title: Four new bioactive lobane diterpenes of the soft coral Lobophytum pauciflorum from Mindoro, Philippines.
abstract: The marine soft coral Lobophytum pauciflorum collected from Mindoro Island, Philippines, yielded four new lobane diterpene derivatives: the acetate congeners of epoxylobatrienol and lobatrienediol (2 and 7, respectively), a methoxyl congener of lobatetraene (10), and an oxepin congener of lobatrienetriol (11), and six known derivatives (1, 3-6, and 8). The structures of the new compounds were unambiguously established on the basis of NMR spectroscopic (1H, 13C, COSY, 1H-detected direct, and long-range 13C-1H correlations) and mass spectrometric (EIMS) data. All of the compounds were active against the phytopathogenic fungus Cladosporium cucumerinum. Compound 1 was found to be active against the Gram-positive bacteria Bacillus subtilis and the yeast Saccharomyces cerevisiae. The isolated lobane diterpenes were also active in the brine shrimp lethality test. In the latter bioassay, compounds 8 and 10 were the most active congeners with LC50's of 0.64 and 4.18 micrograms/mL, respectively.
authors.affiliation: Julius-von-Sachs-Institut für Biowissenschaften, Lehrstuhl für Pharmazeutische Biologie, Würzburg, Germany.
authors.forename: R A
authors.initials: RA
authors.lastname: Edrada
authors.forename: P
authors.initials: P
authors.lastname: Proksch
authors.forename: V
authors.initials: V
authors.lastname: Wray
authors.forename: L
authors.initials: L
authors.lastname: Witte
authors.forename: L
authors.initials: L
authors.lastname: van Ofwegen
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents; D000890:Anti-Infective Agents / Q000302:isolation & purification* / Q000494:pharmacology; D000970:Antineoplastic Agents / Q000494:pharmacology; D001156:Artemia; D001419:Bacteria / Q000187:drug effects; D003063:Cnidaria / Q000737:chemistry*; D004224:Diterpenes / Q000302:isolation & purification* / Q000494:pharmacology; D004354:Drug Screening Assays, Antitumor; D005658:Fungi / Q000187:drug effects; D009682:Magnetic Resonance Spectroscopy; D008826:Microbial Sensitivity Tests; D010679:Philippines
chemical_list: D000900:Anti-Bacterial Agents; D000890:Anti-Infective Agents; D000970:Antineoplastic Agents; D004224:Diterpenes