Gilles Barnathan

Non-methylene-interrupted fatty acids from marine invertebrates: Occurrence, characterization and biological properties.

Marine organisms, in particular invertebrates, have proved to be a major source of unique fatty acid (FA) structures originating from unusual biosynthetic pathways. Among them, non-methylene-interrupted (NMI) FA occur in various molluscs in the wide ranges of concentrations (up to 20%), such as the most often encountered 20:2 Delta5,11, 20:2 Delta5,13, 22:2 Delta7,13 or 22:2 Delta7,15. Such NMI FA have also been reported from algae, echinoderms, sponges, tropical rays, and many other invertebrates. The most intriguing marine invertebrates seem to be sponges that commonly contain very long-chain Delta5,9 FA. A third double bond can occur in the NMI FA as reported in some marine organisms, such as 20:3 Delta7,13,16 or 30:3 Delta5,9,23. Lipids of invertebrates from deep-sea hydrothermal and cold-seep vents gave rise to an intense research activity including reports on unprecedented NMI polyunsaturated FA. The bivalve molluscs are able to synthesize de novo the NMI FA but their precise biological interest is presently not well-known, although structural and functional roles in biological membranes have been suggested, in particular a higher resistance to oxidative processes and microbial lipases. Biosynthetic pathways of Delta5,9 FA in sponges were demonstrated up to C(26) FA structures and include particular elongation and desaturation steps. Recently, intense research effort has been conducted to investigate the biomedical potential of these unusual FA. Thus, Delta5,9 FA displayed interesting antiplasmodial activity. The most promising FA topoisomerase I inhibitors to date seem to be the long-chain Delta5,9 FA. This inhibitory activity is probably partially responsible for the toxicity displayed by some of the Delta5,9 FA towards cancer cell lines.

New unsaturated long-chain fatty acids in the phospholipids from the axinellida spongesTrikentrion loeve andPseudaxinella cf.Lunaecharta

In order to identify new structures and especially those involved as biosynthetic intermediates, the fatty acid composition of whole phospholipids from two Senegalese marine sponges from the order Axinellida,Trikentrion loeve andPseudaxinella cf.lunaecharta, has been investigated by analytical gas chromatography and gas chromatography/mass spectrometry. Several new fatty acids were identified as methyl esters andN-acyl pyrrolidies, namely 16-eicosenoic, 11-tetracosenoic, 5-pentacosenoic, 11-hexacosenoic, 11-oxtacosenoic, 23-triacontenoic, 17,21-hexacosadienoic, 19,23-octacosadienoic, 9,23-triacontadienoic, 5,9,21-hexacosatrienoic, and 5,9,25-triacontatrienoic.Trikentrion loeve andP. cf.lunaecharta contain fifteen 25.7% of the total acid mixture) and thirteen (30.4%) °5,9 fatty acids, respectively. Based on gas chromatography/Fourier transform infrared experiments, the double bonds were assigned the (Z) configuration. Biosynthesis of dienoic and trienoic demospongic acids possessing an n-5 or an n-7 terminal double bond is discussed.

Lipids and fatty acids in muscle, liver and skin of three edible fish from the Senegalese coast: Sardinella maderensis, Sardinella aurita and Cephalopholis taeniops

Lipid content and fatty acid composition were determined in three species of edible fish caught in Senegalese waters during the upwelling season (January, 1993). Sardinella maderensis and Sardinella aurita are fat fish containing more than 5% (fresh wt.) of lipids, whereas Cephalopholis taeniops is a lean fish with approximately 1% of lipids. Skin, liver and muscle were studied for each fish species. About 40 fatty acids were identified by GC and GC/MS as methyl esters and N-acyl pyrrolidides. Palmitic acid was the main acid in the muscle and skin of all samples studied (20-33% of total fatty acids). Oleic acid was the main fatty acid in the liver of S. maderensis (27.2%+/-0.1) and S. aurita (44.7%+/-0.1). Arachidonic acid was a minor component in all samples. The flesh (muscle) of the three fish species contained high concentrations of omega3 polyunsaturated fatty acids (PUFA), ranging from 16.0 to 29.1% and including 20:5 omega3 (eicosapentaenoic acid, EPA) and 22:6 omega3 (docosahexaenoic acid, DHA) acids as major components. These two acids together accounted for 24.7%+/-0.1 and 12.9%+/-0.1 of total acids in the skin of S. maderensis and S. aurita, respectively. The percentages of PUFA found in the fish studied were very similar to those in fish used commercially as sources of PUFA. Muscle sterols, which accounted for 9-11% of total lipids, consisted mainly of cholesterol (up to 97% of total sterols).

