Altered acyl chain compositions of alkylacyl, alkenylacyl, and diacyl subclasses of choline and ethanolamine glycerophospholipids in rat heart by dietary fish oil

The effects of dietary fish oil containing n - 3 polyunsaturated fatty acids on the fatty acid compositions of the alkylacyl and alkenylacyl species of choline glycerophospholipids (CGP) and ethanolamine glycerophospholipids (EGP) were studied in rat heart and compared with the corresponding diacylglycerophospholipids. After a 7 week feeding period, all phospholipid classes from the fish oil group exhibited much higher levels of the n - 3 polyunsaturated fatty acids including eicosapentaenoic acid (20:5(n - 30)), docosapentaenoic acid (22:5(n - 3)) and docosahexaenoic acid (22:6(n - 3)), as well as lower levels of the n - 6 series (18:2, 20:4, 22:4 and 22:5), relative to animals given sunflower seed oil-enriched in 18:2(n - 6). However, the docosahexaenoic acid rather than eicosapentaenoic acid provided a much greater contribution to the n - 3 accumulation (fish oil group) in the ether-containing CGP, as indicated by the 20:5(n - 3)/22:6(n - 3) molar ratios of 0.32, 0.26 and 0.56 in the alkylacyl, alkenylacyl and diacyl classes, respectively. In addition to accumulating very high levels of docosahexaenoic acid (e.g., 47.2 mol% of fatty acids in alkenylacylglycerophosphoethanolamine of fish oil group), both ether-linked classes of EGP exhibited significantly higher levels of docosapentaenoic acid than the diacylglycerophosphoethanolamine (GPE) and all classes of CGP. These findings may bear relevance to possible beneficial effects of dietary fish oil on pathophysiological states (including myocardial ischemia) in cardiac tissue and their mediation via platelet-activating factor, 1-alkyl-2-acetylglycerophosphocholine (PAF) and arachidonic acid (20:4(n - 6))-derived eicosanoids.     

Effects of dietary polyunsaturated fatty acid deficiencies on mortality, growth and gill structure in the turbot, Scophthalmus maximus

The preparation of fish oil concentrates containing only ( n -3) polyunsaturated fatty acids (PUFA) with different ratios of 20:5 ( n -3)/22:6 ( n -3) is described. Three groups of turbot were maintained on different diets containing: 1, 10% of the dry weight of the diet as natural fish oil, equivalent to 2.5% ( n -3) PUFA and 0–23% ( n -6) PUFA; 2, 10% of the dry weight of the diet as palmitic acid, i.e. no PUFA; 3, 8–7% palmitic acid and 1–3% of the dry weight as ( n -3 PUFA and negligible ( n -6) PUFA. Only the fish on the diet containing natural fish oil showed significant growth over a 15-week period. In addition there were high mortalities on the two experimental diets (2 and 3). Changing the ratio of 20:5 ( n -3)/22:6 ( n -3) from 13–8 to 2–2 in the diet containing 1 3% (n-3) PUFA and negligible ( n -6) PUFA markedly decreased the mortalities. Fish fed the two experimental diets (2 and 3) developed gross changes in gill structure involving the disappearance of chloride cells, a 'sloughing off' of the epithelium along the primary and secondary filaments and an accumulation of cellular material in the inter-lamellar spaces. The tissue ultimately disintegrated to leave a skeleton of connective tissue and a mass of cellular material in the inter-lamellar spaces. It is concluded that 22:6 (n-3) is an essential fatty acid for turbot and that the gill epithelium is a sensitive indicator of this deficiency in this species.     

Spray-dried milk supplemented with alpha-linolenic acid or eicosapentaenoic acid and docosahexaenoic acid decreases HMG Co A reductase activity and increases biliary secretion of lipids in rats

