Linoleic Acid (linoleic + acid)

Distribution by Scientific Domains
Distribution within Life Sciences

Kinds of Linoleic Acid

  • conjugated linoleic acid
  • free linoleic acid

  • Terms modified by Linoleic Acid

  • linoleic acid content
  • linoleic acid system

  • Selected Abstracts


    EFFECT OF WATER ACTIVITY ON PHYSICAL PROPERTIES OF CONJUGATED LINOLEIC ACID (CLA) MICROCAPSULES

    JOURNAL OF FOOD PROCESS ENGINEERING, Issue 3 2010
    MARIBEL JIMENEZ
    ABSTRACT The physical properties of spray drying powders must be considered for the design of equipment. Conjugated linoleic acid (CLA) microcapsules were spray dried by using the following as wall materials: whey protein concentrate (WPC), a blend of whey protein concentrate,maltodextrins (WPC-MD) and gum arabic (GA). These were prepared and their physical properties were studied. The bulk density, packed density, particle density, compressibility and color of the microcapsules were evaluated in a range of water activities from 0.108 to 0.898. No significant differences in the physical properties were found when WPC was used as a wall material in the microcapsules stored at the whole range of water activities tested. Maltodextrins conferred changes in some of the physical properties of the microcapsules (WPC-MD) upon storage at high water activities. GA microcapsules showed drastic changes in all physical properties studied at water activities above 0.628. PRACTICAL APPLICATIONS This work shows the best conditions for storing conjugated linoleic acid (CLA) microcapsules elaborated with different wall materials, which have been reported to have a high potential as a food additive because of the nutraceutical properties of CLA. This research should reveal the behavior of water activity during storage on physical properties, and make it possible to predict what characteristics need to be added to a food, besides being important for the design of equipment, packing and transport. [source]


    Further support for the Protective Effect of Linoleic Acid Against Psoriasis

    INTERNATIONAL JOURNAL OF DERMATOLOGY, Issue 6 2005
    Mohammad R. Namazi MD
    No abstract is available for this article. [source]


    Lipase-mediated Acidolysis of Fully Hydrogenated Soybean Oil with Conjugated Linoleic Acid

    JOURNAL OF FOOD SCIENCE, Issue 1 2004
    J. Ortega
    ABSTRACT: Interesterification (acidolysis) of fully hydrogenated soybean oil (melting point = 69.9 °C) with conjugated linoleic acid (CLA) was carried out in a batch reactor at 75 °C. Lipases from Candida antarctica, Rhizomucor miehei, Pseudomonas sp., and Thermomyces lanuginosus were used at 5% (wt/wt) of the total substrate load. The lipase from Rhizomucor miehei produced the fastest reaction rates, and the greatest extent of incorporation of CLA residues in acylglycerols was achieved in 12 h. Lipases from C. antarctica and T. lanuginosus produced slower initial rates, and maximum extents of incorporation of CLA residues were achieved in 24 h. The lipase from Pseudomonas sp. produced the slowest initial rate. The corresponding maximum extent of incorporation was reached in 48 h. Differential scanning calorimetry analysis of the triacylglycerol (TAG) fractions produced by C. antarctica, R. miehei, and T. lanuginosus lipases after purification by solid phase extraction showed little variation in melting point (60.4 °C, 62.8 °C, and 60.1 °C, respectively). By contrast, the corresponding TAG fraction produced by the Pseudomonas sp. lipase melted at 48.4 °C. The positional distribution of the TAGs produced by the lipase from Pseudomonas sp. differed appreciably from those produced by the other enzymes. [source]


    Effects of Linoleic Acid on Conjugated Linoleic Acid Production by Planktonic Rumen Bacteria from Grain-fed Cows

    JOURNAL OF FOOD SCIENCE, Issue 5 2003
    Y. J. Kim
    ABSTRACT Ruminal conjugated linoleic acid (CLA) production from linoleic acid (LA) was characterized in vitro. Rumen bacteria from grain-fed cows were more active in BH than those from hay-fed cows. Particleassociated bacteria produced more hydrogenated products leaving less CLA than the planktonic bacteria (P < 0.05). CLA production by planktonic bacteria did not always correlate to LA given; longer incubations generally decreased CLA concentration and increased c9, t11/t10, c12 ratio, especially at higher LA concentrations. The preincubated cells to LA produced more CLA than the unexposed ones and the increase was more evident with c9, t11 CLA (P < 0.05). This study provides insight into how cattle diet and LA feedings affect ruminal CLA production. [source]


    Bioconversion of Linoleic Acid into Conjugated Linoleic Acid by Immobilized Lactobacillus reuteri

