Deoxyspongiaquinones: New Sesquiterpene Quinones and Hydroquinones From a Southern Australian Marine Sponge Euryspongia sp.

1996 ◽  
Vol 49 (5) ◽  
pp. 611 ◽  
Author(s):  
S Urban ◽  
RJ Capon

Chemical investigation of a marine sponge, Euryspongia sp., collected from the Great Australian Bight, Australia, resulted in the isolation of two new sesquiterpene quinones , deoxyspongiaquinone (4) and (E)-chlorodeoxyspongiaquinone (5), as well as two sesquiterpene hydroquinones, deoxyspongiaquinol (6) and (E)-chlorodeoxyspongiaquinol (7). The structures for (4)-(7) were determined by detailed spectroscopic analysis, as well as chemical interconversion and degradation.


1993 ◽  
Vol 46 (8) ◽  
pp. 1245 ◽  
Author(s):  
RJ Capon ◽  
DR Groves ◽  
S Urban ◽  
RG Watson

A chemical investigation of a large purple sponge, Spongia sp., from the Great Australian Bight, resulted in the isolation of a new sesquiterpene/quinone (8), together with the known compounds dehydrocyclospongiaquinone-1 (4) and spongiaquinone (2). The last compound was also isolated as the potassium salt (9), this being the first recorded account of a naturally occurring marine sesquiterpene/quinone salt. The structure for (8) was assigned by detailed spectroscopic analysis. A re-investigation into the stereostructure of spongiaquinone (2) resulted in the first unambiguous assignment of absolute stereochemistry, and uncovered the peculiar chiroptical properties of spongiaquinone (2) and its potassium salt (9).



1995 ◽  
Vol 48 (10) ◽  
pp. 1757 ◽  
Author(s):  
NH Tran ◽  
JNA Hooper ◽  
RJ Capon

Chemical investigation of a Dictyodendrilla sp. from Port Phillip Bay, Victoria, yielded three new oxygenated sesquiterpenes, dictyodendrillin -A (6), -B (7) and -C (8), together with the known sesquiterpene dendrolasin (9). Structures for all these metabolites were established by spectroscopic analysis.



1997 ◽  
Vol 50 (12) ◽  
pp. 1137 ◽  
Author(s):  
Sean Bassett, ◽  
Simon P. B. Ovenden ◽  
Robert W. Gable ◽  
Robert J. Capon

A Sigmosceptrella sp. of sponge collected during trawling operations in the Great Australian Bight, Australia, has yielded a series of new norterpenes. These include a new bisnorditerpene, sigmosceptrin-A (5); two new norditerpenes, sigmosceptrin-B (14) and sigmosceptrin-C (15), isolated as their methyl esters (6) and (7) respectively; and an ethylated artefact, sigmosceptrin-B ethyl ester (8). Complete stereostructures were assigned to the sigmosceptrins by spectroscopic analysis, chemical degradation, derivatization, and by a single-crystal X-ray structural analysis. A biosynthetic pathway is proposed that requires a common biosynthetic precursor to both the sigmosceptrins and norterpene cyclic peroxides.



1992 ◽  
Vol 45 (8) ◽  
pp. 1255 ◽  
Author(s):  
S Urban ◽  
RJ Capon

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).



1996 ◽  
Vol 49 (7) ◽  
pp. 767 ◽  
Author(s):  
RA Barrow ◽  
LM Murray ◽  
TK Lim ◽  
RJ Capon

An Australian marine sponge Arenochalina mirabilis (Lendenfeld 1887) collected from the Great Australian Bight has been found to contain six tricyclic alkaloids, mirabilins A-F (5)-(10), isolated and identified as their N-acetyl derivatives (11)-(16). Structures for the mirabilins were secured by detailed spectroscopic analysis.



