Different Numbers Of Double Bonds Research Articles

The role of C18 fatty acids in improving the digestion and retrogradation properties of highland barley starch

In this study, five C18 fatty acids (FA) with different numbers of double bonds and configurations including stearic acid (SA), oleic acid (OA), elaidic acid (EA), linoleic acid (LA), and α-linolenic acid (ALA), were selected to prepare highland barely starch (HBS)-FA complexes to modulate digestibility and elaborate the underlying mechanism. The results showed that HBS-SA had the highest complex index (34.18 %), relative crystallinity (17.62 %) and single helix content (25.78 %). Furthermore, the HBS-C18 FA complexes were formed by EA (C18 FA with monounsaturated bonds) that had the highest R1047/1022 (1.0509) and lowest full width at half-maximum (FWHM, 20.85), suggesting good short-range ordered structure. Moreover, all C18 FAs could form two kinds of V-type complexes with HBS, which can be confirmed by the results of CLSM and DSC measurements, and all of them showed significantly lower digestibility. HBS-EA possessed the highest resistant starch content (20.17 %), while HBS-SA had the highest slowly digestible starch content (26.61 %). In addition, the inhibition of HBS retrogradation by fatty acid addition was further proven, where HBS-SA gel firmness (37.80 g) and aging enthalpy value were the lowest, indicating the most effective. Overall, compounding with fatty acids, especially SA, could be used as a novel way to make functional foods based on HBS.

Comprehensive utilization of Hainan cashew nut shell: Process optimization of cashew nut shell liquid extraction and cardanol refinement by catalytic transfer hydrogenation

In this work, an eco-friendly approach to the extraction of cashew nut shell liquid (CNSL) and the refinement of cardanol were explored for the first time using cashew nut produced in Hainan, China as raw material. Cashew nut shell (CNS) are usually disposed of as waste from agricultural processing, but CNSL extracted from CNS by solvent extraction or supercritical CO2 extraction has a high value. The composition of CNSL extracted by different conditions varies, and more CNSL is extracted by relatively less polar solvent. Supercritical CO2 extraction, as an environmentally friendly method, also showed good superiority in the extraction of CNSL. CNSL produced from Hainan cashew nuts contains high level of anacardic acid. The extracted CNSL can be decarboxylated and separated to obtain a mixture of cardanol consisting of four olefins containing different numbers of double bonds. Cardanol can be converted to saturated cardanol by catalytic hydrogenation and catalytic transfer hydrogenation, and the catalytic transfer hydrogenation also exhibits selectivity by selecting a suitable hydrogen donor to obtain high purity cardanol, monoene. Both saturated cardanol and cardanol, monoene have good prospects for utilization due to their chemical structure.

Electrocyclizations of Conjugated Azapolyenes Produced in Reactions of Azaheterocycles with Metal Carbenes

Conjugated azapolyenes (azabuta-1,3-dienes, aza-/diaza-/oxaza-/oxadiazahexa-1,3,5-trienes) are highly reactive in electrocyclization reactions, which makes them convenient precursors for the synthesis of a wide range of four-, five-, and six-membered nitrogen heterocycles that are of relevance for medicinal chemistry. Ring opening reactions of 2H-azirines and azoles containing an N–N or N–O bond, initiated by a transition metal carbene, have become increasingly important in recent years, since they easily allow the generation of azapolyenes with different numbers of double bonds and heteroatoms in various positions. This review summarizes the literature, published mainly in the last decade, on the synthetic and mechanistic aspects of electrocyclizations of azapolyenes generated by the carbene method.

