Composition of lipids, fatty acids and sterols in Okinawan corals

A survey of lipid composition was made for 15 cnidarians from Okinawa, Japan. Eleven zooxanthellate scleractinian corals, an azooxanthellate scleractinian coral Tubastrea sp., a soft coral Lobophytum crassum, a hydroid coral Millepora murrayi and a sea anemone Boloceroides sp. were examined to elucidate the total lipid content, fatty acid composition for each lipid class and sterol composition. All specimens contained monoalkyldiacylglycerol which migrated between the triacylglycerols and esters on thin layer chromatography (TLC). Analysis by high performance thin layer chromatography (HPTLC) and Gas chromatography-mass spectrometry (GC-MS) revealed that these cnidarians were rich in wax ester and triacylglycerol, and that palmitic acid (16:0) was the most abundant fatty acid component of these lipid classes, followed by stearic (18:0) and oleic (18:1, n-9) acid in order of concentration. Of 11 sterols separated, four sterols were identified. It is suggested that sterol composition may be more useful for the biochemical classification of these cnidarians than fatty acid composition.     

Fatty acids of plant vacuolar membrane lipids

Fatty acid (FA) composition of vacuolar membrane lipids from storage tissues of umbelliferous plants, viz., parsnip (Pastinaca sativa L.), parsley (Petroselinium crispum L.), and carrot (Daucus carota L.) is studied by gas-liquid chromatography and the FA biosynthetic pathways are considered. Vacuolar membrane lipids are characterized by high (78% of the total FA pool) content of unsaturated FA among which linoleic acid is predominant. Its content in vacuolar lipids of parsnip, parsley and carrot is 53.5, 55.1, and 54.9%, respectively. Parsnip and parsley vacuolar lipids contain large amounts of hexadecadienoic C16:2ω6 acid (8.0 and 4.6%, respectively). The content of α-linolenic acid in vacuolar lipids of tested plants varies from 4.8 to 7.3%. Palmitic acid (18.0–20.7%) predominates among saturated FA. High content of linoleic and hexadecadienoic acid in parsnip and parsley vacuolar lipids is suggestive of a crucial role of the microsomal ω6 fatty-acid desaturase fad2 gene in resistance and acclimation of plants to low temperatures.     

Rat liver nuclear lipids. Composition and biosynthesis

A characteristic of rat liver nuclear lipids is their high content in neutral lipids especially of tryglycerides and free fatty acids. These compounds do not arise due to hydrolysis of more complex lipids during the isolation of the nuclei. The neutral lipids fatty acid pattern is more saturated than the phospholipid one. The presence of phosphatidylinositol mono- and diphosphate in nuclei has been confirmed. Nuclei are unable to synthesize de novo phospholipids but are capable of incorporating inorganic phosphate into lipids synthesized via a kinase pathway.     

Fatty acids and carbohydrate-containing lipids in four Micrococcaceae strains

Fatty acid composition and lipidic carbohydrate to lipidic phosphorus molar ratio of yellow pigmented micrococci are compared to red pigmented ones and may be summarized by three indexes. These bacteria show wide differences in their fatty acid composition: three strains possess saturated branched chain fatty acids and one has unsaturated straight chain ones. A significant increase in 'anteiso/iso indexes' is observed between pink (M. roseus) and yellow colored bacteria (M. lysodeikticus, S. lutea). There is no significant difference (P greater than 0.05) between the 'unsaturation indexes' of the red pigmented parental D. radiodurans strain and its colorless mutant. Radioresistant strains exhibit a higher 'carbohydrate/phosphorus index' than other strains. There seems to be a relationship between a high carbohydrate-containing lipid content and a high resistance to physical and chemical agents, in particular to radiations. These differences observed in the lipid composition have implications in taxonomy and in establishing an evolutionary scheme.     

Fatty acids in the roe lipids of common food fishes

The roe lipid fatty acids of Baltic herring, roach, perch, burbot and rainbow trout were quantitatively studied by capillary-GLC. The composition of roe fatty acids remain fairly stable during the fish maturation. The fatty acid profiles are very similar in various fish roes though differences exist in the relative amounts of individual components. On average perch and burbot have longer chain lengths and higher unsaturation degrees in their roe fatty acids compared to the other species. Variations in the fatty acids can be related to the roe lipid compositions and apparently also to the diet of the parent fish.     

