The Bastadins Revisited: New Chemistry From the Australian Marine Sponge Ianthella basta

1991 ◽  
Vol 44 (2) ◽  
pp. 287 ◽  
Author(s):  
MS Butler ◽  
TK Lim ◽  
RJ Capon ◽  
LS Hammond

A specimen of Ianthella basta, collected from the Great Barrier Reef, Australia, has been found to contain the recently reported tetramer of bromotyrosine , bastadin-9 (6a), along with a new example of this structure class, bastadin-12 (9a). The structure for bastadin-12 (9a) was confirmed by detailed spectroscopic analysis and derivatization, and represents the first reported example of this structure class derived from an alternative oxidative cyclization . As earlier biosynthetic arguments to the structure elucidation of some bastadins were based on the premise that only one cyclization pathway was possible (leading to 13,32-dioxa-4,22-diazabastarane), the discovery of (9a) introduces an added dimension to the identification of new and known bastadins. Also isolated and identified as their methyl ethers were two new dimers of bromotyrosine, hemibastadin-1 (10) and hemibastadin-2 (11).


2010 ◽  
Vol 63 (6) ◽  
pp. 873 ◽  
Author(s):  
Chongsheng Peng ◽  
G. M. Kamal B. Gunaherath ◽  
Andrew M. Piggott ◽  
Zeinab Khalil ◽  
Melissa Conte ◽  
...  

Chemical fractionation of a southern Australian marine sponge, Trachycladus laevispirulifer, yielded 9-(5′-deoxy-5′-thio-β-d-xylofuranosyl)adenine disulfide as the first recorded natural occurrence of a nucleoside disulfide, and only the second of a xylo-nucleoside. Structure elucidation of the disulfide was achieved by detailed spectroscopic analysis and comparison to synthetic model compounds. The antibacterial, antifungal, and anticancer properties of the disulfide are documented and the literature surrounding natural and synthetic thionucleosides is reviewed.



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.



1991 ◽  
Vol 44 (10) ◽  
pp. 1393 ◽  
Author(s):  
RA Barrow ◽  
RJ Capon

Eleven alkyl and alkenyl resorcinols have been isolated from the Australian marine sponge Haliclona sp. Three of these, (3), (5) and (10), have previously been described from Australian terrestrial and marine plant sources. The remaining eight, (13)-(20), are new natural products whose structures have been secured by a combination of spectroscopic analysis and chemical degradation. This report represents the first account of this structure class being isolated from a non-plant source.



1997 ◽  
Vol 50 (2) ◽  
pp. 139 ◽  
Author(s):  
Eric J. Dumdei ◽  
Jamie S. Simpson ◽  
Mary J. Garson ◽  
Karl A. Byriel ◽  
Colin H. L. Kennard

Three new chlorinated metabolites, namely 3-(3,3-dichloro-2-methylpropyl)-6-(3,3-dichloro-2-methyl-propylidene)-1,4-dimethylpiperazine-2,5-dione (3), 1-methyl-3-(3,3,3-trichloro-2-methylpropyl)-6-(3,3,3-richloro-2-methylpropylidene)piperazine-2,5-dione (4) and 5,5-dichloro-4-methyl-2-[methyl(4,4-dichloro-3-methyl-1-oxobutyl)amino]-N-(thiazol-2-ylmethyl)pentanamide (8), have been isolated from collections of Dysidea herbacea from the southern region of the Great Barrier Reef. The relative and absolute stereochemistry of (4) was determined by X-ray crystallographic analysis.



1994 ◽  
Vol 47 (1) ◽  
pp. 191 ◽  
Author(s):  
GV Alea ◽  
AR Carroll ◽  
BF Bowden

A marine sponge, Coscinoderma sp., from the Great Barrier Reef, Australia, contained a new sesterterpene hydroquinone, coscinoquinol (1). The structure was elucidated by one-dimensional and two-dimensional n.m.r. techniques. Cytotoxicity and other biological activities are reported for (1).



1994 ◽  
Vol 47 (10) ◽  
pp. 1919 ◽  
Author(s):  
S Urban ◽  
MS Butler ◽  
RJ Capon

A specimen of Dendrilla cactos collected during trawling operations in Bass Strait, Australia, has yielded two new alkaloids, lamellarin-O (17) and lamellarin-P (18). Both these metabolites are examples of the lamellarin structure class, previously reported from tunicates and a mollusc; however, in these examples the pyrrole ring system is not fused to adjacent aromatic rings. The structures of (17) and (18) were secured by spectroscopic analysis and partial synthesis.



2000 ◽  
Vol 53 (4) ◽  
pp. 299 ◽  
Author(s):  
Bruce F. Bowden ◽  
Leanne Towerzey ◽  
Peter C. Junk

Samples of Dysidea herbacea collected at Pelorus Island, Great Barrier Reef, Australia, afforded a new polybrominated diphenyl ether (1). The structure was determined by n.m.r. two-dimensional methods and by an X-ray diffraction study. N.m.r. spectral assignments for (1) and some previously reported isomeric polybrominated diphenyl ethers are discussed.





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