Benzothiazolium Derivative-Capped Silica Nanocomposites for β-Amyloid Imaging In Vivo

Alzheimer’s disease (AD) is a neurodegenerative disease, and β-amyloid (Aβ) is believed to be a causative factor in AD pathology. The abnormal deposition of Aβ is believed to be responsible for progression of AD. In order to facilitate the imaging of Aβ in vivo, suitable probe molecules with a near-infrared emission wavelength that can penetrate the blood–brain barrier (BBB) were utilized. The commercial fluorescent probe thioflavin-T (ThT) is used to image Aβ; however, because of its short emission wavelength and poor BBB penetration, ThT can only be used in vitro. With this research, based on ThT, we design three fluorescent probes (SZIs) having a longer emission wavelength in order to image Aβ aggregates. SZIs with different numbers of double bonds respond to Aβ aggregates. The SZIs have a structure similar to ThT, and as such, the SZIs are also unable to penetrate the BBB. To deal with the problem, we develop nanocomposites (MSN-Lf@SZIs) to deliver SZIs into the brain of AD mouse and image Aβ successfully. These new nanocomposites are able to deliver the dyes into the brain and facilitate Aβ imaging in vivo.

Fatty acids of microalgae: diversity and applications

The possibility of obtaining commercially valuable products from microalgae stimulates scientific research in this direction. The ability of microalgae to accumulate lipids is very promising from the point of view of practical application. The diversity of the composition of microalgae lipids makes it possible to study a wide range of their applications: biofuel production, food products, feed for farm animals and birds, for aquaculture, food additives, etc. Fatty acids (FAs) are involved in the metabolic pathways of formation and conversion of most lipid classes, and their composition largely determines their properties and practical use. As a result, much attention is paid to the study of the composition of fatty acids in microalgae (including cyanobacteria). This review summarizes information on the diversity of the fatty acid composition of microalgae and cyanobacteria, taking into account their rare and unusual categories. The total variety of FA profile of microalgae from different habitats is formed by 135 FAs. Taking into account the length of the hydrocarbon chain, its structure and the presence of substituents, they are distributed into several groups: with an even number of carbon atoms in the chain—81 (short-chain FAs—2, medium-chain FAs—14, long-chain FAs—28, very-long-chain FAs—37), with an odd number of carbon atoms—33, with a branched hydrocarbon chain and additional functional groups—21. Among FAs of microalgae there are both saturated and unsaturated FAs with different numbers of double bonds: saturated FAs—19, monounsaturated FAs—26, polyunsaturated FAs—68. The FA profile of microalgae is rich in omega-3 and omega-6 fatty acids. The review also considers the use of fatty acids as an industrial resource, as well as a biomarker.

Cover Feature: Crystal Structures and Fluorescence Spectroscopic Properties of a Series of α,ω‐Di(4‐pyridyl)polyenes: Effect of Aggregation‐Induced Emission (ChemPlusChem 9/2020)

The Cover Feature shows dipyridylpolyene molecules with different numbers of double bonds, and the constellation Orion. The monoene (bpe) and the diene are strongly fluorescent in the solid state because of the aggregation-induced emission effect, whereas the triene and the longer polyenes are only weakly fluorescent. The two highly emissive molecules are located at the positions of the two brightest stars, Rigel and Betelgeuse, in the constellation. More information can be found in the Full Paper by Y. Sonoda and co-workers (DOI: 10.1002/cplu.202000285).

Tunable Phospholipid Nanopatterns Mediated by Cholesterol with Sub-3 nm Domain Size.

The interactions between phospholipids and cholesterol have been extensively studied in the aqueous systems because of their vital functionalities in the cell membrane. In this study, instead of the self-assembly in water, we explored the microphase-separated structures of phospholipids in bulk and thin films in the absence of solvents and created a series of ordered nanostructures by incorporation of cholesterol into phospholipids. Three zwitterionic two-tailed phospholipids, that is, phosphatidylcholines (PCs), with different numbers of double bonds on the hydrocarbon tails were investigated, including egg PC, 1,2-dioleoyl- sn-glycero-3-phosphocholine (DOPC), and 1,2-dipalmitoyl- sn-glycero-3-phosphocholine (DPPC). We find that the nanostructures are highly dependent on the conformation of the tails on the PCs, which can be tailored by the number of double bonds on tails and the molar ratio of cholesterol to PC. By changing the molar ratio, egg PC with one double bond organizes into rich microdomains, including lamellae, spheres, and cylinders, whereas DOPC with two double bonds form spheres and cylinders and DPPC with no double bond forms lamellae only. The sizes of the microdomains are less than 3 nm, smaller than those of typical block copolymers. The biomolecule-based nanopatterns developed in this work provide a platform toward future applications of nanotechnology and biotechnology.

