Studies of Australian Soft Corals .XXXVII. The Structure Determination of 2 Cembranolide Diterpenes From Soft Corals of the Genus Efflatounaria (Coelenterata, Octocorallia, Alcyonacea)

1986 ◽  
Vol 39 (1) ◽  
pp. 123 ◽  
Author(s):  
BF Bowden ◽  
JC Coll ◽  
LM Engelhardt ◽  
GV Meehan ◽  
GG Pegg ◽  
...  
Keyword(s):  
Structure Determination ◽  
Soft Coral ◽  
Soft Corals ◽  
X Ray ◽  
X Ray Crystallography ◽  
Coral Genus ◽  
Relative Stereochemistry ◽  
Chemical Correlation ◽  
Absolute Stereochemistry

Two isomeric 7,8-epoxycembra-3,11,15-trien-16,2-olides have been isolated from different species of the soft coral genus Efflatounaria. The structure of each was deduced spectroscopically , and the relative stereochemistry of one was determined by X-ray crystallography. The absolute stereochemistry of each cembranolide was obtained by chemical correlation with known compounds.

Studies of Australian Soft Corals .XXXVI. The Isolation and Structure Determination of 11 Calamenene-Based Sesquiterpenes From Lemnalia-Cervicornis (Coelenterata, Octocorallia, Alcyonacea)

1986 ◽  
Vol 39 (1) ◽  
pp. 103 ◽  
Author(s):  
BF Bowden ◽  
JC Coll ◽  
LM Engelhardt ◽  
DM Tapiolas ◽  
AH White
Keyword(s):  
Structure Determination ◽  
Soft Coral ◽  
Soft Corals ◽  
X Ray ◽  
Chemical Correlation ◽  
Derivatives Of ◽  
Absolute Stereochemistry

The soft coral Lemnalia cervicornis May 1898 has afforded 13 novel sesquiterpenoid metabolites. The majority were derivatives of calamenen-7-ol and the structures were deduced by 1H and 13C n.m.r . spectroscopy. Absolute stereochemistry of compounds (3)-(13) was determined by chemical correlation with 7-hydroxycalamenen-3-one (3) for which an X-ray structure determination of its 7-p-bromobenzoyl derivative is reported. Two minor metabolites (15) and (16) were not aromatic, but were structurally related to the algal metabolite zonarene (21) for which absolute stereochemistry was available.

Studies of Australian Soft Corals. XLI. Structure Determination of a New Sesquiterpene From Xenia novae-britanniae and an Investigation of a Xenia Species

1987 ◽  
Vol 40 (8) ◽  
pp. 1483 ◽  
Author(s):  
BF Bowden ◽  
JC Coll ◽  
LM Engelhardt ◽  
A Heaton ◽  
AH White
Keyword(s):  
Single Crystal ◽  
Structure Determination ◽  
Soft Coral ◽  
Soft Corals ◽  
X Ray ◽  
X Ray Crystallography ◽  
Relative Stereochemistry

.A novel sesquiterpene (1 Z,2R*,4R*,7S*,11S*)-3,3,7,11-tetramethyltricyclo[6.3.0.02,4]undec-1(8)-en-4-ol (3) was isolated from the soft coral Xenia novae-britanniae. Its structure was tentatively deduced by n.m.r. spectroscopy, and the structure with relative stereochemistry was confirmed by single-crystal X-ray crystallography. Investigation of a Xenia species afforded the known metabolite waixenicin -A previously isolated from Anthelia edmondsoni .

The structure determination of a new cembranolide diterpene from the soft coral Lobophytum cristigalli (Coelenterata, Octocorallia, Alcyonacea)

1984 ◽  
Vol 37 (3) ◽  
pp. 545 ◽  
Author(s):  
BF Bowden ◽  
JC Coll ◽  
MSL de Costa ◽  
MF Mackay ◽  
M Mahendran ◽  
...  
Keyword(s):  
Sri Lanka ◽  
Structure Determination ◽  
Soft Coral ◽  
X Ray ◽  
X Ray Crystallography

A specimen of Lobophytum cristigalli collected in Sri Lanka afforded two cembranolide diterpenes (7E,11E,1R,2S,3R,4R,14S)-14-acetoxy-3,4-epoxycembra-7,11,15-trien-17,2-olide (6)* and the corresponding alcohol (7). Their structures were deduced spectroscopically and detailed stereochemistry of (6) was determined by X-ray crystallography.