    BIOTECHNOLOGY PROGRESS, Issue 3 2003
    Sun-Ok Lee
    Lactobacillus reuteri was immobilized on silica gel to evaluate the bioconversion of linoleic acid (LA) into conjugated linoleic acid (CLA), consisting of cis -9,trans -11 and trans -10,cis -12 isomers. The amount of cell to carrier, the reaction time, and the substrate concentration, pH, and temperature for CLA production were optimized at 10 mg of cells/(g of carrier), 1 h, 500 mg/L LA, 10.5, and 55 °C, respectively. In the presence of 1.0 mM Cu2+, CLA production increased by 110%. Under the optimal conditions, the immobilized cells produced 175 mg/L CLA from 500 mg/L LA for 1 h with a productivity of 175 mg/(L·h) and accumulated 5.5 times more CLA than that obtained from bioconversion by free washed cells. The CLA-producing ability of reused cells was investigated over five reuse reactions and was maximal at pH 7.5, 25 °C, and 1.0 mM Cu2+. The total amount of CLA by the combined five reuse reactions was 344 mg of CLA/L reaction volume. This was 8.6 times higher than the amount obtained from reuse reactions by free washed cells. [source]


    Biochemistry of PUFA Double Bond Isomerases Producing Conjugated Linoleic Acid

    CHEMBIOCHEM, Issue 12 2008
    Alena Liavonchanka Dr.
    Abstract The biotransformation of linoleic acid (LA) into conjugated linoleic acid (CLA) by microorganisms is a potentially useful industrial process. In most cases, however, the identities of proteins involved and the details of enzymatic activity regulation are far from clear. Here we summarize available data on the reaction mechanisms of CLA-producing enzymes characterized until now, from Butyrivibrio fibrisolvens, Lactobacillus acidophilus, Ptilota filicina, and Propionibacterium acnes. A general feature of enzymatic LA isomerization is the protein-assisted abstraction of an aliphatic hydrogen atom from position C-11, while the role of flavin as cofactor for the double bond activation in CLA-producing enzymes is also discussed with regard to the recently published three-dimensional structure of an isomerase from P. acnes. Combined data from structural studies, isotopic labeling experiments, and sequence comparison suggest that at least two different prototypical active site geometries occur among polyunsaturated fatty acid (PUFA) double bond isomerases. [source]


    Fatty acid incorporation in endothelial cells and effects on endothelial nitric oxide synthase

    EUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 9 2007
    S. Couloubaly
    Abstract Background The nature of fatty acids provided by the diet as well as plasma lipid metabolism can modify the composition and properties of plasma membrane and thus the activity of membrane proteins. In humans, as well as in experimental models, diabetes is associated with both an alteration in serum lipid profile and a documented endothelial dysfunction. This in vitro study investigated on an immortalized human endothelial cell line (EA.hy 926) the specific effects of several free fatty acids (FFAs) on the composition of cellular membranes and the regulation of endothelial nitric oxide synthase (eNOS). Materials and methods 0·1% of lipid deprived serum was added to the incubation medium with 25 mm glucose in order to study the effects of individual fatty acids: myristic acid, palmitic acid, stearic acid, oleic acid or linoleic acid at 100 µm bound with albumin. The effects of the FFAs on the endothelial nitric oxide synthase were investigated on mRNA level by quantitative PCR, on protein level and Ser1177 phosphorylation by Western blot and on enzymatic activity on living cells using radiolabelled arginine. Results Free linoleic acid increased the membrane content in n-6 fatty acids (mainly C18: n-6 and its metabolites) with a decrease in saturated and monounsaturated fatty acids. These conditions decreased the basal eNOS activity and reduced the phosphorylation of eNOS-Ser1177 due to activation by histamine. Free palmitic acid enriched the membranes with 16 : 0 with a slight decrease in monounsaturated fatty acids. These conditions increased eNOS activation without increasing Ser1177 phosphorylation upon histamine activation. The addition of the other FFAs also resulted in modifications of membrane composition, which did not to affect eNOS-Ser1177 phosphorylation. Conclusion Among the fatty acids used, only modification of the membrane composition due to linoleic acid supply disturbed the basal enzymatic activity and Ser1177 phosphorylation of eNOS in a way that limited the role of histamine activation. Linoleic acid might involve the dysfunction of both eNOS basal activity and its phosphorylation status and may then contribute to an impaired vasodilatation in vivo. [source]


    Effect of feeding rate on fatty acid composition of sharpsnout seabream (Diplodus puntazzo)

    AQUACULTURE NUTRITION, Issue 5 2004
    M. Rondán
    Abstract The effects of different feeding rates on the lipids fatty acid profile of sharpsnout seabream (Diplodus puntazzo) tissues were studied. During a 15-day period, four fish groups were allowed to feed to satiation, at two-thirds and one-third of satiety, and starved, respectively. Reducing food intake progressively increased the n-3:n-6 relationship by increase of n-3 (mainly Highly Unsaturated Fatty Acids) and decrease of n-6 fatty acid percentages. In perivisceral fat, this n-3:n-6 value was already statistically significant lower for the group fed to satiety (1.29 versus 1.71, 1.80 and 1.65 for the two-third-fed, one-third-fed and fasted groups, respectively), whereas in the white muscle (1.69 versus 2.13 and 2.12) and liver (0.83 versus 1.40 and 2.66) the differences were statistically significant only for the one-third-fed and fasted groups. Linoleic acid was the main contributor to the n-6 drop, whereas the n-3 fatty acids preferentially preserved were for the most part essential fatty acids. Fat quality indices (thrombogenic and atherogenic) were not affected by food restriction except for liver, being the former significantly lower in the one-third-fed and fasted groups. Food intake restriction to one-third of satiety levels was enough to trigger the mechanisms that preserve essential fatty acids. [source]