In our earlier study, we have shown that rats fed spray-dried milk containing alpha-linolenic acid (LNA 18:3 n-3) or eicosapentaenoic acid (EPA 20:5 n-3) and docosahexaenoic acid (DHA 22:6 n-3) had significantly lower amounts of serum and liver cholesterol. To evaluate the mechanism for hypocholesterolemic effect of n-3 fatty acids containing milk formulation, we fed male Wistar rats with spray-dried milk containing linseed oil (LSO) (source of LNA) or fish oil (FO) (source of EPA+DHA) for 8 weeks. Feeding n-3 fatty acid containing milk formulation lowered the hepatic 3-hydroxy-methylglutaryl coenzyme A (HMG Co A) activity by 17-22% compared to rats given control diet devoid of n-3 fatty acids. The cholesterol level in liver microsomes was found to be decreased by 16% and 20%, respectively, in LSO and FO containing formulation fed rats. The bile flow was enhanced to an extent of 19-23% in experimental groups compared to control animals. The biliary cholesterol and phospholipid secretion was increased to an extent of 49-55% and 140-146%, respectively, in rats fed n-3 fatty acid containing formulation. The increase in the total bile acids secretion in bile was mainly reflected on an increase in the levels of taurine conjugated bile acids. These results indicated that n-3 fatty acid containing spray-dried milk formulation would bring about the hypocholesterolemic effect by lowering HMG Co A reductase activity in liver and by increasing the secretion of bile constituents.     

Evaluation of some biological parameters of Opuntia ficus indica. 1. Influence of a seed oil supplemented diet on rats

Cactus pear (Opuntia ficus indica) is native to Tunisia and the fruit is consumed exclusively as fresh fruit. The seed oil is rich in polyunsaturated fatty acids but the nutritive value of the oil is unknown. The objective of our research was to determine the fatty acid content of cactus pear seed oil and to evaluate the effect of an oil supplemented diet on rats. The main fatty acids of prickly pear seed oil were C16:0, C18:0, C18:1, C18:2 with an exceptional level of linoleic acid, up to 700 g kg(-1), and a total content of unsaturated fatty acids of 884.8 g kg(-1). Feed intake and body weight of rats were measured every two days during the nine weeks of treatment. Digestibility, feed conversion efficiency and protein efficiency ratio were determined. No difference in digestibility was noted for the oil enriched diet. The results indicated a significant decrease in serum glucose concentration (22%) over the control group. However, an increase in the concentration of glycogen was noted in liver and muscle. Blood cholesterol and low density lipoprotein (LDL)-cholesterol decreased in the treated group. High density lipoprotein (HDL)-cholesterol concentration remained unaltered during the treatment. These findings support the nutritional value of cactus pear as a natural source of edible oil containing essential fatty acids and reinforce the possibility of cactus pear as a new crop for Tunisia especially in semi-arid regions, where conventional crops are difficult to establish.     

Alterations in the Fatty Acid Composition of Rat Brain Cells (Neurons, Astrocytes, and Oligodendrocytes) and of Subcellular Fractions (Myelin and Synaptosomes) Induced by a Diet Devoid of n-3 Fatty Acids

Abstract: Rats were fed through four generations with a semisynthetic diet containing 1.0% sunflower oil (6.7 mg/ g n-6 fatty acids, 0.04 mg/g n-3 fatty acids). Ten days before mating, half of the animals received a diet in which sunflower was replaced by soya oil (6.6 mg/g n-6 fatty acids, 0.8 mg/g n-3 fatty acids) and analyses were performed on their pups. Fatty acid analysis in isolated cellular and subcellular material from sunflower-fed animals showed that the total amount of unsaturated fatty acids was not reduced in any cellular or subcellular fraction (except in 60-day-old rat neurons). All material from animals fed with sunflower oil showed an important reduction in the docosahexaenoic acid content, compensated (except in 60-day-old rat neurons) by an increase in the n-6 fatty acids (mainly C22:5 n-6). When comparing 60-day-old animals fed with soya oil or sunflower oil, the n-3/n-6 fatty acid ratio was reduced 16-fold in oligodendrocytes, 12-fold in myelin, twofold in neurons, sixfold in synaptosomes, and threefold in astrocytes. No trienes were detected. Saturated and monounsaturated fatty acids were hardly affected. This study provides data on the fatty acid composition of isolated brain cells.     

Dependence on dietary cholesterol for n-3 polyunsaturated fatty acid-induced changes in plasma cholesterol in the Syrian hamster.

