Lipid profile and fatty acid composition of two silurid fish eggs

The lipid content and the composition pattern of the lipid class including fatty acid composition in the eggs of two different Indian silurid cat fishes Ompok pabda and Wallagu attu have been examined. The lipid content of O. pabda and W. attu (on dry basis) are about 14.7% and 17.8% respectively. The major lipid classes are phospolipid (PL) and triacylglycerol (TAG). The O. pabda egg lipid contains more PL while the W. attu egg lipid contains more TAG. Phosphatidylcholine (PC) constitutes the major phospholipid followed by phosphatidylinositol (PI). PI represents in about 31.7% and 21.3% of total PC in O. pabda and W. attu respectively while phosphatidylethanolamine (PE) (about 28.0%) is significantly higher in the egg of W. attu than O. pabda (9.6%). Cholesterol content in egg of O. pabda is also higher (about 9.6%) than W. attu (4.1%). The lipids are rich in polyunsaturated fatty acids (PUFAs) and they are mainly concentrated in the respective PL fractions. Among PUFAs the arachidonic acid (20:4 n-6 AA) is present at about 9.3% in both egg PL. Eicosapentaenoic acid (20:5 n-3 EPA) is significantly lower in egg lipids of both W. attu (1.8%) and O. pabda (3.2%), whereas docosahexaenoic acid (22:6 n-3 DHA) is predominantly higher (14.6% and 18.1% in W. attu and O. pabda respectively) in their PL fractions.     

Effect of starvation on lipid metabolism and stability of DHA content of lipids in horse mackerel (<Emphasis Type="Italic">Trachurus japonicus</Emphasis>) tissues

For the purpose of characterizing the effect of starvation on 22∶6n−3 (DHA) content in marine fish tissues, horse mackerel (Trachurus japonicus) were reared in a tank containing filtered, sterilized seawater under nonfeeding conditions for 107 d (survival rate of the fish was 96.5%). The crude total lipids (TL) of ordinary dorsal muscle, dorsal skin, and viscera of the starved individuals were separated into classes on silicic acid columns, and the constituents of the TL were quantified by gravimetric recovery from column chromatography. The TL, initially>85% TAG in dorsal muscle, and even more in skin lipids, decreased dramatically within the first 44 d of starvation, and then decreased more gradually during the remainder of the test period, whereas the visceral TL decreased more slowly. The percentages of both saturated and monoenoic FA in the muscle TL also decreased somewhat, but those of DHA increased significantly in muscle during the test periods. Decreases in PE and PC initially were much smaller than TAG, but DHA levels remained high in both PE and PC. These findings indicate that all of the FA in the depot lipids of horse mackerel tissues are easily metabolized for energy production during starvation, but DHA in muscle lipids of the starved fish was maintained at a consistently high level, indicating that starvation did not affect DHA stability in phospholipids. The findings suggest that preservation of DHA in cell membrane lipid PE and PC is necessary for self-protection functions in starving fish.     

Seasonal Variations of Lipid Content and Composition in <Emphasis Type="Italic">Perna viridis</Emphasis>

The total lipid content, composition of main lipid classes, composition of sterols and composition of fatty acids in the main glycerolipids of Perna viridis were analyzed through four seasons using TLC-FID and GLC. Mussel samples were collected during different seasons between 2003 and 2004 from Shengsi Island, Zhejiang Province, China and stored frozen prior to freeze-drying and lipid extraction. Ten grams of dried mussel powder of each season were analyzed. Total lipid content ranged from 14.5 g/100 g in spring month to 7.8 g/100 g dried mussel powder in autumn month. The predominant lipid in spring month was triacylglycerol (TAG), however, in the other three seasons the phospholipids (PL) was the main lipid class. The most abundant fatty acid in TAG, PL and phosphatidylcholine (PC) was 16:0, with the summer samples having the highest proportion (24-30% of total fatty acid) and winter the lowest (14-22%). In phosphatidylethanolamine (PE), the spring samples had the highest proportions of 16:0. The predominant polyunsaturated fatty acids (PUFA) were 22:6n-3 and 20:5n-3 in TAG, PL, PE and PC (25-40%). The proportions of 22:6n-3 and 20:5n-3 were higher in spring than in other seasons in PL and PE. There were nine sterols identified, with cholesterol being the predominant sterol, and other main ones were desmostersol/brassicasterol and 24-methylenecholesterol. Proportions of other fatty acids in different lipid fractions and the sterol compositions as well also varied seasonally. There were subject to the seasonal variations. Differences in lipid content and composition, fatty acid composition in different lipid fractions may be caused by multiple factors such as lifecycle, sex, variation of plankton in different seasons and temperature, which could influence physiological activities and metabolism.     

