Non-methylene Interrupted Fatty Acids Research Articles

Complete Genome Sequence of Paraclostridium bifermentans DSM 14991

ABSTRACTThe complete genome sequence of Paraclostridium bifermentans was obtained by assembly of Illumina and Oxford Nanopore (ONT) reads. The sequence will enable study into the organism’s ability to biohydrogenate unsaturated acyl chains in the transformation of C20 polyunsaturated fatty acids (PUFAs) into the corresponding bioactive non-methylene-interrupted fatty acids (NMIFAs).

Novel Non-methylene-Interrupted Dienoic and Trienoic Fatty Acids with a Terminal Double Bond in Ovaries of the Limpet Cellana toreuma.

In this study, to obtain further information on the structural diversity of non-methylene-interrupted (NMI) fatty acids (FA) in the gonads of the limpet Cellana toreuma, previously unreported minor NMI FA, fractionated by argentation thin-layer chromatography (TLC), in the ovaries were characterized by gas chromatography-mass spectrometry (GC-MS) analysis of their 3-pyridylcarbinol derivatives. As a result, five novel NMI FA were identified as 5,14-pentadecadienoic acid (15: 2Δ5,14), 5,9,18-nonadecatrienoic acid (19:3Δ5,9,18), 5,9,20-heneicosatrienoic acid (21:3Δ5,9,20), 7,13,20-heneicosatrienoic acid (21:3Δ7,13,20), and 5,9,22-tricosatrienoic acid (23:3Δ5,9,22). Possible biosynthetic pathways for these FA are also discussed in relation to structural variations of NMI FA regioisomers. This study clearly reinforces the findings of our previous works with structurally diverse NMI FA with a terminal double bond.

Specific regulations of gill membrane fatty acids in response to environmental variability reveal fitness differences between two suspension-feeding bivalves (Nodipecten subnodosus and Spondylus crassisquama).

Bivalves' physiological functions (i.e. growth, reproduction) are influenced by environmental variability that can be concomitant with trophic resource variations in terms of quality and quantity. Among the essential molecules that bivalves need to acquire from their diet to maintain physiological functions, fatty acids (FAs) such as polyunsaturated fatty acids (e.g. 20:4n-6 (arachidonic acid), 20:5n-3 (eicosapentaenoic acid) and 22:6n-3 (docosahexaenoic acid)) have been described to play a critical role. The present study examined the FA composition of gill membrane lipids of two bivalve species, Nodipecten subnodosus and Spondylus crassisquama, sampled in a coastal lagoon of the Northeastern Pacific (Ojo de Liebre, Mexico), at two contrasting locations (inner versus outer part of the lagoon) and at two different periods (February and August 2016). Spatiotemporal variations showed that FA composition of gill membrane lipids was highly correlated to FA composition of reserve lipids from digestive gland. This highlights the marked impact of the diet on FA composition of gill membranes. Interestingly, both species presented differences in the seasonal accumulations of plasmalogens and of particular FA that are not found in their diet (e.g. non-methylene interrupted FA, 22:4n-9trans, 20:1n-11), suggesting specific regulations of FA incorporation and lipid class composition in gill membranes to maintain optimal membrane function in their specific and changing environment. This study highlights the importance to characterize the spatial and temporal variability of food resources in order to apprehend the physiological consequences of environmental variability, as well as species differential regulation capacities in a changing world.

Identification and Total Synthesis of Two Previously Unreported Odd-Chain Bis-Methylene-Interrupted Fatty Acids with a Terminal Olefin that Activate Protein Phosphatase, Mg2+/Mn2+-Dependent 1A (PPM1A) in Ovaries of the Limpet Cellana toreuma.