Male Syrian hamsters consumed diets containing incremental increases in dietary n-3 fatty acids from fish oil with either low (0.015% w/w) or moderate (0.1% w/w) dietary cholesterol content. Animals consuming diets containing moderate cholesterol, but not animals consuming diets containing low cholesterol, had increased plasma very low (VLDL)- and low density lipoprotein (LDL)-cholesterol levels with increasing fish oil consumption. The plasma concentration of high density lipoprotein (HDL)-cholesterol decreased by 43 and 32% with the consumption of the highest fish oil diets in the low and moderate dietary cholesterol groups, respectively. Hepatic LDL-receptor binding activity did not change with the consumption of low cholesterol diets, but gradually decreased with fish oil consumption in animals consuming the moderate cholesterol diets. Hepatic LDL-receptor binding and plasma LDL-cholesterol levels of the different dietary fish oil groups were highly correlated (r = -0.91). Fish oil consumption also caused an increase in hepatic free cholesterol but a decreased cholesteryl ester content. Therefore, in the Syrian hamster, the consumption of n-3 fatty acids increases LDL-cholesterol levels which can be partially explained by decreased hepatic LDL-receptor binding and this response to dietary n-3 fatty acids is dependent on the dietary cholesterol content. However, the effects of dietary n-3 fatty acids on HDL-cholesterol are independent of dietary cholesterol content.     

Growth and fatty acid composition of freshwater prawn, Macrobrachium rosenbergii, larvae fed diets containing various ratios of cod liver oil–corn oil mixture

A feeding trial was conducted to determine the effect of replacing costly cod liver oil with corn oil as a source of dietary lipid on the growth and fatty acid composition of the larval freshwater prawn, Macrobrachium rosenbergii de Man. Prawn larvae were weaned to artificial diets containing cod liver oil and corn oil either singly or in various combinations (2 : 1, 1 : 1, 1 : 2, w/w). Weaning to artificial diets from Artemia nauplii commenced at larval stage III with complete substitution by stage X. The reference group was reared solely on Artemia nauplii during the entire experiment. Incorporation of corn oil at 33–67% of dietary supplemental oil did not have significant effects on the post‐larval production. However, larvae fed with corn oil alone revealed a significantly lower post‐larval production compared to other experimental diets as well as to the reference group. No significant differences (P > 0.05) were observed in dry weight, protein and lipid concentration among larvae fed on various dietary treatments. Palmitic (16 : 0) and oleic/vaccenic (18 : 1) acids were the dominant saturated and monounsaturated fatty acids in larval tissues, respectively, whereas the polyunsaturated fraction was dominated by eicosapentaenoic (20 : 5n‐3) acid. The polyunsaturated fatty acid composition was dominated by n‐3 acids rather than n‐6 fatty acids. The fatty acid composition of the prawn in general reflected that of the diet. Larvae on diets containing higher concentrations of corn oil rich in linoleic (18 : 2n‐6) acid showed a higher concentration of this acid in their tissues. No evidence of de novo synthesis of linoleic (18 : 2n‐6) acid was found. Higher levels of stearic (18 : 0), arachidonic (20 : 4n‐6) and eicosapentaenoic (20 : 5n‐3) acids found in larvae as compared with those fed Artemia and artificial diets strongly indicated the larval ability in chain elongation and desaturation of palmitic (16 : 0), linoleic (18 : 2n‐6) or linolenic (18 : 3n‐3) acids, respectively. Despite a large variation of n‐3 to n‐6 ratios of the live and artificial diets, larval n‐3 to n‐6 ratios were relatively stable among different dietary treatments, possibly indicative of the importance of such a ratio in the larval fatty acid metabolism.     

Human absorption of fish oil fatty acids as triacylglycerols, free acids, or ethyl esters

The transient rise in plasma triacylglycerol fatty acids after single-dose ingestion of fish oil as triacylglycerols, free acids, or ethyl esters with linseed oil as an absorption standard was used to determine the relative absorption of fish oil fatty acids in eight men. As free acids, the fish oil fatty acids were well absorbed (greater than or equal to 95%). As triacylglycerols, eicosapentaenoic acid (1.00 g) and docosahexaenoic acid (0.67 g) were absorbed only 68% and 57% as well as the free acids. The ethyl esters were absorbed only 20% and 21% as well as the free acids. The incomplete absorption of eicosapentaenoic and docosahexaenoic acids from fish oil triacylglycerols correlates well with known in vitro pancreatic lipase activity.     

