bluuebunny/crossref_metadata_2025_split huggingface dataset:
Head group‐modified sophorolipids: Synthesis of new cationic, zwitterionic, and anionic surfactants
Authors: Zerkowski Jonathan A. , Solaiman Daniel K. Y. , Ashby Richard D. , Foglia Thomas A. 
Published: November 2006

AbstractAmino acid‐glycolipid conjugates were prepared using carbodiimide‐mediated coupling methods. The amino acid units were multifunctional and possessed a para‐aminobenzoic acid linker. The glycolipid used was a stearic sophoroside. The aim of preparing these modified sophorolipids was to increase their water solubility as well as to introduce sites at the polar head groups that permitted further chemical derivatization. After acidolytic or hydrogenolytic deprotection of the amino acid N‐terminus or side chain, water‐soluble compounds were obtained that displayed good surfactant properties. Critical micelle concentration values were clustered in the range of high 10−6 to low 10−5 M, and minimum surface tension values were below 40 mN m−1. Two of the compounds represented more complicated structural classes, namely, gemini and bolaform surfactants.
Precipitation in solutions containing mixtures of synthetic anionic surfactant and soap. I. Effect of sodium octanoate on hardness tolerance of sodium dodecyl sulfate
Authors: Rodriguez Cheryl H. , Chintanasathien Chanin , Scamehorn John F. , Saiwan Chintana , Chavadej Sumaeth 
Published: November 2006

AbstractThe effect of sodium octanoate (SO) and pH on the precipitation of sodium dodecyl sulfate (SDS) with calcium (hardness tolerance) in water was investigated. SO can exist as octanoate anion (O−) or as the protonated nonionic fatty acid (HO) with the HO/O− ratio increasing with decreasing pH. At intermediate pH levels, SO or SO/SDS systems are composed of mixtures of anionic and nonionic surfactants, resulting in enhancement of micelle formation due to nonideal mixed micelle formation. Above the critical micelle concentration (CMC), the highest hardness tolerance at each pH level occurs at a mole ratio of 80∶20 SDS/SO due to synergism in the SDS/SO mixtures. This synergism also results in an increase in hardness tolerance of SDS with decreasing pH above the CMC.
Properties of soaps derived from distilled palm stearin and palm kernel fatty acids
Authors: Kuntom Ainie , Kifli Hamirin 
Published: November 2006

AbstractSoaps made from blends of distilled palm stearin (PS) and palm (PK) kernel fatty acids were evaluated for total fatty matter, sodium chloride content, moisture content, hardness, Hunter whiteness, foamability, iodine value, titer value, and acid value. Data showed that these soaps had properties similar to palm‐based soaps made from distilled palm oil and palm kernel fatty acids. The soaps showed good whiteness (greater than 80%) and foamability. Total fatty matter ranged from 10–18%, sodium chloride content was 0.5%, and free caustic was 0.1% except for blend 8 containing 10 PS:90 PK, which had a free caustic of 0.03%. Initial penetration value, a reflection of soap hardness, ranged from 32–126 mm, with an average value of 54 mm. This value is within the range of the best blends of palm‐based soaps (50–63 mm). There was no obvious trend observed. Penetration value, however was found to stabilize after a month of storage with an average value of 19.4 mm. Soap with this hardness value is relatively hard and therefore should be blended with a small amount of soft oils.
Enhancing storage stability of emulsions by binding detergents with soy protein isolate and its hydrolysates
Authors: Wu Wu , Hettiarachchy N. S. , Rhee K. C. 
Published: November 2006

AbstractSodium dodecyl sulfate (SDS) is a frequently used anionic detergent, and proteins are among the widely used minor ingredients in cosmetic products. Proteins may enhance the detergent functions and protect human skin from irritation caused by detergents. Soy protein hydrolysates (SPH) were prepared by modifying soy protein (SP) with papain. Varying concentrations of SP or SPH were mixed with various concentrations of SDS at different pH values to determine: (i) molecular characteristics, degree of hydrolysis (DH), and surface hydrophobicity (S0) of SP and SPH; (ii) the effect of SDS concentrations on the S0 of SP; (iii) the storage stabilities of oil‐in‐water emulsions formed by SDS, SP, SPH, SP‐SDS, and SPH‐SDS; and (iv) the effect of protein concentration (0.01 to 1.5%), DH (1.2 to 12.5%), and pH (3.0, 5.0, 7.0, and 9.0) on storage stabilities of emulsions formed by SP‐SDS or SPH‐SDS. An increase in emulsion stability (ES) with increasing protein concentration was observed. The ES values of emulsions formed by SPH‐SDS complexes were significantly higher than those formed by SP‐SDS at pH 7.0 and 9.0. The ES of emulsions formed by the complexes were low at pH 5.0 and increased with increasing pH. At pH 3.0 the emulsions formed by SP‐SDS at 1 to 1.5% protein concentration and by SPH‐SDS at 1.5% protein concentration were very stable. The results indicate that at least one‐half of SDS content can be replaced by SP or SPH while maintaining emulsion stability.
Colloidal flocculation of micellar solutions of anionic surfactants
Authors: Paton P. , Talens‐Alesson F. I. 
Published: November 2006