Diverse non-methylene-interrupted (NMI) fatty acids (FAs) with odd-chain lengths have been recognized in triacylglycerols and polar lipids from the ovaries of the limpet Cellana toreuma, however their biological properties remain unclear. In this study, two previously unreported odd-chain NMI FAs, (12Z)-12,16-heptadecadienoic (1) and (14Z)-14,18-nonadecadienoic (2) acids, from the ovary lipids of C. toreuma were identified by a combination of equivalent chain length (ECL) values of their methyl esters and capillary gas chromatography-mass spectrometry (GC-MS) of their 3-pyridylcarbinol derivatives. On the basis of the experimental results, both 1 and 2 were synthesized to prove their structural assignments and to test their biological activity. The ECL values and electron impact-mass (EI-MS) spectra of naturally occurring 1 and 2 were in agreement with those of the synthesized 1 and 2. In an in vitro assay, both 1 and 2 activated protein phosphatase, Mg2+/Mn2+-dependent 1A (PPM1A) up to 100 μM in a dose-dependent manner.

Diverse Odd-Chain Monoenoic Fatty Acids and Novel Non-Methylene-Interrupted Heptadecadienoic Acids in Ovaries of the Limpet Cellana toreuma.

Highly diverse dienoic fatty acids (FA), especially non-methylene-interrupted (NMI) FA, have been recognized in triacylglycerols (TAG) and polar lipids of ovaries of the limpet Cellana toreuma. To gain additional insights into the structural diversity of FA in ovaries, this study aimed to clarify previously undescribed minor monoenoic FA isomers and unidentified minor NMI FA by combined argentation thin-layer chromatography (TLC) and gas chromatography-mass spectrometry (GC-MS) of their 3-pyridylcarbinol derivatives. A total 66 monoenoic FA from C14 to C22, including 12 branched-chain FA, were identified. A surprising finding was a series of 13 heptadecenoic acids with double bonds at either Δ5, Δ6, Δ7, Δ8, Δ9, Δ10, Δ11, Δ12, Δ13, Δ15, or Δ16 positions. Besides previously identified NMI FA, 7,18-nonadecadienoic (19:2Δ7,18), 9,18-nonadecadienoic (19:2Δ9,18), 11,18-nonadecadienoic (19:2Δ11,18), 7,20-heneicosadienoic (21:2Δ7,20), and 11,20-heneicosadienoic (21:2Δ11,20) acids, two novel related NMI FA, 5,16-heptadecadienoic (17:2Δ5,16) and 7,16-heptadecadienoic (17:2Δ7,16) acids, were found in TAG. These findings could provide new insights into clarifying the biological characteristics of marine NMI FA.

Novel Odd-Chain Fatty Acids with a Terminal Double Bond in Ovaries of the Limpet Cellana toreuma.

Our previous study characterized highly diverse dienoic fatty acids (FA), in particular an uncommon non-methylene-interrupted (NMI) FA, in the ovaries of the Japanese limpet Cellana toreuma belonging to the archaeogastropods, but many minor chemically unidentified FA remain. In this study, among previously unidentified FA (less than 0.1% of total FA), four novel NMI FA with a terminal double bond [7,18-nonadecadienoic (19:2Δ7,18), 11,18-nonadecadienoic (19:2Δ11,18), 7,20-heneicosadienoic (21:2Δ7,20), and 11,20-heneicosadienoic (21:2Δ11,20) acids] were found, along with known 14-pentadecenoic (15:1Δ14), 16-heptadecenoic (17:1Δ16), and 9,18-nonadecadienoic (19:2Δ9,18) acids, based on capillary GC-MS of their methyl esters, 3-pyridylcarbinol derivatives, and argentation thin-layer chromatography. From our findings, possible biosynthetic pathways for the novel FA are discussed.

Survival of juvenile northern quahogs during seasonal temperature decline likely a function of diet and NMI-fatty acid synthesis

ABSTRACTAquacultured northern quahogs, Mercenaria mercenaria, set in the environment for overwintering have experienced episodes of anomalous, highly variable and site-specific overwinter mortality. Prior research has revealed factors likely contributing to mortality during isothermal winter lows, when M. mercenaria do not feed, and the postwinter approach to spring. However, a synthesis of prior studies suggests juvenile M. mercenaria survival during the prewinter period of temperature may be subject to the timely dietary availability of two highly unsaturated fatty acids, 20:5n-3, eicosapentaneoic acid, and 22:6n-3, docosahexaneoic acid, and the biosynthesis of the nonmethylene interrupted fatty acids, 22:2Δ7,13 and 22:2Δ7,15.

