scholarly journals Study of Synthesis Pathways of the Essential Polyunsaturated Fatty Acid 20:5n-3 in the Diatom Chaetoceros Muelleri Using 13C-Isotope Labeling

Biomolecules ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 797 ◽  
Author(s):  
Marine Remize ◽  
Frédéric Planchon ◽  
Ai Ning Loh ◽  
Fabienne Le Grand ◽  
Antoine Bideau ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Polyunsaturated Fatty Acid ◽  
Isotope Labeling ◽  
Neutral Lipids ◽  
Chaetoceros Muelleri ◽  
13C Isotope ◽  
Lipid Fatty Acid ◽  
Neutral Lipid Fatty Acid ◽  
Essential Polyunsaturated Fatty Acid

The present study sought to characterize the synthesis pathways producing the essential polyunsaturated fatty acid (PUFA) 20:5n-3 (EPA). For this, the incorporation of 13C was experimentally monitored into 10 fatty acids (FA) during the growth of the diatom Chaetoceros muelleri for 24 h. Chaetoceros muelleri preferentially and quickly incorporated 13C into C18 PUFAs such as 18:2n-6 and 18:3n-6 as well as 16:0 and 16:1n-7, which were thus highly 13C-enriched. During the experiment, 20:5n-3 and 16:3n-4 were among the least-enriched fatty acids. The calculation of the enrichment percentage ratio of a fatty acid B over its suspected precursor A allowed us to suggest that the diatom produced 20:5n-3 (EPA) by a combination between the n-3 (via 18:4n-3) and n-6 (via 18:3n-6 and 20:4n-6) synthesis pathways as well as the alternative ω-3 desaturase pathway (via 20:4n-6). In addition, as FA from polar lipids were generally more enriched in 13C than FA from neutral lipids, particularly for 18:1n-9, 18:2n-6 and 18:3n-6, the existence of acyl-editing mechanisms and connectivity between polar and neutral lipid fatty acid pools were also hypothesized. Because 16:3n-4 and 20:5n-3 presented the same concentration and enrichment dynamics, a structural and metabolic link was proposed between these two PUFAs in C. muelleri.

scholarly journals Use of the Signature Fatty Acid 16:1ω5 as a Tool to Determine the Distribution of Arbuscular Mycorrhizal Fungi in Soil

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Christopher Ngosong ◽  
Elke Gabriel ◽  
Liliane Ruess
Keyword(s):  
Fatty Acid ◽  
Mycorrhizal Fungi ◽  
Plant Root ◽  
Background Level ◽  
Arbuscular Mycorrhizal ◽  
Am Fungi ◽  
Biomass Estimation ◽  
Lipid Fatty Acid ◽  
Neutral Lipid Fatty Acid ◽  
Root Symbionts

Biomass estimation of arbuscular mycorrhiza (AM) fungi, widespread plant root symbionts, commonly employs lipid biomarkers, predominantly the fatty acid 16:1ω5. We briefly reviewed the application of this signature fatty acid, followed by a case study comparing biochemical markers with microscopic techniques in an arable soil following a change to AM non-host plants after 27 years of continuous host crops, that is, two successive cropping seasons with wheat followed by amaranth. After switching to the non-host amaranth, spore biomass estimated by the neutral lipid fatty acid (NLFA) 16:1ω5 decreased to almost nil, whereas microscopic spore counts decreased by about 50% only. In contrast, AM hyphal biomass assessed by the phospholipid (PLFA) 16:1ω5 was greater under amaranth than wheat. The application of PLFA 16:1ω5 as biomarker was hampered by background level derived from bacteria, and further enhanced by its incorporation from degrading spores used as microbial resource. Meanwhile, biochemical and morphological assessments showed negative correlation for spores and none for hyphal biomass. In conclusion, the NLFA 16:1ω5 appears to be a feasible indicator for AM fungi of the Glomales group in the complex field soils, whereas the use of PLFA 16:1ω5 for hyphae is unsuitable and should be restricted to controlled laboratory studies.

