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D J Faulkner

Publications and source records attributed to D J Faulkner.

At least 37 records · Page 2Linked to original sources
PubMed1997

Two new sesterterpenoids and a new 9,11-secosterol from Spongia matamata.

Two novel sesterterpenoids, 12 alpha-acetoxy-19 beta-hydroxyscalara-15,17- dien-20,19-olide (3) and 12 alpha,-16 beta-diacetoxyscalarolbutenolide (5), and a new 9,11-secosterol, 3 beta-hydroxy-5 alpha,6 alpha-epoxy-9-oxo-9,11-seco-5 alpha-cholest-7-en-11-al (6), were isolated from the marine sponge Spongia matamata from Palau together with the known compounds scalarin (1) and 12 alpha-acetoxy-16 beta-hydroxyscalarolbutenolide (4). The structures were determined by interpretation of spectroscopic data.

Animals↗
PubMed1997

Plakinidine D, a new pyrroloacridine alkaloid from two ascidians of the genus Didemnum.

A previously undescribed red Didemnum sp. collected in Indonesia contained a novel pyrroloacridine, plakinidine D (4), along with the known compounds 3,5-diiodo-4-methoxyphenethylamine (5) and ascididemin (6), both of which had previously been isolated from ascidians of the genus Didemnum. Plakinidine D (4) and 3,5-diiodo-4-methoxyphenethylamine (5) were also isolated from Didemnum rubeum from the Republic of Palau. Interestingly, a collection of D. rubeum from Indonesia did not contain plakinidine D (4), but instead contained 3,5-diiodo-4-methoxyphenethylamine (5) and ascididemin (6). The structure of plakinidine D (4) was elucidated by analysis of its spectral data. Plakinidine D (4) is closely related to plakinidines A-C (1-3), previously isolated from the sponge Plakortis sp.

Alkaloids↗
PubMed1996

Two classes of metabolites from Theonella swinhoei are localized in distinct populations of bacterial symbionts.

The marine sponge Theonella swinhoei (lithistid Family Theonellidae, Order Astrophorida) has yielded many important, bioactive natural products, most of which share structural features with bacterial natural products. The presence of microbial symbionts in T. swinhoei has been reported, and it was originally suggested that the cytotoxic macrolide swinholide A and many of the bioactive cyclic peptides from T. swinhoei were all produced by simbiotic cyanobacteria. By transmission electron microscopy, we found four distinct cell populations to be consistently present in T. swinhoei: eukaryotic sponge cells, unicellular heterotrophic bacteria, unicellular cyanobacteria and filamentous heterotrophic bacteria. Purification and chemical analyses of each cell type showed the macrolide swinholide A to be limited to the mixed population of unicellular heterotrophic bacteria, and an anti-fungal cyclic peptide occurred only in the filamentous heterotrophic bacteria. Contrary to prior speculation, no major metabolites were located in the cyanobacteria or sponge cells.

Animals↗
PubMed1995

The structure of U17 isolated from Streptomyces clavuligerus and its properties as an antioxidant thiol.

The predominant low-molecular-mass thiol produced by streptomycetes is a cysteine derivative previously designated as U17 [Newton, G. L., Fahey, R. C., Cohen, G. & Aharonowitz, Y. (1993) J. Bacteriol. 175, 2734-2742]. In this study we report the elucidation of the structure of the monobromobimane derivative of U17, which establishes the structure of U17 as 2-(N-acetylcysteinyl)amido-2-deoxy-alpha-D-glucopyranosyl-myo-inositol. The presence of the N-acetylcysteine moiety was indicated by formation of N-acetylcysteine-monobromobimane during acid hydrolysis of the monobromobimane derivative of U17. Complete hydrolysis released 1 mol glucosamine/mol cysteine as determined by carbohydrate and amino acid analysis. High-resolution mass spectral analysis gave a precise mass consistent with the molecular formula C27H40N4O14S. Analysis of 13C-NMR, one-dimensional 1H-NMR and two-dimensional NMR experiments identified the remaining C6H12O6 moiety as myo-inositol, confirmed the presence of N-acetylcysteine and glucosamine, and established the connectivity of the components. Two chemical properties of this novel thiol make it suitable as an intracellular storage form of cysteine and as an antioxidant thiol. First, it undergoes heavy-metal-ion catalyzed autoxidation at a rate dramatically lower than that for cysteine and markedly lower than that for glutathione or N-acetylcysteine. Secondly, the alpha-(1-->1) glycosidic link between glucosamine and myo-inositol is resistant to acid hydrolysis, hydrolysing at a rate comparable to that of the two amide bonds in the molecule.

Antioxidants↗
PubMed1995

Metabolites of the Palauan sponge Axinyssa aplysinoides.

The Palauan sponge Axinyssa aplysimoides contained (3S*,5R*,6R*,9R*)-3-isocyano-1(10)-cadinene[2],(3S*,5R*,6R*, 9R*)-3-formamido-1(10)-cadinene[3], and (E)-(4-hydroxystyryl)trimethylammonium chloride [6], together with the known diterpenes (-)-neoverrucosan-5beta-ol[4] and (+)-homoverrucosan-5beta-ol[5].

Animals↗
PubMed1995

Oceanapamine, a sesquiterpene alkaloid from the Philippine sponge Oceanapia sp.

The major metabolite of the Philippine sponge Oceanapia sp. is the antimicrobial alkaloid oceanapamine [1], which was isolated as a trifluoroacetate salt. The structure and the absolute configuration of oceanapamine, which consists of a monocyclic sesquiterpene attached to a histamine residue, were elucidated by interpretation of spectroscopic data.

Alkaloids↗
PubMed1995

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.

Animals↗
PubMed1995

Makaluvamines H-M and damirone C from the pohnpeian sponge Zyzzya fuliginosa.

