Update of spectroscopic data for 4-hydroxydictyolactone and dictyol E isolated from a Halimeda stuposa - Dictyota sp. assemblage.

The methanol extract of an assemblage of Halimeda stuposa and a Dictyota sp., yielded three natural products characteristic of Dictyota sp., and one of Halimeda sp.

A new diketopiperazine, cyclo-(4-S-hydroxy-R-proline-R-isoleucine), from an Australian specimen of the sponge Stelletta sp.

While investigating the cytotoxic activity of the methanol extract of an Australian marine sponge Stelletta sp. (Demospongiae), a new diketopiperazine, cyclo-(4-S-hydroxy-R-proline-R-isoleucine) (1), was isolated together with the known bengamides; A (2), F (3), N (4), Y (5), and bengazoles; Z (6), C(4) (7) and C(6) (8). The isolation and structure elucidation of the diketopiperazine (1), together with the activity of 1-8 against a panel of human and mammalian cell lines are discussed.

Metachromins U-W: cytotoxic merosesquiterpenoids from an Australian specimen of the sponge Thorecta reticulata.

Three new merosesquiterpenoids, metachromins U, V, and W (1-3), were isolated from a specimen of the marine sponge Thorecta reticulata collected off Hunter Island, Tasmania, Australia. Structures of the new compounds were elucidated through extensive NMR investigations and comparison with literature values. The cytotoxicities of 1-3 were assessed against a panel of human tumor cell lines (SF-268, H460, MCF-7, and HT-29) and a mammalian cell line (CHO-K1).

Comosusols A-D and comosone A: cytotoxic compounds from the brown alga Sporochnus comosus.

Bioassay-guided fractionation of extracts of the brown alga Sporochnus comosus led to the isolation of five new compounds, comosusols A-D (3-6) and comosone A (7). The structures of all isolated compounds were elucidated using standard one- and two-dimensional NMR techniques, as well as comparison with literature values. The cytotoxic activity of all compounds was investigated against a panel of human tumor and mammalian cell lines.

Sesquiterpene benzoxazoles and sesquiterpene quinones from the marine sponge Dactylospongia elegans.

A new sesquiterpene benzoxazole, nakijinol B (3), its acetylated derivative, nakijinol B diacetate (6), and two new sesquiterpene quinones, smenospongines B (4) and C (5), were isolated from the methanol extract of the marine sponge Dactylospongia elegans. Also isolated were the known compounds dactyloquinone B and a 1:1 mixture of ilimaquinone and 5-epi-ilimaquinone. Their structures were determined on the basis of spectroscopic analyses and comparison with literature data.

ESI FTICR-MS analysis of larvae from the marine sponge Luffariella variabilis.

The viviparous Great Barrier Reef sponge Luffariella variabilis (Poléjaeff 1884) contains a range of secondary metabolites, including manoalide (1) and manoalide monoacetate (3). ESI (+) FTICR-MS accurate mass determination has, for the first time, been used to detected the presence of 3 only in an organic extract of a single L. variabilis larva showing that the parentally produced 3 is sequestered in the larva.

Eusynstyelamides A, B, and C, nNOS inhibitors, from the ascidian Eusynstyela latericius.

Eusynstyelamides A-C (1-3) were isolated from the Great Barrier Reef ascidian Eusynstyela latericius, together with the known metabolites homarine and trigonelline. The structures of 1-3, with relative configurations, were elucidated by interpretation of their spectroscopic data (NMR, MS, UV, IR, and CD). The NMR data of 1 were found to be virtually identical to that reported for eusynstyelamide (4), isolated from E.

FTICR-MS and LC-UV/MS-SPE-NMR applications for the rapid dereplication of a crude extract from the sponge Ianthella flabelliformis.

Dereplication of a methanolic extract of the marine sponge Ianthella flabelliformis using FTICR-MS accurate mass determination and MS(n) techniques enabled rapid and unambiguous detection of a new compound among a plethora of known compounds. Isolation of this compound and the known 19-deoxy analogue using the hyphenated technique LC-UV/MS-SPE-NMR was undertaken, and the structures were confirmed, from a single chromatographic run, as 19-hydroxyaraplysillin-I N(20)-sulfamate (1) and araplysillin-I N(20)-sulfamate (2).

Candidaspongiolides, distinctive analogues of tedanolide from sponges of the genus Candidaspongia.

Fractionation of cytotoxic extracts of specimens of a newly described sponge genus, Candidaspongia, has yielded the candidaspongiolides (3), a complex mixture of acyl esters of a macrolide related to tedanolide. The general structure of the candidaspongiolides was determined by analyses of various 2D NMR and MS data sets. The acyl ester components were identified by GC-MS analysis of the derived fatty acid methyl esters.

Antiherbivore chemistry of Eucalyptus-cues and deterrents for marsupial folivores.

Formylated phloroglucinol compounds (FPCs) are the single most important factor determining the amount of foliage that marsupial folivores eat from individual Eucalyptus trees. Folivores need to recognize which trees contain FPCs if they are to avoid them and forage efficiently, they are challenged by great diversity in the types and quantities of FPCs present, even within eucalypt species. We investigated the relationship between FPCs and terpenoids in species with both simple and complex FPC profiles and found strong positive correlations between terpenes generally, and several monoterpenes in particular, and FPCs.

Lihouidine, a novel spiro polycyclic aromatic alkaloid from the marine sponge Suberea n. sp. (Aplysinellidae, Verongida).

An investigation of a new species of sponge from the genus Suberea collected at Lihou Reef in the Coral Sea afforded lihouidine, an unprecedented cytotoxic spiro nonacyclic polyaromatic alkaloid. The structure of the alkaloid, which was racemic, was determined by a combination of 1D and 2D NMR techniques and single-crystal X-ray structural analysis.