Sesquiterpenoids from the Formosan soft coral Lemnalia flava

Four new nardosinane-type sesquiterpenoids, flavalins E-H (1-4) and two new nornardosinane-type norsesquiterpenoids, flavalins I (5) and J (6), along with five known compounds (7-11) have been isolated from a Formosan soft coral Lemnalia flava. The structures of these compounds were elucidated on the basis of their spectroscopic data. Moreover, the absolute configuration of 10 was further determined by Mosher's method.     

Physiological activity of diterpenoids from the soft coral Sarcophyton trocheliophorum

Pacific Ocean Institute of Bioorganic Chemistry, Far Eastern Branch, Academy of Sciences of the USSR, Vladivostok. Translated from Khimiya Prirodnykh Soedinenii, No. pp. 137–139, January–February, 1988.     

New prostanoids from soft coral

Four new anti-tumor active prostanoids, named claviridenone-a (3), claviridenone-b (4). claviridenone-c (5), and claviridenone-d (6), as well as 20-acetoxy-claviridenone-b (7) and 20-acetoxy-claviridenone-c (8), have been isolated from the Okinawan soft coral (stolonifer) Clavularia viridis Quoy and Gaimard (Stolonifera, Clavulariidae). The absolute stereostructures of these six prostanoids have been elucidated on the basis of chemical and physicochemical evidence which includes the application of the CD exciton chirality method to their various benzoyl derivatives having benzoate and conjugated diene chromophores. Claviridenones possess a characteristic cross-conjugated dienone-enone chromophore.     

Stolonilactone, a novel terpenoid-related compound, isolated from the Okinawan soft coral Clavularia koellikeri

A novel terpenoid-related compound, stolonilactone (1), was isolated from the Okinawan soft coral Clavularia koellikeri. The structure of 1 was elucidated on the basis of spectroscopic analysis. A possible biogenesis of 1 through the [4 + 2]-cycloaddition of a trisnorsesquiterpenoid-type diene and a cembranolide-type dienophile is proposed.     

Glycolipids from the formosan soft coral Lobophytum crassum

Three glycolipids (1--3), possessing a sugar moiety at C-2 of glycerol ether, have been isolated from the Formosan soft coral Lobophytum crassum. Their structures were elucidated by spectroscopic methods, particularly in 1D- and 2D-NMR experiments. The absolute configurations on the sugar portion and lipid aglycon of 1--3 were determined by methanolysis, chemical transformation and the application of Mosher's method on 1 and 3. Compounds 1--3 exhibited weak cytotoxic activities.     

Synthesis of cytotoxic spermidine metabolites from the soft coral

Two unusual cytotoxic agents, the first spermidine derivatives from marine organisms, have been synthesized directly from the parent polyamine using new methodology.     

Tricycloclavulone and clavubicyclone, novel prostanoid-related marine oxylipins, isolated from the Okinawan soft coral Clavularia viridis

Two novel prostanoid-related marine oxylipins, tricycloclavulone (1) and clavubicyclone (2), were isolated from the Okinawan soft coral Clavularia viridis. The structures of 1, having a tricyclo[5.3.0.0(1,4)]decane ring system, and 2, having a bicyclo[3.2.1]octane ring system, were elucidated on the basis of spectroscopic analysis. Clavubicyclone showed a moderate growth inhibition activity against tumor cells in vitro.     

New cytotoxic cembranolides from the soft coral Lobophytum michaelae

Eleven new cytotoxic cembranolides, michaolides A-K (1-11), and crassolide (12) were isolated from the CH(2)Cl(2) extract of the Formosan soft coral Lobophytum michaelae. Their structures were established by extensive spectral analysis. The cytotoxicity of the isolates against selected cancer cells was measured in vitro.     

New hemiketal steroid from the soft coral Cladiella sp

[structure: see text] A new hemiketal steroid, named cladiellin A (1), was first isolated from the soft coral Cladiella sp. Its structure was determined by spectroscopic methods and X-ray analysis. Compound 1 easily converted to 1a when NMR spectra were measured in CDCl(3) solution and quickly changed to 1b when pyridine was used. The structures of dehydrated products 1a and 1b were determined by spectroscopic analysis. Bioassay showed that all these three compounds showed antioxidant activity.     

Nardosinane sesquiterpenoids from the formosan soft coral Nephthea elongata

Seven new nardosinane sesquiterpenoids, elongatols A-G (1-7) were isolated from the methylene chloride solubles of the Formosan soft coral Nephthea elongata. Their structures were elucidated by extensive spectroscopic analysis and their cytotoxicity against selected cancer cells was measured in vitro.     

