Investigation into the Absolute Stereochemistry of the Marine Sponge Alkaloid Pyrinodemin A.

ChemInform ◽  
2004 ◽  
Vol 35 (5) ◽  
Author(s):  
Stuart P. Romeril ◽  
Victor Lee ◽  
Jack E. Baldwin ◽  
Timothy D. W. Claridge ◽  
Barbara Odell
Keyword(s):  
Marine Sponge ◽  
The Absolute ◽  
Absolute Stereochemistry

Beyond Polygodial: New Drimane Sesquiterpenes From a Southern Australian Marine Sponge, Dysidea sp.

1993 ◽  
Vol 46 (8) ◽  
pp. 1255 ◽  
Author(s):  
MS Butler ◽  
RJ Capon
Keyword(s):  
Marine Sponge ◽  
Structure Elucidation ◽  
Spectroscopic Analysis ◽  
Marine Metabolites ◽  
Ecological Relationship ◽  
Chemical Correlation ◽  
The Absolute ◽  
First Time ◽  
Absolute Stereochemistry

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.

Trunculins G - I: New Norsesterterpene Cyclic Peroxides from a Southern Australian Marine Sponge, Latrunculia sp.

1998 ◽  
Vol 51 (7) ◽  
pp. 573 ◽  
Author(s):  
Simon P. B. Ovenden ◽  
Robert J. Capon
Keyword(s):  
Marine Sponge ◽  
Spectroscopic Analysis ◽  
Methyl Esters ◽  
I 11 ◽  
The Absolute ◽  
Cyclic Peroxide ◽  
Absolute Stereochemistry

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.

The Luffarins (A-Z), Novel Terpenes From an Australian Marine Sponge, Luffariella geometrica

1992 ◽  
Vol 45 (10) ◽  
pp. 1705 ◽  
Author(s):  
MS Butler ◽  
RJ Capon
Keyword(s):  
Natural Products ◽  
Marine Sponge ◽  
Coastal Waters ◽  
Marine Natural Products ◽  
Spectroscopic Analysis ◽  
Marine Metabolites ◽  
Chemical Correlation ◽  
The Absolute ◽  
Great Australian Bight ◽  
Absolute Stereochemistry

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).

Investigation into the absolute stereochemistry of the marine sponge alkaloid pyrinodemin A

2003 ◽  
Vol 44 (42) ◽  
pp. 7757-7761 ◽  
Author(s):  
Stuart P. Romeril ◽  
Victor Lee ◽  
Jack E. Baldwin ◽  
Timothy D.W. Claridge ◽  
Barbara Odell
Keyword(s):  
Marine Sponge ◽  
The Absolute ◽  
Absolute Stereochemistry

Absolute Stereochemistry of (-)-Wieland-Miescher Ketone as Established by the X-ray Crystallographic and CD Exciton Chirality Methods

1992 ◽  
Vol 57 (7) ◽  
pp. 1459-1465 ◽  
Author(s):  
Nobuyuki Harada ◽  
Tatsuo Sugioka ◽  
Hisashi Uda ◽  
Takeo Kuriki
Keyword(s):  
Structure Analysis ◽  
Absolute Configuration ◽  
X Ray ◽  
The Absolute ◽  
Absolute Stereochemistry

The 8aR absolute stereochemistry of Wieland-Miescher ketone (-)-I was established by the X-ray structure analysis of its bis(4-bromobenzoate) derivatives (1R,6R,8aR)-(+)-IV and (1R,6S,8aR)-(-)-V. The absolute configuration of (-)-I was corroborated further by the application of the CD exciton chirality method to bis(4-bromobenzoates) (+)-IV and (-)-V.

