Studies of Australian Soft Corals. XLIII. The Structure Elucidation of a New Diterpene From Alcyonium molle

1989 ◽  
Vol 42 (5) ◽  
pp. 665 ◽  
Author(s):  
BF Bowden ◽  
JC Coll ◽  
MC Dai
Keyword(s):  
Absolute Configuration ◽  
High Field ◽  
Structure Elucidation ◽  
Kinetic Resolution ◽  
Soft Coral ◽  
Soft Corals ◽  
Resolution Method ◽  
The Absolute ◽  
First Time

The isolation of a new cladiellin based diterpene (6), (1S,2R,3S,4R,SR,6S,8E,11S,12R,13S,14S)-3-acetoxy-2,12-dibutanoyloxycladiell-8-ene-4,11-diol is reported from the soft coral Alcyonium molle (Octocorallia, Alcyonacea, Alcyoniidae). The structure was deduced by high-field n.m.r. spectroscopy including 13C-lH shift correlated 2D n.m.r. experiments and n.O.e. measurements. The absolute configuration was based on the kinetic resolution method of Horeau. This highly derivatized diterpene (6) is the first alcyonacean derived metabolite to possess hydroxy functionalities protected as butyrate esters, although this feature is relatively common among gorgonacean metabolites. Gorgosterol (7), which cooccurs with (6) in A. molle was identified and its 13C n.m.r. spectrum reported for the first time.

scholarly journals Absolute Configuration of Cembrane Diterpenoids from Bursera multijuga

2014 ◽  
Vol 9 (9) ◽  
pp. 1934578X1400900 ◽  
Author(s):  
Juan D. Hernández-Hernández ◽  
Hugo A. García-Gutiérrez ◽  
Luisa U. Román-Marín ◽  
Yunuen I. Torres-Blanco ◽  
Carlos M. Cerda-García-Rojas ◽  
...  
Keyword(s):  
Molecular Modeling ◽  
Absolute Configuration ◽  
2D Nmr ◽  
Vibrational Circular Dichroism ◽  
Conformational Preference ◽  
X Ray Diffraction ◽  
X Ray ◽  
The Absolute ◽  
First Time ◽  
Good Agreement

The stems of Bursera multijuga afforded (-)-(1 S,3 E,7 R,8 R,11 E)-7,8-epoxycembra-3,11-dien-1-ol (1) and its acetate 2, together with cembrene A (3), nephthenol (4), and cembrenol (5). The structures of 1 and 2 were elucidated by 1D and 2D NMR, HRESIMS, and X-ray diffraction. The conformational preference of flexible 1 was studied by molecular modeling at the DFT B3LYP/DGDZVP level of theory. Good agreement between calculated and experimental vibrational circular dichroism curves established the absolute configuration of 1. This is the first time that cembrane derivatives have been isolated from the genus Bursera.

A new aspect of the high-field NMR application of Mosher's method. The absolute configuration of marine triterpene sipholenol A

1991 ◽  
Vol 56 (3) ◽  
pp. 1296-1298 ◽  
Author(s):  
Ikuko Ohtani ◽  
Takenori Kusumi ◽  
Yoel Kashman ◽  
Hiroshi Kakisawa
Keyword(s):  
Absolute Configuration ◽  
High Field ◽  
The Absolute

scholarly journals Isolation and structure elucidation of natural products of three soft corals and a sponge from the coast of Madagascar

2017 ◽  
Vol 15 (12) ◽  
pp. 2593-2608 ◽  
Author(s):  
Marie Pascaline Rahelivao ◽  
Tilo Lübken ◽  
Margit Gruner ◽  
Olga Kataeva ◽  
Rahanira Ralambondrahety ◽  
...  
Keyword(s):  
Natural Products ◽  
Structure Elucidation ◽  
Soft Coral ◽  
Soft Corals

The Madagascan soft coralCapnella fungiformisprovided the two diastereoisomeric ethyl furancarboxylates1and2and the diepoxyguaiane sesquiterpene oxyfungiformin (3).

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.