Xeniaphyllane-derived terpenoids from the formosan soft coral Sinularia gibberosa

New xeniaphyllane-derived metabolites (1-7) were isolated from the EtOAc extract of the Formosan soft coral Sinularia gibberosa. The structures and relative configurations of these compounds were elucidated on the basis of extensive spectroscopic analysis (including 2D NMR) and by comparison of their spectral data with those of related compounds. In vitro cytotoxic evaluation of the above metabolites towards a limited panel of cancer cell lines is also described.     

Prenylbicyclogermacrane diterpenoids from the formosan soft coral Nephthea elongata

Seven new prenylbicyclogermacrane diterpenoids, pacificins K--Q (1--7), were isolated from the methylene chloride solubles of the Formosan soft coral Nephthea elongata. Their structures were elucidated by extensive spectroscopic analysis and their cytotoxicity against selected cancer cells was measured in vitro.     

Two new glycosides from the soft coral Sinularia firma

Two new glycosides, named Firmacosides A and B, together with known fatty esters, batyl alcohol, Delta(5,20) sterol and sphingosine derivatives have been isolated from the soft coral Sinularia firma TIX-DUR. On the basis of spectroscopic analysis ((1)H-NMR, (13)C-NMR, (1)H-(1)H COSY, HMQC, HMBC and FAB-MS), Firmacoside A was established as hexadecanyl-1-O-alpha-D-arabinopyranosyloxy (1-->4)-alpha-D-arabinopyranosyloxy (1-->4)-alpha-D-arabinopyranoside (1), and firmacoside B was elucidated as docosanyl-1-O-alpha-D-arabinopyranosyloxy (1-->4)-3-O-acetyl-alpha-arabinopyranosyloxy (1-->4)-alpha-D-arabinopyranoside (2).     

Stolonidiol,a new marine diterpenoid with a strong cytotoxic activity from the Japanese soft coral

Structures of stolonidiol (1) and stolonidiol monoacetate (2), new marine diterpenoids with a strong cytotoxic activity from the Japanese soft coralClavularia sp., were established by means of spectroscopic analyses, chemical reactions, and X-ray crystallographic analysis.     

Novel steroids from the soft coral Nephthea chabrolii

Three new metabolites including two new steroids, chabrolosteroids A and B (1 and 2), and a novel spirosteroid chabrolosteroid C (3), were isolated from the organic extract of a Taiwanese soft coral Nephthea chabrolii. The structures of these metabolites were elucidated by extensive spectroscopic analysis and by comparison of the spectral data with those of related steroids. This is the first report of a steroid with a spiro-ring A, B system in natural products.     

Two new lipid analogues from the soft coral Sinularia flexibilis

Soft corals of the genus Sinularia are widely distributed in the South China Sea. Two new lipid analogues (Z)-N-(3,4-dihydroxyphenethyl)-3-methyldo-dec-2-enamide (1) and (E)-1-(2,5-dihydroxy-4-methylphenyl)-6-acetoxy-2,3,7-trihydroxy-3,7,11,15-tetramethylhexadeca-11,14-dien (2), together with three known compounds (3–5) were isolated from the soft coral Sinularia flexibilis. Their structures were elucidated on the basis of extensive spectroscopic analysis, including one and two-dimensional NMR, MS, IR, UV, as well as by comparison with published data.     

Two new diterpenoids from the marine Soft coral Clavularia viridis

Two new dolabellane diterpenoids named clavudiol B(2)and clavirolide F(5),have been iso-lated from the soft coral Clavularia viridis,collected from Xisha Islands in the South China Sea.Theirstructures have been determined as 2 and 5 by spectral analysis and chemical reactions.     

Terpenoids-LXXIV: The sesquiterpenes from the soft coral sinularia mayi

Eleven sesquiterpene hydrocarbons, one [sinularene 11] with a new non-famesolic skeleton, and two new sesquiterpene diols from S. mayi were identified or structurally elucidated. Four 4,7-aromadendranediols were synthesized for reference purposes from spathulenol 23 and the stereochemistry assigned by ¹³C spectroscopy.     

Cytotoxic cembranoids from the Red Sea soft coral Sarcophyton glaucum

One new cembrane diterpene, 2R,7R,8R-dihydroxydeepoxysarcophine (1), together with three known compounds, 7alpha,8beta-dihydroxydeepoxysarcophine (2), 7beta-acetoxy-8alpha-hydroxydeepoxysarcophine (3), and sarcophine (4), have been isolated from the Red Sea soft coral Sarcophyton glaucum. Their structures were determined using 1D and 2D NMR spectroscopy. 7beta-Acetoxy-8alpha-hydroxydeepoxysarcophine (3) exhibits cytotoxic activity against HepG2, HCT-116, and HeLa cells with IC50 values of 3.6, 2.3, and 6.7 microg/mL, respectively.