Search results for "Diglycerides"
showing 10 items of 18 documents
The Nonbilayer Lipid MGDG and the Major Light-Harvesting Complex (LHCII) Promote Membrane Stacking in Supported Lipid Bilayers.
2018
The thylakoid membrane of algae and land plants is characterized by its intricate architecture, comprising tightly appressed membrane stacks termed grana. The contributions of individual components to grana stack formation are not yet fully elucidated. As an in vitro model, we use supported lipid bilayers made of thylakoid lipid mixtures to study the effect of major light-harvesting complex (LHCII), different lipids, and ions on membrane stacking, seen as elevated structures forming on top of the planar membrane surface in the presence of LHCII protein. These structures were examined by confocal laser scanning microscopy, atomic force microscopy, and fluorescence recovery after photobleachi…
Oxidative stability of virgin olive oil: evaluation and prediction with an adaptive neuro-fuzzy inference system (ANFIS).
2019
Background An adaptive neuro-fuzzy inference system (ANFIS) was employed to predict the oxidative stability of virgin olive oil (VOO) during storage as a function of time, storage temperature, total polyphenol, α-tocopherol, fatty acid profile, ultraviolet (UV) extinction coefficient (K268 ), and diacylglycerols (DAGs). Results The mean total quantities of polyphenols and DAGs were 1.1 and 1.9 times lower in VOOs stored at 25 °C than in the initial samples, and the mean total quantities of polyphenols and DAGs were 1.3 and 2.26 times lower in VOOs stored at 37 °C than in the initial samples, respectively. In a single sample, α-tocopherol was reduced by between 0.52 and 0.91 times during sto…
Surfactant effect on the physicochemical characteristics of cationic solid lipid nanoparticles
2016
Solid lipid nanoparticles (SLNs) may be considered as a new approach for therapeutics for many diseases. In addition to drug delivery, their use as non-viral vectors for gene delivery can be obtained by including cationic lipids, which provide a positive surface potential that favors binding to the nucleic acids as DNA, siRNA, miRNA, etc. In fact, the addition of cationic surfactants is indispensable for obtaining nanoparticles with surface positive charge. In this study, three different cationic lipids (dioctadecyl dimethyl ammonium bromide, cetyltrimethyl ammonium bromide, cetylpyridinium chloride) and Brij 76 as nonionic surfactant were employed to formulate Precirol ATO 5 based cSLN usi…
Mitogenic effects of phospholipase D and phosphatidic acid in transiently permeabilized astrocytes: effects of ethanol.
2003
Investigations of lipid-mediated signalling pathways are often limited by a lack of methods for the intracellular delivery of lipid messengers. We established a procedure for the transient permeabilization of astrocytes by an oxygen-insensitive mutant of streptolysin-O (SLO) to investigate the participation of the phospholipase D (PLD) signalling pathway in astroglial cell proliferation. Exogenous PLD, when incubated in the presence of SLO, caused an increase in DNA synthesis (measured by thymidine incorporation) which was completely suppressed by ethanol (0.3%, v/v). In parallel experiments, phosphatidic acid also induced a dose-dependent mitogenic response which, however, was not affected…
Microscale synthesis of phosphatidyl-[3H]choline from 1,2-diacylglycerol. Assessment of isomerization by reversed-phase high-performance liquid chrom…
1995
The synthesis of rac-1-palmitoyl-2-oleoylglycero-3-phospho-[3H]choline of high specific activity was carried out on a microscale by making 7 mumol of rac-1-palmitoyl-2-oleoylglycerol react first with an equimolar amount of POCl3 and then of [3H]choline. After purification by thin-layer chromatography and normal-phase high-performance liquid chromatography and normal-phase high-performance liquid chromatography (HPLC), the yield of the synthesis of [3H]phosphatidylcholine (120 microCi/mumol) was 22%. rac-1-Palmitoyl-2-oleoylglycerol was purified before use by reversed-phase HPLC under conditions which were nonisomerizing and allowed the separation of 1,2- and 1,3-isomers of diacylglycerol. E…
