Neutral Lipid Composition Research Articles

Characteristics of the flesh and quality of products of catfishes

Specificities of the structural, chemical, physical and sensory characteristics of the flesh are reviewed and related to different aspects of flesh quality. Potential for processing of catfish is high in terms of mechanization but rather low in terms of processing yields. The variability observed in body conformation traits supports the possibility to improve processing yields by genetic selection. Little is known on the structure of catfish flesh but a higher cohesiveness due both to greater connective tissue strength and probably a greater homogeneity of muscle tissues is observed, compared to other freshwater species. Although the presence of adipose tissues has not been demonstrated, intermuscular adipose tissues contributes with red muscle to lipid deposits in commercial size. Lipid content in catfish flesh increases with age but even at commercial size it is still lower than what is reported in other cultured fish. There is however a tendency in recent years for an increase in lipid content in catfish flesh due to increased lipid content in the diet. Thus, further information on the control of lipid deposits is required in future especially in a view to improve taste and processing yields. The lipid composition of neutral lipids reflects that of the diet with high levels of monounsaturated fatty acids and a low w3/w6 ratio. Flesh colour is very subtle but it could be controlled either by the use of pigment supplementation in the diet or by rearing non pigmented catfish. Other physical characteristics of the flesh are very stable during the cooking process. Cooked flesh has a relatively low water-holding capacity and a low resistance to mechanical stress (compression, extrusion) thus contributing to the juiciness and tenderness of the flesh. The sensory characteristics of the flesh are somewhat neutral but consumers are able to detect the specific characteristics of different species such as Channel catfish, African catfish and European catfish. Significant efforts to standardize the sensory evaluation of Channel catfish have been made in the USA but flavor and aroma of catfish seem to be more related to the fish itself than to other factors such as the diet composition. New data is available on off-flavors related to geosmin and methyl-iso-borneol. Specific control of the phytoplankton species which produce these compounds appears to be possible. Storage on ice affects the flesh acceptability as it does for other fish species, but catfish flesh seems to be stable at least physically during freezing. Traditional processing is used for preservation of the flesh. New processing methods have been tested for the diversification of catfish products or to produce substitutes for other animal products. Catfishes are generally shown to be suitable for processing.

Fatty acids and egg quality in great scallop

Spawners of the great scallop, Pecten moximus, were conditioned on three microalgal diets: T-Isochrysis, a mixture of four species (PTSC) and Chaetoceros calcitrans. The polyunsaturated fatty acid (PUFA) composition of neutral and polar lipids of eggs was related to the fatty acid composition of the diet. However, the 20 and 22 carbon PUFAs were maintained at significant levels independent of those of the diet when these fatty acids were present in the diet at low levels. This effect was more pronounced in the polar than in the neutral lipids. A preferential incorporation of 22:6(Ω-3) and 20:4(Ω-6) was demonstrated in the polar lipids. This emphasizes their role in ovogenesis and embryogenesis. The 22:6(Ω-3) requirement of P. maximus was better satisfied by T-Isochrysis, which favoured the highest incorporation of this essential fatty acid in the eggs. The good success in reproduction obtained with this monospecies diet led us to modify multispecies diets by increasing the level of 22:6(Ω-3).

Lipid classes and fatty acid composition of rotifers (Brachionus plicatilis) fed two algal diets