Interactions of saturated, n-6 and n-3 polyunsaturated fatty acids to modulate arachidonic acid metabolism

Anti-thrombotic effects of omega-3 (n-3) fatty acids are believed to be due to their ability to reduce arachidonic acid levels. Therefore, weanling rats were fed n-3 acids in the form of linseed oil (18:3n-3) or fish oil (containing 20:5n-3 and 22:6n-3) in diets containing high levels of either saturated fatty acids (hydrogenated beef tallow) or high levels of linoleic acid (safflower oil) for 4 weeks. The effect of diet on the rate-limiting enzyme of arachidonic acid biosynthesis (delta 6-desaturase) and on the lipid composition of hepatic microsomal membrane was determined. Both linseed oil- or fish oil-containing diets inhibited conversion of linoleic acid to gamma-linolenic acid. Inhibition was greater with fish oil than with linseed oil, only when fed with saturated fat. delta 6-Desaturase activity was not affected when n-3 fatty acids were fed with high levels of n-6 fatty acids. Arachidonic acid content of serum lipids and hepatic microsomal phospholipids was lower when n-3 fatty acids were fed in combination with beef tallow but not when fed with safflower oil. Similarly, n-3 fatty acids (18:3n-3, 20:5n-3, 22:5n-3, and 22:6n-3) accumulated to a greater extent when n-3 fatty acids were fed with beef tallow than with safflower oil. These observations indicate that the efficacy of n-3 fatty acids in reducing arachidonic acid level is dependent on the linoleic acid to saturated fatty acid ratio of the diet consumed.     

Catalytic hydrothermal processing of microalgae: decomposition and upgrading of lipids

Hydrothermal processing of high lipid feedstock such as microalgae is an alternative method of oil extraction which has obvious benefits for high moisture containing biomass. A range of microalgae and lipids extracted from terrestrial oil seed have been processed at 350 °C, at pressures of 150-200 bar in water. Hydrothermal liquefaction is shown to convert the triglycerides to fatty acids and alkanes in the presence of certain heterogeneous catalysts. This investigation has compared the composition of lipids and free fatty acids from solvent extraction to those from hydrothermal processing. The initial decomposition products include free fatty acids and glycerol, and the potential for de-oxygenation using heterogeneous catalysts has been investigated. The results indicate that the bio-crude yields from the liquefaction of microalgae were increased slightly with the use of heterogeneous catalysts but the higher heating value (HHV) and the level of de-oxygenation increased, by up to 10%.     

Effects on animal growth and lipid composition of heart, liver, and adipose tissue in male rats fed different levels and types of fats

Weanling male rats were fed diets containing 5, 10, or 20% (by weight) fat. Diets were made isocaloric by decreasing the amount of starch as the diet fat level increased. At each fat level, three oil mixtures were fed which contained 13, 32, or 79% saturated fatty acids. The polyunsaturate level was 11% of total fatty acids in all mixtures. After 12 weeks, animals eating the high fat diets had gained significantly less weight and had eaten less feed. These animals also had significantly lighter livers and more liver lipids. The level and type of fat in the diet affected the amount (mg/g) of several phospholipids in the liver and heart. The fatty acid patterns (total saturates, n - 3, n - 6 fatty acids) of the major phospholipids were generally constant, the monounsaturated fatty acids being the major exception.     

Formula alpha-linolenic (18:3(n - 3)) and linoleic (18:2(n - 6)) acid influence neonatal piglet liver and brain saturated fatty acids, as well as docosahexaenoic acid (22:6(n - 3)).