HPLC profile and evolution during storage of triglycerides and diglycerides in virgin olive oils
2008
High-performance liquid chromatography has been used for determining the triglyceridice and diglyceridice composition of olive oils from main, minor and neglected Sicilians cultivars. The HPLC analysis has allowed the identification and the quantification of 16 triglycerides. Among these, OOO, POO+SOL, OOL and POL, have shown a content higher than 84% of the total area of peaks in the chromatographic profile. Dioleine (OO) and oleopalmitine (OP) resulted the most representative diglycerides. Analyses have been made in January 2007 and repeated after six months, submitting samples to a simulation of shelf life, to verify as the storage conditions may influence the hydrolitic processes of tri…
Activation of TRPC6 calcium channels by diacylglycerol (DAG)-containing arachidonic acid: A comparative study with DAG-containing docosahexaenoic acid
2006
We synthesized a diacylglycerol (DAG)-containing arachidonic acid, i.e., 1-stearoyl-2-arachidonyl-sn-glycerol (SAG), and studied its implication in the modulation of canonical transient receptor potential sub-type 6 (TRPC6) channels in stably-transfected HEK-293 cells. SAG induced the influx of Ca(2+), and also of other bivalent cations like Ba(2+) and Sr(2+), in these cells. SAG-evoked Ca(2+) influx was not due to its metabolites as inhibitors of DAG-lipase (RHC80267) and DAG-kinase (R50922) failed to inhibit the response of the same. To emphasise that SAG exerts its action via its DAG configuration, but not due to the presence of stearic acid at sn-1 position, we synthesized 1-palmitoyl-2…
Melatonin modulates diacylglycerol and arachidonic acid metabolism in the anterior pituitary of immature rats.
1990
In pituitary glands of immature rats prelabeled in vitro with [3H]arachidonic acid, melatonin diminished the luteinizing hormone-releasing hormone (LHRH)-induced increase in [3H]diacylglycerol accumulation as well as [3H]arachidonic acid release from the tissue. Melatonin reduced also LHRH-stimulated incorporation of [3H]glycerol into pituitary [3H]diacylglycerol. The effect was day-time dependent: in the evening experiment melatonin was effective at 0.1 nM concentration while in the morning it had no effect even at 10 nM concentration. The effect of melatonin was also abolished by pretreatment with pertussis toxin. Diacylglycerol and/or arachidonic acid might serve as 2nd messengers transd…
Inhibition of astroglial cell proliferation by alcohols: interference with the protein kinase C-phospholipase D signaling pathway.
2000
Abstract Ethanol inhibits astroglial cell proliferation, an effect that may contribute to the development of alcoholic embryopathy in humans. In the present study, we investigated inhibitory effects of ethanol and butanol isomers (1-, 2- and t -butanol) on astroglial cell proliferation induced by the strongly mitogenic phorbol ester, 4s-phorbol-12α,13s-dibutyrate (PDB). 4s-Phorbol-12α,13s-dibutyrate (PDB) induced a 10-fold increase of [3H]thymidine incorporation in cortical astrocytes prepared from newborn rats (EC 50 : 70 nM) which was blocked by Ro 31-8220, a cell-permeable protein kinase C (PKC) inhibitor. Ethanol blocked PDB-induced astroglial proliferation in a concentration-dependent …
Diacylglycerols containing Omega 3 and Omega 6 fatty acids bind to RasGRP and modulate MAP kinase activation.
2003
We elucidated the effects of different diacylglycerols (DAGs), i.e. 1-stearoyl-2-arachidonoyl-sn-glycerol (SAG), 1-stearoyl-2-docosahexaenoyl-sn-glycerol (SDG), and 1-stearoyl-2-eicosapentaenoyl-sn-glycerol (SEG), on [3H]PDBu binding to RasGRP. The competition studies with these DAGs on [3H]PDBu binding to RasGRP revealed different Ki values for these DAG molecular species. Furthermore, we transfected human Jurkat T cells by a plasmid containing RasGRP and assessed the implication of endogenous DAGs on activation of MAP kinases ERK1/ERK2, induced by phorbol-12-myristate-13-acetate (PMA). In control cells, GF109203X, a protein kinase C inhibitor, inhibited ERK1/ERK2 activation. However, this…