Predation on soft corals (Octocorallia: Alcyonacea) on the Great Barrier Reef, Australia

1994 ◽  
Vol 45 (7) ◽  
pp. 1281 ◽  
Author(s):  
JK Griffith
Keyword(s):  
Great Barrier Reef ◽  
Soft Coral ◽  
Barrier Reef ◽  
Soft Corals ◽  
Quantitative Evidence ◽  
Bite Marks ◽  
First Time ◽  
Predation Rates

Quantitative evidence on predation rates on soft corals is presented for the first time. These measured predation rates were low. Less than 1% of the soft coral colonies present in mapped areas at Heron Island and Beaver Reefs had bite marks. Evidence suggests that over 51% of these bite marks were more than two months old. Predators included the mollusc Ovula ovum and two species of chaetodontid fishes that have not been recorded before as feeding on soft corals.

scholarly journals Enzyme-catalyzed kinetic resolution of N-Boc-trans-3-hydroxy-4-phenylpyrrolidine

2014 ◽  
Vol 12 (1) ◽  
pp. 25-32 ◽  
Author(s):  
Ferenc Faigl ◽  
Ervin Kovács ◽  
Dóra Balogh ◽  
Tamás Holczbauer ◽  
Mátyás Czugler ◽  
...  
Keyword(s):  
Single Crystal ◽  
Absolute Configuration ◽  
Kinetic Resolution ◽  
Diffraction Method ◽  
Pure Form ◽  
X Ray Diffraction ◽  
Resolution Method ◽  
X Ray ◽  
Temperature Optimization ◽  
Acetate Derivative

AbstractThe first enzyme-catalyzed kinetic resolution of tert-butyl-3-hydroxy-4-phenylpyrrolidine-1-carboxylate is presented. Enzyme, solvent and temperature optimization resulted in a new resolution method with E = 40 enantioselectivity. The acetate derivative of the (+)-(3S,4R) enantiomer formed while the (−)-(3R,4S) isomer remained intact. Very good enantioselectivities (E > 200) were achieved in the enzyme-catalyzed alcoholysis of the racemic acetate in i-propanol and t-butanol where the (+)-(3S,4R) enantiomer was prepared in pure form (ee > 99.7%). Absolute configuration of the (−)-(3R,4S)-enantiomer was determined by single crystal X-ray diffraction method.

scholarly journals New Cembranoid Diterpene from the South China Sea Soft Coral Sarcophyton sp

2013 ◽  
Vol 8 (12) ◽  
pp. 1934578X1300801 ◽  
Author(s):  
Fei Cao ◽  
Jing Zhou ◽  
Kai-Xia Xu ◽  
Meng-Qi Zhang ◽  
Chang-Yun Wang
Keyword(s):  
South China Sea ◽  
South China ◽  
Absolute Configuration ◽  
Soft Coral ◽  
The South China Sea ◽  
The South ◽  
China Sea ◽  
The Absolute ◽  
Reported Data ◽  
Modified Mosher’S Method

One new oxygenated cembranoid diterpene, named sarcophytol W (1), along with six known analogues (2–7) were isolated from a soft coral Sarcophyton sp. collected from the South China Sea. Their structures were elucidated by spectroscopic analyses and by comparison with previously reported data. The absolute configuration of 1 was assigned on the basis of the absolute configuration of the related congener 2, which was determined by application of the modified Mosher's method. All the compounds were evaluated for their antibacterial and antifouling activities.

Kinetic Resolution in a Bridgehead Lithiation Mediated by a Chiral Bis-lithium Amide:  Assignment of the Absolute Configuration of Clusianone

2007 ◽  
Vol 72 (11) ◽  
pp. 4265-4267 ◽  
Author(s):  
Vincent Rodeschini ◽  
Nigel S. Simpkins ◽  
Claire Wilson
Keyword(s):  
Absolute Configuration ◽  
Kinetic Resolution ◽  
Lithium Amide ◽  
The Absolute

scholarly journals 11β,20β-Epoxybriaranes from the Gorgonian Coral Junceella fragilis (Ellisellidae)

Marine Drugs ◽  
2020 ◽  
Vol 18 (4) ◽  
pp. 183
Author(s):  
Tung-Pin Su ◽  
Tsu-Jen Kuo ◽  
San-Nan Yang ◽  
Gene-Hsiang Lee ◽  
Yen-Tung Lee ◽  
...  
Keyword(s):  
Absolute Configuration ◽  
Model Compound ◽  
Raw 264.7 Cells ◽  
X Ray Diffraction ◽  
Gorgonian Coral ◽  
X Ray ◽  
The Absolute ◽  
Oxide Synthase ◽  
First Time ◽  
Inducible Nitric Oxide

Two 11,20-epoxybriaranes, including a known compound, juncenolide K (1), as well as a new metabolite, fragilide X (2), have been isolated from gorgonian Junceella fragilis collected off the waters of Taiwan. The absolute configuration of juncenolide K (1) was determined by single-crystal X-ray diffraction analysis for the first time in this study and the structure, including the absolute configuration of briarane 2 was established on the basis of spectroscopic analysis and compared with that of model compound 1. One aspect of the stereochemistry of the known compound 1 was revised. Briarane 2 was found to enhance the generation of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) release from RAW 264.7 cells.

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