Investigating the essential fatty acids in the common cuttlefish Sepia officinalis (Mollusca, Cephalopoda): Molecular cloning and functional characterisation of fatty acyl desaturase and elongase

Some polyunsaturated fatty acids (PUFA) play critical roles in physiology and are essential for normal growth and development of aquatic animals including cephalopods like the common cuttlefish Sepia officinalis. This is particularly true for early life stages when neuronal tissues are rapidly developing and accumulating PUFA. The specific fatty acids (FAs) that can satisfy the essential requirements of any animal species depend upon the enzymatic capability to convert dietary FA into those physiologically important FAs required for normal function. In order to identify the dietary essential FA for the common cuttlefish, we have performed the molecular cloning and functional characterisation of two key enzymes involved in PUFA biosynthesis in this species, namely a fatty acyl desaturase (Fad) and an elongation of very long-chain fatty acid (Elovl) protein. The gene product of the cuttlefish Fad exhibited ∆5-desaturase activity, enabling this species to potentially biosynthesise the physiologically essential FAs eicosapentaenoic (20:5n-3, EPA) and arachidonic (20:4n-3, ARA) acids from 20:4n-3 and 20:3n-6, respectively. However, the cuttlefish Fad did not show ∆6 or ∆8 activity and therefore the biosynthesis of EPA and ARA from C18 PUFA precursors could be limited, suggesting that both may be essential FAs for cuttlefish. Moreover, the cuttlefish Fad also lacked ∆4-desaturase activity suggesting that DHA biosynthesis was not possible and thus DHA is also an essential FA for this species. The cuttlefish ∆5 Fad was able to produce non-methylene-interrupted (NMI) FA, a group of PUFAs typically found in marine invertebrates. The cuttlefish Elovl was able to elongate C18 and C20 PUFA substrates, but showed no activity towards C22 PUFA. Overall the results obtained in the present study allowed the prediction of the biosynthetic pathways of PUFA, including NMI FA, in the common cuttlefish. It was concluded that EPA, ARA and DHA were likely to be essential dietary FA for this species as endogenous production from precursor FA appears to be limited. Statement of RelevanceSome PUFA are dietary essential for the common cuttlefish.

Phospholipid Incorporation of Non-Methylene-Interrupted Fatty Acids (NMIFA) in Murine Microglial BV-2 Cells Reduces Pro-Inflammatory Mediator Production.

Sciadonic acid (SCA), pinolenic acid (PNA), and Δ7-eicosatrienoic acid (Δ7-ETrA) are three non-methylene-interrupted fatty acids (NMIFA). Using murine microglial BV-2 cells, this study determined how NMIFA incorporation modulated phospholipid fatty acid composition and the production of pro-inflammatory mediators. Each NMIFA was rapidly taken up and incorporated in BV-2 cells, resulting in the differential redistribution of total lipids. The cellular phospholipid fatty acid compositions were altered, and a significant decrease in the proportions of total monounsaturated fatty acids (MUFA) was observed while the proportions of NMIFA and its metabolites accounted for 38% of the fatty acid total. Incubation of microglial cells with NMIFA suppressed production of LPS-stimulated pro-inflammatory mediators, including nitric oxide (NO), prostaglandin E2 (PGE2), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α), as well as the over-expression of inducible nitric oxide synthase (iNOS) and type 2 cyclooxygenase (COX-2). These inhibitory effects could be accounted for, in part, by the inactivation of mitogen-activated protein kinases (MAPK) signaling. In conclusion, Δ7-ETrA, PNA, and SCA are anti-inflammatory NMIFA that may be useful in suppressing in vitro immune responses involved in neural inflammation.