Rotifers (Brachionus plicatilis), maintained on baker's yeast, were fed for 24h upon two algal diets, Isochrysis galbana (diet A) and Isochrysis galbana + Nannochloropsis gaditana (diet B). (These algal diets were selected for their potential use as essential fatty acid (EFA) boosters, taking into account the requirements of fish larvae). The effect of these algal diets on total lipid content, lipid classes and fatty acid composition was studied. The total lipid content increased after feeding upon both diets but no significant differences were found between the two types. Neutral lipid and polar lipid contents increased and a positive correlation was observed between the neutral lipids content of rotifers and that of the food supplied. However, the content of polar lipids in rotifers did not depend upon that of the diet. The increase in neutral lipid content was found to be higher in rotifers fed upon diet B, compared to diet A which increased the phospholipid content. Non-enriched rotifers contained only small amounts of polyenoic fatty acids, i.e. 18:3n-6, 18:3n-3, 20:4n-6, 20:5n-3 and 22:6n-3, the contents of which increased significantly by feeding both diets. The EFA composition (20:4n-6, 20:5n-3 and 22:6n-3) of neutral lipids and phopholipids in rotifers reflected the EFA composition of each diet. Diet B-fed rotifers had the highest content in 20:4n-6 and 20:5n-3, whereas rotifers fed diet A and the highest 22:6n-3 content. The mixed diet I. galbana + N. gaditana enhanced substantially the composition of lipid classes i.e. neutral lipids and of n-3 PUFA of rotifers in comparison with Isochrysis or yeast diets.

Effect of food fatty acid and sterol quality on Pecten maximus gonad composition and reproduction process

Spawning individuals of the scallop Pecten maximus were conditioned on three test diets: Tahiti Isochrysis, a mixture (PTSC) and Chaetoceros calcitrans. The scallops fed T- Isochrysis showed a better hatching rate and lower atresia than those fed the other two diets. Proximate composition of the female gonads was not modified by the differences in the diets. Enrichment of gonads with sterol esters and triglycerides, characteristic of storage of lipids, observed with the broodstock fed the diatoms, did not result in successful gametogenesis and spawning. The monounsaturated fatty acid (MUFA) and polyunsaturated fatty acid (PUFA) composition of neutral and polar lipids of gonads was related to the fatty acid composition of the diet. However, the 20 and 22 carbon PUFA were maintained at levels relatively independent of those of the diet; when these fatty acids were low in the diet, their concentration in the lipids of the gonads decreased but still remained significant. This effect was more pronounced in the polar than the neutral lipids. The preferential incorporation of 22:6 n − 3, 20:4 n − 6 and 20:5 n − 3 in the polar lipids indicates their role in gametogenesis and embryogenesis. The sterol composition of the gonads (free sterols and sterol esters) reflected that of the diet; however, the cholesterol, mainly found in the esterified fraction, was maintained at stable levels independent of dietary supply. Two sterols (22-dehydrocholesterol and 24-methylenecholesterol) that were either absent from, or present only in trace amounts in the diets, were found to occur at constant levels in the female gonads, regardless of the nature of the diet.

Lipidic characterization of full-grown amphibian oocytes and their plasma membrane-enriched fractions.

The content and composition of neutral lipids and phosphoglycerides from full-grown prophase-arrested Bufo arenarum Hensel oocytes and from their ghost preparations were studied. The ghosts obtained are highly enriched in plasma membrane as suggested by the activity of 5'-nucleotidase, a marker enzyme, and the level of typical membrane components such as sphingomyelin, phosphatidylserine (PS), phosphatidylinositol (PI), and phosphatidic acid. In whole oocytes, triacylglyceride (TAG) comprises about 60% of the total lipids followed by phosphatidylcholine (PC), cholesterol, and phosphatidylethanolamine (PE). TAG and diacylglycerides have a similar unsaturation index. PC and PE account for about 80% of the phosphoglycerides in the whole oocyte and in their plasma membrane-enriched fractions. Arachidonic acid (20:4n-6), 18:0, and 16:0 make up about 80 mol% of the total fatty acids in PI in whole oocytes and ghost fractions. The unsaturation index in PS is higher in intact oocytes than in ghost preparations, probably owing to the significant amount of 20:4n-6 which comprises 23 mol% of the total fatty acids in whole oocytes. The fatty acid profile in phosphatidic acid from whole oocytes is rather different from that in ghosts. Sphingomyelin contains mainly saturated and monounsaturated fatty acids, 24:1 being the principal very long chain unsaturated fatty acid in both oocytes and ghosts.