    Partial replacement of fishmeal with sunflower cake and corn oil in diets for tilapia Oreochromis niloticus (Linn): effect on whole body fatty acids

    AQUACULTURE RESEARCH, Issue 8 2003
    J G Maina
    Abstract The objective of this study was to determine the effect of replacing fishmeal with high-fibre and low-fibre sunflower cakes (HFSC and LFSC) on whole body fatty acid composition in tilapia Oreochromis niloticus (Linn). Sex-reversed O. niloticus males with an initial weight of approximately 16g ± 0.95 (SD) were used. A control diet based on herring meal and soybean meal was formulated. Six test diets were formulated such that low-fibre (LF) and high-fibre (HF) sunflower cakes (SC) contributed 30%, 60% and 80% of the dietary protein, and the diets were designated as LFSC-30, LFSC-60, LFSC-80, HFSC-30, HFSC-60, and HFSC-80 respectively. All fish were held at 25,28°C. They were fed three times daily their prescribed experimental diets for 70 days. At the end of this period they were starved for 24 h and weighed. Five fish representing the average weight of each replicated group (n=3) were frozen in plastic bags at ,22°C for determination of fatty acid composition. Fatty acids in the fish were significantly influenced by diet. Palmitic, oleic and linoleic acids were the most abundant fatty acids in both the diets and the fish. Linoleic acid (18:2 ,6) was the most abundant fatty acid in diets based on sunflower cake. The levels of this fatty acid were also higher in fish fed diets with high contents of the sunflower cakes (LFSC-60, LFSC-80 and HFSC-80) (31.3%, 34.7% and 29.7% respectively) than fish fed the control diet (13.8%). Percentages of long chain polyunsaturated acids of the ,-3 family viz., docosahexaenoic (22:6 ,3) and eicosapentaenoic (20:5 ,3) were low in the diets and in the fish bodies. Fish fed the control diet had a higher level of 22:6 ,3 than those fed the other diets. The possible implications of the preceding findings for human health will be discussed. [source]


    Natural vegetable fats in the prevention of irritant contact dermatitis

    CONTACT DERMATITIS, Issue 1 2002
    S. Schliemann-Willers
    Chronic irritant contact dermatitis (ICD) is one of the most pressing problems in occupational medicine and is common in the food processing industry. To date, protective creams that fulfil the special requirements in the foodstuffs industry have not been available. Therefore, we studied the efficacy of pre-exposure application of natural vegetable fats in the prevention of experimentally induced ICD. A panel of 20 healthy volunteers was tested with a repetitive irritation test using sodium lauryl sulfate (SLS) as a standard irritant in a randomized study. Application sites were assessed clinically and by the use of bioengineering techniques (evaporimetry, chromametry, and corneometry). Rape seed and palm fats showed significant protective potential. Gas-chromatographic analysis revealed differences in the fatty acid composition of the vegetable. Higher content of linoleic acid and lower content of oleic acid was associated with beneficial effects. Our results are a new approach in the prevention of ICD and towards the development of new protective preparations for workplaces in the foodstuffs industry. [source]


    Fatty acid incorporation in endothelial cells and effects on endothelial nitric oxide synthase

    EUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 9 2007
    S. Couloubaly
    Abstract Background The nature of fatty acids provided by the diet as well as plasma lipid metabolism can modify the composition and properties of plasma membrane and thus the activity of membrane proteins. In humans, as well as in experimental models, diabetes is associated with both an alteration in serum lipid profile and a documented endothelial dysfunction. This in vitro study investigated on an immortalized human endothelial cell line (EA.hy 926) the specific effects of several free fatty acids (FFAs) on the composition of cellular membranes and the regulation of endothelial nitric oxide synthase (eNOS). Materials and methods 0·1% of lipid deprived serum was added to the incubation medium with 25 mm glucose in order to study the effects of individual fatty acids: myristic acid, palmitic acid, stearic acid, oleic acid or linoleic acid at 100 µm bound with albumin. The effects of the FFAs on the endothelial nitric oxide synthase were investigated on mRNA level by quantitative PCR, on protein level and Ser1177 phosphorylation by Western blot and on enzymatic activity on living cells using radiolabelled arginine. Results Free linoleic acid increased the membrane content in n-6 fatty acids (mainly C18: n-6 and its metabolites) with a decrease in saturated and monounsaturated fatty acids. These conditions decreased the basal eNOS activity and reduced the phosphorylation of eNOS-Ser1177 due to activation by histamine. Free palmitic acid enriched the membranes with 16 : 0 with a slight decrease in monounsaturated fatty acids. These conditions increased eNOS activation without increasing Ser1177 phosphorylation upon histamine activation. The addition of the other FFAs also resulted in modifications of membrane composition, which did not to affect eNOS-Ser1177 phosphorylation. Conclusion Among the fatty acids used, only modification of the membrane composition due to linoleic acid supply disturbed the basal enzymatic activity and Ser1177 phosphorylation of eNOS in a way that limited the role of histamine activation. Linoleic acid might involve the dysfunction of both eNOS basal activity and its phosphorylation status and may then contribute to an impaired vasodilatation in vivo. [source]