Seven new pyrroloiminoquinone alkaloids, makaluvamines H-M [19-24] and damirone C[25], together with the known compounds, makaluvamines C[13], D[14], and G[17], were isolated from the sponge Zyzzya fuliginosa collected at Nahpali Island, Pohnpei, Micronesia. The structures of the new compounds were elucidated by interpretation of spectral data. The chemotaxonomic relationships involving the makaluvamines and related pyrroloiminoquinone alkaloids are discussed.

Animals↗
PubMed1994

Six new diterpene isonitriles from the sponge Acanthella cavernosa.

Six new diterpene isonitriles, 10-epi-isokalihinol F [1], 10-epi-isokalihinol H [2], 1-epi-kalihinene [4], 15-isothiocyanato-1-epi-kalihinene [5], 1,10-diepi-kalihinene [6], and kalihipyran [7] were isolated, together with the known compound isokalihinol B [3], from Acanthella cavernosa collected in the Seychelles. The structures of the new diterpenes were elucidated by interpretation of spectral data. The ring system of kalihipyran [7] differs from that of the kalihinols and kalihinenes.

Animals↗
PubMed1994

New cladiellane diterpenes from the soft coral Cladiella australis of the Andaman and Nicobar Islands.

Five new cladiellane diterpenes, (1R*,2R*,3R*,6S*,7S*,9R*,10R*,14R*)-3- acetoxy-6-(3-methylbutanoyloxy)cladiell-11(17)-en-7-ol [2], (1R*,2R*,3R*,6S*,7S*,9R*, 10R*,14R*)-3-butanoyloxycladiell-11(17)-en-6,7-diol [3], (1R*,2R*,3R*,6S*,9R*,10R*,14R*)-3-acetoxycladiell-7(16),11(1 7)-dien-6-ol [4], 3-acetoxycladiell-11(17)-en-6-one [5], and its stereoisomer [6], have been isolated from the soft coral Cladiella australis collected on the coasts of the Andaman and Nicobar Islands of the Indian Ocean. In addition, sclerophytins C [7] and E [8], reported earlier from Sclerophytum capitalis, were also isolated. The structures of these metabolites were elucidated by interpretation of spectral data.

Acetylation↗
PubMed1994

Unstable enol sulfates from a two-sponge association.

An inseparable two-sponge association, consisting of a Haliclona sp. and a choristid sponge, yielded two unstable enol sulfates, (1E)-2- (3',4'-dihydroxyphenyl)ethylene sulfate [3] and (1Z)-2-(3',4'-dihydroxyphenyl)ethylene sulfate [4]. Methanolysis converted the enol sulfates into 2-(3',4'-dihydroxyphenyl)-1,1,2-trimethoxyethane [5] by an oxidative mechanism.

Animals↗
PubMed1993

A siderophore from a marine bacterium with an exceptional ferric ion affinity constant.

Virtually all microorganisms require iron for growth. The paucity of iron in surface ocean water (approximately 0.02-1.0 nM (refs 1, 2)) has spurred a lively debate concerning iron limitation of primary productivity, yet little is known about the molecular mechanisms used by marine microorganisms to sequester iron. Terrestrial bacteria use a siderophore-mediated ferric uptake system. A siderophore is a low-molecular-mass compound with a high affinity for ferric ion which is secreted by microorganisms is response to low-iron environments; siderophore biosynthesis is regulated by iron levels, with repression by high iron. Although open-ocean marine microorganisms (such as phytoplankton and bacteria) produce siderophores, the nature of these siderophores has not been investigated. We report here the first structure determination, to our knowledge, of the siderophores from an open-ocean bacterium, alterobactin A and B from Alteromonas luteoviolacea. A. luteoviolacea is found in oligotrophic and coastal waters. Alterobactin A has an exceptionally high affinity constant for ferric ion. We suggest that at least some marine microorganisms may have developed higher-affinity iron chelators as part of an efficient iron-uptake mechanism which is more effective than that of their terrestrial counterparts.

Amino Acid Sequence↗
PubMed1993

Complete vesiculation of Golgi membranes and inhibition of protein transport by a novel sea sponge metabolite, ilimaquinone.

We have identified a novel natural metabolite, ilimaquinone (IQ), from sea sponges that causes Golgi membranes to break down completely in vivo into small vesicular structures (called vesiculated Golgi membranes [VGMs]). Under these conditions, transport of newly synthesized proteins from endoplasmic reticulum (ER) to the cis-Golgi-derived VGMs is unaffected; however, further transport along the secretory pathway is blocked. Upon removal of the drug, VGMs reassemble rapidly into a Golgi complex, and protein transport is restored. By employing a cell-free system that reconstitutes vesicular transport between successive Golgi cisternae, we provide evidence that the inhibition of protein transport by IQ is specifically due to an inhibition of transport vesicle formation. In addition, like brefeldin A (BFA), IQ treatment prevents the association of beta-COP and ADP-ribosylation factor to the Golgi membranes; however, unlike BFA treatment, there is no retrograde transport of Golgi enzymes into ER.

Animals↗
PubMed1992

Phospholipase A2 inhibitors from marine organisms.

This review of phospholipase A2 (PLA2) inhibitors from marine organisms presents a compilation of research in this field over the past decade. As an introduction to the research on marine natural products, there is an overview of the role of PLA2 in inflammation that provides a rationale for seeking inhibitors of PLA2 as anti-inflammatory agents. A radiometric assay to measure inhibition of bee venom PLA2 is described in detail. Examples of marine natural products that inhibit PLA2 are manoalide and its derivatives, scalaradial and related compounds, the pseudopterosins, the vidalols, and a group of terpenoids that contain masked 1,4-dicarbonyl moieties.

Animals↗