New Trichobrachins, 11-residue peptaibols from a marine strain of Trichoderma longibrachiatum

A marine strain of Trichoderma longibrachiatum isolated from blue mussels (Mytilus edulis) was investigated for short peptaibol production. Various 11-residue peptaibols, obtained as microheterogenous mixtures after a chromatographic fractionation, were identified by positive mass spectrometry fragmentation (ESI-IT-MS(n), CID-MS(n) and GC/EI-MS). Thirty sequences were identified, which is the largest number of analogous sequences so far observed at once. Twenty-one sequences were new, and nine others corresponded to peptaibols already described. These peptaibols belonged to the same peptidic family based on the model Ac-Aib-xxx-xxx-xxx-Aib-Pro-xxx-xxx-Aib-Pro-xxol. They were named trichobrachin A when the residue in position 2 was an Asn, and trichobrachin C when it was a Gln. Major chromatographic sub-fractions, corresponding to purified peptaibols, were assayed for their cytotoxic activity. Trichobrachin A-IX and trichobrachin C exhibited the highest activities. There was an exponential relation between their relative hydrophobicity and their cytotoxicity on KB cells.

Phospholipid fatty acids and sterols of two Cinachyrella sponges from the Saudi Arabian Red Sea: comparison with Cinachyrella species from other origins

Phospholipid class compositions, fatty acids and sterols of the sponges Cinachyrella alloclada and C. kükenthali from the Saudi Arabian Red Sea were studied and compared with previous results for other Cinachyrella spp. collected in Senegal (East Atlantic) and New Caledonia (West Pacific). More than 50 fatty acids were identified as methyl esters and N-acyl pyrrolidides in each phospholipid mixture by GC/MS. Six fatty acids not hitherto found in nature were identified, namely 17-methyltetracosanoic in C. kükenthali and 18-methyltetracosanoic, 18-methylpentacosanoic, 18-methylhexacosanoic, 18,24-dimethyl-hexacosanoic and 6-bromo-5,9-nonacosadienoic acids in C. alloclada. Approximately 20 Delta 5,9 unsaturated fatty acids were found, including three 6-brominated acids. The presence of bacteria was evidenced by the relatively high proportions of phosphatidylglycerol and high levels of branched short-chain fatty acids. A total of 20 free 3beta-hydroxysterols were found by GC/MS, including clerosterol in relatively high amounts and gorgosterol in low amounts. The latter sterol has not been reported to date in a sponge. Comparisons with Cinachyrella species from other geographical areas show marked differences for both phospholipid fatty acid and sterol compositions.

New phospholipid fatty acids from the marine spongeCinachyrella alloclada uliczka

The fatty acid composition of phospholipids from the Senegalese spongeCinachyrella alloclada was examined. Two new fatty acids not hitherto found in nature, namely 10,13-octadecadienoic acid and 16-tricosenoic acid, were identified. 8-Hexadecenoic, 13-nonadecenoic and 5,9,13-trimethyltretradecanoic fatty acids were also found for the first time in sponges. The latter compound (1.4% of the total fatty acid mixture), an isoprenoid fatty acid, accompanies the major fatty acid 4,8,12-trimethyltridecanoic acid (19.7%). The monomethyl branched fatty acids (22%) identified include 23-methylpentacosanoic acid (anteiso-26∶0), not previously observed in sponged. The major long-chain fatty acids encountered were the known 17-tetracosenoic 19-heptacosadienoic and 5,9,23-tricontatrienoic acid. Some sixty fatty acids were identified as methyl esters andN-acyl pyrrolidides by gas chromatography and gas chromatography/mass spectrometry.

Sponge fatty acids. 3. Occurrence of series of n−7 monoenoic andiso-5,9 dienoic long-chain fatty acids in the phospholipids of the marine spongeCinachyrella aff.schulzei keller

The fatty acid composition of phospholipids from the New Caledonian spongeCinachyrella aff.schulzei Keller was studied. More than 60 fatty acids were identified as methyl esters andN-acyl pyrrolidides by gas chromatography and gas chromatography/mass spectrometry. Two isoprenoid fatty acids also were shown to be present, namely 4,8,12-trimethyltridecanoic and 5,9,13-trimethyltetradecanoic acids. The unusual 6-tetradecenoic, 6-pentadecenoic, 12-nonadecenoic and 26-methylheptacosanoic (iso-28∶0) acids were found for the first time in sponge phospholipids. A series of six n−7 monoenoic long-chain fatty acids (C23 to C28) were identified, including the rare 16-tricosenoic, 18-pentacosenoic and 21-octacosenoic acids. Fifteen fatty acids possessing the typical 5,9 dienoic moiety accounted for 30% of the total fatty acid mixture. Two new fatty acids were identified, namely 5(Z)-octacosenoic and 27-methyl-5(Z),9(Z)-octacosadienoic (iso-5,9-29∶2). Based on gas chromatography/Fourier transform infrared experiments, the double bonds were assigned the (Z) configuration.