AbstractMicellar solutions of anionic surfactants usually precipitate in the presence of cations, following a mechanism by which initially cations bind themselves to the micellar surface until saturation is achieved. At higher cation concentrations, unbound cations precipitate with surfactant monomers. In a few cases cations, and especially Al3+, cause surfactant micelles to flocculate. These flocs have properties as adsorbents of acidic organic compounds, which might be used in water treatment processes. Both α‐olefinsulfonates C14−C16, and laurylsulfate micellar solutions are fast flocculation colloidal systems in the presence of Al3+.
Improving solubilization in microemulsions with additives. Part III: Lipophilic linker optimization
Authors: Salager Jean‐Louis , Graciaa Alain , Lachaise Jean 
Published: November 2006

AbstractPolar oil additives are able to substantially improve the solubilization in surfactant‐oil‐water microemulsions through the so‐called lipophilic linker effect. Long‐chain alcohols (above C8) and their low ethoxylation derivatives were found to produce such an improvement. A method is proposed to evaluate the lipophilic linker performance and to compare lipophilic linker candidates in different oil‐surfactant systems. The best lipophilic linker was found to have a hydrophobe chain length as an average between that of the surfactant tail and the n‐alkane oil. The experimental data agree with that obtained by using a simple model based on the estimation of molecular interactions.
Diversity of mouse lipoxygenases: Identification of a subfamily of epidermal isozymes exhibiting a differentiation‐dependent mRNA expression pattern
Authors: Heidt Markus , Fürstenberger Gerhard , Vogel Sonja , Marks Friedrich , Krieg Peter 
Published: November 2006

AbstractBy using reverse transcription‐polymerase chain reaction technology (RT‐PCR) and Northern blot analysis, the tissue‐specific mRNA expression patterns of seven mouse lipoxygenases (LOX)—including 5S‐, 8S‐, three isoforms of 12S‐, 12R‐LOX, and a LOX of an as‐of‐yet unknown spacificity, epidermis‐type LOX‐3 (e‐LOX‐3)—were investigated in NMRI mice. Among the various tissues tested epidermis and forestomach were found to express the broadest spectrum of LOX. With the exception of 5S‐and platelet‐type 12S‐LOX (p12S‐LOX) the remaining LOx showed a preference to exclusive expression in stratifying epithelia of the mouse, in particular the integumental epidermis. The expression of the individual LOX in mouse epidermis was found to depend on the state of terminal differentiation of the keratinocytes. mRNA of epidermis‐type 12S‐LOX (e12S‐LOX) was detected in all layers of neonatal and adult NMRI mouse skin, whereas experission of p12S‐LOX, 12R‐LOX, and e‐LOX‐3 was restricted to suprabasal epidermal layers of neonatal and adult mice. 8S‐LOX mRNA showed a body‐sitedependent expression in that it was detected in stratifying epithelia of footsole and forestomach but not in back skin epidermis. In the latter, 8S‐LOX mRNA was strongly induced upon treatment with phorbol esters. With the exception of e12S‐LOX and p12S‐LOX, the isozymes that are preferentially expressed in stratifying epithelia are structurally related and may be grouped together into a distinct subgroup of epidermis‐type LOX.
Liver and intestinal fatty acid‐binding protein expression increases phospholipid content and alters phospholipid fatty acid composition in L‐cell fibroblasts
Authors: Murphy Eric J. , Prows Daniel R. , Stiles Thomas , Schroeder Friedhelm 
Published: November 2006