Profiling and catalytic upgrading of commercial palm oil-derived biodiesel fuels for high-blend fuels

Commercial palm oil-derived biodiesel fuels (palm BDFs) were thoroughly profiled based on the specifications of international fuel standards. Their main components were found to be fatty acid methyl esters (FAME) with different numbers of double bonds in the fatty acid tails in addition to small amounts of unreactive glycerides and impurities, the concentrations of which varied slightly among the regional producers in Thailand. The fuel properties of the as-received commercial palm BDFs met international fuel standards; unfortunately, the fuel degraded significantly over time, presumably due to the presence of polyunsaturated fatty acid methyl esters (poly-FAME) and impurities. To prevent this degradation, the commercial palm BDFs were upgraded into partially hydrogenated fatty acid methyl esters with outstanding oxidation stability (H-FAME, a new type of biodiesel fuel enriched in monounsaturated fatty acid methyl esters (mono-FAME)) over supported Pd catalysts with metallic Pd nanoparticles as the catalytically active sites in a batch-type glass reactor under mild conditions (80 °C and 0.5 MPa H2). In the upgrading process, the unwanted component poly-FAME, which had low oxidation stability, was selectively converted into the target component, mono-FAME with high oxidation stability. Although the impurities in the commercial palm BDFs poisoned the supported Pd catalysts, particularly the sulfur species, the homemade mesoporous silica-supported Pd catalyst with a high Pd dispersion of 47% gave higher activity and tolerance to the impurities in the synthesis of palm H-FAMEs than the commercial alumina-supported Pd catalyst, which had a low Pd dispersion of 16%. In the accelerated oxidation stability test, the B20 fuels formulated by blending petro-diesel with the palm H-FAMEs with enhanced oxidation stability produced almost no deposits or sludges, whereas the fuels formulated by blending petro-diesel with commercial palm BDFs were seriously degraded and acidified, and formed deposits and sludges. Moreover, the palm H-FAMEs could be further purified by selective removal of the monoglycerides (MG) and steryl glucosides (SG) through wintering and adsorption posttreatments, and were determined to be a reliable BDF source with high safety and security for use in high blend fuels.

Superoxide anion scavenging activity of alk(en)yl phenol compounds by using PMS-NADH system.

Anacardic acid C15:3 and cardol C15:3 sigmoidally suppressed superoxide anion (O2-) generation using xanthine oxidase. To study this suppression activity, anacardic acids, cardanols and cardols having different numbers of double bonds in alk(en)yl chains were prepared. The O2- scavenging activity and H2O2 formation from O2- using PMS-NADH were examined. Anacardic acids and cardols indicated sigmoidal O2- scavenging activity but cardanols did not. The O2- scavenging activity of anacardic acid C15:3 was weaker than the suppression activity using xanthine oxidase, but the scavenging activity of cardol C15:3 was quite similar to the suppression using xanthine oxidase. The H2O2 formation from O2- decreased by the addition of anacardic acids, cardanols and cardols but increased by the addition of gallic and caffeic acids. From these results, we deduced that the O2- suppression activity of xanthine oxidase reaction with cardols is the O2- scavenging activity and that anacardic acids and cardols are O2- scavengers having low prooxidant property.

The role of lipid droplet formation in the protection of unsaturated fatty acids against palmitic acid induced lipotoxicity to rat insulin-producing cells.