Determination of the Absolute Stereochemistry of Cyclosmenospongine

2003 ◽  
Vol 66 (9) ◽  
pp. 1263-1265 ◽  
Author(s):  
Natalia K. Utkina ◽  
Vladimir A. Denisenko ◽  
Olga V. Scholokova ◽  
Aleksandra E. Makarchenko
Keyword(s):  
The Absolute ◽  
Absolute Stereochemistry

Stereoselective deprotonation of tropinone and reactions of tropinone lithium enolate

1992 ◽  
Vol 70 (10) ◽  
pp. 2618-2626 ◽  
Author(s):  
Marek Majewski ◽  
Guo-Zhu Zheng
Keyword(s):  
Acetic Acid ◽  
Ring Opening ◽  
Aldol Reaction ◽  
Ethyl Chloroformate ◽  
Lithium Diisopropylamide ◽  
Silver Acetate ◽  
Lithium Amides ◽  
Lithium Enolate ◽  
The Absolute ◽  
Absolute Stereochemistry

Tropinone (6) was deprotonated with lithium diisopropylamide and with chiral lithium amides (18–24) and the resulting enolates (two enantiomers) were treated with electrophiles. The aldol reaction with benzaldehyde and deuteration were both diastereoselective. The former yielded only one isomer (exo, anti) of the aldol 8a; the latter proceeded from the exo face. This selectivity permitted us to probe the deprotonation of tropinone with lithium amides; it was concluded that the reaction involves predominantly the exo axial protons. The reaction of tropinone enolate with ethyl chloroformate led, via a ring opening, to the cycloheptenone derivative 9. The reaction with methyl cyanoformate yielded, in the presence of silver acetate and acetic acid, the β-ketoester 8b; however, in the absence of these additives, and especially when 12-crown-4 was added to the enolate, a ring opening leading to the pyrrolidine derivative 10 occurred instead. Deprotonation of tropinone with chiral lithium amides proceeded with modest enantioselectivity. A synthesis of non-racemic anhydroecgonine via this strategy allowed establishing the absolute stereochemistry of deprotonation.

First synthesis and determination of the absolute stereochemistry of iso-cladospolide-B and cladospolides-B and C

2006 ◽  
Vol 47 (37) ◽  
pp. 6537-6540 ◽  
Author(s):  
G.V.M. Sharma ◽  
K. Laxmi Reddy ◽  
J. Janardhan Reddy
Keyword(s):  
The Absolute ◽  
Absolute Stereochemistry

The absolute stereochemistry of the ester functions of fumonisin B1

1999 ◽  
Vol 40 (24) ◽  
pp. 4515-4518 ◽  
Author(s):  
Oliver E. Edward ◽  
Barbara A. Blackwell ◽  
Alex B. Driega ◽  
Corrine Bensimon ◽  
John W. ApSimon
Keyword(s):  
Fumonisin B1 ◽  
The Absolute ◽  
Absolute Stereochemistry

scholarly journals Cytotoxic Sesterterpenes from Thai Marine Sponge Hyrtios erectus

Marine Drugs ◽  
2018 ◽  
Vol 16 (12) ◽  
pp. 474 ◽  
Author(s):  
Wirongrong Kaweetripob ◽  
Chulabhorn Mahidol ◽  
Pittaya Tuntiwachwuttikul ◽  
Somsak Ruchirawat ◽  
Hunsa Prawat
Keyword(s):  
Methyl Ether ◽  
Marine Sponge ◽  
Indole Alkaloids ◽  
Cytotoxic Activities ◽  
Spectroscopic Methods ◽  
The Absolute ◽  
Modified Mosher’S Method

Four sesterterpenes, erectusolides B, C, D, and seco-manoalide-25-methyl ether, two 2-furanone derivatives, erectusfuranones A and B, together with thirteen known sesterterpenes, (6Z)-neomanoalide-24-acetate, two diastereomers of 24-O-methylmanoalide, luffariolide B, manoalide, (6E)- and (6Z)-neomanoalide, seco-manoalide, scalarafuran, 12-acetylscalarolide, 12-epi-O-deacetyl-19-deoxyscalarin, 12-epi-scalarin, and 12-O-deacetyl-12-epi-scalarin, three indole alkaloids, 5-hydroxy-1H-indole-3-carbaldehyde, hyrtiosine A, and variabine B, and one norterpene, cavernosine were isolated from the marine sponge Hyrtios erectus. Their structures were determined by means of spectroscopic methods and the absolute configurations of the asymmetric centers were determined using the modified Mosher’s method. The cytotoxic activities for the isolated compounds have been reported.

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