    Oxidative stability of Echium plantagineum seed oil bodies

    EUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY, Issue 7 2010
    David A. Gray
    Abstract Echium plantagineum seed contains a highly polyunsaturated oil (approximately 14% linoleic acid, 10% ,-linolenic acid, 33% ,-linolenic acid and 14% stearidonic acid); almost half of the fatty acids are omega-3 fatty acids, so there is an interest in the possible health benefits of this oil, which, once extracted, is prone to oxidation. For the first time in reported literature, oil bodies (OBs), the organelles that store the oil in mature seed, were recovered from E. plantagineum seeds. The oxidative stability of these organelles ex vivo, dispersed in an aqueous continuous phase, was tested against processed E. plantagineum oil emulsions stabilised with either SDS or Tween 20. For both primary and secondary oxidation products the OBs were the most stable form of dispersed oil, and the dispersed systems were all more stable than bulk E. plantagineum oil after incubating at 40°C for 7 days. The possible reasons for the enhanced chemical stability of E. plantagineum OBs are explored in this paper. Practical applications: OBs, the natural store of oil in oilseeds, can be recovered from seeds intact and are relatively stable to oxidation ex vivo. Echium seed OBs, enriched in physiologically active omega-3 fatty acids, therefore offer an attractive alternative to traditional oil extraction methods and overcome the need to encapsulate the omega-3 rich oil. [source]


    Effects of tocopherols and tocotrienols on the inhibition of autoxidation of conjugated linoleic acid

    EUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY, Issue 4 2010
    Soon-Nam Ko
    Abstract The effect of eight vitamin E homologues, i.e. ,-, ,-, ,-, and ,-tocopherol and ,-, ,-, ,, and ,-tocotrienol, on the inhibition of autoxidation of conjugated linoleic acid (CLA) were investigated. The oxidation was carried out in the dark for 21 days at 50,°C and monitored by peroxide values (PV) and TBA values. The levels of the individual vitamin E homologues in CLA during storage were determined by HPLC. ,-Tocopherol exhibited the highest antioxidant activity among the homologues tested in this study when the antioxidant activities of the individual homologues in CLA were compared by PV. The order of antioxidant activity of eight homologues was ,-tocopherol,>,,-tocopherol,=,,-tocotrienol , ,-tocotrienol,>,,-tocopherol,=,,-tocotrienol,>,,-tocopherol,=,,-tocotrienol. The degradation rates of , -tocopherol and , -tocotrienol were faster than those of the other homologues, whereas ,-tocopherol had the highest stability in CLA during storage. All homologues exhibited an antioxidant activity by inhibiting the formation of secondary oxidation products. It appears that ,-tocotrienol and ,-tocotrienol have significantly higher antioxidant activities for secondary oxidation in CLA than ,-tocopherol and ,-tocopherol. Meanwhile, the other homologues, namely ,-tocopherol, ,-tocotrienol, ,-tocopherol, and ,-tocotrienol, exhibited similar antioxidant activity for secondary oxidation in CLA. [source]


    Commercial Runner peanut cultivars in the USA: Fatty acid composition

    EUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY, Issue 2 2010
    Eui-Cheol Shin
    Abstract Though peanuts are classified as a high-fat food, they possess good proportions of fatty acids deemed as heart healthy. The fatty acid compositions of Runner peanuts were determined for commercially grown cultivars over two recent crop years. GC-FID analyses revealed that the fatty acid levels for Runner peanuts were significantly (p,<0.05) different among the normal, mid-, and high-oleic peanuts investigated. Oleic acid-to-linoleic acid (O/L) ratios were found to be 1.93,±,0.30, 5.25,±,1.12, and 16.9,±,5.20 for normal, mid-, and high-oleic peanut lipids, respectively. Tamrun OL01 possessed a fatty acid profile characteristic of a mid-oleic cultivar. From the sample set (n,=,151), mean %,weights for oleic acid and linoleic acid were 52.09,±,2.84 and 27.38,±,2.60 in normal, 69.33,±,3.18 and 13.66,±,2.35 in mid-oleic, and 78.45,±,2.05 and 5.11,±,1.67 in high-oleic peanuts, respectively. Cluster analysis segregated cultivars based on fatty acids into normal, mid-, and high-oleic groups. Factorial analysis revealed that cultivar effects were significant (p,<0.01) for all fatty acids, except for lignoceric acid. Cultivar effects were also highly significant (p,<0.001) for O/L, IV, unsaturated/saturated fatty acid (U/S) ratio, and %,saturation. Significant crop year effects were shown for palmitic, oleic, arachidic, gondoic, and lignoceric acids, as well as U/S ratio and %,saturation. Healthy unsaturated fats accounted for ,80% in all crop years and cultivars. [source]