BackgroundType 2 diabetes is associated with increased plasma concentrations of non-esterified fatty acids (NEFAs), which trigger pancreatic β-cell dysfunction and apoptosis. Only long-chain saturated NEFAs induced lipotoxicity in rat insulin-producing cells in in vitro experiments, whereas unsaturated NEFAs were not toxic. Some unsaturated NEFAs even protected against lipotoxicity. In former studies it was suggested that long-chain unsaturated NEFAs, which induce the formation of lipid droplets, can cause sequestration of palmitic acid into lipid droplets. In the present structure-activity-relationship study the correlation between lipid droplet formation and the protection against palmitic acid induced lipotoxicity by unsaturated NEFAs in rat insulin-producing cells was examined.MethodsRat insulin-producing RINm5F and INS-1E tissue culture cells were incubated in the presence of palmitic acid and unsaturated NEFAs with different chain lengths and different numbers of double bonds. The expression of the lipid droplet associated proteins perilipin 1 and 2 was repressed by the shRNA technique and the expression analyzed by qRT-PCR and Western blotting. Viability was measured by MTT assay and the accumulation of lipid droplets was quantified by fluorescence microscopy after Oil Red O staining.ResultsLong-chain unsaturated NEFAs strongly induce the formation of lipid droplets in rat insulin-producing RINm5F and INS-1E cells. In RINm5F cells incubated with 11-eicosenoic acid (C20:1) 27 % of the cell area was covered by lipid droplets corresponding to a 25-fold increase in comparison with control cells. On the other hand the saturated NEFA palmitic acid only induced minor lipid droplet formation. Viability analyses revealed only a minor toxicity of unsaturated NEFAs, whereas the cells were markedly sensitive to palmitic acid. Long-chain unsaturated NEFAs antagonized palmitic acid induced lipotoxicity during co-incubation, whereby no correlation existed between protection and the ability of lipid droplet formation. Perilipin 1 and 2 expression was decreased after incubation with C20:1 to about 80 % by shRNA. For the protective effect of long-chain unsaturated NEFAs against lipotoxicity of saturated NEFAs repression of perilipin was not of crucial importance.ConclusionsLong-chain unsaturated fatty acids protected rat insulin-producing cells against lipotoxicity of saturated fatty acids. This protective effect was not dependent on lipid droplet formation. Thus lipid droplet formation is apparently not essential for the protective effect of unsaturated NEFAs against palmitic acid toxicity.Electronic supplementary materialThe online version of this article (doi:10.1186/s12986-016-0076-z) contains supplementary material, which is available to authorized users.

The unique liquid chromatographic properties of Group 11 transition metals for the separation of unsaturated organic compounds

Silver(I) and copper(I) are known to form reversible complexes with π bonds, which have been exploited in LC for separating unsaturated organic compounds. Prominent examples include the use of AgNO3-impregnated silica gel in LC, and the use of copper(I) salts for selective extraction of alkenes from hydrocarbon mixtures. The Dewar-Chatt-Duncanson model is often invoked to explain the interaction between Ag(I) and Cu(I) and π bonds. However, it is unclear if such a reversible interaction is directly related to their d(10) outer electronic configurations. Particularly, Au(I) has not been reported to separate olefins with different numbers of double bonds in LC. Also, there has not been a systematic comparison of the liquid chromatographic properties of other d(10) transition metal salts (e.g., Zn(II), Cd(II)), making it difficult to fully understand the observed reversible interactions of Ag(I) and Cu(I) with π bonds. We demonstrate for the first time that silica gel impregnated with all three Group 11 transition metals with 1+ oxidation state strongly and similarly retain olefin compounds in LC, while transition metals from Groups 10 and 12 do not. We also tested a range of functionalized silica gels to improve the stability of Cu(I) and Au(I) ions on the surface of the silica.