Autoradiographic studies with fatty acids and some other lipids: A review

In this review, we have mainly included studies in which whole-body autoradiography was used. In lipid research, most studies have been done with fatty acids. These studies showed some common characteristics in the pattern of tissue distribution. A major uptake was seen in the brown fat, liver and adrenal cortex but also to some extent in other tissues with a high metabolic activity or high cell turn-over, e.g. the gastric and intestinal mucosa, diaphragm, kidney cortex and bone marrow. Low levels of radioactivity were generally found in the brain, testes, thymus, white fat, skeletal muscles, lungs and spleen. Most fatty acids showed some specific features, e.g the strong uptake of erucic, arachidonic and docosahexaenoic acid in myocardium and of eicosapentaenoic acid in the adrenal cortex. Studies with PGE1 and LTC3 showed that the liver and kidney and to a lesser degree the lungs were the major sites of metabolism. The distribution of free cholesterol and triolein emulsion labelled in the fatty acid moieties did show some similarities with respect to the general pattern found with most fatty acids. Specific for cholesterol was a very strong uptake in the adrenal cortex. There was also a significant uptake in the spleen whereas the uptake in the brown fat was not as marked as for most fatty acids. Specific for triolein was a marked uptake in the spleen and myocardium, in fed animals also in the white adipose tissue. These studies show that whole-body autoradiography can give much valuable information of the uptake and distribution of lipids that would be rather difficult to obtain with conventional methods. Combined with electron-microscopy, autoradiography can be used to study cellular and even subcellular distribution, and thus given further data on the metabolism of lipids in the body.     

Fatty acids in liver microsomal lipids of rats exposed to hypoxia, tetrachloromethane, or both

Arachidonic and docosahexaenoic acid in hepatic microsomal lipids from male Sprague-Dawley rats are greatly lowered when the animals have been exposed to tetrachloromethane; at the same time, palmitic, oleic and linoleic acid are significantly increased. Hypoxia alone causes similar derangements, but to a lesser extent. These are largely corrected 18 h after exposure; the effects induced by tetrachloromethane are persistent. The increases in 16:0, 18:1 and 18:2 suggest that in both cases microsomal enzymes involved in fatty acid metabolism are inhibited, either reversibly or irreversibly. Reduction of oxygen partial pressure during tetrachloromethane exposure has little effect upon hepatotoxicity as judged by hepatic enzymes in serum; only the onset of their release into the bloodstream is earlier.     

Fatty acids of plasma and red blood cell lipids in a normal population

A detailed study of the fatty acid composition of each of the lipids present in plasma and red blood cells of 62 healthy subjects of our area (Barcelona and surrounding counties), by coupling thin-layer and gas chromatography techniques has been made. The results are presented as normative data for comparison with those found in pathological situations. No significant sex differences were found. With increasing age, there was a tendency for the proportion of linoleic acid to decrease. Correlation analyses between the fatty acid composition of different lipids suggested that the interchange of fatty acids between plasma and cells mainly affects the phosphatidylcholine of the latter.     

Fatty acids bound to serum albumin potentiate platelet prostaglandin biosynthesis.

Utilization of arachidonic acid by human platelets is increased when the fatty acid content of serum albumin is increased as well. Platelet aggregation induced by arachidonic acid and by low concentrations of thrombin is thus potentiated, suggesting that platelet responsiveness to aggregating agents is influenced by the plasma content in free fatty acids.     

Lipid biosynthesis in developing mustard seed: formation of triacylglycerols from endogenous and exogenous Fatty acids

Cotyledons of developing mustard (Sinapis alba L.) seed have been found to synthesize lipids containing the common plant fatty acids and very long-chain monounsaturated (icosenoic, erucic, and tetracosenic) and saturated (icosanoic, docosanoic, and tetracosanoic) fatty acids from various radioactive precursors. The in vivo pattern of labeling of acyl lipids, either from fatty acids synthesized `endogenously' from radioactive acetate or malonate, or from radioactive fatty acids added `exogenously', indicates the involvement of the following pathways in the biosynthesis of triacylglycerols. Palmitic, stearic, and oleic acid, synthesized in the acyl carrier protein-track, are channeled to the Coenzyme A (CoA)-track and converted to triacylglycerols via the glycerol-3-phosphate pathway. Pools of stearoyl-CoA and oleoyl-CoA are elongated to very long-chain saturated and monounsaturated acyl-CoA, respectively. Most of the very long-chain saturated acyl-CoAs acylate preformed diacylglycerols. Very long-chain monounsaturated acyl-CoAs are converted to triacylglycerols, partly via phosphatidic acids and diacylglycerols, and partly by acylation of preformed diacylglycerols.     

Fatty acid distribution of the normal sciatic nerve lipids in the rat

We isolated and purified the main lipids of the rat sciatic nerve. After methanolysis, fatty acids were isolated and purified by thin layer chromatography, and studied by gas chromatography. C 16 and C 18 fatty acids are the most abundant. Among the long-chain fatty acids, arachidonic acid (20:4) is present in some lipids; highly desaturated fatty acids in C 22 and C 24 are also present. In general, the fatty acids are highly saturated; cholesterol esters and ethanolamine phosphoglyceride fatty acids are highly unsaturated.     

Regional distribution of total lipids, free fatty acids and free carnitine in human heart

The concentration of total lipids, free fatty acids and free carnitine in seven different regions of human ventricular myocardium has been studied. Statistically significant differences were found in the concentration of these compounds in the studied regions, with a similar behaviour for free carnitine and free fatty acids (their highest concentrations were found in the lower zones of the left ventricle). The results obtained support the theory of a different metabolic requirement in relation to the intensity of muscular contractile activity.