Sylvia Urban

Lamellarins-O and Lamellarin-P - New Aromatic Metabolites From the Australian Marine Sponge Dendrilla-Cactos

A specimen of Dendrilla cactos collected off the coast of New South Wales, Australia, has yielded two new alkaloids, lamellarins Q (19) and R (20), the structures of which were secured by spectroscopic analysis and by chemical derivatization.

Marine Sesquiterpene Quinones and Hydroquinones - Acid-Catalyzed Rearrangements and Stereochemical Investigations

Acid treatment of both ilimaquinone (3) and 5-epi-ilimaquinone (9) yielded the same rearrangement products, (7) and (8), thus defining a common absolute stereochemistry. Likewise, acid- catalysed rearrangement of avarol (10) and arenarol (11) yielded the common product aureol (13), allowing the absolute stereochemistry of arenarol (11) and its related quinone arenarone (12) to be assigned. This latter acid- catalysed rearrangement also yielded an unexpected electrophilic aromatic cyclization product (15), the dimethyl ether (17) of which could be obtained in quantitative yield from acid treatment of avarol dimethyl ether (16).

A NEW LIPID FROM AN AUSTRALIAN MARINE SPONGE, CALLYSPONGIA SP.

A specimen of the sponge Callyspongia sp. collected off the coast of New South Wales, Australia, has yielded the novel lipid (6Z,9Z,12Z,15Z)-1,6,9,12,15-octadecapenten-3-one, together with (4Z,7Z,10Z,13Z)-4,7,10,13-hexadecatetraenoic acid.

A New Alkaloid From an Australian Marine Sponge, Spongosorites sp.

A specimen of a marine sponge, Spongosorites sp., collected in Port Phillip Bay, Victoria, Australia, has yielded the alkaloid (2). The structure of (2) was secured by spectroscopic analysis, chemical derivatization and synthesis of a dihydro derivative (4). The antibiotic property of the crude ethanol extract of this sponge was attributed to (2).

Corymbones A and B, Phloroglucinols with Thyrotropin Releasing Hormone Receptor 2 Binding Affinity from the Flowers of Corymbia peltata

High-throughput screeing of a plant and marine invertebrate extract library to find natural products with rat thytotropin releasing hormone receptor 2 binding affinity led to the isolation of two new active acylphloroglucinols, corymbones A and B (1 and 2) from flowers of the Queensland tree Corymbia peltata. Their structures were assigned from interpretation of 2D NMR and high-resolution ESIMS data. Compounds 1 and 2 showed rat TRH receptor 2 binding affinity with IC 50 values of 23 and 19 microM, respectively.

Beta-carboline alkaloids from a New Zealand marine bryozoan, Cribricellina Cribraria

The crude extract of a New Zealand marine bryozoan Cribricellina cribraria was examined and resulted in the isolation of the previously described, 6-hydroxyharman ( 1 ) and the new g -carboline metabolite, 8-hydroxyharman ( 2 ).

Cometins (A-C), New Furanosesterterpenes From an Australian Marine Sponge, Spongia sp.

The known marine furanosesterterpene furospinosulin-1 (1), together with three new furanosesterterpenes, namely cometin-A (2), cometin-B (3) and cometin-C (4), were isolated from a marine sponge, Spongia sp., collected during commercial trawling operations in the Great Australian Bight. The structures of these metabolites were determined by detailed spectroscopic analysis and chemical derivatization . The antibiotic property of the crude ethanol extract of this sponge was attributed solely to the furanosesterterpene tetronic acid cometin -A (2).

A New Sesquiterpene Alcohol From An Antarctic Sponge

An Antarctic sponge, has yielded the antibiotic sesquiterpene alcohol (8). The relative stereostructure of (8) was secured by detailed spectroscopic analysis, while the absolute configuration was tentatively assigned by examination of the CD spectrum.

A New Furanoditerpene from a Southern Australian Marine Sponge, Thorectandra choanoides

A specimen of the marine sponge Thorectandra choanoides from Bass Strait, Australia, has yielded the new furanoditerpene (7), the structure of which was secured by spectroscopic analysis.