Fatty acids and algal lipids as precursors of chlorination by-products

Six common algal fatty acids (FAs) with different numbers of double bonds, lipophilic fractions and proteins extracted from the diatom Navicula pelliculosa and algal cells were chlorinated to evaluate their potential in generating disinfection by-products (DBPs). The result showed that the more double bonds in the FAs, the higher the amounts of chloroform and dichloroacetic acid (DCAA) produced, but such a pattern was not observed for trichloroacetic acid (TCAA). Based on the previously reported composition of fatty acids in algal lipids, the DBP generation potentials of algal lipids were calculated. These predicted values were much lower than those measured in the chlorinated algal lipophilic fraction, suggesting unknown lipophilic fraction(s) served as potent DBPs precursors. Another calculation attempted to predict DBP production in algal cells based on algal lipid and protein composition, given quantified measured DBP production per unit algal lipid and proteins. The analysis showed that the observed DBP production was similar to that predicted (< 35% difference), suggesting that algal biochemical compositions may serve as a bioindicator for preliminary estimation of chloroform, DCAA and TCAA formation upon chlorinating algae.

On the dependence of electronic properties on geometric structure for cubane derivatives and oligomers with donor and acceptor groups

We report on the theoretical investigation of some structural and electronic properties for several families of cubane-based compounds. All these compounds consist on cubane building blocks with electron donor and acceptor groups linked to molecular structure in different positions, with different numbers of double bonds and also saturated and unsaturated oligomers. Our calculations show that the increase of the number of double bonds leads to the decrease of the energy gap, simultaneously with the increase of the heat of formation. This property also depends of the number and positions of the double bonds in the compounds. According to our simulations, the electron transfer from the donor group to the acceptor group is a typical phenomenon in the cubane compounds. Therefore, the cubane or cubatriene based oligomers with the NH 2 and NO 2 groups can be regarded as perspective materials to be used as nano-size push–pull systems.

Cold adaptation of eicosapentaenoic acid-less mutant of Shewanella livingstonensis Ac10 involving uptake and remodeling of synthetic phospholipids containing various polyunsaturated fatty acids

An Antarctic psychrotrophic bacterium, Shewanella livingstonensis Ac10, produces cis-5,8,11,14,17-eicosapentaenoic acid (EPA), a long-chain polyunsaturated fatty acid (LPUFA), as a component of membrane phospholipids at low temperatures. The EPA-less mutant generated by disruption of the EPA synthesis gene becomes cold-sensitive. We studied whether the cold sensitivity could be suppressed by supplementation of various LPUFAs. The EPA-less mutant was cultured at 6 degrees C in the presence of synthetic phosphatidylethanolamines (PEs) that contained oleic acid at the sn-1 position and various C20 fatty acids with different numbers of double bonds from zero to five or cis-4,7,10,13,16,19-docosahexaenoic acid (DHA) at the sn-2 position. Mass spectrometric analyses revealed that all these fatty acids became components of various PE and phosphatidylglycerol species together with shorter partner fatty acids, indicating that large-scale remodeling followed the incorporation of synthetic PEs. As the number of double bonds in the sn-2 acyl chain decreased, the growth rate decreased and the cells became filamentous. The growth was restored to the wild-type level only when the medium was supplemented with phospholipids containing EPA or DHA. We found that about a half of DHA was converted into EPA. The results suggest that intact EPA is best required for cold adaptation of this bacterium.