    Chemical evaluation of some paprika (Capsicum annuum L.) seed oils

    EUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY, Issue 12 2009
    Bertrand Matthäus Dr.
    Abstract The oil contents of seeds from paprika (Capsicum annuum L.) collected from different locations in Turkey and Italy varied in a relatively wide range from 8.5,g/100,g to 32.6,g/100,g. The fatty acid, tocopherol and sterol contents of the oils from different paprika seeds were investigated. The main fatty acids in paprika seed oils were linoleic acid (69.5,74.7,g/100,g), oleic acid (8.9,12.5,g/100,g) and palmitic acid (10.7,14.2,g/100,g). The oils contained an appreciable amount of ,-tocopherol (306.6,602.6,mg/kg), followed by ,-tocopherol (7.3,148.7,mg/kg). The major sterols were ,-sitosterol (1571.4,4061.7,mg/kg), campesterol (490.8,1182.7,mg/kg), and ,5 -avenasterol (374.5,899.6,mg/kg). The total concentration of sterols ranged from 3134.0,mg/kg to 7233.7,mg/kg. Remarkable amounts of cholesterol were found in the different samples (164.6,491.0,mg/kg). The present study showed that paprika seeds are a potential source of valuable oil that could be used for edible and industrial applications. [source]


    Supercritical extraction of borage seed oil coupled to conventional solvent extraction of antioxidants

    EUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY, Issue 11 2008
    Carmen Soto
    Abstract This paper describes the extraction of borage seed oil by supercritical carbon dioxide (SC-CO2) and the further extraction of antioxidants from the SC-CO2 -defatted borage meal with organic solvents (water, methanol, ethanol and ethyl acetate). The optimal conditions for oil extraction were obtained at 303 and 323,K at 200,bar, 2.5,h and a continuous flow of CO2 of 1.5,L/h introduced through the bottom when the operating pressure and temperature were reached, attaining a yield of 60%. Borage oil is rich in unsaturated fatty acids; oleic acid, linoleic acid and linolenic acid accounted for 74% of the total fatty acid content under the above conditions. The highest extraction yield was achieved using water or methanol as extracting solvent from the SC-CO2 -defatted borage meal at 303,K and pressures of 200 and 150,bar for water and methanol, respectively. The most potent extracts, according to all methods tested, were obtained with water and methanol. [source]


    Role of biohydrogenation intermediates in milk fat depression

    EUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY, Issue 8 2007
    Kevin J. Shingfield
    Abstract Fat is the most variable constituent in milk and is reduced on low-fiber/high-concentrate diets or on rations containing lipid supplements rich in polyunsaturated fatty acids. The biohydrogenation theory attributes the causal mechanism underlying diet-induced milk fat depression (MFD) to changes in ruminal lipid metabolism leading to increased formation of specific biohydrogenation intermediates that exert anti-lipogenic effects. Trans -10, cis -12 conjugated linoleic acid (CLA) is the only intermediate shown unequivocally to inhibit milk fat synthesis. However, increases in ruminal trans -10, cis -12 CLA formation do not provide a universal explanation for the reductions in milk fat during diet-induced MFD, suggesting that other biohydrogenation intermediates may also be involved. Post-ruminal infusion experiments have provided tentative evidence that cis -10, trans -12 CLA and trans -9, cis -11 CLA also exert anti-lipogenic effects. Diet-induced MFD is consistently associated with an increase in milk fat trans -10 18:1 concentrations, but recent direct evidence offers little support for a role of this intermediate in the regulation of milk fat synthesis. Further research is required to characterize the structure and function of other biohydrogenation intermediates, as well as considering the contribution of more global changes in ruminal lipid metabolism to provide a more universal explanation of diet-induced MFD. [source]


    Geometrical isomerisation of eicosapentaenoic and docosahexaenoic acid at high temperatures

    EUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY, Issue 7 2006
    Svein A. Mjøs
    Abstract Concentrates of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) were heated at 140,240,°C for 2,8,h under nitrogen. The trans isomers were analysed by gas chromatography-mass spectrometry on a BPX-70 cyanopropyl column. All geometrical isomers of EPA and DHA with one trans double bond were observed. The rate constants (k) for the isomerisation of the all- cis isomers were calculated and found to be higher than previously reported for linoleic acid and ,-linolenic acid. Arrhenius plots showed a linear relationship between ln,k and the reciprocal absolute temperature above 180,°C. The distribution patterns of isomers with one trans double bond are approximately constant up to a degree of isomerisation of 25%. The degree of isomerisation can therefore be estimated from selected trans peaks. [source]


    Chemo-enzymatic epoxidation of linoleic acid: Parameters influencing the reaction

    EUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY, Issue 2 2006
    Cecilia Orellana-Coca
    No abstracts. [source]


