Jean-Michel Kornprobst

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.

Composition and antiviral activities of a sulfated polysaccharide from schizymenia dubyi (rhodophyta, gigartinales)

Abstract Schizymenia dubyi (Gigartinales, gymnophlaeaceae) contains an unusual sulfated heteropolysaccharide with uronic acids that is active against several viruses including human immunodeficiency virus type-1 (HIV-1), Herpes simplex hominis type 1 and type 2 (HSV-1 and HSV-2) and vesicular stomatitis virus (VSV).

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.

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.

Trikentramine, an unusual pyrrole derivative from the sponge trikentrion loeve carter

Abstract Trikentramine, an unusual pyrrole, has been isolated from the Senegalese sponge Trikentrion loeve and characterized by spectroscopic and X-ray diffraction techniques.

Labiatamides A, B, and other eunicellan diterpenoids from the Senegalese gorgonian Eunicella labiata

Abstract Five new diterpenoids of the eunicellan class, labiatamides A-B ( 1,2 ) and labiatins A-C ( 3–5 ) have been isolated from the organic extract of the Senegalese gorgonian Eunicella labiata . A unique feature of labiatamides A and B ( 1,2 ) is the N -methyl acetamide group, an uncommon functionality in soft coral metabolites. Labiatin A ( 3 ), possesses an unprecedented ether linkage between C-2 and C-6. The structure elucidations of the new secondary metabolites were provided by comprehensive spectroscopic analyses. Labiatin B exhibited cytotoxic activity against human colon cancer cells (HCT-116) with ED 50 = 0.85 μ g/ml.

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.

Sponge Fatty Acids-4. Co-occurrence of Two Isoprenoid Fatty Acids (4,8,12-Trimethyltridecanoic and 5,9,13-Trimethyltetradecanoic) in Phospholipids of Marine Sponges from the Genus Cinachrella

Abstract Two isoprenoid fatty acids, 4,8,12-trimethyltridecanoic and 5,9,13-trimethyltetradecanoic, were identified in all specimens studied of the Senegalese sponges Cinachyrella alloclada and C. kukenthali and the New-Caledonian sponge Cinachyrella aff. schulzei. The fatty acids were identified as methyl esters or N-acyl pyrrolidides by gas chromatography/mass spectrometry analyses. 4,8,12-Trimethyltridecanoic acid was found to be the major component in all Senegalese sponge fatty acid mixtures(up to 36%). The co-occurrence of these isoprenoid acids may have implications for chemotaxonomy and biosynthetic pathways.

Effects in vitro of sulfated polysaccharide from Schizymenia dubyi (Rhodophyta, Gigartinales) on a non-small-cell bronchopulmonary carcinoma line (NSCLC-N6).

An unusual sulfated heteropolysaccharide containing uronic acids, previously isolated from the red alga Schizymenia dubyi, was studied in vitro for its effect on asynchronous cells of a human non-small-cell-bronchopulmonary carcinoma line (NSCLC-N6). Cell growth appeared to be inhibited in the G1 phase of the cell cycle, and kinetic studies in pretreated cells showed that this growth arrest was irreversible. These events are related to a terminal maturation induction.

New trends in phospholipid class composition of marine sponges.

The exceptional ability of marine sponges to adapt to often drastic changes of their environments could be due to special structural features in cell membranes, including firstly phospholipids (PL). Thus, PL class composition was investigated in marine sponges (22 species from 19 genera to 15 families) originating from various locations (East Atlantic, North Atlantic, South-West Pacific, Mediterranean Sea, Red Sea, Arabian-Persian Gulf). The quantitative determination of PL class composition was obtained by high-performance thin-layer chromatography (HPTLC) with scanning densitometry of the different spots. Previous reports have shown phosphatidylethanolamine (PE) as the major PL class in marine sponges, followed by phosphatidylcholine (PC), while other papers described PC as a minor class and even lacking. This survey found PE as the major PL class in only two species, while PC was the major class in 13 species including a calcareous one. The great abundance of bacteria in some sponges was evidenced from the relatively high proportions of particular PL classes. Various PL distributions were observed even for the sponge species collected in the same area and belonging to the same genus. Thus, no clear rule on PL composition in marine sponges can be stated to date.