Maternal polyunsaturated fatty acids and risk for autism spectrum disorder in the MARBLES high-risk study

Autism ◽  
2020 ◽  
Vol 24 (5) ◽  
pp. 1191-1200 ◽  
Author(s):  
Yunru Huang ◽  
Ana-Maria Iosif ◽  
Robin L Hansen ◽  
Rebecca J Schmidt
Keyword(s):  
Autism Spectrum Disorder ◽  
Fatty Acids ◽  
Fatty Acid ◽  
Polyunsaturated Fatty Acids ◽  
Polyunsaturated Fatty Acid ◽  
Autism Spectrum ◽  
Spectrum Disorder ◽  
Fatty Acid Intake ◽  
Third Trimester ◽  
Acid Intake

Prior research studies suggest that maternal polyunsaturated fatty acids could have protective effects on neurodevelopmental outcomes. The objective of this study was to examine associations between maternal polyunsaturated fatty acid intake during pregnancy and risk for autism spectrum disorder and other non-typical development in a prospective cohort. Eligible women already had a child with autism spectrum disorder and were planning a pregnancy or were pregnant with another child. Children were clinically assessed longitudinally and diagnosed at 36 months. Maternal polyunsaturated fatty acid intake during pregnancy was estimated using food frequency questionnaires. Maternal third-trimester plasma polyunsaturated fatty acid concentration was measured by gas chromatography. In all, 258 mother–child pairs were included. Mothers consuming more total omega-3 in the second half of pregnancy were 40% less likely to have children with autism spectrum disorder (relative risk = 0.6, 95% confidence interval: 0.3–0.98). No significant associations were observed between maternal third-trimester plasma polyunsaturated fatty acid subtype concentrations and risk of autism spectrum disorder. However, higher plasma eicosapentaenoic acid and docosahexaenoic acid concentrations were associated with lower non-typical development risk (relative risk ranging from 0.47 to 0.88). This study provides suggestive evidence of associations between risk of autism spectrum disorder in the children and maternal omega-3 intake in late pregnancy but not with third-trimester plasma polyunsaturated fatty acids. Further research is needed to evaluate these potential relationships. Lay abstract Prior studies suggest that maternal polyunsaturated fatty acids intake during pregnancy may have protective effects on autism spectrum disorder in their children. However, they did not examine detailed timing of maternal polyunsaturated fatty acid intake during pregnancy, nor did they evaluate plasma concentrations. This study investigates whether maternal polyunsaturated fatty acids in defined time windows of pregnancy, assessed by both questionnaires and biomarkers, are associated with risk of autism spectrum disorder and other non-typical development in the children. Food frequency questionnaires were used to estimate maternal polyunsaturated fatty acid intake during the first and second half of pregnancy. Gas chromatography measured maternal plasma polyunsaturated fatty acid concentrations in the third trimester. In all, 258 mother–child pairs from a prospective cohort were included. All mothers already had a child with autism spectrum disorder and were planning a pregnancy or pregnant with another child. Children were clinically assessed longitudinally and diagnosed at 36 months. For polyunsaturated fatty acid intake from questionnaires, we only found mothers consuming more omega-3 in the second half of pregnancy were 40% less likely to have children with autism spectrum disorder. For polyunsaturated fatty acid concentrations in the third-trimester plasma, we did not observe any statistical significance in relation to the risk of autism spectrum disorder. However, our study confirmed associations from previous studies between higher maternal docosahexaenoic acid and eicosapentaenoic acid plasma concentrations in the late pregnancy and reduced risk for non-typical development. This study markedly advanced understandings of whether and when maternal polyunsaturated fatty acid intake influences risk for autism spectrum disorder and sets the stage for prevention at the behavioral and educational level.

scholarly journals Observations on the nature and origin of lipids in the small intestine of the sheep

1968 ◽  
Vol 22 (2) ◽  
pp. 237-246 ◽  
Author(s):  
Aileen M. Lennox ◽  
A. K. Lough ◽  
G. A. Garton
Keyword(s):  
Fatty Acids ◽  
Small Intestine ◽  
Fatty Acid ◽  
Bile Acids ◽  
Neutral Lipids ◽  
Intestinal Lumen ◽  
Total Lipids ◽  
Total Fatty Acids ◽  
Proportional Contribution ◽  
Conjugated Bile Acids