AbstractAlthough fatty acid‐binding proteins (FABP) differentially affect fatty acid uptake, nothing is known regarding their role(s) in determining cellular phospholipid levels and phospholipid fatty acid composition. The effects of liver (L)‐ and intestinal (I)‐FABP expression on these parameters were determined using stably transfected L‐cells. Expression of L‐ and I‐FABP increased cellular total phospholipid mass (nmol/mg protein) 1.7‐ and 1.3‐fold relative to controls, respectively. L‐FABP expression increased the masses of choline glycerophospholipids (ChoGpl) 1.5‐fold, phosphatidylserine (PtdSer) 5.6‐fold, ethanolamine glycerophospholipids 1.4‐fold, sphingomyelin 1.7‐fold, and phosphatidylinositol 2.6‐fold. In contrast, I‐FABP expression only increased the masses of ChoGpl and PtdSer, 1.2‐ and 3.1‐fold, respectively. Surprisingly, both L‐ and I‐FABP expression increased ethanolamine plasmalogen mass 1.6‐ and 1.1‐fold, respectively, while choline plasmalogen mass was increased 2.3‐ and 1.7‐fold, respectively. The increase in phospholipid levels resulted in dramatic 48 and 33% decreases in the cholesterol‐to‐phospholipid ratio in L‐ and I‐FABP expressing cells, respectively. L‐FABP expression generally increased polyunsaturated fatty acids, primarily by increasing 20∶4n−6 and 22∶6n−3, while decreasing 18∶1n−9 and 16∶1n−7. I‐FABP expression generally increased only 20∶4n−6 proportions. Hence, expression of both I‐ and L‐FABP differentially affected phospholipid mass, class composition, and acyl chain composition. Although both proteins enhanced phospholipid synthesis, the effect of L‐FABP was much greater, consistent with previous work suggesting that these two FABP differentially affect lipid metabolism.
Dietary n−3 long‐chain polyunsaturated fatty acid deprivation, tissue lipid composition, ex vivo prostaglandin production, and stress tolerance in juvenile dover sole (Solea solea L.)
Authors: Logue J. A. , Howell B. R. , Bell J. G. , Cossins A. R. 
Published: November 2006

AbstractLarval Dover sole fed an Artemia diet supplemented with n−3 long‐chain (C20+C22) polyunsaturated fatty acids (PUFA) are known to be more resistant to low‐temperature injury. Here we explore the relationship between tissue fatty acid composition and tolerance of stressful environmental conditions over the larval and early juvenile periods. Artemia nauplii supplemented with n−3 long‐chain PUFA‐deficient and PUFA‐enriched oil emulsions were fed to two groups of larvae. Whole body tissue samples from the resulting PUFA‐deficient and‐enriched juveniles possessed 12.1 and 21.9% n−3 long‐chain PUFA, respectively. These differences were at the expense of C18 PUFA, while proportions of saturated fatty acids, monousaturated fatty acids, and total PUFA were unaffected. Brain and eye tissues from the PUFA‐deficient fish contained lower levels of 22∶6n−3, known to be important for optimal nervous system function, incorporation instead a range of fatty acids of lower unsaturation. PUFA‐deprived juveniles showed substantially greater mortality when exposed to a combination of low temperature and low salinity, as well as to high temperature and to hypoxia. After adaptation to the different diets, both dietary groups were fed a common formulated feed high in n−3 long‐chain PUFA. Tissue PUFA in both groups progressively increased to the same high value, with a consequent loss of the differences in cold‐susceptibility. These correlated changes support a link between dietary manipulation of n−3 long‐chain PUFA and development of a stress‐sensitive phenotype. PUFA deprivation had no detectable effect upon static hydrocarbon order of purified brain membranes (as assessed by fluorescence polarization) but was associated with an increase in the whole‐body content of prostaglandins. We conclude that susceptibility to environmental stress is responsive to dietary n−3 long‐chain PUFA manipulation, possibly due to altered tissue development or the overproduction of eicosanoids.
Determination of the conjugated linoleic acid‐containing triacylglycerols in New Zealand bovine milk fat
Authors: Robinson Nicholas P. , MacGibbon Alastair K. H. 
Published: November 2006