Fatty acid composition in Mytilus galloprovincialis organs: trophic interactions, sexual differences and differential anatomical distribution

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 528:221-234 (2015) - DOI: https://doi.org/10.3354/meps11280 Fatty acid composition in Mytilus galloprovincialis organs: trophic interactions, sexual differences and differential anatomical distribution María-José Fernández-Reiriz*, José Luis Garrido, Jade Irisarri Consejo Superior de Investigaciones Científicas (CSIC), Instituto de Investigaciones Marinas (IIM), C/Eduardo Cabello 6, 36208 Vigo, Spain *Corresponding author: mjreiriz@iim.csic.es ABSTRACT: The fatty acid (FA) profiles in neutral lipids (NLs) and polar lipids (PLs) of the gills, digestive gland and mantle of female and male mussels Mytilus galloprovincialis (cultured in Ría de Arousa, Galicia, NW Spain, and studied during an annual seasonal cycle) reflected dietary, sexual and functional differences. Seasonal differences arose from variations in the trophic environment, with diatom FA biomarkers dominating during the spring bloom, biomarkers from dinoflagellate-rich diets dominating during winter mixing, and a combination of both sources apparent during the summer and autumn transitory periods. The influence of diet was more pronounced in the NL (energetic reserves) than in the PL (structural membrane components) FA signatures of all organs, although dietary changes were mirrored more clearly in the digestive gland. Differences between males and females were restricted to the mantle and probably resulted from gonadal ripeness during spring. The NL and PL FA profile of the mantle was characterized by the abundance of 14:0, 16:0 and 16:1n-7 in females and predominance of 18:0, 18:3n-3 and 22:6n-3 in males, suggesting that each gender has distinct energetic and structural requirements during gametogenesis. Lipids containing alkenyl ethers or non-methylene interrupted (NMI) FAs were mostly found in the PLs of the gills and the mantle, supporting their role as structural and functional components in the membranes of organs directly exposed to physicochemical fluctuations. Competition between NMI and polyunsaturated fatty acids (PUFAs) was only evident in the mantle, suggesting that deficiencies in PUFAs might provoke de novo biosynthesis of NMI to satisfy reproductive demands. KEY WORDS: Mussels · Neutral and polar lipids · Non-methylene interrupted fatty acids · Biomarkers · Sexual variation · Bivalve organs Full text in pdf format Supplementary material PreviousNextCite this article as: Fernández-Reiriz MJ, Garrido JL, Irisarri J (2015) Fatty acid composition in Mytilus galloprovincialis organs: trophic interactions, sexual differences and differential anatomical distribution. Mar Ecol Prog Ser 528:221-234. https://doi.org/10.3354/meps11280 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 528. Online publication date: May 28, 2015 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2015 Inter-Research.

Fatty acid biomarkers reveal niche separation in an Arctic benthic food web

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 336:305-309 (2007) - doi:10.3354/meps336305 Fatty acid biomarkers reveal niche separation in an Arctic benthic food web Suzanne M. Budge1,*, Alan M. Springer2, Sara J. Iverson3, Gay Sheffield4 1Department of Process Engineering and Applied Science, Dalhousie University, Halifax, Nova Scotia B3J 2X4, Canada 2Institute of Marine Sciences, University of Alaska Fairbanks, Fairbanks, Alaska 99775, USA 3Department of Biology, Dalhousie University, Halifax, Nova Scotia B3H 4J1, Canada 4Alaska Department of Fish and Game, Fairbanks, Alaska 99701, USA *Email: suzanne.budge@dal.ca ABSTRACT: Marine fatty acids (FA) are synthesized primarily by phytoplankton and have a wide variety of structures. Biochemical restrictions on the synthesis or modification of FA in animals make it possible to recognize those derived from their prey; numerous studies have demonstrated the transfer of FA from prey to predator at various trophic levels. Although rarely occurring, a few FA found in animals, including the C20 and C22 non-methylene-interrupted (NMI) FA, can be traced to quite specific prey types. These unusual lipids are synthesized de novo by certain benthic mollusks, particularly bivalves, through chain elongation and desaturation of common monounsaturated FA precursors. Their proportions vary among species, suggesting that they might be particularly suitable as biomarkers in food web studies. We recently discovered NMI FA in 2 species of sympatric, benthic-feeding pinnipeds in Alaska, bearded seals Erignathus barbatus and Pacific walruses Odobenus rosmarus. Significant differences in proportions of 6 NMI FA, and patterns of other FA, demonstrated considerable dietary separation between the bearded seals and walruses. This is the first report of NMI FA in marine mammals, and the first use of these specific FA biomarkers in evaluating trophic pathways in mammals. These individual FA biomarkers, together with suites of other FA, have wide application in understanding marine food webs, including those in the Arctic where rapid environmental change threatens fragile ecosystems. KEY WORDS: Fatty acids · Non-methylene interrupted · Trophic ecology · Bearded seals · Walruses · Diet Full text in pdf format PreviousExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 336. Online publication date: April 27, 2007 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2007 Inter-Research.