Saturated fatty acids can be synthesized de novo and play a role in determining properties of structural membranes. The effect of dietary essential fatty acids, linoleic acid (18:2(n - 6)) and alpha-linolenic acid (18:3(n - 3)), on the saturated fatty acid content of membrane phospholipid has not previously been considered in newborn nutrition. The studies report the effect of low (1% fatty acids) or high (4%) formula 18:3(n - 3) with low (16%) or high (30-35%) formula 18:2(n - 6) on the saturated and unsaturated fatty acid composition of liver and brain structural lipid of piglets fed formula from birth for 15 days. A significant inverse relationship between the formula % 18:3(n - 3), but not 18:2(n - 6), and the liver phospholipid palmitic acid (16:0) was found. This may indicate a possible effect of dietary 18:3(n - 3) on de novo synthesis of 16:0 and requires further investigation. Monounsaturated fatty acids in both liver and brain were significantly lower in response to high 18:3(n - 3) and to high 18:2(n - 6) plus low 18:1(n - 9) in the formula. Liver phospholipid and brain total lipid % docosahexaenoic acid (22:6(n - 3)) were significantly higher when formula containing 4% rather than 1% 18:3(n - 3) was fed, suggesting that 1% 18:3(n - 3) may limit tissue (n - 3) fatty acid accretion. These results suggest that future studies of essential fatty acid requirements, specifically 18:3(n - 3), should consider possible influences on the saturated fatty acids which also play a functional role in tissue structural lipids.     

Fatty acid metabolism in Atlantic salmon (Salmo salar L.) hepatocytes and influence of dietary vegetable oil

Isolated hepatocytes from Atlantic salmon (Salmo salar), fed diets containing either 100% fish oil or a vegetable oil blend replacing 75% of the fish oil, were incubated with a range of seven (14)C-labelled fatty acids. The fatty acids were [1-(14)C]16:0, [1-(14)C]18:1n-9, 91-(14)C]18:2n-6, [1-(14)C]18:3n-3, [1-(14)C]20:4n-6, [1-(14)C]20:5n-3, and [1-(14)C]22:6n-3. After 2 h of incubation, the hepatocytes and medium were analysed for acid soluble products, incorporation into lipid classes, and hepatocytes for desaturation and elongation. Uptake into hepatocytes was highest with [1-(14)C]18:2n-6 and [1-(14)C]20:5n-3 and lowest with [1-(14)C]16:0. The highest recovery of radioactivity in the cells was found in triacylglycerols. Of the phospholipids, the highest recovery was found in phosphatidylcholine, with [1-(14)C]16:0 and [1-(14)C]22:6n-3 being the most prominent fatty acids. The rates of beta-oxidation were as follows: 20:4n-6>18:2n-6=16:0>18:1n-9>22:6n-3=18:3n-3=20:5n-3. Of the fatty acids taken up by the hepatocytes, [1-(14)C]16:0 and [1-(14)C]18:1n-9 were subsequently exported the most, with the majority of radioactivity recovered in phospholipids and triacylglycerols, respectively. The major products from desaturation and elongation were generally one cycle of elongation of the fatty acids. Diet had a clear effect on the overall lipid metabolism, with replacing 75% of the fish oil with vegetable oil resulting in decreased uptake of all fatty acids and reduced incorporation of fatty acids into cellular lipids, but increased beta-oxidation activity and higher recovery in products of desaturation and elongation of [1-(14)C]18:2n-6 and [1-(14)C]18:3n-3.     

Low density lipoprotein from humans supplemented with n-3 fatty acids depresses both LDL receptor activity and LDLr mRNA abundance in HepG2 cells.

Fish oil supplementation in humans is often associated with an expanded low density lipoprotein (LDL) pool that is not thought to reflect increased production. Since data on clearance of LDL after fish oil supplementation (FO-LDL) are equivocal, normal volunteers (four men and three women) received ten capsules containing 3.6 g eicosapentaenoic acid and 2.9 g docosahexaenoic acid (approximately 2.5% total calories as methyl esters) for 2 weeks. Total plasma cholesterol was unchanged, but triglycerides decreased 30%. Low density lipoprotein cholesterol (LDL-C) and high density lipoprotein cholesterol (HDL-C) were unchanged. Analysis of the LDL particles revealed that increased esterified cholesterol caused the FO-LDL core/surface ratio to be greater than baseline LDL (BL-LDL), resulting in a shift in mean LDL density from 1.060 to 1.056. N-3 fatty acids in FO-LDL were also increased greater than 40% at the expense of n-6 and n-9 fatty acids. Human hepatoma HepG2 cells were used to study the effects of FO-LDL on LDL receptor activity and mRNA abundance for the LDL receptor, 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, and various apolipoproteins associated with cholesterol metabolism. In this system FO-LDL reduced LDL receptor activity compared to BL-LDL. Scatchard analysis revealed that LDL receptor number (Bmax) was reduced to one-third normal (P less than 0.001) whereas particle binding affinity was unchanged. The mRNA abundance for the LDL receptor and apoA-I were also depressed, even by low concentrations (10 micrograms/ml and 20 micrograms/ml LDL protein) of FO-LDL as compared to BL-LDL. HepG2 cells incubated with FO-LDL had decreased cellular free cholesterol but increased cholesteryl esters. Thus, moderate supplementation with fish oil n-3 fatty acids in normal humans enriches their LDL particles in cholesteryl esters and n-3 fatty acids. These particles depress both LDL receptor activity and LDL receptor mRNA abundance in HepG2 cells.     