1. Total lipids were extracted from digesta obtained from the rumen, abomasum and upper small intestine (jejunum) of each of four slaughtered sheep. The lipids were fractionated into unesterified fatty acids, neutral lipids and phospholipids and the proportional contribution of each fraction to the total fatty acids was determined.2. The contribution made by phospholipids to the total fatty acids in the digesta showed a marked increase in the samples from the small intestine compared with those from the rumen and abomasum. This increase was apparently due to the presence of biliary phospholipids.3. Total lipids and conjugated bile acids were extracted from sheep bile, the lipids were fractionated and their fatty-acid composition was determined. Phospholipids predominated and these consisted mainly of phosphatidylcholine, together with some lysophosphatidylcholine.4. Both phospholipids contained significant amounts of unsaturated C18 components which could account, at least in part, for the previously reported increament to the proportion of these acids in the digesta when it enters the upper jejunum.5. The overall fatty acid compositions of the two biliary phospholipids were very similar and, in common with other naturally occurring phosphatidylcholines, the fatty acids present in position 2 of the phosphatidylcholine of bile were found to consist almost entirely of unsaturated components.6. Total lipids and conjugated bile acids were extracted from samples of digesta obtained from three sheep with cannulas in different positions in the jejunum. Analysis of the lipids indicated that biliary phospholipids, in particular phosphatidylcholine, underwent progressive hydrolysis in the intestinal lumen.7. The distribution of conjugated bile acids, unesterified fatty acids and phospholipids between the solid (particulate) and liquid (micellar) phases of the intestinal digesta was determined. These chyme constituents were, for the most part, associated with the particulate matter and thus, at any given time, it appears that only a small fraction of the total fatty acids is available for absorption in micellar form. It is suggested that the micellar solubilization of fatty acids may be facilitated by the presence of lysophosphatidylcholine.

scholarly journals The same rat Δ6-desaturase not only acts on 18- but also on 24-carbon fatty acids in very-long-chain polyunsaturated fatty acid biosynthesis

2002 ◽  
Vol 364 (1) ◽  
pp. 49-55 ◽  
Author(s):  
Sabine D'ANDREA ◽  
Hervé GUILLOU ◽  
Sophie JAN ◽  
Daniel CATHELINE ◽  
Jean-Noël THIBAULT ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Polyunsaturated Fatty Acid ◽  
Unsaturated Fatty Acids ◽  
Fatty Acid Biosynthesis ◽  
Chain Polyunsaturated Fatty Acid ◽  
Acid Biosynthesis ◽  
Highly Unsaturated Fatty Acids ◽  
Long Chain ◽  
Δ6 Desaturase

The recently cloned Δ6-desaturase is known to catalyse the first step in very-long-chain polyunsaturated fatty acid biosynthesis, i.e. the desaturation of linoleic and α-linolenic acids. The hypothesis that this enzyme could also catalyse the terminal desaturation step, i.e. the desaturation of 24-carbon highly unsaturated fatty acids, has never been elucidated. To test this hypothesis, the activity of rat Δ6-desaturase expressed in COS-7 cells was investigated. Recombinant Δ6-desaturase expression was analysed by Western blot, revealing a single band at 45kDa. The putative involvement of this enzyme in the Δ6-desaturation of C24:5n-3 to C24:6n-3 was measured by incubating transfected cells with C22:5n-3. Whereas both transfected and non-transfected COS-7 cells were able to synthesize C24:5n-3 by elongation of C22:5n-3, only cells expressing Δ6-desaturase were also able to produce C24:6n-3. In addition, Δ6-desaturation of [1-14C]C24:5n-3 was assayed invitro in homogenates from COS-7 cells expressing Δ6-desaturase or not, showing that Δ6-desaturase catalyses the conversion of C24:5n-3 to C24:6n-3. Evidence is therefore presented that the same rat Δ6-desaturase catalyses not only the conversion of C18:3n-3 to C18:4n-3, but also the conversion of C24:5n-3 to C24:6n-3. A similar mechanism in the n-6 series is strongly suggested.

scholarly journals Fatty Acids Profiles of Stipe and Blade from the Norwegian Brown Macroalga Laminaria hyperborea, Using Off-Line SPE and GC-MS

2016 ◽  
Author(s):  
Lena Oksdøl Foseid ◽  
Hanne Devle ◽  
Yngve Stenstrøm ◽  
Carl Fredrik Naess-Andresen ◽  
Dag Ekeberg
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Polyunsaturated Fatty Acids ◽  
Neutral Lipids ◽  
Methyl Esters ◽  
Lipid Fraction ◽  
Environmental Benefits ◽  
Laminaria Hyperborea ◽  
Alpha Linolenic Acid ◽  
Lipid Fractions