AbstractReversed‐phase high‐performance liquid chromatography (HPLC) with ultraviolet (UV) detection at 233 nm was used to separate, quantify, and identify the triacylglycerols (TAG) of milk fat that contain conjugated linoleic acid (CLA). The absorbance at 233 nm was substantially due to CLA‐TAG (chromatography of some representative TAG devoid of CLA, such as tripalmitin and triolein, showed poor responses at 233 nm, 1/800th that of CLA‐TAG). A CLA molar extinction coefficient at 233 nm of 23 360 L mol−1 cm−1 and an HPLC UV response factor were obtained from a commercially available cis‐9, trans‐11‐CLA standard. This molar extinction coefficient was only 86% reported literature values. Summation of all chromatographic peaks absorbing at 233 nm using the corrected response factor gave good agreement with independent determinations of total CLA by gas chromatography and UV spectrophotometry. This agreement allowed quantification of individual CLA‐TAG peaks in the HPLC separation of a typical New Zealand bovine milk fat. Three CLA‐containing TAG, CLA‐dipalmitin, CLA‐oleoyl‐palmitin and CLA‐diolein, were prepared by interesterification of tripalmitin with the respective fatty acid methyl esters and used to assign individual peaks in the reversed‐phase chromatography of total milk fat, of which CLA‐oleoyl‐palmitin was coincident with the largest UV peak. Band fractions from argentation thin‐layer chromatography of total milk fat were similarly employed to identify five predominant CLA‐TAG groups in total milk fat: CLA‐disaturates, CLA‐oleoyl‐saturates, CLA‐vaccenyl‐saturates, CLA‐vaccenyl‐olein, and CLA‐diolein.
Gas chromatography—High resolution selected‐ion mass spectrometric identification of trace 21∶0 and 20∶2 fatty acids eluting with conjugated linoleic acid isomers
Authors: Roach John A. G. , Yurawecz Martin P. , Kramer John K. G. , Mossoba Magdi M. , Eulitz Klaus , Ku Yuoh 
Published: November 2006

AbstractHigh‐resolution selected‐ion recording (SIR) of the exact molecular ion mass was used to confirm unambiguously the presence of conjugated linoleic acid (CLA) derivatives in biological matrices and standard mixtures and to differentiate non‐CLA derivatives from CLA derivatives in the CLA region of the gas chromatogram. The success of this method was based on the selectivity of the SIR technique and its sensitivity, which was comparable to that of flame‐ionization detection. A minor fatty acid methyl ester (FAME) was identified as methyl heneicosanoate (21∶0), and six isomers of 20∶2 FAME were found to elute in the CLA region. Isomerization of a standard CLA mixture resulted in a non‐CLA flame‐ionization response eluting in the CLA region of the gas chromatogram. It is therefore recommended that the identification of minor CLA isomers in natural products of biological matrices should include their direct confirmation by mass spectrometry
The role of docosahexaenoic acid in retinal function
Authors: Jeffrey Brett G. , Weisinger Harrison S. , Neuringer Martha , Mitchell Drake C. 
Published: November 2006

AbstractAn important role for docosahexaenoic acid (DHA) within the retina is suggested by its high levels and active conservation in this tissue. Animals raised on n‐3‐deficient diets have large reductions in retinal DHA levels that are associated with altered retinal function as assessed by the electroretinogram (ERG). Despite two decades of research in this field, little is known about the mechanisms underlying altered retinal function in n‐3‐deficient animals. The focus of this review is on recent research that has sought to elucidate the role of DHA in retinal function, particularly within the rod photoreceptor outer segments where DHA is found at its highest concentration. An overview is also given of human infant studies that have examined whether a neonatal dietary supply of DHA is required for the normal development of retinal function.
Randomized trials with polyunsaturated fatty acid interventions in preterm and term infants: Functional and clinical outcomes
Authors: Gibson Robert A. , Chen Wenxiong , Makrides Maria 
Published: November 2006

AbstractThe role of polyunsaturated fatty acids (PUFA) in infant nutrition has now been well studied through many randomized controlled trials (RCT) that provide us with high‐quality evidence, particularly in relation to efficacy. As a result of a systematic search of the literature for RCT of supplementation of formulas of term and preterm infants with long‐chain polyunsaturated fatty acids (LC‐PUFA), we have identified 21 studies that have physiological responses or growth as outcomes. There have been 11 RCT involving preterm infants, and many of these claim a beneficial effect on visual, neural, or developmental outcomes. There are some reports of negative effects on growth in relation to the addition of n−3 LC‐PUFA to preterm formulas but not when AA is added with n−3 LC‐PUFA. Small studies have shown no differences in prostanoid formation or peroxidative stress between n−3 IC‐PUFA‐supplemented and unsupplemented infants. There have been 10 RCT involving term infants; whereas some studies report an effect on visual/neural/developmental outcomes, an equal number report no effect. There have been no reports of negative effects of n−3 LC‐PUFA on growth in term infants. In summary, there appear to be few safety concerns relating to the use of LC‐PUFA in infant nutrition. The potential medium‐ and long‐term effects of including these compounds in the early diet of infants remain to be assessed.
Essential fatty acids in visual and brain development
Authors: Uauy Ricardo , Hoffman Dennis R. , Peirano Patricio , Birch David G. , Birch Eileen E. 
Published: November 2006