Synthesis of structured lipid with balanced omega-3: Omega-6 ratio by lipase-catalyzed acidolysis reaction: Optimization of reaction using response surface methodology

The present study deals with the production of structured lipid containing omega-3 and omega-6 fatty acids in the ratio of 1:1 by incorporating omega-3 fatty acids (α-linolenic acid) from linseed oil into groundnut oil using lipase (Lipozyme IM from Rhizomucor miehei) catalyzed acidolysis reaction in hexane. The reaction conditions were optimized by response surface methodology with a four-variable five-level central composite rotatable experimental design. The influence of four independent parameters, namely ratio of fatty acid concentrate from linseed to groundnut oil (0.66–1.98, w/w), reaction temperature (30–60 °C), enzyme concentration (1–5%) and reaction time (2–54 h) on omega-3 fatty acids incorporation into groundnut oil were optimized. Optimal conditions for the structured lipid containing omega-3 to omega-6 fatty acids in the ratio of 1:1 were determined to be; enzyme concentration 3.75% (w/w), temperature 37.5 °C, incubation time 30.81 h and ratio of free fatty acid concentrate from linseed oil to groundnut oil 1.16 (w/w).     

Lipid composition of lactational diets influences the fatty acid profile of the progeny before and after suckling

The purpose of the present study was to compare the influence of adding no or 8% fat of varying sources (coconut oil, fish oil, rapeseed oil and sunflower oil) to diets for sows 1 week prior to farrowing and during lactation on the composition of fatty acids in plasma and tissues of the progeny while sucking and 3 weeks after weaning from the sow. A control diet without supplemental fat and four diets supplemented with 8% of coconut oil, rapeseed oil, fish oil or sunflower oil were provided to lactating sows (n = 15), and during the post-weaning period the same weaner diet was provided to all piglets (n = 15 litters), which were housed litterwise. The dietary ratio of n-6:n-3 fatty acids of the maternal diets largely influenced the progeny, as the ratio varying from 1.2 (fish oil) to 12.2 (sunflower oil) in the sow milk was reflected in plasma and adipose tissues of the sucking progeny. The liver showed similar variations according to dietary treatments, but a lower n-6:n-3 fatty acids ratio. From day 4 to later on during the suckling period, the concentration of C14:0, C16:0 and C18:1 in the liver of the piglets decreased, irrespective of the dietary treatments of sows. In plasma and liver, the total concentration of saturated fatty acids (SAFA), monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA) did not differ markedly in piglets sucking sows fed different dietary fatty acids, whereas the adipose tissue of piglets sucking sows fed sunflower oil and coconut oil showed the highest proportion of PUFA and SAFA, respectively. Weaning lowered the concentration of lipid-soluble extracts in plasma and the concentration of fatty acids in the liver of the piglets. Within the post-weaning period, dietary treatments of sows, rather than age of piglets, influenced the fatty acid composition of plasma and adipose tissue of the piglets, whereas the hepatic fatty acid profile was more affected by the age of the piglets during the post-weaning period. This study shows that the fatty acid profile of plasma and tissues of the progeny is highly dependent on the maternal dietary composition, and that the dietary impact persists for up to 3 weeks after the suckling period.     