Occurrence of Novel Nonmethylene-Interrupted C24Polyenoic Fatty Acids in Female Gonad Lipids of the LimpetCellana grata

The occurrence of positional isomers of minor C(24) unsaturated fatty acids in female gonad lipids of the limpet Cellana grata was clarified by gas chromatography-mass spectrometry of the combination of their 4,4-dimethyloxazoline and picolinyl ester derivatives. In this study, in addition to 5,9-24:2, 9,15-24:2, 5,9,15-24:3, and 5,9,17-24:3, previously identified, 24:4n-6, 24:5n-3, and four novel nonmethylene-interrupted fatty acids, 9,17-24:2, 9,15,18-24:3, 5,9,15,18-24:4, and 5,9,15,18,21-24:5, were newly recognized. All C(24) unsaturated fatty acids detected were present only in triacylglycerols.

Distribution of Novel Nonmethylene-Interrupted Fatty Acids over Neutral and Polar Lipids of Ophiuroidea (Brittle Star).

Fatty acid compositions of neutral lipids (NL) and polar lipids (PL) have been analyzed for a unique sample of Ophiuroidea (brittle star) Ophiura sarsi containing novel nonmethylene-interruped (NMI) fatty acids, 7E,13E-icosadienoic (20:2), 7E,13E,17Z-icosatrienoic (20:3), 9E,15E,19Z-docosatrienoic (22:3), and 4Z,9E,15E,19Z-docosatetraenoic (22:4) acids. All of the NMI fatty acids were concentrated in NL (mainly triacylglycerols) rather than in PL (mainly phosphatidylcholines and phosphatidylethanolamines). On the other hand, 6,9,12,15,18,21-tetracosahexaenoic acid (24:6n-3) usually observed in Ophiuroidea lipids was found in PL at higher concentration than in NL. Biological property and origin of the novel NMI fatty acids appear to be different from those of 24:6n-3.

Non-methylene-Interrupted Polyunsaturated Fatty Acids: Effective Substitute for Arachidonate of Phosphatidylinositol

In mammalian tissues and cells, a characteristic of phosphatidylinositol (PI) is a high abundance of arachidonic acid (AA) relative to the other phospholipids. In this study, we investigated the effects of supplementation of several polyunsaturated fatty acids (PUFAs) on the AA concentration of the PI fraction using a cultured cell system. Neither α-linolenic acid nor eicosapentaenoic acid supplement reduced the level of AA in PI of HepG2 cells. In contrast to the n-3 series PUFAs, adding podocarpic acid (20:3, Δ-5,11,14) and pinolenic acid (18:3, Δ-5,9,12) reduced the AA content of the PI fraction from a control value of 15.9% to 7.0 and 8.7%, respectively. In the experiments with pinolenic acid, selective and significant accumulation of 20:3 (Δ-7,11,14), the chain-elongated metabolite of pinolenic acid, was observed in the PI fraction. On the other hand, adding columbinic acid (18:3, Δ-5t,9,12) had no effect on AA content of the PI fraction. Because both podocarpic acid and pinolenic acid are non-methylene-interrupted fatty acids (NMIFAs) that are not converted to AA metabolically, these NMIFAs may be interesting experimental tools for research on the function of PI-origin bioactive lipids.