Polar and Neutral Lipid Composition in the Pelagic Tunicate <Emphasis Type="Italic">Pyrosoma atlanticum</Emphasis>

Structure and functioning of colonial pyrosomes are largely undescribed and their lipid characteristics have received limited attention. The aim of this paper is to fill this gap on one of the dominant species Pyrosoma atlanticum. Lipid content is tightly coupled to size and weight. Lipid composition shows a large dominance of structural polar lipids. Neutral lipids were dominated by sterols with low levels of acylglycerols and free fatty acids. Phospholipids show a dominance of PC with intermediate percentages of PE and DPG. Other constituents (PS, PI, LPC, sphingolipids) were present at lower levels. Fatty acid composition of DAG and TAG showed a dominance of saturated acids (16:0, 14:0), DHA and intermediate levels of MUFA. Phospholipids were dominated by DHA with values exceeding 30% of total FA in all categories except for PI, where lower percentages occurred. Saturated acids were second in abundance with MUFA showing intermediate concentrations. Sterols were dominated by 24-methylcholesta-5,22E-dien-3beta-ol with more than 22% of the total sterol. Cholesterol (cholest-5-en-3beta-ol) represented only 12 % of the total while 24-methylcholesta-5,24(28)E-dien-3beta-ol accounted for 11% of the total sterols. The low levels of triacylglycerols and free fatty acids, coupled with high concentrations of glycolipids and phytoplankton-derived degraded chloropigments, is evidence of a direct link with the digestive activity and substantiate the idea of a high physiological turnover as an alternative to large lipid accumulation. The fatty acid and sterol profiles are consistent with a diverse phytoplankton diet, and a strong contribution of phospholipid classes to energy needs, including locomotion.     

Lipidic pattern of 25 Mexican marine fishes with special emphasis in their n-3 fatty acids as nutraceuticals components

The aim of this study was to characterize and to evaluate the lipidic composition of mexican marine fishes with special emphasis in n-3 fatty acids as nutraceuticals. The edible portion of 25 species: humidity (H), crude protein (CP), total lipids (TL) and fatty acids (FA). The average content (g/100g edible portion) of H was 75.20, PC was 18.40, TL was 3.60. Four n-3 FA were identified in all the samples and they were found in the next abundance order (mg/100g edible portion): C22:6n-3 (DHA)(229.60), C20:5 n-3 (EPA)(52.10), C18:3 n-3 (ALA)(11.80) and C20:3 n-3 (2.25). By their origin and climate there were no difference. By their biologycal classification, n-3 FA content was higher in bony fishes than cartilaginous fishes. It was detected a proportional relation with the n-3 FA concentration and total lipid content. According to their ecotic distribution there were numerical differences in DHA content (mg/100g edible portion) between pelagics (420.70), benthopelagics (125.30) and demersals fishes (225.40). Fatty fishes had higher content of EPA and DHA (mg/100g edible portion) (109.27 and 552.72) than semifatty fishes (56.12 and 226.29) and leanness (15.95 and 96.52), respectively. Bony, fatty and pelagic fishes had a higher content of EPA+DHA. According with the international recommendation values (200 to 600 mg EPA+DHA/day) the 44% of the analyzed species could be considered as functional foods due to their high content of EPA + DHA in a range of 220 to 1300 mg/100g.     

