title: New polyoxygenated briarane diterpenoids, briaexcavatolides O-R, from the gorgonian Briareum excavatum.
abstract: Four new polyoxygenated briarane-type diterpenoids, briaexcavatolides O-R (1-4), have been isolated from a gorgonian octocoral Briareum excavatum. Their structures were determined using spectroscopic and chemical methods. Metabolites 1-3 were found to contain oxygenated substituents at C-2, C-3, and C-4, and the relative configurations were assigned as 2R*,3R*,4R* at these three positions. Briaranes containing this type of stereochemistry are reported for the first time. The structures of metabolites 1 and 2 were further confirmed by single-crystal X-ray analyses. Compound 2 has been shown to exhibit significant cytotoxicity toward P-388 and HT-29 cancer cells.
authors.affiliation: Department of Marine Resources, National Sun Yat-Sen University, Kaohsiung 804, Taiwan, Republic of China.
authors.forename: S L
authors.initials: SL
authors.lastname: Wu
authors.forename: P J
authors.initials: PJ
authors.lastname: Sung
authors.forename: M Y
authors.initials: MY
authors.lastname: Chiang
authors.forename: J Y
authors.initials: JY
authors.lastname: Wu
authors.forename: J H
authors.initials: JH
authors.lastname: Sheu
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D000972:Antineoplastic Agents, Phytogenic / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D003063:Cnidaria / Q000737:chemistry*; D003110:Colonic Neoplasms; D018360:Crystallography, X-Ray; D004224:Diterpenes / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D004354:Drug Screening Assays, Antitumor; D006801:Humans; D007945:Leukemia, Lymphoid; D008175:Lung Neoplasms; D051379:Mice; D008968:Molecular Conformation; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D013237:Stereoisomerism; D013624:Taiwan; D014407:Tumor Cells, Cultured / Q000187:drug effects
chemical_list: D000970:Antineoplastic Agents; D000972:Antineoplastic Agents, Phytogenic; D004224:Diterpenes