Search results for "LECITHIN"
showing 10 items of 61 documents
Coreconstitution of bacterial ATP synthase with monomeric bacteriorhodopsin into liposomes. A comparison between the efficiency of monomeric bacterio…
1987
The conditions for coreconstitution of a bacterial ATP synthase and bacteriorhodopsin into lecithin liposomes and for light driven ATP synthesis have been optimized. A rate of maximally 280 nmol ATP min-1 mg ATP synthase-1 was achieved with monomerized bacteriorhodopsin compared with a rate of up to 45 nmol ATP min-1 mg-1 found for proteoliposomes containing bacteriorhodopsin in the form of purple membrane patches. The different rates are explained by the finding that monomeric bacteriorhodopsin is more homogeneously distributed among the liposomes than the purple membrane patches. The final activities depended on both the purification method for the two proteins and the coreconstitution pr…
Structural Investigation of Water/Lecithin/Cyclohexane Microemulsions by FT-IR Spectroscopy
1995
Abstract FT-IR spectra of water/lecithin/deuterated cyclohexane microemulsions as a function of water/lecithin molar ratio R ( R = [water]/[lecithin]) at various volume fractions ( O ) of the micellar phase have been recorded at 25°C. After elimination of the small spectral contributions due to deuterated cyclohexane and normalization, the shape of the C–H stretching band due to lecithin has been found dependent upon R and O whereas that of the O–H stretching band has been found dependent only upon R . The change in shape of the C–H band was interpreted in terms of a modification of the lecithin alkyl chain packing order. The analysis of the O–H band provides evidence that the hydroxylic gr…
Portulaca oleracea reduces triglyceridemia, cholesterolemia, and improves lecithin: cholesterol acyltransferase activity in rats fed enriched-cholest…
2014
Abstract Purpose The effects of Portulaca oleracea ( Po ) lyophilized aqueous extract were determined on the serum high-density lipoproteins (HDL 2 and HDL 3 ) amounts and composition, as well as on lecithin: cholesterol acyltansferase (LCAT) activity. Methods Male Wistar rats ( n = 12) were fed on 1% cholesterol-enriched diet for 10 days. After this phase, hypercholesterolemic rats (HC) were divided into two groups fed the same diet supplemented or not with Portulaca oleracea ( Po -HC) (0.5%) for four weeks. Results Serum total cholesterol (TC) and triacylglycerols (TG), and liver TG values were respectively 1.6-, 1.8-, and 1.6-fold lower in Po -HC than in HC group. Cholesterol concentrat…
Identification of Abies sibirica L. Polyprenols and Characterisation of Polyprenol-Containing Liposomes
2020
The needles of conifer trees are one of the richest sources of natural polyprenols. Polyprenol homologs from Abies sibirica L. lipophilic 80% purified extract were analyzed and quantified. In total, 10 peaks (Prenol-11 to Prenol-20) were observed in the ultra-high-performance liquid chromatography&ndash
Spectrophotometric investigation of the binding of vitamin E to water-containing reversed micelles.
2002
The distribution constants of vitamin E partitioned between apolar organic phase and water-containing reversed micelles of sodium bis (2-ethylhexyl) sulfosuccinate (AOT), didodecyldimethylammonium bromide (DDAB), soybean phosphatidylcholine (lecithin) and tetraethylene glycol monododecyl ether (C12E4) have been evaluated by a spectrophotometric method. The results suggest that in the presence of domains from apolar organic solvent to surfactant and to water, vitamin E is partitioned between the micellar palisade layer and the organic solvent and also that its binding strength to reversed micelles depends mainly by specific interactions between the head group of vitamin E and that of the sur…
Dielectric properties of water/lecithin/cyclohexane gels
1993
Dielectric relaxation measurements in the frequency range 0.1–15 GHz have been carried out on water/lecithin/cyclohexane gels using a time domain reflectometry method (TDR). Dielectric dispersions describable in terms of a power law typical of percolated systems, but with exponents significantly different from those characterizing statically or dynamically percolated systems are observed. The dielectric dispersions, attributed to water and/or lecithin head group rotational motions, indicate that these motions are characterized by a wide spectrum of relaxation times.
Transcutol containing vesicles for topical delivery of minoxidil
2010
The aim of this work was to evaluate the ability of Transcutol (Trc) to produce elastic vesicles with soy lecithin (SL) and study the influence of the obtained vesicles on in vitro (trans)dermal delivery of minoxidil. To this purpose, so-called penetration enhancer-containing vesicles (PEVs) were prepared using Trc aqueous solutions (5-10-20-30% v/v) as hydrophilic phase. SL liposomes, without Trc, were used as control. Prepared formulations were characterized in terms of size distribution, morphology, zeta potential, deformability, and rheological behavior. The influence of the obtained PEVs on (trans)dermal delivery of minoxidil was studied by in vitro diffusion experiments through pig sk…
Thymus essential oil extraction, characterization and incorporation in phospholipid vesicles for the antioxidant/antibacterial treatment of oral cavi…
2018
The aim of the work was to extract, characterize, and formulate Thymus capitatus (Tymbra capitata) essential oil in phospholipid vesicles: liposomes, glycerosomes and Penetration Enhancer-containing Vesicles (PEVs). The steam-distilled essential oil was mainly composed of carvacrol. The oil was mixed with lecithin and water to produce liposomes, or different ratios of water/glycerol or water/propylene glycol (PG) to produce glycerosomes and PG-PEVs, respectively. Cryo-TEM showed the formation of unilamellar, spherical vesicles, and light scattering disclosed that their size increased in the presence of glycerol or PG, which improved long-term stability. The formulations were highly biocompa…
Low Serum Choline Concentrations Are Associated with Worse Cognitive Performance in Subjects with Metabolic Syndrome
2020
OBJECTIVES: Choline is an essential nutrient critical for components of the cell membrane, such as choline-containing phospholipids (phosphatidylcholine and sphingomyelin), and in synthesis of the neurotransmitter acetylcholine. Choline has been shown to exert neuroprotective effects, but the association between serum choline and cognitive performance has been scarcely investigated. Our aims are: 1) To study the association between serum total choline, phosphatidylcholine and sphingomyelin with cognitive performance in subjects with metabolic syndrome; and 2) to analyze genetic variants and dietary intake most associated with cholines in this population. METHODS: We analyzed 426 subjects (a…
Influence of the electrical interface properties on the rheological behavior of sonicated soy lecithin dispersions
2006
A significant effect, on the rheological behavior, due to the electrical properties of vesicles formed from concentrated soy lecithin dispersions have been studied in this work. The rheopectic behavior of concentrated soy lecithin dispersions (120, 150, 180, 210 and 240 g L−1) prepared by swelling–light sonication–freezing–unfreezing procedure is studied and it is specially emphasized on the transition under steady shear from lamellar phase of planar sheets to closed structures as multilamellar vesicles. Samples have been exposed to a different number of sonication cycles (from 0 to 100) and the changes in the hysteresis loop area, the apparent viscosity and the electrophoretic mobility hav…