An Efficient Method for Isolating Individual Long-Chain Alkenones for Compound-Specific Hydrogen Isotope Analysis

Hydrogen isotope ratios (2H/H or D/H) of long-chain unsaturated ketones (alkenones) preserved in lake and marine sediments hold great promise for paleoclimate studies. However, compound-specific hydrogen isotope analysis of individual alkenones has not been possible due to chromatographic coelution of alkenones with the same carbon chain length but different numbers of double bonds. Published studies have only reported the deltaD values of the mixture of coeluting alkenones. We developed an efficient procedure to isolate individual alkenones based on double-bond numbers using silica gel impregnated with silver nitrate. The chromatographic procedure is simple, inexpensive, and highly reproducible, offers 87-100% sample recovery, and allows for the first time hydrogen isotopic measurement on individual alkenones. deltaD values of specific di-, tri- and tetraunsaturated C37 alkenones produced by an Emiliania huxleyi culture, as well as those isolated from Greenland lake sediments, differ consecutively by 43-65 per thousand. These findings suggest that alkenones with different numbers of carbon-carbon double bonds express significantly different deltaD values and that coelution of different alkenones may lead to erroneous source water deltaD reconstructions. Our alkenone isolation approach opens a new avenue for paleoclimate reconstructions using hydrogen isotope ratios of individual alkenones.

Effect of octadecanoyl acetal sodium sulphite series with different numbers of double bonds on their immunological and surface activities

The relationship between the immunological activities and their surface activities of octadecanoyl acetal sodium sulphite series containing different numbers of double bonds (HOU-C18:n ; n = 1, Δ9; n = 2, Δ9,12; n = 3, Δ9,12,15) were studied. The results showed that HOU-C18:n were able to increase the carbon granular clearance rate K, the NK cell activity in spleen and the activity of lysozymes in serum as well as inhibit Staphylococcus aureus and lysozymes in vitro to some degree. As the number of double bonds in HOU-C18:n increased along with the hydrophobic properties and the ability to improve the immune activity, NK cell activity and lysozyme activity decreased, but the bacteriostatic activity increased. It is speculated that HOU-C18:n could improve immunity and bacteriostasis realised by the interaction between the hydrophobic chain and membranes of cells. From the results of the effects of HOU-C18:n on lysozymes in vivo and in vitro, it is speculated that HOU-C18:0 could initiate and greatly enhance lysozyme activity in serum by increasing the amount of lysozymes, while unsaturated HOU-C18:n might do so mainly by increasing the number of lysozymes.

Phospholipid Dependence and Liposome Reconstitution of Purified Hyaluronan Synthase

Previous radiation inactivation and enzyme characterization studies demonstrated that the Streptococcus equisimilis hyaluronan synthase (seHAS) is phospholipid-dependent and that cardiolipin (CL) is the best phospholipid for enzyme activation. Here we investigated the ability of seHAS, purified in the absence of added lipid, to be activated by synthetic phosphatidic acid (PA), phosphatidylserine, or CL lipids containing fatty acyl chains of different length or different numbers of double bonds. The most effective lipid was tetraoleoyl CL (TO-CL), whereas tetramyristoyl CL (TM-CL) was ineffective. None of the phosphatidylserine species tested gave significant activation. PAs containing C10 to C18 saturated acyl chains were not effective activators, and neither were oleoyl lyso PA, dilinoleoyl PA, or PA containing one oleoyl chain and either a palmitoyl or stearoyl chain. In contrast, dioleoyl PA stimulated seHAS approximately 10-fold, to approximately 20% of the activity observed with TO-CL. The tested acidic lipids such as PA and CL activated the enzyme most efficiently if they contained only oleic acid. Mixing experiments showed that the enzyme interacts preferentially with TO-CL in the presence of TM-CL. Similarly, seHAS incorporated into phosphotidylcholine-based liposomes showed increasing activity with increasing TO-CL, but not TM-CL, content. Inactivation of membrane-bound seHAS by solubilization with Nonidet P-40 was prevented by TO-CL, but not TM-CL. The pH dependence of seHAS in the presence of synthetic or naturally occurring CLs showed the same pattern of lipid preference between pH 6 and 10.5. Unexpectedly, HAS showed lipid-independent activity at pH 11.5. The results suggest that Class I HAS enzymes are lipid-dependent and that assembly of active seHAS-lipid complexes has high specificity for the phospholipid head group and the nature of the fatty acyl chains.