AbstractEssential fatty acids are structural components of all tissues and are indispensable for cell membrane synthesis; the brain, retina and other neural tissues are particularly rich in long‐chain polyunsaturated fatty acids (LC‐PUFA). These fatty acids serve as specific precursors for eicosanoids, which regulate numerous cell and organ functions. Recent human studies support the essential nature of n‐3 fatty acids in addition to the well‐established role of n−6 essential fatty acids in humans, particularly in early life. The main findings are that light sensitivity of retinal rod photoreceptors is significantly reduced in newborns with n−3 fatty acid deficiency, and that docosahexaenoic acid (DHA) significantly enhances visual acuity maturation and cognitive functions. DHA is a conditionally essential nutrient for adequate neurodevelopment in humans. Comprehensive clinical studies have shown that dietary supplementation with marine oil or single‐cell oil sources of LC‐PUFA results in increased blood levels of DHA and arachidonic acid, as well as an associated improvement in visual function in formula‐fed infants matching that of human breast‐fed infants. The effect is mediated not only by the known effects on membrane biophysical properties, neurotransmitter content, and the corresponding electrophysiological correlates but also by a modulating gene expression of the developing retina and brain. Intracellular fatty acids or their metabolites regulate transcriptional activation of gene expression during adipocyte differentiation and retinal and nervous system development. Regulation of gene expression by LC‐PUFA occurs at the transcriptional level and may be mediated by nuclear transcription factors activated by fatty acids. These nuclear receptors are part of the family of steroid hormone receptors. DHA also has significant effects on photoreceptor membranes and neurotransmitters involved in the signal transduction process; rhodopsin activation, rod and cone development, neuronal dendritic connectivity, and functional maturation of the central nervous system.
Mechanisms of action of docosahexaenoic acid in the nervous system
Authors: Salem Norman , Litman Burton , Kim Hee‐Yong , Gawrisch Klaus 
Published: November 2006

AbtractThis review describes (from both the animal and human literature) the biological consequences of losses in nervous system docosahexaenoate (DHA). It then concentrates on biological mechanisms that may serve to explain changes in brain and retinal function. Brief consideration is given to actions of DHA as a nonesterified fatty acid and as a docosanoid or other bioactive molecule. The role of DHA‐phospholipids in regulating G‐protein signaling is presented in the context of studies with rhodopsin. It is clear that the visual pigment responds to the degree of unsaturation of the membrane lipids. At the cell biological level, DHA is shown to have a protective role in a cell culture model of apoptosis in relation to its effects in increasing cellular phosphatidylserine (PS); also, the loss of DHA leads to a loss in PS. Thus, through its effects on PS, DHA may play an important role in the regulation of cell signaling and in cell proliferation. Finally, progress has been made recently in nuclear magnetic responance studies to delineate differences in molecular structure and order in biomembranes due to subtle changes in the degree of phospholipid unsaturation.
Application of new methods and analytical approaches to research on polyunsaturated fatty acid homeostasis
Authors: Cunnane Stephen C. 
Published: November 2006

AbstractNew methods and analytical approaches are important to challenge and/or validate established beliefs in any field including the metabolism of polyunsaturated fatty acids (PUFA; polyunsaturates). Four methods that have recently been applied toward obtaining a better understanding of the homeostasis of PUFA include the following: whole‐body fatty acid balance analysis, magnetic resonance imaging (MRI), 13C nuclear magnetic resonance (NMR) spectroscopy, and gas chromatography‐combustion‐isotope ratio mass spectrometry (GC‐C‐IRMS). Whole‐boby balance studies permit the measurement of both the percentage of oxidation of linoleate and α‐linolenate and their conversion to long‐chain PUFA. This method has shown that β‐oxidation to CO2 is normally the predominant metabolic fate of linoleate and α‐linolenate. Furthermore, models of experimental undernutrition in both humans and animals show that β‐oxidation of linoleate and α‐linolenate markedly exceeds their intake, despite theoretically sufficient intake of linoleate or α‐linolenate. Preliminary results suggest that by using MRI to measure body fat content, indirect whole‐body linoleate balance can be done in living humans, 13C NMR spectroscopy provided unexpected evidence that linoleate and α‐linolenate were metabolized into lipids synthesized de novo, an observation later quantified by tracer mass balance done using GC‐C‐IRMS. This latter method showed that within 48 h of dosing with 13C‐α‐linolenate, >80% underwent β‐oxidation to CO2 by suckling rats, whereas 8–9% was converted to newly synthesized lipids and <1% to docosahexaenoate. Further application of these recently developed methods in different models should clarify the emerging importance of β‐oxidation and carbon recycling in PUFA homeostasis in mammals including humans.