Lipids and Fatty Acids of the Gonads of Sea Urchin Diadema setosum (Echinodermata) From the Coastal Area of the Nha Trang Bay,Central Vietnam

The sea urchin Diadema setosum is edible and desirable as food by locals in central Vietnam and a promising target for potential fishing. The lipid profiles of the gonads of the sea urchin inhabiting the coastal area in Nha Trang Bay are studied for the first time. The determination of the content of the total lipids (TL), total phospholipids (PL), monoacylglycerols (MAG), diacylglycerols (DAG), triacylglycerols (TAG), cholesterol (Chol), sterol esters, and free fatty acids (FFA) is analyzed by high-performance thin layer chromatography (HPTLC); the phosphatidylserine (PS), phosphatidylethanolamine (PE), phosphatidylinositol (PI), phosphatidylcholine (PC), lysophosphatidylcholine (LPC), and sphingomyelin (SM) are determined by high-pressure liquid chromatography (HPLC); and the fatty acid levels of TLs are identified using gas chromatography (GC). Non-polar TAG, FFA, Chol, and DAG dominated. The content of total PL is significant. PC is abundant among PL fractions, followed by PE, PI, and PS. The TLs contain a high proportion of PUFA, mainly due to arachidonic fatty acid and eicosapentanoic fatty acid. The (n−6)/(n−3) ratio is 1.68, and the atherogenic and thrombogenic indexes of D. setosum are 1.13 and 0.73. The results can be used in the development of marine bioprospecting and methodological approaches for the creation of functional substances.     

Differences in Lipid Characteristics Among Populations: Low-Temperature Adaptability of Ayu, Plecoglossus altivelis

The lipid and fatty acid compositions of the total lipids of three cultured populations (migratory between fresh and salt water, Lake Biwa landlocked, and Setogawa River forms) of ayu, Plecoglossus altivelis, were investigated to clarify the difference in lipid characteristics and temperature adaptability among the three groups. Triacylglycerols were the dominant depot lipids of the three populations, while phospholipids, such as phosphatidylcholine and phosphatidylethanolamine, were found to be the major components of the polar lipids, and their lipid classes are similar to each other. The major fatty acids in the triacylglycerols of all specimens were 16:0, 18:0, 16:1n-7, 18:1n-7, 18:1n-9, 18:2n-6 (linoleic acid), 20:5n-3 (EPA, icosapentaenoic acid), and 22:6n-3 (DHA, docosahexaenoic acid), similar to the tissue phospholipids of the three populations, 16:0, 18:0, 16:1n-7, 18:1n-7, 18:1n-9, 18:2n-6, 20:4n-6, EPA, and DHA. All classes had high levels of 18:2n-6, which originates from their dietary lipids. Compared with the lower DHA levels of the triacylglycerols, the higher levels in the phospholipids suggest their selective accumulation or a biosynthetic pathway to DHA as in freshwater fish. Two populations (the migratory and Setogawa River forms) adapted to lower temperatures with comparatively high levels of polyunsaturated fatty acids (PUFA) for their membrane fluidities. With significantly higher levels of n-3 PUFA and total PUFA, the mean DHA content in the lipids of the Setogawa River form (the population that adapted to lower temperatures) was significantly higher than that of the migratory form. From these results, we concluded that the Setogawa River population actively concentrates long-chain PUFA in its polar lipids and has high adaptability to low temperature.     

Cholesterol,Lipid Content,and Fatty Acid Composition of Different Tissues of Farmed Cobia (<Emphasis Type="Italic">Rachycentron canadum</Emphasis>) from China

Marine fishes are rich in n-3 polyunsaturated fatty acids (PUFA), especially eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), which are extremely important for human health. The objective of our work was to determine the content and composition of lipids and fatty acids in the different tissues of cobia from China and to evaluate their nutritional value. The results showed that cobia from China was rich in lipids; the neutral lipid content was above 82%; the content of cholesterol and phospholipid was low. Eighteen fatty acids were identified. Myristic (C14:0), palmitic (C16:0), and stearic acids (C18:0) were the main saturated acids; palmitoleic (C16:1n-7) and oleic acid (C18:1n-9) were the main monounsaturated fatty acids. EPA and DHA were the main PUFA; n-3 and n-6 PUFA were present as 12–18% and 2.6–3.2% of the total fatty acids, respectively. The n-6/n-3 ratio was in the range from 0.18 to 0.22, which was far lower than that (5:1) recommended by WHO/FAO. Therefore, cobia lipids from China have a high nutritional value.     