Influence of dietary n − 3 highly unsaturated fatty acids levels on juvenile gilthead seabream ( Sparus aurata) growth and tissue fatty acid composition

Gilthead seabream juveniles (11.5 ± 0.2 g mean weight) were fed diets containing different levels of n − 3 highly unsaturated fatty acids ( n − 3 HUFA) for 8 weeks. The fatty acid composition of neutral and polar lipids from gills, liver, muscle and brain, as well as fish performance were studied. In tissues sampled at the commencement of the feeding study 16:0, 18:1 n − 9 and n − 3 HUFA were the most abundant of the saturated, monounsaturated and polyunsaturated fatty acids, respectively. In both polar and non-polar lipids, the initial ratio of eicosapentaenoic acid (EPA) to docosahexaenoic acid (DHA) in the neutral fraction of all tissues examined was approximately 1:2, whereas in the polar fraction of muscle, liver and gills the ratio comprised between 1:1.5 and 1:1. When the fish were fed a diet with a very low content of n − 3 HUFA (0.19%), a marked decrease in these fatty acids occurred in the neutral fraction, while the reduction in the polar fraction was more moderate in all the tissues. In these fish the relative losses of EPA and DHA were similar in the neutral fraction of the lipids of the gills, muscle and liver, whereas in the polar fraction these values were only similar in muscle and liver. Growth and feed efficiency were higher in fish fed a diet containing 1% n − 3 HUFA. Further elevation of the dietary n − 3 HUFA level from 1% to 1.5% resulted in a worsening of those parameters. It is concluded that the requirement of n − 3 HUFA of gilthead seabream of 11–30 g weight is at least 1 % of the dry diet.

Genetic and nutritional effects on the fatty acid composition of subcutaneous and intramuscular lipids of steers

Genetic and nutritional influences on fatty acid composition of subcutaneous (SNL) and intramuscular neutral lipids (IMNL) and intramuscular phospholipids (IMPL) of steer carcasses were investigated by removing the effect of carcass fat percentage (CFP) or slaughter age (SA) on the fatty acid composition. To investigate the genetic influences, steer progenies from two dam breed-types (Japanese Black (JB) and f 1 between JB bull and Holstein cows) and three different maturing types of JB sires were used. Dam breed-type did not affect any of the fatty acids except 17:0 in SNL and none of those in IMNL. Percentages of 16:0, 16:1, 18:2, SFA, MUFA and PUFA in SNL differed among sires of JB dam breed-type group ( p < 0.05) even after removing the effect of CFP. Studies on the effects of two nutritional planes [high(H) and medium-high(MH)] on the fatty acid composition of SNL, IMNL and IMPL were done using JB steers. The SNL and IMNL of the H plane steers contained greater percentages of saturated fatty acids at the same CFP but less at the same SA than the MH plane animals. The reverse was true for the unsaturated fatty acid contents.

Polyunsaturated fatty acids in neutral lipids and phospholipids of some freshwater insects

The fatty acid compositions of total neutral lipids and total polar lipids from eight species of freshwater insects were determined: stonefly nymphs (Plecoptera), beetle larvae (Coleoptera), Chironomidae (Diptera), water boatmen (Corixidae and Notonecta; Heteroptera) and mayfly nymphs ( Ecdyonurus venosus, Caenis, Ephemerella; Ephemeroptera). In addition, the compositions of individual phosphoglycerides were determined for four of the species (Plecoptera, Corixidae, Ecdyonurus venosus and Emphemerella). Saturated and monounsaturated fatty acids together represented up to 85% of the fatty acids of total neutral lipids with 16:0 (18–31%) being the most abundant saturated fatty acid and 16:1n-7 (10–28%), 18:1n-9 (6–12%) and 18:1n-7 (3–12%) the most abundant monounsaturates. Polyunsaturated fatty acids (PUFA) accounted for between 16% and 33% of the total fatty acids of neutral lipids, with 20:5n-3 (4–12%), 18:3n-3 (3–30%) and 18:2n-6 (1–8%) all being major components. Arachidonic acid, 20:4n-6 (0.4-1.0%) and 22:6n-3 were, respectivety, minor and insignificant components of total neutral lipids. PUFA were major fatty acids (34–56% of the total) in total polar lipids and in phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine and phosphatidylinositol. The major PUFA present were 20:5n-3 (14–27%) and 18:3n-3 (6–23%). The most abundant n-6 PUFA, especially in phosphoglycerides from Corixidae, was 18:2n-6 (3–11%). Arachidonic acid, 20:4n-6, was present in all phosphoglycerides accounting for 1–4% of the total fatty acids, except in the phosphatidylinositol of Corixidae where it accounted for 12% of the total. 22:6(n-3) was not present in significant amounts in any phosphoglyceride in any species. 18:1n-9 (8–20%) and 18:1n-7 (2–14%) were the most abundant monounsaturated fatty acids, especially in phosphatidylethanolamine. 16:0 was abundant in phosphatidylcholine (11–21%), and 18:0 (17–23%) was abundant in phosphatidylserine. The results are discussed in relation to the functions and origins of PUFA in freshwater insects.

