Dysidea Fragilis Research Articles

Two New Unprecedented Acetonyl‐Bearing Sesquiterpenes from the Hainan Sponge Dysidea fragilis

Two new acetonyl-bearing sesquiterpenes, dysifragilisins A and B (1 and 2, resp.), have been isolated from the Hainan marine sponge Dysidea fragilis. The structures of the new compounds were elucidated on the basis of detailed spectroscopic analyses and by comparison of their NMR data with those of structurally related compounds. A plausible biogenetic pathway is proposed for the origin of compounds 1 and 2.

Long-Chain 2H-Azirines with Heterogeneous Terminal Halogenation from the Marine Sponge Dysidea fragilis

Three new omega-halogenated long-chain 2H-azirines were isolated from the sponge Dysidea fragilis. Their structures revealed heterogeneity in both the composition of the terminal 1,1-dihalo-vinyl group and enantiomeric ratios at C2 of the azirine-2-carboxylate ester terminus. Azirine-2-carboxylate esters were shown to racemize spontaneously. A hypothesis is proposed for the biosynthesis of the azirinecarboxylate family of natural products that involves enzyme-catalyzed free radical halogenation followed by elimination of hydrohalic acid.

Highly Efficient Stereocontrolled Total Synthesis of (+)‐Upial

Dual benefit:(+)-Upial, isolated from the sponge Dysidea fragilis (Kaneohe Bay, Hawaii), as a nonisoprenoid sesquiterpene aldehyde lactone, was efficiently synthesized. The key step involved an intramolecular carbonyl–ene reaction, in which the stereocontrolled construction of a bicyclo[3.3.1]nonane ring with five asymmetric carbon centers and the facile introduction of the exo-methylene unit were achieved in a single step (see scheme).

A new spiro-sesquiterpene from the sponge Dysidea fragilis

A new spiro-sesquiterpene, spirofragilin (1), along with a known related sesquiterpene, dehydroherbadysidolide (2), have been isolated from the marine sponge Dysidea fragilis collected in the South China Sea. The structure of 1 was elucidated on the basis of detailed spectroscopic analysis.

Exploiting 2-Halo-2H-Azirine Chemistry

H-Azirines are the smallest unsaturated heterocyclic compounds containing nitrogen. Despite their strain many stable azirines are known. Due to the high reactivity 2H-azirines have been explored extensively for various synthetic purposes. The ring system occurs naturally in the antibiotics azirinomycin, isolated from Streptomyces auras cultures. Moreover, both enantiomers of (R)-(+)- and (S)-(-)-dysidazirine and (S)-(+)- antazirine were isolated from the marine sponge Dysidea fragilis. The chemistry of 2H-azirines is dominated by ring strain and processes in which the strain is relieved are very favoured. 2H -Azirines undergo reactions in which they can function either as a nucleophile or as an electrophile. They can participate in cycloadditions as 2π -components and undergo ring cleavage on photochemical excitation to give nitrile ylides which can act as 4π -component in dipolar cycloadditions. Thermal ring cleavage originates vinyl nitrenes which allows for ring expansion reactions. X-Ray crystallographic structure determinations reported to highly substituted 2H-azirines indicate an unusually long C2-N bond explaining the preferential C2-N cleavage in thermal reactions of 2H-azirines. The photolysis of azirines bearing a conjugative substituent (e.g. phenyl, vinyl) at C-2 leads to nitrile ylides with conjugative groups which can participate in 1,5-dipolar electrocyclic ring closure. The study of the reactivity of 2-halo-2H-azirines is of particular interest since this system bears an extra functional group.

A furodysinin lactone derivative from the marine spongeDysidea fragilis

The title compound, 4a,5,6,8a,9,9a-hexahydro-9a-hydroxy-4,4,7-trimethylnaphtho[2,3-b]furan-2(4H)-one, C15H20O3, is a sesquiterpenoid isolated from the marine sponge Dysidea fragilis. The furodysinin lactone skeleton consists of two six-membered rings, which adopt chair and half-chair conformations, and a furan ring. The mol­ecules are arranged in a helical pattern through O—H⋯O hydrogen bonds.

A beta-amino acid containing tripeptide from a Pseudomonas-alteromonas bacterium associated with a black sea sponge.

A novel tripeptide, 1, was isolated from the extracellular extract of a Pseudomonas-Alteromonas bacterium that was associated with the Black Sea sponge Dysidea fragilis. Compound 1 contains the novel beta-aminopimelic acid described for the first time from a natural product. The structure of 1 is suggested on the basis of the analysis of spectroscopic data and chemical degradation.