Lipid components of borage (Borago officinalis L.) seeds and their changes during germination

The changes in composition of total and neutral lipids (NL) as well as glycolipids (GL) and phospholipids (PL) of borage (Borago officinalis L.) seeds, germinated in the dark at 25^°C for 10 d, were studied. Total lipids constituted 34.0% of the dry matter of borage seeds. During germination, the content of total lipids was decreased by 95%. NL accounted for 95.7% of total lipids prior to germination and were composed of triacylglycerols (TAG; 99.1%), diacylglycerols (DAG; 0.06%), monoacylglycerols (MAG;0.02%), free fatty acids (FFA;0.91%), and sterols (0.02%). The content of TAG was significantly (P≤0.05) decreased, while that of other components, such as MAG and FFA, significantly (P≤0.05) increased during germination. However, the content of DAG did not change. GL and PL accounted for 2.0 and 2.3% of total lipids, respectively, and their contents significantly (P≤0.05) increased as germination proceeded. The thin layer chromatography-flame-ionization detection studies showed that phosphatidylcholine (PC; 69.7%) was the major PL present. The total content of phosphatidylserine (PS) and phosphatidylethanolamine (PE), which were coeluted, was 18.2%; phosphatidic acid (PA) was present at 11.2% of the total PL fraction. Lysophosphatidylcholine was detected at 0.9%. The proportion of PC, PS, and PE significantly (P≤0.05) decreased during germination, but that of PA increased (P≤0.05) markedly. The fatty acid composition of lipid fractions changed as germination proceeded. The predominant fatty acids of total lipids, NL, and GL were linoleic and linolenic acids, while those of PL were linoleic and palmitic acids. The present study demonstrated that the overall changes of lipids seen in borage seeds during germination agree well with results for other oilseeds. Changes in lipid compositions during germination result from the formation of tissues and metabolic interconversion of lipid classes. Rapid changes in lipid composition during seed germination may enhance the nutritional value of the sprouts.     

Effects of growth temperature on the fatty acid composition of the free-living nematodeCaenorhabditis elegans

The effects of growth temperature on the fatty acid compositions of the phosphatidylcholine (PC), phosphatidylethanolamine (PE), and total lipid (TL) fractions of the free-living nematodeCaenorhabditis elegans were investigated. A reduction in growth temperature from 25 to 15°C caused the proportions of eicosapentaenoic acid (20∶5n-3) to increase from 23.6 to 32.5% in the PC, from 7.4 to 10.8% in the PE, and from 12.9 to 19.9% in the TL fractions. Conversely, the levels of dihomo-γ-linolenic acid (20∶3n-6) and arachidonic acid (20∶4n-6) in these phospholipid fractions and the TL fraction both decreased with decreasing growth temperature. Analysis of the positional distribution of fatty acids in the PC fraction revealed that the change in the composition of C₂₀ polyunsaturated fatty acid was obvious in positionsn-2. Lowering the growth temperature induced an increase in the level of the diacyl subclass of PE from 58% at 25°C to 71% at 15°C, with a concomitant decrease in the levels of the alkylacyl and alkenylacyl subclass of PE ofC. elegans. These changes observed in the phospholipids ofC. elegans might be one mechanism for adaptation to low temperature. Lipids 31, 1173–1178 (1996).     

Generation and remodeling of highly polyunsaturated molecular species of rat hepatocyte phospholipids

Freshly isolated rat hepatocytes were incubated for 20 min with [U-¹⁴C]glycerol in the presence or absence of unlabeled linoleic (18∶2n-6), arachidonic (20∶4n-6), or docosahexaenoic (22∶6n-3) acid, added as albumin complex in 10% ethanol. Most of the radioactivity (≈95%) recovered in hepatocyte lipids was present in phosphatidylcholine (PC), phosphatidylethanolamine (PF), and triacylglycerol (TAG). The presence of exogenous fatty acids resulted in (i) higher incorporation of [U-¹⁴C]glycerol, (ii) higher percentage of label in TAG, and (iii) enhanced formation of PC and PE molecular species bearing the exogenous fatty acid at both the sn-1 and sn-2 positions of glycerol. In each case, these molecular species contained 60 to 70% of the label in that lipid class. Further incubation of the cells for 40 and 80 min in the absence of labeled substrate and exogenous fatty acids resulted in a redistribution of label among PC and PE molecular species due to deacylation-reacylation at the sn-1 position of glycerol.     