    Antioxidant properties of extracts and compounds from Psoralea morisiana

    EUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY, Issue 7-8 2005
    Antonella Rosa
    Abstract The antioxidant activity of various extracts (MeOH, petroleum ether, EtOAc) from the aerial parts of Psoralea morisiana, an endemic Sardinian plant, was evaluated during autoxidation and iron-mediated oxidation of linoleic acid at 37,°C and during cholesterol oxidation at 140,°C, in the absence of solvent. The activity of erybraedin,C, bitucarpin,A and plicatin,B, isolated from the extracts, was investigated under the same experimental conditions and compared to that of BHT and ,-tocopherol. All the extracts, erybraedin,C (major constituent of the extracts) and plicatin,B showed powerful antioxidant properties. None of the extracts and pure compounds showed any prooxidant activity. The cytotoxicity of the extracts, erybraedin,C, and plicatin,B was further evaluated in VERO cells, a line of fibroblasts derived from monkey kidney. Erybraedin,C, at non-cytotoxic concentrations, showed a strong inhibition of FeCl3 -induced oxidation in VERO cells. [source]


    Influence of TiO2 Nanoparticles Incorporated into Elastomeric Polyesters on their Biocompatibility In Vitro and In Vivo

    ADVANCED ENGINEERING MATERIALS, Issue 11 2009
    Miroslawa El-Fray
    Abstract Fibroblasts proliferation and apoptosis as well as tissue response after implantation of elastomers containing nanocrystalline TiO2 were investigated in the present in vitro and in vivo study. Materials investigated were soft poly(aliphatic/aromatic-ester) multiblock thermoplastic elastomers with poly(ethylene terephthalate) (PET) hard segments and dimerized linoleic acid (DLA) soft segments, respectively, containing 0.2,wt% TiO2 nanoparticles. An investigation of the influence of TiO2 nanoparticles incorporated into polymeric material on in vitro biocompatibility revealed enhanced cell proliferation and diminished number of necrotic and apoptotic cells as compared to nanoparticles-free polymer. Implantation tests indicated that the observed tissue changes were similar to those observed with medical-grade silicone elastomer, no evidence of contact necrosis being observed. The unchanged morphology of rat liver hepatocytes and the lack of parenchymal necrosis also indicated that exposure to the material containing TiO2 nanoparticles, did not cause any cytotoxic reactions. The present study, thus, showed that elastomeric polyester containing TiO2 nanoparticles are interesting biomimetic constructs for improved tissue regeneration. [source]


    Effect of sunlight exposure and aging on skin surface lipids and urate

    EXPERIMENTAL DERMATOLOGY, Issue 2003
    Nobumasa Hayashi
    Abstract Free fatty acids (FFA), squalene, squalene hydroperoxide, and uric acid in the methanol extracts from human skin surface were measured. Levels of FFA and squalene were significantly lower in the older (83.7 ± 9.4 years) than in the younger (22.2 ± 3.9 years) group. FFA are mostly saturated, and linoleic acid is an exclusive polyunsaturated fatty acid. The composition of linoleic acid decreased in the older group by 40%, suggesting age-dependent loss of oxidatively vulnerable polyunsaturated fatty acid. Even monounsaturated acids such as palmitoleic and oleic acids decreased significantly in the older group. This could be interesting because 2-nonenal is the oxidation product of palmitoleic acid and has been identified as the major aged body odor component. Sunlight exposure for 1.5 h did not change levels of FFA and squalene, or FFA composition. However, squalene hydroperoxide increased by 60-fold, as reported previously, suggesting that hydroperoxide is produced by singlet oxygen. Uric acid increased by two-fold, which may be the adaptive response against photo-oxidative stress because uric acid is a good scavenger of singlet oxygen and oxygen radicals. [source]


    Whey-derived free fatty acids suppress the germination of Candida albicans in vitro

    FEMS YEAST RESEARCH, Issue 2 2007
    Martin Clément
    Abstract Bovine whey from the cheese-making industry contains several bioactive factors that promote health and prevent disease. Although many efforts have been made over the years to show that immunoglobulins, lactoperoxidase, lactoferrin, lysosyme and small peptides present in whey have antimicrobial activities against several pathogenic microorganisms, such activities have not been investigated so far for the lipid fraction of whey. Here, we have used an in vitro assay-based fractionation procedure to show that free fatty acids derived from whey cream specifically inhibit the germination of Candida albicans, a morphologic change associated with pathogenicity. Further fractionation by HPLC demonstrated that this activity can be mainly attributed to lauric acid, myristoleic acid, linoleic acid and arachidonic acid. [source]


    Character impact odorants from wild mushroom (Lactarius hatsudake) used in Japanese traditional food