A wide diversity of sulfated polysaccharides are synthesized by different species of marine sponges

Sulfated polysaccharides were extracted from four species of marine sponges by exhaustive papain digestion. These compounds were purified by anion-exchange and gel-filtration chromatography. Analysis of the purified polysaccharides revealed a species-specific variation in their chemical composition and also in their molecular masses. In the species Aplysina fulva we found a sulfated glucan with a glycogen-like structure. The other three species contained sulfated polysaccharides with variable proportions of galactose, fucose, arabinose and hexuronic acid and also with different degrees of sulfation. Although the complex nature of these polysaccharides did not allow complete structure determination, we detected the occurrence of 4-sulfated residues of fucose and arabinose in the species Dysidea fragilis. The biological role of these sulfated polysaccharides requires further investigation. They may be involved in the species-specific aggregation of sponge cells and/or in the structural integrity of sponge, resembling the proteoglycans of mammalian connective tissues.

Metabolites from a marine bacterium Pseudomonas/Alteromonas, associated with the sponge Dysidea fragilis

The lipophylic extract from a Black Sea bacterium, associated with the sponge Dysidea fragilis, was investigated. Saturated hydrocarbons and fatty acids of the lipids were identified. The concentrations of the polycyclic compounds appeared to be negligible. The main components appeared to be phosphatidyl ethanolamine, followed by phosphatidyl serine. The first was investigated by FAB mass spectrometry and a series of molecular species partially identified.

Anatomical and ultrastructural studies of chemical defence in the sponge Dysidea fragilis

The marine sponge Dysidea fragilis from El Mar Menor, a hypersaline coastal lagoon (Murcia, Spain), contains the furanosesquiterpenoid ent-furodysinin as the major secondary metabolite. D. fragilis emits a defensive white fluid when it is disturbed. Electron micrographs of this fluid revealed intact vesiculated cells together with other amorphous material. Dissociated cells are more rounded in shape but maintain the same ultrastructural features as cells observed in ultra-thin sections of the whole sponge. The defensive secretion is composed mainly of sponge cells with abundant light vesicles. Sometimes these light vesicles appear to open into the intercellular space; this correlates with surface blebs on these cells observed under scanning electron microscopy. The intracellular location of ent-furodysinin was confirmed by Erlich staining. In laboratory assays, we examined the role of ent-furodysinin as a feeding deterrent to generalist fish predators. It was isolated from D. fragilis and incorporated into a carrageenan-based artificial diet. The addition of ent-furodysinin to the artificial diet reduced feeding by the fish Thalassoma pavo. Similarly, fish did not feed on artificial diet above which defensive secretion of D. fragilis had been ejected with a small syringe.

A New Diketopiperazine Derivative from the South China Sea SpongeDysideafragilis

A new diketopiperazine, dysamide D (1), has been isolated from the marine sponge Dysidea fragilis, collected in the South China Sea. The structure of dysamide D was determined by spectral data.

ChemInform Abstract: New Azacyclopropene Derivatives from Dysidea fragilis Collected in Pohnpei.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

The chemistry of the demosponge Dysidea fragilis from the lagoon of Venice

In a study of the filtering organisms of the lagoon of Venice a series of specimens of the cosmopolitan keratose sponge Dysidea fragilis has been examined. This study led to the isolation of two new sesquiterpenes, 4 and 5, in addition to three known sesquiterpenoids ( 1–3) isolated previously from different sources. The remarkable differences existing between the secondary metabolites of Venice sponges and those reported in the literature, for specimens from other geographic localities, still remain unexplained. They may be related either to real specific differences or less probably to a geographic influence on the metabolites production.

Use of marine sponges as stress indicators in marine ecosystems at Algeciras Bay (southern Iberian Peninsula)