Demospongic Acids Revisited

The well-known fatty acids with a Δ5,9 unsaturation system were designated for a long period as demospongic acids, taking into account that they originally occurred in marine Demospongia sponges. However, such acids have also been observed in various marine sources with a large range of chain-lengths (C16–C32) and from some terrestrial plants with short acyl chains (C18–C19). Finally, the Δ5,9 fatty acids appear to be a particular type of non-methylene-interrupted fatty acids (NMA FAs). This article reviews the occurrence of these particular fatty acids in marine and terrestrial organisms and shows the biosynthetic connections between Δ5,9 fatty acids and other NMI FAs.

Recovery of valuable soluble compounds from washing waters generated during small fatty pelagic surimi processing by membrane processes

Abstract This work focuses on the treatment of washing waters coming from surimi manufacturing using ultrafiltration technology at a laboratory scale. Four membrane materials (poly‐ether sulfone, polyacrilonytrile, poly vinylidene fluoride and regenerated cellulose) and 5 Molecular Weight Cut‐Off (from 3 to 100 kDa) have been studied at bench laboratory scale using the pilot Rayflow® 100, commercialised by Rhodia Orelis. The investigation deals with the ability for membranes to offer a high retention of biochemical compounds (proteins and lipids). Results obtained during adsorption tests showed that the regenerated cellulose material seems to be the most appropriate with regards to pore size reduction due to the protein‐adsorption. During the ultrafiltration of the washing water, the regenerated cellulose material leads to the best results, followed by the polyacrylonitrile and poly‐vinylidene fluoride materials. Poor results were obtained with poly‐ether sulfone membrane. Compared to the other materials, the regenerated cellulose is the easiest to regenerate, with minimal cleaning water and no chemical treatment necessary. Biochemical characterization of the fractions generated during the ultrafiltration with the polyacrilonytrile, poly vinylidene fluoride and regenerated cellulose membranes showed that all the membranes provided a high recovery rate of the lipids and proteins. The 10 kDa regenerated cellulose membrane had the highest performance and was further evaluated. With such a treatment, the chemical oxygen demand was reduced by 75%. By performing hydrolysis followed by a centrifugation, biochemical composition of the sludge and liquid fraction were modified, producing an insoluble fraction containing fats and few proteins and a soluble fraction containing proteins and few fats. The sludge, initially insoluble, was mainly solubilized during hydrolysis, and lipids and peptides were concentrated by ultrafiltration.

New branched-chain fatty acids from the senegalese gorgonianLeptogorgia piccola (white and yellow morphs)

Fatty acids from total lipids of the gorgonianLeptogorgia piccola (white and yellow morphs), collected from the same area at two different periods with regard to the average water temperature, were studied. More than fifty fatty acids were identified as methyl esters andN-acyl pyrrolidides by gas chromatography and gas chromatography/mass spectrometry. Three new, branched-chain unsaturated fatty acids were identified in addition to the unusual 7-methyl-6-hexadecenoic acid, namely 10-methyl-6-hexadecenoic, 7,9-dimethyl-6-hexadecenoic, and 10-methyl-6,9-heptadecadienoic acids. Also 6,9-heptadecadienoic acid was identified. The fatty acid patterns of specimens harvested in colder waters were quite different from those harvested in warmer waters in that the former contained high amounts of methylene-interrupted polyunsaturated acids, including tetracosapolyenoic acids, especially 6,9,12,15,18–24∶5 (up to 15.8% of the total acid mixture) and 6,9,12,15,18,21–24∶6 (up to 5.3%). Arachidonic acid was, nevertheless, a major component in all the fatty acid mixtures studied (13.6–20.5%). Based on gas chromatography/Fourier transform infrared experiments, the double bonds were assigned the (Z) configuration. Several fatty aldehydes and their dimethyl acetals were also detected, of which the most abundant was octadecanal.