    FLAVOUR AND FRAGRANCE JOURNAL, Issue 4 2010
    Mitsuo Miyazawa
    Abstract The components of the volatile oil from wild mushroom (Lactarius hatsudake), used in Japanese traditional food, were analysed and quantified for the first time by capillary GC and GC,MS. Seventy-six components were separated from the oil and of these 71 components were identified. The main components of the oil were oxidized sesquiterpenes [cis -isolongifolanone (624.9,,g/100,g), , -cedrene epoxide (578.7,,g/100,g), humulene epoxide III (453.9,,g/100,g), clovane (425.4,,g/100,g)], aliphatic acids [linoleic acid (585.9,,g/100,g) and palmitoleic acid (333.3,,g/100,g)]. Odour evaluation of the volatile oil from L. hatsudake was also carried out using GC,MS/olfactometry (GC,MS/O) and aroma extract dilution analysis (AEDA), from which it was found that hexanal, 4-dehydroviridiflorol, myliol and phenylacetaldehyde seem to contribute to the green, spicy and sweet odour of L. hatsudake. Copyright © 2010 John Wiley & Sons, Ltd. [source]


    The Egyptian Eucalyptus camaldulensis var. brevirostris: chemical compositions of the fruit volatile oil and antioxidant activity

    FLAVOUR AND FRAGRANCE JOURNAL, Issue 4 2002
    Ahmed H. El-Ghorab
    Abstract The fruit volatile oil of E. camaldulensis var. brevirostris was isolated by hydrodistillation and thereafter the fruit marc was extracted by ethanol. The volatile oil obtained was subjected to analysis using gas chromatography,mass spectrometry. Thirty-eight volatile components were identified. The main volatile compounds in the fruit volatile oil were: aromadendrene (17.99%), ,-pinene (12.68%), p -cymenene (5.39%), ,-gurjunene (6.65%), cubenol (9.23%), thymol (1.62%) and p -cymen-7-ol (0.73%). The volatile components were classified into four groups: monoterpenes (20.6%), sesquiterpenes (33.8%), light-oxygenated (8.1%) and heavily-oxygenated (37.6%) compounds. The results showed that the concentration of sesquiterpenes and heavily-oxygenated compounds were higher than the other two classes. The main compound in the ethanol extract of fruit of E. camaldulensis was isolated by semi-preparative HPLC and identified as ellagic acid. The antioxidant activities of the fruits volatile oil and the ethanol extract as well as that of the tree bark were evaluated by the thiocyanate method. The ethanol extract of Eucalyptus fruit exhibited considerable activity compared with butylated hydroxyanisole (BHA) and tertiary butylated hydroquinone (TBHQ). The high inhibitory effect of the ethanol extract of fruit upon linoleic acid after 12 days might be related to the higher ellagic acid content. Copyright © 2002 John Wiley & Sons, Ltd. [source]


    Components of the essential oil from Glehnia littoralis

    FLAVOUR AND FRAGRANCE JOURNAL, Issue 3 2001
    Mitsuo Miyazawa
    Abstract The chemical composition of the essential oils from Glehnia littoralis of aerial and root parts growing cultivated in Niigata Collage of Pharmacy were examined by GC, GC,MS and 1H-NMR. Sixty seven components were characterized of G. littoralis aerial parts, with ,-phellandrene (12.96%), propyl octanoate (16.89%), hexadecanoic acid (14.45%), linoleic acid (8.79%) and methyl linolenate (5.47%) as the major constituents. Sixty six components were identified in the oil of root parts, with ,-pinene (13.40%), ,-phellandrene (22.93%) and germacrene B (6.68%) as the major constituents. Copyright © 2001 John Wiley & Sons, Ltd. [source]


    Epoxidation of Polyunsaturated Fatty Acid Double Bonds by Dioxirane Reagent: Regioselectivity and Lipid Supramolecular Organization

    HELVETICA CHIMICA ACTA, Issue 10 2006
    Stanislav
    Abstract The use of dimethyldioxirane (DMD) as the epoxidizing agent for polyunsaturated fatty acids was investigated. With fatty acid methyl esters, this is a convenient method for avoiding acidic conditions, using different solvents, and simplifying the isolation procedures, with less contamination due to by-products. The reagent was also tested with free fatty acids in water. In this case, the supramolecular organization of fatty acids influenced the reaction outcome, and the epoxidation showed interesting regioselective features. The CC bonds closest to the aqueous-micelle interface is the most favored for the interaction with dimethyldioxirane. The preferential epoxidation of linoleic acid (=,(9Z,12Z)-octadeca-9,12-dienoic acid) to the 9,10-monoepoxy derivative was achieved, with a high yield and 65% regioselectivity. In case of arachidonic acid (=,(5Z,8Z,11Z,14Z)-eicosa-5,8,11,14-tetraenoic acid) micelles, the regioselective outcome with formation of the four possible monoepoxy isomers was studied under different conditions. It resulted to be a convenient synthesis of ,cis -5,6-epoxyeicosatrienoic acid' (=,3-[(2Z,5Z,8Z)-tetradeca-2,5,8-trienyl]oxiran-2-butanoic acid), whereas in reverse micelles, epoxidation mostly gave ,cis -14,15-epoxyeicosatrienoic acid (=,(5Z,8Z,11Z)-13-(3-pentyloxiran-2-yl)trideca-5,8,11-trienoic acid). [source]