1992 ◽  
Vol 45 (10) ◽  
pp. 1705 ◽  
Author(s):  
MS Butler ◽  
RJ Capon

A marine sponge, Luffariella geometrica Kirkpatrick, collected from the southern Australian coastal waters of the Great Australian Bight, has been found to contain 14 new bicyclic sesterterpenes, luffarin-A (14), -B (15), -C (16), -D (17), -E (18), -F (19), -G (20), -H (21), -I (22), -J (23), -K (24), -L (25), -M (26) and -N (27), a new bicyclic bisnorsesterterpene, luffarin-O (30), a new monocyclic sesterterpene, luffarin-P (32), six new acyclic sesterterpenes, luffarin-Q (35), -R (36), -S (37), -T (38), -U (39) and -V (40), two new diterpenes, luffarin-W (41) and -X (44), and two new bisnorditerpenes luffarin-Y (45) and -Z (46). These novel marine metabolites have been assigned structures, including stereochemistry, on the basis of detailed spectroscopic analysis, chemical correlation, derivatization, and biosynthetic considerations. Studies directed at the absolute stereochemistry of the luffarins have also permitted assignment of absolute stereochemistry to the known marine natural products (E)-neomanoalide (3), (Z)-neomanoalide (4) and dehydroambliol-A (47).



1993 ◽  
Vol 46 (8) ◽  
pp. 1295 ◽  
Author(s):  
R Davis ◽  
RJ Capon

A specimen of the marine sponge Spongia hispida ( Lamarck , 1814), collected in the Great Australian Bight, has yielded the known marine sesterterpene hyrtiosal (1), together with two new scalarane sesterterpenes, isoscalarafuran-A (2) and isoscalarafuran -B (3). The structures for these two new metabolites were secured by detailed spectroscopic analysis, comparison with model compounds, and molecular modelling.



1998 ◽  
Vol 51 (2) ◽  
pp. 169 ◽  
Author(s):  
Robert J. Capon ◽  
Simon P. B. Ovenden ◽  
Tim Dargaville

A specimen of the sponge Dendrilla sp. collected during commercial trawling operations in the Great Australian Bight, Australia, analyses for a very high natural abundance of the new amino acid cis-3-hydroxy-N-methyl-L-proline (1). The complete stereostructure for (1) was determined by spectroscopic analysis and chemical derivatization.



Marine Drugs ◽  
2021 ◽  
Vol 19 (2) ◽  
pp. 97
Author(s):  
Shamsunnahar Khushi ◽  
Angela A. Salim ◽  
Ahmed H. Elbanna ◽  
Laizuman Nahar ◽  
Robert J. Capon

Thorectandra choanoides (CMB-01889) was prioritized as a source of promising new chemistry from a library of 960 southern Australian marine sponge extracts, using a global natural products social (GNPS) molecular networking approach. The sponge was collected at a depth of 45 m. Chemical fractionation followed by detailed spectroscopic analysis led to the discovery of a new tryptophan-derived alkaloid, thorectandrin A (1), with the GNPS cluster revealing a halo of related alkaloids 1a–1n. In considering biosynthetic origins, we propose that Thorectandrachoanoides (CMB-01889) produces four well-known alkaloids, 6-bromo-1′,8-dihydroaplysinopsin (2), 6-bromoaplysinopsin (3), aplysinopsin (4), and 1′,8-dihydroaplysinopsin (10), all of which are susceptible to processing by a putative indoleamine 2,3-dioxygenase-like (IDO) enzyme to 1a–1n. Where the 1′,8-dihydroalkaloids 2 and 10 are fully transformed to stable ring-opened thorectandrins 1 and 1a–1b, and 1h–1j, respectively, the conjugated precursors 3 and 4 are transformed to highly reactive Michael acceptors that during extraction and handling undergo complete transformation to artifacts 1c–1g, and 1k–1n, respectively. Knowledge of the susceptibility of aplysinopsins as substrates for IDOs, and the relative reactivity of Michael acceptor transformation products, informs our understanding of the pharmaceutical potential of this vintage marine pharmacophore. For example, the cancer tissue specificity of IDOs could be exploited for an immunotherapeutic response, with aplysinopsins transforming in situ to Michael acceptor thorectandrins, which covalently bind and inhibit the enzyme.



1994 ◽  
Vol 47 (10) ◽  
pp. 1901 ◽  
Author(s):  
RA Barrow ◽  
RJ Capon

The marine sponge Phakellia carduus obtained during commercial trawling operations in the Great Australian Bight yielded a series of new C23 acetylenic acids, carduusynes (A-E) [(3)-(7)], which were isolated, characterized and identified as their respective ethyl esters [(8)-(12)].



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