Synthesis and characterization of poly(3-hydroxyalkanoates) from Brassica carinata oil with high content of erucic acid and from very long chain fatty acids

Pseudomonas aeruginosa produced medium chain length poly(3-hydroxyalkanoates) (mcl-PHAs) when grown on substrates containing very long chain fatty acids (VLCFA, C>20). Looking for low cost carbon sources, we tested Brassica carinata oil (erucic acid content 35-48%) as an intact triglyceride containing VLCFA. Oleic (C18:1), erucic (C22:1), and nervonic (C24:1) acids were also employed for mcl-PHA production as model substrates. The polymers obtained were analyzed by GC of methanolyzed samples, GPC, 1H and 13C NMR, ESI MS of partially pyrolyzed samples, and DSC. The repeating units of such polymers were saturated and unsaturated, with a higher content of the latter in the case of the PHA obtained from B. carinata oil. Statistical analysis of the ion intensity in the ESI mass spectra showed that the PHAs from pure fatty acids are random copolymers, while the PHA from B. carinata oil is either a pure polymer or a mixture of polymers. Weight-average molecular weight varied from ca. 56,000 g/mol for the PHA from B. carinata oil and oleic acid, to about 120,000 g/mol for those from erucic and nervonic acids. The PHAs from erucic and nervonic acids were partially crystalline, with rubbery characteristics and a melting point (Tm) of 50°C, while the PHAs from oleic acid and from B. carinata oil afforded totally amorphous materials, with glass transition temperatures (Tg) of -52°C and -47°C, respectively.     

缅甸蟒脂肪酸分析

用气相色谱法测定了缅甸蟒油20种脂肪酸,其中不饱和脂肪酸含量达67.5%,多不饱和脂肪酸含量达10.3%.含量较高的脂肪酸有油酸、棕榈酸、亚油酸、棕榈油酸,特有脂肪酸DHA、α-亚麻酸,并且明显不同于其他蟒和蛇的脂肪酸含量.缅甸蟒油具有重要的药用和保健品开发利用价值.     

The role of polyene fatty acids in the development of acute inflammation in rats]

The effect of n6 and n3 polyunsaturated fatty acids (PUFA) on development of acute inflammation in rats has been studied. During 4 weeks male Wistar rats (initial weight 140-150 g) were on feed containing as lipid component 6% butter and 3% fish oil obtained from Sardinops sagax melanosticta (n3 PUFA-diet). The development of paw oedema induced by subplantar injection of dextran or carrageenan inhibited when the animals were on diet where prevailed n3 PUFA. In contrast, the state of paw oedema, caused by intraperitoneal administration of egg white was similarly high in rats given both n6 and n3 PUFA.     

Brain Phospholipids as Dietary Source of (n-3) Polyunsaturated Fatty Acids for Nervous Tissue in the Rat

Abstract: In a previous work, we calculated the dietary α-linolenic requirements (from vegetable oil triglycerides) for obtaining and maintaining a physiological level of (n-3) fatty acids in developing animal membranes as determined by the cervonic acid content [22:6(n-3), docosahexaenoic acid]. The aim of the present study was to measure the phospholipid requirement, as these compounds directly provide the very long polyunsaturated fatty acids found in membranes. Two weeks before mating, eight groups of female rats (previously fed peanut oil deficient in α-linolenic acid) were fed different semisynthetic diets containing 6% African peanut oil supplemented with different quantities of phospholipids obtained from bovine brain lipid extract, so as to add (n-3) polyunsaturated fatty acids to the diet. An additional group was fed peanut oil with rapeseed oil, and served as control. Pups were fed the same diet as their respective mothers, and were killed at weaning. Forebrain, sciatic nerve, retina, nerve endings, myelin, and liver were analyzed. We conclude that during the combined maternal and perinatal period, the (n-3) fatty acid requirement for adequate deposition of (n-3) polyunsaturated fatty acids in the nervous tissue (and in liver) of pups is lower if animals are fed (n-3) very long chain polyunsaturated fatty acids found in brain phospholipids [this study, ˜60 mg of (n-3) fatty acids/100 g of diet, i.e., ˜130 mg/1,000 kcal] rather than α-linolenic acid from vegetable oil triglycerides [200 mg of (n-3) fatty acids/100 g of diet, i.e., ˜440 mg/1,000 kcal].