title: A great barrier reef Sinularia sp. yields two new cytotoxic diterpenes.
abstract: The methanol extract of a Sinularia sp., collected from Bowden Reef, Queensland, Australia, yielded ten natural products. These included the new nitrogenous diterpene (4R*,5R*,9S*,10R*,11Z)-4-methoxy-9-((dimethylamino)-methyl)-12,15-epoxy-11(13)-en-decahydronaphthalen-16-ol (1), and the new lobane, (1R*,2R*,4S*,15E)-loba-8,10,13(14),15(16)-tetraen-17,18-diol-17-acetate (2). Also isolated were two known cembranes, sarcophytol-B and (1E,3E,7E)-11,12-epoxycembratrien-15-ol, and six known lobanes, loba-8,10,13(15)-triene-16,17,18-triol, 14,18-epoxyloba-8,10,13(15)-trien-17-ol, lobatrientriol, lobatrienolide, 14,17-epoxyloba-8,10,13(15)-trien-18-ol-18-acetate and (17R)-loba-8,10,13(15)-trien-17,18-diol. Structures of the new compounds were elucidated through interpretation of spectra obtained after extensive NMR and MS investigations and comparison with literature values. The tumour cell growth inhibition potential of 1 and 2 along with loba-8,10,13(15)-triene-16,17,18-triol, 14,17-epoxyloba-8,10,13(15)-trien-18-ol-18-acetate, lobatrienolide, (1E,3E,7E)-11,12-epoxycembratrien-15-ol and sarcophytol-B were assessed against three human tumour cell lines (SF-268, MCF-7 and H460). The lobanes and cembranes tested demonstrated 50% growth inhibition in the range 6.8-18.5 µM, with no selectivity, whilst 1 was less active (GI₅₀ 70-175 µM).
authors.affiliation: Australian Institute of Marine Science, PMB no. 3, Townsville MC, Townsville, QLD 4810, Australia.
authors.forename: Anthony D
authors.initials: AD
authors.lastname: Wright
authors.affiliation: Australian Institute of Marine Science, PMB no. 3, Townsville MC, Townsville, QLD 4810, Australia.
authors.forename: Jonathan L
authors.initials: JL
authors.lastname: Nielson
authors.affiliation: Australian Institute of Marine Science, PMB no. 3, Townsville MC, Townsville, QLD 4810, Australia.
authors.forename: Dianne M
authors.initials: DM
authors.lastname: Tapiolas
authors.affiliation: Australian Institute of Marine Science, PMB no. 3, Townsville MC, Townsville, QLD 4810, Australia.
authors.forename: Catherine H
authors.initials: CH
authors.lastname: Liptrot
authors.affiliation: Australian Institute of Marine Science, PMB no. 3, Townsville MC, Townsville, QLD 4810, Australia.
authors.forename: Cherie A
authors.initials: CA
authors.lastname: Motti
mesh_terms: D000818:Animals; D037421:Anthozoa / Q000737:chemistry*; D000970:Antineoplastic Agents / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D045744:Cell Line, Tumor; D057894:Coral Reefs; D004224:Diterpenes / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D009369:Neoplasms / Q000188:drug therapy* / Q000473:pathology; D011793:Queensland
chemical_list: D000970:Antineoplastic Agents; D004224:Diterpenes