Increased production of TNF-α and decreased levels of dienoic eicosanoids, IL-6 and IL-10 in mice fed menhaden oil and juniper oil diets in response to an intraperitoneal lethal dose of LPS

Eicosapentaenoic acid (EPA) and the non-methylene interrupted fatty acids (NMIFA) displace arachidonic acid (AA: 20:4ω6 -5,8,11,14) in the membrane phospholipids. Unlike EPA (20:5ω3 -5,8,11,14,17), the NMIFA (20:3ω6 -5,11,14 and 20:4ω3 -5,11,14,17) lacking the Δ-8 double bond are not substrates for the formation of eicosanoids. For 20 days, the mice were fed diets containing 5wt% dietary fats from various sources. The magnitudes in the production of eicosanoids and cytokines produced in response to an intraperitoneal injection of endotoxin in mice fed menhaden fish oil (MO) diets enriched with EPA were compared with those maintained on juniper oil (JO) containing NMIFA or on safflower oil (SO), a major source of the AA precursor, linoleic acid. The levels of PGE 2, 6-keto-PGF 1α and TXB 2 were markedly lower ( P < 0.01) in animals fed either MO or JO diets compared to the controls. The plasma levels of tumor necrosis factor (TNF)-α were significantly higher ( P < 0.05) with a concomitant decrease of interleukin (IL)-6 and of IL-10 in mice fed MO or JO diets ( P < 0.01) compared to those fed SO diet. These data suggest that the effects of consuming NMIFA of JO despite their inability to form eicosanoids are similar to those of feeding EPA which forms biologically active alternate metabolites.

Purification and gas chromatographic-mass spectrometric characterization of non-methylene interrupted fatty acid incorporated in rat liver

A C20 non-methylene interrupted trienoic acid detected in the liver of rat fed with a pine ( Pinus koraiensis) seed oil diet was purified by two-step argentation thin-layer chromatography (AgTLC) and characterized by gas chromatography-mass spectrometry (GC-MS). First, a C20 methyl trienoate fraction was obtained from fatty acid methyl esters prepared from rat liver by 5% AgTLC developed with petroleum ether-diethyl ether-acetic acid (70:20:2, v/v) as a solvent system. The fraction was then subjected to AgTLC developed with benzene-acetone-diethyl ether-acetic acid (65:15:15:5, v/v) which could separate non-methylene interrupted fatty acids (NMIFA) from usual MIFAs. The purified C20 NMIFA was partially hydrogenated, and the resulting three kinds of the C20 monoenoate were analyzed by GC-MS after conversion to their dimethyl disulfide (DMDS) adducts. The results revealed that the original C20 non-methylene interrupted trienoic acid detected in the liver of rats fed with a pine seed oil diet was Δ-5,11,14/20:3, a minor component of pine seed oil.

