects; D006801:Humans; D020128:Inhibitory Concentration 50; D008826:Microbial Sensitivity Tests; D008968:Molecular Conformation; D015394:Molecular Structure; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology; D012717:Sesquiterpenes / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D013211:Staphylococcus aureus / Q000187:drug effects; D013329:Structure-Activity Relationship
chemical_list: D000900:Anti-Bacterial Agents; D004365:Drugs, Chinese Herbal; D010936:Plant Extracts; D012717:Sesquiterpenes