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 135:109-122 (1996) - doi:10.3354/meps135109 Use of marine sponges as stress indicators in marine ecosystems at Algeciras Bay (southern Iberian Peninsula) Carballo JL, Naranjo SA, García-Gómez JC Infralittoral sponge fauna was studied as part of a multidisciplinary investigation of benthic communities in Algeciras Bay. On a monthly basis over 1 year, a series of environmental variables were measured (hydrodynamism, silting, suspended solids, dissolved organic matter, % organic matter in silt). The only abiotic variable that was significantly correlated with beta diversity was hydrodynamism, with a linear regression model between the 2 variables showing a correlation coefficient of 0.66. The distributional pattern of the sponges (based on the relative abundance matrix) was correlated with the environmental variables by matching sample similarities using the Spearman rank correlation, thus showing that the variable combination that best explains the patterns of distribution is hydrodynamism/organic matter in silt (rhos = 0.6). Of the species considered, Phorbas fictitius, Cliona celata, Cliona viridis, Crella elegans, Oscarella lobularis, Dysidea fragilis were among those showing the greatest adaptive plasticity in their relationship to environmental variables, depth, and selection by substrate, and are categorized as eurytopic species present in areas subject to great environmental stress. Other species such as Phorbas tenacior, Reniera fulva, Reniera mucosa, Cliona rhodensis proved to be much more sensitive to these variables, and were categorized as stenotopic species, indicators of normal conditions. Due to the particular environmental conditions where it is located, Mycale micracanthoxea was categorized as a good indicator species in port environments. Others such as Dysidea avara, Halichondriabowerbanki or Crella elegans presented morphological differentiations which have permitted them to adapt to sedimentary environments. Sponge communities . Abiotic environment . Bioindicator species . Stress . Port environments Full text in pdf format PreviousNextExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 135. Publication date: May 17, 1996 Print ISSN:0171-8630; Online ISSN:1616-1599 Copyright © 1996 Inter-Research.

New cytotoxic steroids from the marine sponge Dysidea fragilis coming from the lagoon of Venice

The sterol composition of the sponge Dysidea fragilis, coming from the lagoon of Venice, has been investigated; our results confirmed the variability of D. fragilis biochemistry. The sponge elaborates, in addition to eight usual 3β-hydroxy sterols, thirteen polyhydroxysterols, eight of them ( 6–13) were novel compounds. Their structures were established by spectroscopic data. New compounds 3β,5α,6β,7α-tetrahydroxy-cholest-8(9)-en-11-one ( 8), 3β,5α,6α-trihydroxy-9,11-secocholest-7-en-9-one ( 9) and 3β,5α,6α,9α-tetrahydroxy-cholest-7-ene-6-sulfate ( 11) were proved to be cytotoxic on two different tumor cell lines in vitro.

New azacyclopropene derivatives from Dysidea fragilis collected in Pohnpei.

The sponge Dysidea fragilis from Pohnpei contained four azacyclopropene derivatives, (4E)-S-dysidazirine [2], which is the optical enantiomer of the known compound dysidazirine [1], (4Z)-dysidazirine [3], (4E)-S-antazirine [4], and (4Z)-antazirine [5]. The structures of the new compounds were elucidated by interpretation of spectral data.

Two furano‐sesquiterpenes from the South China Sea Sponge Dysidea fragilis

AbstractA new sesquiterpene, ent‐furodysin (1), has been isolated from the South China Sea Sponge Dysidea fragilis, along with a known sesqui‐terpene, ent‐furodysinin (2). The structure and relative stereochemistry of 1 and 2 were established by spectral analysis.

Sterol composition and biosynthesis in the Black Sea sponge Dysidea fragilis

The sterol composition of Dysidea fragilis from the Black Sea is reported. Three groups of sterols, Δ 5, Δ 0 and Δ 5,7, were found. The isolated 5α,8α- epidioxy sterols appeared to be predominantly, if not exclusively, artifacts. The auto-oxidation of native Δ 5,7- sterols to 5α,8α- epidioxy sterols has been investigated. A transformation of dietary Δ 5- sterols to Δ 5,7- sterols has been demonstrated in Dysidea fragilis.

Structure of a new sterol from the South China sponge Dysidea fragilis

AbstractA new sterol, 5α‐cholesta‐8(14),24(25)‐diene‐3β, 6α‐diol (1) and a known sterol (24Z)‐24‐ethyl‐cholesta‐7(8),24(28)‐diene‐3β,5α,6β‐triol (2) have been isolated from the South China Sea sponge Dysidea fragilis. The structure and relative stereochemistry of 1 were established by spectral analysis, including 2D NMR experiments.

Three New Diketopiperazines from a Marine Sponge Dysidea fragilis

Three new polychlorinated diketopipeeazines, dysamides A [1], B [2], and C [3], and the known compound 4 have been isolated from a marine sponge Dysidea fragilis collected off Hainan Island. Their structures were established by spectroscopic methods, and complete nmr assignments were made. The absolute configuration and conformation of 1 were determined by X-ray crystallographic diffraction analysis