Alterations in surfactant neutral lipid composition during the development of bleomycin-induced pulmonary fibrosis

The purpose of this investigation was to correlate changes in the neutral lipids of pulmonary surfactant with previously observed changes in surfactant phospholipids and lung compliance in the rat model of bleomycin-induced pulmonary fibrosis. Bronchoalveolar lavage fluid (BAL) obtained at 0, 1, 3, 7, 14, 30 and 120 days after transtracheal instillation of bleomycin was used as a source of surfactant lipids. The mean concentration of neutral lipids in normal BAL was 439 nmol/lung and was composed of 55% cholesterol (CHO), 27% cholesterol ester (CE) and 19% free fatty acids (FFA). CHO was elevated at 1 day, reaching a maximum 4-fold increase in concentration at 14 days before subsiding to normal at 120 days. In contrast to CHO, CE and FFA were significantly reduced at 1 day after bleomycin with FFA below detectable levels. However, both these species were twice normal levels at 3–30 days before returning to normal at 120 days. The fatty acid composition of CE did not change; however, unsaturated fatty acids were significantly increased in FFA between 3 and 120 days. The data indicate that there are significant alterations in the neutral lipid composition of pulmonary surfactant at various stages of bleomycin induced lung injury. The significance of these changes are not fully understood; however, the possibility exists that an abnormal surfactant results which in turn affects lung function.

Composition of Pneumocystis carinii neutral lipids and identification of coenzyme Q10 as the major ubiquinone homolog.

The lipids of purified preparations of Pneumocystis carinii carinii freshly isolated from infected rats were analyzed and compared with those of whole lungs from normal and methylprednisolone-immunosuppressed uninfected rats. In this study, the neutral lipid fraction was examined in detail; the relative concentrations of individual classes making up this fraction were quantified. Of particular interest was the nature of the organism's ubiquinone (coenzyme Q, CoQ) fraction because atovaquone, a hydroxynaphtho-quinone (566C80) analog of ubiquinone, is efficacious in the treatment of P. carinii pneumonia. The ubiquinone concentration in both P. carinii and lung tissues was relatively low compared to that present in rat heart and liver tissues. Two homologs were identified in the organism: CoQ10 was the predominant homolog with lesser amounts of CoQ9 present. In contrast, the lungs of normal and immunosuppressed uninfected rats had CoQ9 and lesser amounts of CoQ8, but no detectable CoQ10. Furthermore, radiolabeled mevalonic acid was incorporated in vitro into the ubiquinone fraction of P. carinii indicating that the organism has the de novo branch of the isoprenoid biosynthetic pathway leading to polyprenyl formation. Hence, it was concluded that CoQ10 (if not both CoQ10 and CoQ9) in P. carinii was not scavenged from the host but was synthesized by the organism. Although lung tissues contained substantial free fatty acids, the organism was enriched in these lipids. The high concentration of free fatty acids and relatively low level of triglycerides in P. carinii suggest that fatty acids may represent major carbon sources for ATP production by the organism.

