title: Lobophytones A-G, new isobiscembranoids from the soft coral Lobophytum pauciflorum.
abstract: Seven new biscembranoids, lobophytones A-G (1-7), together with three known biscembranes were isolated from the Chinese soft coral Lobophytum pauciflorum. Their structures were elucidated by the analysis of 1D and 2D NMR (COSY, HSQC, HMBC, and NOESY) data in association with IR and MS experiments. The absolute configurations of compound 1 were determined by X-ray diffraction using the Flack parameter. Lobophytones A-G differ from the "normal" biscembranoids due to the antipodal Diels-Alder cycloaddition between cembranoid-diene and cembranoid-dienophile. The biogenetic pathway of the isolated compounds is depicted. Compound 4 showed significant inhibition toward LPS-induced nitric oxide (NO) in mouse peritoneal macrophage with IC(50) = 4.70 microM.
authors.affiliation: State Key Laboratory of Natural and Biomimetic Drugs, Peking University, Beijing 100083, China.
authors.forename: Pengcheng
authors.initials: P
authors.lastname: Yan
authors.forename: Yang
authors.initials: Y
authors.lastname: Lv
authors.forename: Leen
authors.initials: L
authors.lastname: van Ofwegen
authors.forename: Peter
authors.initials: P
authors.lastname: Proksch
authors.forename: Wenhan
authors.initials: W
authors.lastname: Lin
mesh_terms: D000818:Animals; D037421:Anthozoa / Q000737:chemistry*; D018360:Crystallography, X-Ray; D004224:Diterpenes / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D020128:Inhibitory Concentration 50; D008070:Lipopolysaccharides / Q000494:pharmacology; D017737:Macrophages, Peritoneal / Q000187:drug effects; D051379:Mice; D008968:Molecular Conformation; D015394:Molecular Structure; D009569:Nitric Oxide / Q000096:biosynthesis; D019906:Nuclear Magnetic Resonance, Biomolecular
chemical_list: D004224:Diterpenes; D008070:Lipopolysaccharides; C551342:lobophytone D; D009569:Nitric Oxide