Lipid characteristics of hydrothermal vent organisms from 9°N, East Pacific Rise

Abstract Lipid compositions are reported for three distinctive deep-sea hydrothermal vent invertebrate species collected around 9°N East Pacific Rise: Riftia pachyptila Jones, a vestimentiferan tubeworm; Bathymodiolus thermophilus Kenk and Wilson, a mussel; and Halice hesmonectes Martin et al. , an amphipod crustacean. The lipid compositions of all these organisms were dominated by components characteristic of diets based on bacteria, with only very minor contributions from carbon derived from the oceanic photic zone. In all the organisms studied, large abundances of n-7 fatty acids, polyunsaturated fatty acids with unsaturations separated by more than one methylene bond, and sterol distributions dominated by cholesterol were observed. Branched fatty acids were generally of low abundance, whereas polyunsaturated fatty acids separated by single methylene groups were either absent, as in the case of R. pachyptila , or in very low abundance, as in the case of B. thermophilus and H. hesmoncetes . Monounsaturated fatty acids were the most abundant component of R. pachyptila lipids, whereas non-methylene interrupted fatty acids were particularly abundant in the lipids of B. thermophilus (up to 450f total fatty acids). The lipids of H. hesmonectes were dominated by storage lipids (e.g. wax esters). Stable carbon isotope analyses of individual sterols from the organisms examined allow specific sources to be proposed for these biochemicals. The δ 13 C values of sterols from R. pachyptila were consistent with de novo biosynthesis, whereas that of cholesterol from B. thermophilus corresponded to that from marine phytoplankton. The δ 13 C values of sterols from H. hesmonectes fell into two different groups and suggest that at least two distinct sources of sterols are available to these crustacea in the vent ecosystem, one of which derives from phytoplankton. Overall, the combination of the interpretation of lipid structure and distribution with compound specific isotope analyses can lead to valuable insights into trophic relationships within the deep-sea hydrothermal ecosystem.

Nonmethylene-interrupted fatty acids of hydrocarbon seep mussels: Occurrence and significance

1. 1. Characterization of fatty acid composition of hydrocarbon seep mussels reveals that the mussels contained a striking diversity of nonmethylene-interrupted dienoic (NMID) and trienoic (NMIT) fatty acids. 2. 2. The concentrations of the NMI acids are unusually high, accounting for 12.2–17.7% of the total fatty acids. 3. 3. The NMI acids are primarily ω7 and ω9 series, and the position of double bonds of the NMI acids are primarily at or near the center of the fatty acyl chains. 4. 4. The biosynthesis of NMI acids and their physiological significance are discussed.

Comparative investigation of phospholipids and fatty acids of freshwater molluscs from the Volga river basin

1. 1. Four Gastropoda species and two Bivalvia species from the Volga river basin were examined. 2. 2. Distribution of phospholipids in the molluscs was studied by qualitative and quantitative micro thin-layer chromatography. 3. 3. Major phospholipid classes, phosphatidylethanolamine and phosphatidylcholine, were found to contain plasmalogens. 4. 4. One mollusc species notably contained 67 fatty acids including 25 saturated (both iso and anteiso), 24 monoenoic, five dienoic, four trienoic and eight polyenoic compounds identified by capillary gas chromatography; fatty acid contents in the other studied species were considerably lower. 5. 5. Relatively high concentrations of nonmethylene-interrupted fatty acids were detected in certain examined species.

Cis-5-Olefinic Nonmethylene-Interrupted Fatty Acids in Lipids of Seeds, Arils and Leaves of Japanese Yew

Fatty acids from the lipids of the Japanese yew Taxus cuspidata seeds collected at various districts all contained rich amounts of cis-5, cis-9-octadecadienoic acid (5, 9-18 : 2) (16.118.9%) with small amounts of 5, 9, 12-18 : 3 (1.83.4%) and 5, 11, 14-20 : 3 (1.02.8%) as cis-5-olefinic nonmethyleneinterrupted (NMI) acids. On the other hand, fatty acids from the neutral lipids of the arils and leaves contained appreciable amounts of 5, 11, 14-20 : 3 (leaves 8.1%and arils 1.2%) and 5, 11, 14, 17-20 : 4 (leaves 6.2% and arils 1.5%), but 5, 9-18 : 2was not detected or detected only in a trace amount in them. Fatty acids from the galactolipids of the leaves also contained small amounts of the NMI acids (5, 9, 12, 15-18 : 4 0.3%, 5, 11, 14-20 : 3 0.4%, 5, 11, 14, 17-20 : 4 1.8%), in addition to a large amount of linolenic acid (72.8%). The 5-olefinic NMI acids were generally more rich in neutral lipids than in polar lipids. The yew seeds showed nearly the same fatty acid composition during maturation.