Spongiaquinone Revisited: Structural and Stereochemical Studies on Marine Sesquiterpene/Quinones From a Southern Australian Marine Sponge, Spongia sp.

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).

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.


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).


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.


1993 ◽  
Vol 46 (8) ◽  
pp. 1255 ◽  
Author(s):  
MS Butler ◽  
RJ Capon

This report describes the isolation and structure elucidation of four new drimane sesquiterpenes (14)-(17) from a southern Australian marine sponge Dysidea sp. The structures for (14)-(17) were secured by detailed spectroscopic analysis, chemical interconversion and derivatization. Also reported are the known metabolites (+)- euryfuran (7), dihydropallescensin-2 (18), (-)- pallescensin-A (19) and (-)-7-deacetoxyolepupane (6). The rare co-occurrence of two antipodes, (7) and (19), in the same specimen highlights the dangers in assigning absolute stereochemistry based on 'unproven' biosynthetic relationships. The absolute stereochemistry for (6) has been unambiguously established for the first time by chemical interconversion to (7). Furthermore, the absolute stereochemistry of the new marine metabolites listed above, (14)-(17), were determined by chemical correlation to (6). A biosynthetic and ecological relationship is proposed between the metabolites from Dysidea sp. with the known marine and terrestrial antifeedant polygodial (8). Chemical investigations are reported that support this proposition.


1998 ◽  
Vol 51 (7) ◽  
pp. 573 ◽  
Author(s):  
Simon P. B. Ovenden ◽  
Robert J. Capon

A Latrunculia sp. collected off Port Phillip Bay, Victoria, returned three new norsesterterpene cyclic peroxides. Trunculins G (9), H (10) and I (11) were isolated as their methyl esters (12), (13) and (14) respectively. Gross structures for these new trunculins were assigned on the basis of spectroscopic analysis, while the absolute stereochemistry about the cyclic peroxide terminus was established by application of the Horeau and Mosher procedures.


1994 ◽  
Vol 47 (5) ◽  
pp. 933 ◽  
Author(s):  
R Davis ◽  
RJ Capon

A reinvestigation of the known marine natural product strobilinin has revealed it not to be a single compound (2), but to consist of two naturally occurring geometric isomers, neither of which corresponds to the structure originally assigned. These isomers, (8E,13Z,20Z)- strobilinin (10) and (8Z,13E,20Z)-strobilinin (11), were resolved, characterized and identified as their respective acetate derivatives (6) and (7), and their structures assigned by spectroscopic analysis. It would appear that the absolute stereochemistry of the strobilinins is very likely opposite to that of co-occurring variabilin (1).


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.


1993 ◽  
Vol 46 (9) ◽  
pp. 1363 ◽  
Author(s):  
MS Butler ◽  
RJ Capon

A specimen of Latrunculia conulosa from southern Australian coastal waters, previously observed to contain conulosin-A (6) and conulosin-B (7), has also been found to yield the known marine natural product trunculin-C methyl ester (14), along with three new norterpenes, trunculin-F (10), contrunculin-A (11) and contrunculin-B (12). Trunculin-F (10) was isolated, characterized and identified as its methyl ester (13), and its absolute stereochemistry determined by Horeau analysis. The structures for all new compounds were secured by detailed spectroscopic analysis.


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