Modification of Brassica Oil Using Conventional and Transgenic Approaches

ABSTRACTModifying the fatty acid composition of Brassica seed oil to increase its value as a nutritional or as an industrial oil has been a major objective in Brassica breeding programs worldwide. The conventional approach to fatty acid modification has explored natural or induced mutations occurring in the same plant species or close relatives within the Brassica genus. These mutations have been shown to be associated with a few enzymes in the biosynthetic pathway of the fatty acids. Several types of Brassica oil with significantly altered levels of the long chain fatty acid erucic acid (C22:1) and medium chain fatty acids such as oleic acid (C18:1) and linolenic acid (C18:3) have been developed for different end uses through conventional breeding. When the necessary genetic variation is not available within Brassica species, gene transfer by genetic transformation has been applied, as this approach is not restricted by the sexual incompatibility barrier across species. The fatty acids targeted by the transgenic approach included fatty acids with various carbon chain lengths ranging from C8 to C22, with different numbers of double bonds, and with various functional groups such as epoxy and hydroxy fatty acids. A commercial specialty oil with high level of a novel fatty acid, lauric acid (C12:0), was produced as a result of the transfer of a FatB thioesterase gene from a distantly related plant species that produces seed oil with high level of this unusual fatty acid. Considerable progress has been achieved in altering the relative levels of the fatty acids found in Brassica oils for increased health and economic benefits and in developing Brassica oils which contain other unusual fatty acids, mainly through genetic transformation. Although the use of natural or induced mutations in the fatty acid biosynthesis within Brassica remains a valid option for oil modification, the transgenic approach will play an increasingly important role in the development of Brassica oils with altered novel fatty acid composition.

Effect of the surface activity on the antibacterial activity of octadecanoyl acetal sodium sulfite series

The relationship between the surface activities and their antibacterial activities of synthesized octadecanoyl acetal sodium sulfite series containing different numbers of double bonds (HOU-C 18: n ) was studied. The results showed that with an increasing number of double bonds in HOU-C 18: n , the hydrophobic activity and adsorbed amount on the surface would be decreased, while the antibacterial activity of HOU-C 18: n and the membrane permeability of bacteria caused by HOU-C 18: n would be increased. It was discussed that HOU-C 18:0 exerted the bacteriostasis by hydrophobic adsorption and free diffusion through the membrane of bacteria, and unsaturated HOU-C 18: n exerted the bacteriostasis mainly by double bonds and destructing the membrane.

Regulation of reactive oxygen species (ROS) production by C18 fatty acids in Jurkat and Raji cells

In the present study, the effects of C18 fatty acids with different numbers of double bonds, SA (stearic acid; C18:0), OA (oleic acid; C18:1), LA (linoleic acid; C18:2) and gamma-LNA (gamma-linolenic acid; C18:3), on ROS (reactive oxygen species) production by Jurkat (a human T-lymphocyte-derived cell line) and Raji (a human B-lymphocyte-derived cell line) cells were investigated. ROS production was determined by NBT (Nitro Blue Tetrazolium) reduction (intracellular and extracellular ROS production) and by dihydroethidium oxidation using flow cytometry (intracellular ROS production). The effectiveness on ROS production was gamma-LNA<SA<OA<LA in Jurkat cells and SA<gamma-LNA<OA<LA in Raji cells. LA (found in corn, soya bean and sunflower oils) was more potent than OA (found in olive oil) in stimulating ROS production in both Raji and Jurkat cells. The lower ROS production by OA compared with LA may be one of the benefits of olive oil consumption. As SA and gamma-LNA acids had little or no effect, further studies on the site of ROS production in these cells were carried out with OA and LA only. Activation of NADPH oxidase via PKC (protein kinase C) was found to be the major mechanism of ROS production induced by OA and LA in Jurkat and Raji cells.