Plasmid DNA is Protected against Ultrasonic Cavitation-Induced Damage when Complexed to Cationic Liposomes

AbstractCationic liposomes bound to plasmid DNA are currently used for in vitro and in vivo gene therapy applications, but such complexes readily form large, heterogeneous aggregates that are not appropriate for pharmaceutical development. More importantly, size heterogeneity makes studies focused on optimizing gene transfer to cells difficult to conduct or understand. For this reason we have evaluated the effect of microprobe sonication on these complexes in an effort to acheive process-controlled size homogeneity. Complexes were prepared using a 7.2kb reporter plasmid and the following liposomal lipid combinations: DDAB/DOPE (50:50mol%), DDAB/DOPE/PEG-PE (50:45:5mol%), DDAB/EPC (50:50mol%), DDAB/EPC/PEG-PE (50:45:5, 50:40:10, 50:35:15mol%), DODAC/DOPE (50:50mol%), and DODAC/EPC (50:50mol%) (DDAB, dimethyldioctadecylammonium bromide; DOPE, dioleoylphos-phatidylethanolamine; PEG-PE, monomethoxypolyethylene glycol2000 succinate–distearoylphosphatidylethanolamine; EPC, egg phosphatidylcholine; DODAC, dioleoyldimethylammonium chloride). The influence of complex composition and lipid:DNA ratio was evaluated. Particle size was determined before and after complexation and again after sonication using the quasi-elastic light scattering technique. DNA integrity was assessed via agarose gel electrophoresis. Finally, gene transfection was evaluated using CHO cells that were transfected in vitro with sonicated and unsonicated complexes. It is established in this study that size reduction can occur, but this is dependent on cationic and neutral lipid composition and, in some cases, lipid:DNA ratio. Surprisingly, the process of sonication leaves a significant percentage of the plasmid DNA intact and capable of in vitro transfection. This study shows that plasmid DNA can be protected from damage due to sonication by liposome complex formation. This may indicate that more common pharmaceutical methods for size reduction which subject particles to mechanical stress may be applicable in preparation of liposome/DNA formulations for in vivo application.

Cholesteryl ester transfer activity in liver disease and cholestasis, and its relation with fatty acid composition of lipoprotein lipids

Liver disease is accompanied by major qualitative and quantitative disturbances in plasma lipoprotein metabolism, the extent and intensity of which depend on the degree of parenchymal damage, cholestasis, or both. The main objective of this study was to determine the cholesteryl ester transfer CETP activity and its association with the lipoprotein neutral lipid composition in patients with either liver cirrhosis or cholestasis, as compared to normal controls. Lipoproteins were isolated by ultracentrifugation, lipids and apolipoproteins were measured by conventional methods, and the fatty acid composition was established by gas chromotography; CETP activity in lipoprotein-deficient plasma was measured by determining the transfer of [ 3H]cholesteryl esters from HDL to VLDL. Lipoprotein lipase and hepatic lipase activities were measured in post-heparin plasma by radiochemical methods. In patients with liver cirrhosis, low levels of VLDL, HDL, apo B, and Lp(a) were observed, as well as a change in the composition of HDL particles, with increases in the relative proportion of triglyceride and free cholesterol. Respectively, the last two changes could be attributed in part to the low hepatic lipase activity observed in this study, and to the low lecithin:cholesterol acyltransferase activity previously observed by others. In patients with cholestasis, a moderate hyperlipidemia due to the elevation of LDL was found. In contrast, HDL and apo A-I levels were very low reflecting a low number of HDL particles, which also had altered compositions with increases in the triglyceride and free cholesterol contents relative to apo A-I and esterified cholesterol, respectively. As regards the fatty acid composition of lipoprotein lipids, the two groups of patients showed, in general, a lower proportion of linoleic acid and a compensating higher proportion of oleic acid as compared to the controls, changes that were observed in both cholesteryl esters and triglycerides. In contrast, the proportions of oleic and palmitoleic acids in phospholipids were increased, whereas that of stearic acid was decreased in patients as compared to controls. In patients with liver cirrhosis, as well as in controls, no changes were observed in the fatty acid compositions of cholesteryl ester, triglycerides, or phospholipids among the different lipoproteins, which probably reflects the equilibration reached by the action of CETP. In patients with cholestasis, no differences were observed in fatty acid composition among the lipoprotein phospholipids but, interestingly, cholesteryl esters from VLDL had a significantly lower linoleic acid content than those from HDL, whereas triglycerides from VLDL had significantly higher oleic acid and lower linoleic acid contents than those from HDL. This distinct fatty acid composition of the neutral lipids between lipoproteins was associated with a significant decrease (25%) in the cholesteryl ester transfer activity in patients with cholestasis. We suggest that fat malabsorption due to the biliary defect may induce a decrease in cholesteryl ester transfer protein synthesis or secretion, which in turn would slow the equilibration of the neutral lipids among plasma lipoproteins.