Fatty acid analysis of blood plasma of patients with alzheimer's disease, other types of dementia, and cognitive impairment

Fatty acid differences, including docosahexaenoic acid (DHA; 22:6n-3) have been shown in the brains of Alzheimer's patients (AD) as compared with normal age-matched individuals. Furthermore, low serum DHA is a significant risk factor for the development of AD. The relative concentration of DHA and other fatty acids, however, in the plasma of AD patients compared with patients with other kinds of dementias (other dementias; OD), patients who are cognitively impaired but nondemented (CIND), or normal patients is not known. In this study we analyzed the total phospholipid, phosphatidylcholine (PC), phosphatidylethanolamine (PE), and lysophosphatidylcholine (lysoPC) fractions of plasma from patients diagnosed with AD, OD, or CIND and compared them with a group of elderly control subjects with normal cognitive functioning. Plasma phospholipid and PC levels of 20:5n-3, DHA, total n-3 fatty acids, and the n-3/n-6 ratio were lower in the AD, OD, and CIND groups. Plasma phospholipid 24:0 was lower in the AD, OD, and CIND groups as compared with the group of control patients, and total n-6 fatty acid levels were higher in the AD and CIND groups only. In the plasma PE fraction, levels of 20:5n-3, DHA, and the total n-3 fatty acid levels were significantly lower in the AD, OD, and CIND groups. DHA levels were lower in the lysoPC fraction of CIND individuals only. There were no other differences in the fatty acid compositions of the different phospholipid fractions. Therefore, in AD, OD, and CIND individuals, low levels of n-3 fatty acids in the plasma may be a risk factor for cognitive impairment and/or dementia. Interestingly, a decreased level of plasma DHA was not limited to the AD patients but appears to be common in cognitive impairment with aging.     

High docosahexaenoic acid levels in both neutral and polar lipids of a highly migratory fish: <Emphasis Type="Italic">Thunnus tonggol</Emphasis> (Bleeker)

The lipid and FA compositions of various organs (light muscle, dark muscle, liver, pyloric cecum, and the orbital region) and of the stomach contents of a highly migratory fish species Thunnus tonggol (Bleeker) were analyzed. TAG and phospholipids (PE and PC) were the major lipid classes in the total lipids of T. tonggol. DHA was characteristically the major FA of all the major classes of all its organs except for only one case of liver TAG. The mean DHA contents of the various organs accounted for more than 20% of the total FA (TFA), even though it is a neutral depot lipid. However, DHA in the stomach contents, originating from their prey, fluctuated and was generally low. DHA levels were generally higher in a year (2000) when water temperatures were colder than in one when it was warmer (1998). Furthermore, DHA levels in muscle TAG were consistently high in spite of the fluctuation of those in the visceral TAG, which might be directly influenced by the prey lipids. This phenomenon suggests the physiological selective accumulation of DHA in the muscle, after the migration of the digested FA in the vascular system and absorption of the prey lipids in the intestine. In contrast, the FA composition of other species is generally variable and their DHA contents of TAG are usually less than 20% of TFA.     

Differential Impact of Sex on Seasonal Changes in Mantle and Tentacle Phospholipids and Triacylglycerols in Sepia officinalis

The aim of the present work was to study the effect of season on phospholipids and triacylglycerols (TAG) of mantle and tentacles of female and male wild Sepia officinalis. The identified phospholipids were phosphatidylethanolamine (PtdEtn), phosphatidylcholine (PtdCho), phosphatidylserine (PtdSer), and phosphatidylinositol (PtdIns), and PtdEtn was the major fraction. Results showed apparent seasonal variation of phospholipid content, particularly with female samples. Fatty acid composition of phospholipid classes showed a differentiation much more in the proportions than in the diversity of fatty acids. Results showed that the major saturated fatty acids were 16:0 and 18:0, the major monounsaturated fatty acids were 18:1 and 20:l, and the major polyunsaturated fatty acids were docosahexaenoic acid (22:6n-3) (DHA) and eicosapentaenoic acid (20:5n-3) (EPA). The results relative to TAG demonstrated significant variations. Principal component analysis confirmed the seasonal and sexual effects. This study could be appropriate for the improvement of consistent monitoring of phospholipid and TAG accumulation in cephalopod, which might be important for both physiological studies and food industries.     