A thorough analysis and comparison of the fatty acid profiles of stipe and blade from Laminaria hyperborea, a kelp species found in the northern Atlantic, is presented. Lipids were extracted and fractionated into neutral lipids, free fatty acids and polar lipids, then derivatized to fatty acid methyl esters prior to GC-MS analysis. A total of 42 fatty acids were identified and quantified, including the n-3 fatty acids α-linolenic acid, stearidonic acid and eicosapentaenoic acid. An n-6/n-3 ratio of 0.8:1 was found in blade and 3.5:1 in stipe, respectively. The ratios vary between the lipid fractions within stipe and blade, with the lowest ratio in the polar lipid fraction of blade. The fatty acid amounts are higher in blade than in stipe, and the highest amounts of n-3 fatty acids are found within the neutral lipid fractions. The amounts of polyunsaturated fatty acids are 3.4 times higher in blade than stipe. This study highlights the compositional differences between the lipid fractions of stipe and blade from L. hyperborea. The amount of polyunsaturated fatty acids, compared to saturated- and monounsaturated fatty acids, as well as the n-6/n-3-ratio, is known to influence human health. In the pharmaceutical, food, and feed industries this can be of importance for production and sale of different health products. Additionally, lipids are today among the unused by products of alginate production, exploiting this material for commercial interest should give both economical and environmental benefits.

scholarly journals Les lipides des différentes catégories de pépins de Cabernet Sauvignon au moment de la véraison

OENO One ◽  
1980 ◽  
Vol 14 (3) ◽  
pp. 147
Author(s):  
J. J. Lavaud ◽  
Monique Cherrad
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Acid Content ◽  
Neutral Lipids ◽  
Fatty Acid Content ◽  
Polar Lipids ◽  
Cabernet Sauvignon ◽  
Acides Gras ◽  
The Difference

<p style="text-align: justify;">Cinq catégories de pépins de Cabernet Sauvignon ont été séparées à la véraison. Plus de 95 p. 100 des acides gras sont contenus dans les lipides neutres. La différence de composition en acides gras des lipides polaires montre que la localisation des pépins dans une seule loge ou dans deux loges séparées a pour conséquence une modification du fonctionnement des désaturases.</p><p style="text-align: justify;">+++</p><p style="text-align: justify;">Five categories of Cabernet Sauvignon seeds were separated at the beginning of ripening. The neutral lipids contain more than 95 per cent of the fatty acids. The difference in the fatty acid content of polar lipids shows that seeds localized in just one section or in two separate sections results in a modification of the « desaturase » functioning.</p>

scholarly journals Total, Neutral, and Polar Lipids of Brewing Ingredients, By-Products and Beer: Evaluation of Antithrombotic Activities

Foods ◽  
2019 ◽  
Vol 8 (5) ◽  
pp. 171 ◽  
Author(s):  
Ronan Lordan ◽  
Eoin O’Keeffe ◽  
Alexandros Tsoupras ◽  
Ioannis Zabetakis
Keyword(s):  
Fatty Acid Composition ◽  
Fatty Acid ◽  
Platelet Aggregation ◽  
Acid Composition ◽  
Polar Lipid ◽  
Neutral Lipids ◽  
Fatty Acid Content ◽  
Polar Lipids ◽  
Lipid Fatty Acid ◽  
By Products

The in vitro antithrombotic properties of polar lipid constituents of malted grain (MG), pelleted hops (PH), brewer’s spent grain (BSG), spent hops (SH), wort, and bottled beer from the same production line were assessed in human platelets. The total lipids (TL) were extracted according to the Bligh and Dyer method and further separated into the total neutral lipids (TNL) and total polar lipids (TPL) extracts by counter-current distribution. The TL, TNL, and TPL extracts of all samples were assessed for their ability to inhibit platelet-activating factor (PAF) and thrombin-induced human platelet aggregation. The raw materials, by-products, wort, and beer lipid extracts all exhibited antithrombotic properties against PAF and thrombin. However, the beer TPL exhibited the lowest IC50 values against PAF-induced (7.8 ± 3.9 µg) and thrombin-induced (4.3 ± 3.0 µg) platelet aggregation indicating that these polar lipids were the most antithrombotic. The lipid extracts tended to be more bioactive against the thrombin pathway. The fatty acid content of all the TPL extracts were assessed using GC-MS. The fatty acid composition of the most bioactive TPL extracts, the wort and the beer, shared similar fatty acid profiles. Indeed, it was noted that fermentation seems to play a role in increasing the antithrombotic properties of polar lipids against PAF and thrombin by moderately altering the polar lipid fatty acid composition. Furthermore, the use of brewing by-products as a source of functional cardioprotective lipids warrants further investigation and valorisation.

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