    Proton-Coupled Electron Transfer of Unsaturated Fatty Acids and Mechanistic Insight into Lipoxygenase

    HELVETICA CHIMICA ACTA, Issue 10 2006
    Shunichi Fukuzumi
    Abstract A proton-coupled electron transfer (PCET) process plays an important role in the initial step of lipoxygenases to produce lipid radicals which can be oxygenated by reaction with O2 to yield the hydroperoxides stereoselectively. The EPR spectroscopic detection of free lipid radicals and the oxygenated radicals (peroxyl radicals) together with the analysis of the EPR spectra has revealed the origin of the stereo- and regiochemistry of the reaction between O2 and linoleyl (=,(2Z)-10-carboxy-1-[(1Z)-hept-1-enyl]dec-2-enyl) radical in lipoxygenases. The direct determination of the absolute rates of H-atom-transfer reactions from a series of unsaturated fatty acids to the cumylperoxyl (=,(1-methyl-1-phenylethyl)dioxy) radical by use of time-resolved EPR at low temperatures together with detailed kinetic investigations on both photoinduced and thermal electron-transfer oxidation of unsaturated fatty acids provides the solid energetic basis for the postulated PCET process in lipoxygenases. A strong interaction between linoleic acid (=,(9Z,12Z)-octadeca-9,12-dienoic acid) and the reactive center of the lipoxygenases (FeIIIOH) is suggested to be involved to make a PCET process to occur efficiently, when an inner-sphere electron transfer from linoleic acid to the FeIII state is strongly coupled with the proton transfer to the OH group. [source]


    Reversal of expression of 15-lipoxygenase-1 to cyclooxygenase-2 is associated with development of colonic cancer

    HISTOPATHOLOGY, Issue 4 2007
    M Yuri
    Aims:, Two different pathways of linoleic acid (LA) metabolism have opposite effects on the development of colonic cancer: a protumoral prostaglandin cascade metabolized by cyclooxygenase (COX)-2, and an antitumoral peroxisome proliferator-activated receptor (PPAR)-, ligands metabolized by 15-lipooxygenase (LOX)-1. The aim was to examine the switching of the two LA metabolic pathways in colonic adenomas and carcinomas. Materials and methods:, The expression of 15LOX-1 mRNA and COX-2 protein was examined in 54 adenomas, 21 pTis carcinoma-in-adenoma lesions and 36 pT3/p Stage II carcinomas of the colon by in-situ hybridization and immunohistochemistry, respectively. Results:, 15LOX-1 expression was found in 89% (48 of 54) of adenomas, 43% (nine of 21) of adenomas and 10% (two of 21) of carcinomas in carcinoma-in-adenoma lesions, but not in pT3 carcinomas (P < 0.0001). In contrast, COX-2 production was found in 11% (six of 54) of adenomas, 52% (11 of 21) of adenomas and 71% (15 of 21) of carcinomas in carcinoma-in-adenoma lesions, and 92% (33 of 36) of pT3 carcinomas (P < 0.0001). Concurrence of 15LOX-1 down-regulation and COX-2 up-regulation was found in 6% (three of 54) of adenomas, 33% (seven of 21) of adenomas and 71% (15 of 21) of carcinomas in carcinoma-in-adenoma lesions, and 92% (33 of 36) of pT3 carcinomas (P < 0.0001). Conclusions:, These results suggest that switching of LA metabolism by reversal of the expression of 15LOX-1 and COX-2 is associated with acquisition of malignant potential in colonic neoplasia. [source]


    The effect of diet on the expression of lipase genes in the midgut of the lightbrown apple moth (Epiphyas postvittana Walker; Tortricidae)

    INSECT MOLECULAR BIOLOGY, Issue 1 2010
    J. T. Christeller
    Abstract We have identified lipase-like genes from an Epiphyas postvittana larval midgut EST library. Of the 10 pancreatic lipase family genes, six appear to encode active lipases and four encode inactive lipases, based on the presence/absence of essential catalytic residues. The four gastric lipase family genes appear to encode active proteins. Phylogenetic analysis of 54 lepidopteran pancreatic lipase proteins resolved the clade into five groups of midgut origin and a sixth of non-midgut lipases. The inactive proteins formed two separate groups with highly conserved mutations. The lepidopteran midgut lipases formed a ninth subfamily of pancreatic lipases. Eighteen insect and human gastric lipases were analysed phylogenetically with only very weak support for any groupings. Gene expression was measured in the larval midgut following feeding on five artificial diets and on apple leaves. The artificial diets contained different levels of triacylglycerol, linoleic acid and cholesterol. Significant changes in gene expression (more than 100-fold for active pancreatic lipases) were observed. All the inactive lipases were also highly expressed. The gastric lipase genes were expressed at lower levels and suppressed in larvae feeding on leaves. Together, protein motif analysis and the gene expression data suggest that, in phytophagous lepidopteran larvae, the pancreatic lipases may function in vivo as galactolipases and phospholipases whereas the gastric lipases may function as triacylglycerol hydrolases. [source]