Improving Fatty Acid Composition of Lipids Synthesized by Brachionus plicatilis in Large Scale Experiments

Nannochloropsis oculata and Chlorella sp. were cultivated in industrial scale bioreactors 300?L, under full sunlight and artificial light during night-time at various temperatures. The most abundant fatty acids were C18:3n-3 and C16:0 in Chlorella sp., whereas in N. oculata C16:0, eicosapentaenoic acid (EPA) and C16:1n-9 were predominant. Brachionus plicatilis cultivated in 2,500-L tanks on N. oculata, Chlorella sp. and Saccharomyces cerevisiae, was able to de novo synthesize as well as to elongate and desaturate pre-existing fatty acids in the feed. When fed with S. cerevisiae, B. plicatilis synthesized lipids containing EPA and docosahexaenoic acid (DHA), despite the fact that these fatty acids were absent in yeast lipids. Brachionus fed with Nannochloropsis synthesized DHA in non-negligible quantities. Brachionus enriched with various commercial preparations incorporated into its lipids substrate fatty acids but also synthesized new fatty acids such as C16:1n-9, C18:1n-9, C18:2n-6, EPA and DHA. Neutral lipid was the main lipid fraction while phospholipids predominated over glycolipids plus sphingolipids. The major amounts of EPA and DHA were observed in neutral lipids, noteworthy quantities of these fatty acids were also incorporated into body phospholipids. Interestingly, the high n-3 fatty acids content of rotifer lipids was retained even after the rotifers were grown in low n-3 fatty acid media.     

Phospholipid Composition of <Emphasis Type="Italic">Jatropha curcus</Emphasis> Seed Lipids

Jatropha curcus L. oil has emerged as one of the most important raw materials for biodiesel production. However, no detailed study has been reported on characterizing the lipid constituents of jatropha oil. The present study revealed that the total oil content of jatropha seeds was 32% with a composition of 97.6% neutral lipids, 0.95% glycolipids and 1.45% phospholipids. The fatty acid composition of total lipids, neutral lipids, phospholipids and glycolipids was also determined and found to contain oleic acid (18:1) and linoleic acids (18:2) as major fatty acids. The phospholipids fraction was further characterized and quantified and found to contain phosphatidyl choline (PC) 60.5%, phosphatidyl inositol (PI) 24% and phosphatidyl ethanolamine (PE) 15.5%. The fatty acid composition and the positional distribution of the fatty acids of individual phospholipids were also reported.     

Impact of Frying on Changes in Clam (Ruditapes philippinarum) Lipids and Frying Oils: Compositional Changes and Oxidative Deterioration

The current study shows the compositional changes and oxidation development of clam (Ruditapes philippinarum, R. philippinarum) lipids and frying oils when subjected to different processing conditions. Parameters measured include acid value, peroxide value (POV), thiobarbituric acid-reactive substances (TBARS), total oxidation (TOTOX), lipid classes, fatty acid composition, phosphatidylcholine (PC), and phosphatidylethanolamine (PE) contents together with major glycerophospholipid (GP) molecular species. Deep-fat frying increased triacylglycerol (TAG) content and decreased the contents of PC, PE, and GP molecular species in clam in a time-dependent manner. Meanwhile, minor amounts of free fatty acids, diacylglycerols, monoacylglycerols, and polar lipids were detected in frying oils, indicating lipid migration between the clam and frying oils. The time-dependent increase of POV, TBARS, and TOTOX in fried clams and frying oils with concurrent reduction of docosahexenoic acid and eicosapentaenoic acid indicates extensive oxidative degradation of clam lipids. Moreover, the moisture-rich clam aggravated the deterioration of frying oils. Consequently, deep-fat frying significantly altered the lipid profile and decreased the nutritional value of clams.     