Lipids of silkworm cocoons

The lipid complex of silkworm cocoons had been investigated. The qualitative and quantitative compositions of the total neutral lipids and glyco- and phospholipids have been determined. Considerable differences have been noted in the amounts of individual fatty acids in the neutral lipids and the phospholipids.

The role of concanavalin A-binding glycoproteins (CABG) in cholesterol cyrstallization in native human bile

Bile cholesterol, phospholipids, total bile acids, individual bile acids, and fatty acid compositions of bile neutral lipids and phospholipids were analyzed before, at one month and at six months following jejunoileal bypass surgery in a series of morbidly obese patients. Preoperative mole percentages of cholesterol and lithogenic indices were high, indicating that biles were supersaturated with cholesterol and outside the micellar solubility zone when plotted on triangular coordinates. At the one month post-operative period percentages of cholesterol and lithogenic indices were significantly increased as compared to the pre-operative state. At six months post-operatively these values had decreased to approximately the pre-operative levels. No changes were observed in percentages of lithocholic acid, but deoxycholic acid decreased to markedly low levels at one month and remained low at the six month post-operative interval. Relative proportions of cholic acid increased, and the ratio of cholic to chenodeoxycholic acid was significantly increased at both post-operative intervals. No significant changes were noted in bile neutral lipid or phospholipid fatty acid composition, indicating that no depletion of essential fatty acids had occurred.

Isolation of nonsedimentable lipid-protein particles from insect intestine.

Nonsedimentable lipid-protein particles have been isolated from intestinal tissue of the American cockroach, Periplaneta americana. Most of the particles were within the range 30-50 nm in diameter and appear to originate from larger structures. Lipid analysis of the particles showed them to be enriched in neutral lipid components relative to microsomal membranes. Specifically, there is a decline in the amounts of phosphatidylcholine and phosphatidylethanolamine in the nonsedimentable particles compared with the microsomal membranes. Also, in contrast to microsomal membranes, the particles have a higher content of phosphatidic acid along with 1,2- and 1,3-diacyglycerols, free fatty acids and an unidentified lipid that co-migrates with sterol ester, wax ester and hydrocarbon standards in thin layer chromatograms. The cytosol, separated from the particles by ultrafiltration, contained phosphatidic acid, free fatty acids and the unidentified lipid. By contrast, the composition of neutral lipids in the cytosol resembles that of the particles. SDS-PAGE analysis of microsomal membranes, the particles and particle free cytosol shows an enrichment of low molecular weight proteins in the particles and cytosol. The particles and cytosol appear to possess proteolytic activity that is distinguishable from that of corresponding microsomal membranes since the incubation of these components with BSA resulted in the formation of distinct polypeptides. Many characteristics of these particles resemble those of the deteriosomes that have been isolated from plant tissue.