Tropical Marine Algae. II. The Structure Determination of New Halogenated Monoterpenes From Plocamium hamatum (Rhodophyta, Gigartinales, Plocamiaceae)

1988 ◽  
Vol 41 (11) ◽  
pp. 1743 ◽  
Author(s):  
JC Coll ◽  
BW Skelton ◽  
AH White ◽  
AD Wright
Keyword(s):  
Marine Algae ◽  
Two Dimensional ◽  
X Ray ◽  
X Ray Crystallography ◽  
Halogenated Monoterpenes ◽  
Relative Stereochemistry ◽  
Structure Determinations ◽  
Absolute Stereochemistry ◽  
Related Metabolite

The structure determinations of new halogenated monoterpenes, isolated from collections of Plocamium hamatum J. Agardh , are reported. One collection of P. hamatum afforded (1R*,2R*,4S*,5R*,1′E)-1,2,4- trichloro-5-(2′-chloroethenyl)-1,5-dimethylcyclohexane (1) whose relative stereochemistry was determined by X-ray crystallography. Extensive use of two-dimensional carbon-hydrogen correlation experiments enabled unambiguous assignments of proton and carbon resonances to be made for this new compound. Complete carbon assignments for the related metabolite mertensene (2) are reported. A second collection of P. hamatum afforded three new halogenated monoterpenes. The relative and absolute stereochemistry of (2S,3E,5S,6S,7S)-1,5,7-tribromo-2,6,8-trichloro-2,6-dimethyloct-3-ene (3) was determined by n.m.r . and X-ray crystallography, while for (3R*,4S*,5E)-4,8-dibromo-3,7-dichloro-3,7-dimethylocta-1,5-diene (4) and (2R*,4S*,5R*,1*E)-4-bromo-2-chloro-5-(2′-chloroethenyl)-5-methyl-1-methylenecyclohexane (5), the structures and relative configurations were determined by n.m.r . spectroscopy.

Studies of Australian Soft Corals. XXXVIII. Structure Determination of Several Diterpenes Derived From a Cespitularia Species (Coelenterata, Octocorallia, Xeniidae)

1986 ◽  
Vol 39 (5) ◽  
pp. 803 ◽  
Author(s):  
BF Bowden ◽  
JC Coll ◽  
JM Gulbis ◽  
MF Mackay ◽  
RH Willis
Keyword(s):  
Structure Determination ◽  
Structure Elucidation ◽  
Soft Coral ◽  
Authentic Sample ◽  
Spectroscopic Studies ◽  
Soft Corals ◽  
X Ray ◽  
Spectral Comparison ◽  
Absolute Structure

The structure elucidation of three new diterpenes , isolated from a soft coral Cespitularia species, is reported. Two of the metabolites (3), (7E,11E,1R*,3aS*,4S*,12aR*)-11-iso-propyl-1,4,8-trimethyl- 1,2,3,3a,4,5,6,9,10,12a-decahydrocyclopentacycloundecene-1,4-diol, and (4), (4E,7E,11E)-11-isopropyl-1,4,8-trimethyl-1,2,3,3a,6,9,10,12a-octahydrocyclopentacyclo-undecen-1-ol, are shown to possess a further cyclized cembrane skeleton, the structure of (3) being determined by a single-crystal X-ray determination while that of (4) was deduced from spectral comparison with (3). The structure of the remaining diterpene (5) (4,5-deoxyneodolabelline) was deduced from 1H and 13C n.m.r . spectroscopic studies and shown to be closely related to the recently reported clavularian metabolite neodolabelline (8). An authentic sample of neodolabelline (8) was chemically transformed into (5) by the action of a zinc-copper couple establishing the absolute structure of (5).

Studies of Australian soft corals. XXXII. The structure determination of degraded xenicin-type diterpenes from several Efflatounaria species

1983 ◽  
Vol 36 (11) ◽  
pp. 2279 ◽  
Author(s):  
BF Bowden ◽  
JC Coll ◽  
VA Patrick ◽  
DM Tapiolas
Keyword(s):  
Single Crystal ◽  
Chemical Transformation ◽  
Structure Determination ◽  
High Field ◽  
Soft Corals ◽  
X Ray ◽  
The Third

Three new diterpenes have been isolated from soft corals of the genus Efflatounaria (Coelenterata, Octocorallia, Alcyonacea, Xeniidae). The structure of the first compound (4) was elucidated on the basis of high-field 1H n.m.r. spectroscopy while that of the second metabolite (5) was determined by single-crystal X-ray analysis. The third diterpene (6) was structurally related to (5), and its structure was confirmed by chemical transformation. All three diterpenes can be derived from xenicin-type precursors, by cleavage and recyclization.

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