EPA or DHA Supplementation Increases Triacylglycerol,but not Phospholipid,Levels in Isolated Rat Cardiomyocytes

It is well recognized that a high dietary intake of long-chain polyunsaturated fatty acids (LC-PUFA) has profound benefits on health and prevention of chronic diseases. In particular, in recent years there has been a dramatic surge of interest in the health effects of n-3 LC-PUFA derived from fish, eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids. Notwithstanding, the metabolic fate and the effects of these fatty acids once inside the cell has seldom been comprehensively investigated. Using cultured neonatal rat cardiomyocytes as model system we have investigated for the first time, by means of high-resolution magic-angle spinning nuclear magnetic resonance (HR-MAS NMR) spectroscopy in combination with gas chromatography (GC), the modification occurring in the cell lipid environment after EPA and DHA supplementation. The most important difference between control and n-3 LC-PUFA-supplemented cardiomyocytes highlighted by HR-MAS NMR spectroscopy is the increase of signals from mobile lipids, identified as triacylglycerols (TAG). The observed increase of mobile TAG is a metabolic response to n-3 LC-PUFA supplementation, which leads to an increased lipid storage. The sequestration of mobile lipids in lipid bodies provides a deposit of stored energy that can be accessed in a regulated fashion according to metabolic need. Interestingly, while n-3 LC-PUFA supplementation to neonatal rat cardiomyocytes causes a huge variation in the cell lipid environment, it does not induce detectable modifications in water-soluble metabolites, suggesting negligible interference with normal metabolic processes.     

Unsaturated phosphatidylethanolamine as effective synergist in combination with alpha-tocopherol

The effects of phosphatidylcholine (PC) and phosphatidylethanolamine (PE) on the oxidation of bonito oil triacylglycerol (TAG) were examined under the absence or presence of alpha-tocopherol. Synthesized PC or PE having saturated and unsaturated fatty acids in known position were used in this study. Unsaturated PC and PE promoted TAG oxidation under the absence of alpha-tocopherol. On the contrary, unsaturated PE showed synergistic antioxidant effect with alpha-tocopherol, while PC had little effect. The strongest synergistic effect was found by 1-palmitoyl (16:0, PA)-2-docosahexaenoyl (22:6n-3)-PE, followed by 1-PA-2-arachidonyl (20:4n-6)-PE, 1,2-dioleoyl (18:1n-9)-PE, and 1-PA-2-linoleoyl (18:2n-6)-PE, respectively.     

Practical Syntheses of Triacylglycerol Regioisomers Containing Long-chain Polyunsaturated Fatty Acids

Docosahexaenoic acid (DHA, 22:6n-3) is known to protect against a range of degenerative disease conditions and aid in the development of eye and brain function in infants. In dietary lipids DHA is found primarily in the triacylglycerol (TAG) form. However, the effects of the positional distribution of DHA in TAG on lipid functional properties such as bioactivity and oxidative stability are not clearly understood. Studies on this subject for the most part are limited by a lack of regioisomerically pure TAG model compounds containing DHA or similar long-chain (LC)-polyunsaturated fatty acids (PUFA). This paper reports on the development of a practical procedure, based on chemical and enzymatic reactions, for the syntheses of regioisomerically enriched, symmetrical and unsymmetrical TAG isomers containing two palmitic acid and one of linoleic acid, linolenic acid, or DHA. 1,3-Selective acylation of glycerol with vinyl esters of fatty acids catalyzed by Candida antarctica lipase and direct coupling with fatty acids in the presence of the coupling agents 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and 4-dimethylaminopyridine furnished 1,3-dihexadecanoyl-2-docosahexaenoyl glycerol and its unsymmetrical isomer 1,2-dihexadecanoyl-3-docosahexaenoyl glycerol in 99 and 60% yield, respectively. Critical to the success of the unsymmetrical TAG synthesis is the demonstration that PUFA-containing glycerol acetonides can readily survive appropriately tailored acid-catalyzed conditions. In this way, sufficient quantities of highly regioisomerically enriched PUFA-containing unsymmetrical monoacylglycerols (MAG) and TAG have now become routinely accessible. The methods are amenable to scale-up and could be adopted for regioenriched synthesis of a wide range of TAG.