Effects of diet on the lipid composition of the digestive gland-gonad complex of Biomphalaria Glabrata (Gastropoda) infected with larval Echinostoma Caproni (Trematoda)

This study examined the effects of a larval Echinostoma caproni infection on the neutral lipid composition of the digestive gland-gonad complex (DGG) of Biomphalaria glabrata snails fed hen's egg yolk supplemented with lettuce (Y-L) or lettuce supplemented with Tetramin (L-T). Snails were experimentally infected with the miracidial stage of this echinostome, and their DGGs containing daughter rediae were analyzed for neutral lipids five weeks post-infection by qualitative and quantitative thin-layer chromatography. Light microscopy using Oil Red O (ORO) staining and transmission electron microscopy (TEM) were used to localize neutral lipids in the rediae. The DGGs of infected snails maintained on the Y-L diet showed a significant increase in free sterols and a significant decrease in triacylglycerols compared to uninfected snails maintained on the Y-L diet. The DGGs of infected snails maintained on the L-T diet showed no significant difference in free sterols or triacylglycerols compared to uninfected snails maintained on the L-T diet. ORO staining and TEM showed the presence of lipid droplets in rediae from snails on the Y-L diet. The significant decrease in triacylglycerols in the DGGs of infected snails maintained on the Y-L diet suggests that triacylglycerols were utilized by the rediae.

A new n-C 31:9 polyene hydrocarbon from Antarctic bacteria

The non-saponifiable neutral lipid composition of nineteen bacterial strains isolated from Antarctic sea ice were analysed. Nine of these strains produced a novel highly unsaturated straight chain hydrocarbon as the major non-saponifiable neutral lipid component. The compound was identified as hentriacontanonene (n-C 31.9) by mass spectrometry and the formation of n-C 31:0 following hydrogenation. The occurrence of n-C 31:9 also correlated with the production of polyunsaturated fatty acids (PUFA) by the bacterial strains. n-C 31:9 may therefore represent a novel biomarker for the location of PUFA-producing bacteria from environmental samples.

A new n-C31:9polyene hydrocarbon from Antarctic bacteria

The non-saponifiable neutral lipid composition of nineteen bacterial strains isolated from Antarctic sea ice were analysed. Nine of these strains produced a novel highly unsaturated straight chain hydrocarbon as the major non-saponifiable neutral lipid component. The compound was identified as hentriacontanonene (n-C31.9) by mass spectrometry and the formation of n-C31:0 following hydrogenation. The occurrence of n-C31:9 also correlated with the production of polyunsaturated fatty acids (PUFA) by the bacterial strains. n-C31:9 may therefore represent a novel biomarker for the location of PUFA-producing bacteria from environmental samples.

Carbohydrates and lipids ofBrassica oleracea

Lipids and polysaccharides have been obtained from the leaves ofBrassica oleracea. The qualitative and quantitative compositions of the lipid complex have been studied. The fatty acid compositions of the total neutral lipids and of the phospho- and glycolipids have been determined. The carbohydrate complex of cabbage includes water-soluble polysaccharides, low-methoxyl pectins, hemicelluloses, and free monosugars. The polypeptides have been characterized by their mannoside compositions.

369 Modulation of NAP-2-induced Neutrophil (PMN) Activation by Different Surfactant Preparations

Background: Lung surfactant, a complex composition of phospholipids, neutral lipids and various apoproteins is essential for lung function. In surfactant deficient neonates treatment was done successfully by endotracheal administration of either natural or artificial surfactant preparations. Alteration of the alveolo-capillary membrane may allow blood compounds, such as proteins and cells to interact with surfactant constituents and vice versa.The aim of our study was to investigate surfactant-related effects on PMN since these cells are major effector cells of the primary immune and inflammatory response, involved in pulmonary failure.Methods: PMN, isolated from citrated blood of 3 healthy volunteers were allowed to interact with different surfactant preparations for a time of 30 minutes. Cell activation, reflected by PMN degranulation was detected by measurements of elastase-activity in the supernatant.Results: While NAP-2-induced elastase release was suppressed about by 70% at concentrations of more than 1.0 mg/ml of natural preparations Survanta® and Curosurf®, the only artificial preparation Exosurf® showed slightly stimulating effects. Alveofact®, in contrast seems to combine both, activating and inhibiting properties, interfering with each other. If unstimulated, PMN were not affected by the surfactant preparations.Conclusion: NAP-2-induced activation of isolated PMN is modulated by surfactant. Clinical implications of preparation related effects have to be elucidated.