title: Caulibugulones A-F, novel cytotoxic isoquinoline quinones and iminoquinones from the marine bryozoan Caulibugula intermis.
abstract: An extract of the marine bryozoan Caulibugula intermis, collected in the Indo-Pacific off Palau, produced a distinct pattern of differential cytotoxicity in the National Cancer Institute's 60 cell line antitumor screen. Bioactivity-directed fractionation of the extract provided six new compounds, caulibugulones A-F (1-6). The structures of these novel metabolites were determined by spectrochemical analyses including LC-MS, HRFABMS, 1-D and 2-D NMR experiments, and by comparison with related compounds. The structures of compounds 2 and 3 were confirmed by chemical interconversion. The isolated compounds exhibited IC(50)'s of 0.03-1.67 microg/mL against murine tumor cells in an in vitro cytotoxicity assay.
authors.affiliation: Molecular Targets Development Program, Center for Cancer Research, National Cancer Institute, Building 1052, Room 121, Frederick, MD 21702-1201, USA.
authors.forename: Dennis J
authors.initials: DJ
authors.lastname: Milanowski
authors.forename: Kirk R
authors.initials: KR
authors.lastname: Gustafson
authors.forename: James A
authors.initials: JA
authors.lastname: Kelley
authors.forename: James B
authors.initials: JB
authors.lastname: McMahon
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D002013:Bryozoa / Q000737:chemistry*; D045744:Cell Line, Tumor; D004354:Drug Screening Assays, Antitumor; D007546:Isoquinolines / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D019029:Palau; D011809:Quinones / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology
chemical_list: D000970:Antineoplastic Agents; D007546:Isoquinolines; D011809:Quinones