bluuebunny/crossref_metadata_2025_split huggingface dataset:
Interactions between anionically modified hydroxyethyl cellulose and cationic surfactants
Authors: Lauer H. , Stark A. , Hoffmann H. , Dönges R. 
Published: November 2006

AbstractMacroscopic properties of aqueous solutions of several modified hydroxyethyl cellulose (HEC) samples and their interactions with cationic surfactants are studied by solubility, light scattering, electric birefringence, rheology, and surface tension measurements. Modified HEC samples carry anionic groups (an‐HEC D0) and anionic and hydrophobic groups in random distribution (HM‐an‐HEC D1–D4). The molar substitution of anionic (an) groups is about 0.07 in all samples while that of the hydrophobic (HM) groups ranges from 0 in an‐HEC D0 to 0.012 in HM‐an‐HEC D4. In a 1 wt% solution this corresponds to 2.7 mM anionic and 0 to 0.46 mM hydrophobic groups. In the dilute concentration range the polymers behave like typical polyelectrolytes whereas in the semi‐dilute range they resemble uncharged polymers. On addition of oppositely charged surfactants the phase behavior of all polyelectrolytes is similar. With increasing surfactant concentrations the transparent solutions become turbid and the phases separate. Finally, resolubilization takes place with excess surfactant concentrations. With the HM‐an‐HEC compounds viscoelastic solutions are formed with cationic surfactants. The intermolecular interaction between hydrophobic parts of the polymers and the surfactants and interactions of oppositely charged ionic groups of the two components lead to formation of a temporary network with gel‐like properties. With an‐HEC the interaction can only take place via charges. Viscosity enhancement with increasing surfactant concentration is therefore lower with an‐HEC than with HM‐an‐HEC compounds.
Study on the substrate specificity of α‐amylases that contribute to soil removal in detergents
Authors: Tanaka Atsushi , Hoshino Eiichi 
Published: November 2006

AbstractThe actions of α‐amylases in the degradation of amylose and amylopectin were investigated, and the contribution of the enzymatic hydrolysis of high‐viscosity gelatinized starch to the removal of food stains that contain starch was characterized. α‐Amylases from Bacillus amyloliquefaciens, B. licheniformis, Aspergillus oryzae, and porcine pancreas were used to test the removal of curry stains, which are hard to remove under low‐temperature washing conditions and include large amounts of starch. In a detergent, the enzyme from B. amyloliquefaciens was the most effective in removing stains and hydrolyzed amylopectin more efficiently than amylose as a result of the more efficient formation of an enzyme‐substrate complex in the former case. It is suggested that the cleaning power of α‐amylases is due to their hydrolytic action, with endo‐degradation of amylopectin, which results in an efficient reduction in the degree of polymerization. The liquefaction of amylopectin then accelerates the removal of food stains.
Analysis of ethoxylated fatty amines. Comparison of methods for the determination of molecular weight
Authors: Lang Russell F. , Parra‐Diaz Dennisse , Jacobs Dana 
Published: November 2006

AbstractSpecific lengths of the fatty and polyoxyethylene chains of ethoxylated fatty amines are critical to their performance in specific applications, and thus the ability to characterize these surfactants accurately is crucial. Normal‐phase high‐performance liquid chromatography (HPLC) and matrixassisted laser desorption ionization‐time of flight (MALDI‐TOF) mass spectrometry methods were developed to determine with accuracy the molecular weight and degree of ethoxylation of ethoxylated fatty amines. Ethoxylated fatty amines were analyzed using these methods, and comparison was made to molecular weight determinations using proton nuclear magnetic resonance (NMR), neutralization equivalent weight, and hydroxyl value methods. Molecular weight results from normalphase HPLC analyses were in very good agreement with MALDI‐TOF results, typically varying less than one ethylene oxide unit. A reversed‐phase HPLC method was developed to determine concentrations of polyethylene glycols (PEG) and fatty homologs. PEG interfered with molecular weight determinations by NMR, neutralization equivalent weight, and hydroxyl value methods. PEG caused no interference with molecular weight determinations by normal‐phase HPLC and MALDI‐TOF methods.
Correlation of fatty acid unsaturation of the major liver mitochondrial phospholipid classes in mammals to their maximum life span potential
Authors: Portero‐Otín Manuel , Josep Bellumunt Maria , Cristina Ruiz Maria , Barja Gustavo , Pamplona Reinald 
Published: November 2006

AbstractFree radical damage is considered a determinant factor in the rate of aging. Unsaturated fatty acids are the tissue macromolecules that are most sensitive to oxidative damage. Therefore, the presence of low proportions of fatty acid unsaturation is exprected in the tissues of long‐lived animals. Accordingly, the fatty acid compositions of the major liver mitochondrial phospholipid classes from eight mammals, ranging in maximum life span potential (MLSP) from 3.5 to 46 yr, show that the total number of double bonds is inversely correlated with MLSP in both phosphatidylcholine (PtdCho) and phosphatidylethanolamine (PtdEtn) (r=0.757, P<0.03, and r=0.862, P<0.006, respectively), but not in cardiolipin (P=0.323). This is due not to a low content of unsaturated fatty acids in long‐lived animals, but mainly to a redistribution between kinds of fatty acids on PtdCho and PtdEtn, shifting from arachidonic (r=0.911, P<0.002, and r=0.681, P=0.05, respectively), docosahexaenoic (r=0.931 and r=0.965, P<0.0001, respectively) and palmitic (r=0.944 and r=0.974, P<0.0001, respectively) acids to linoleic acid (r=0.942, P<0.0001, for PtdCho; and r=0.957, P<0.0001, for PtdEtn). For cardiolipin, only arachidonic acid showed a significantly inverse correlation with MLSP (r=0.904, P<0.002). This pattern strongly suggests the presence of a species‐specific desaturation pathway and deacylation‐reacylation cycle in determining the mitochondrial membrane composition, maintaining a low degree of fatty acid unsaturation in long‐lived animals.
Inhibitory effects of triterpenoids and sterols on human immunodeficiency virus‐1 reverse transcriptase
Authors: Akihisa Toshihiro , Ogihara Jun , Kato Jun , Yasukawa Ken , Ukiya Motohiko , Yamanouchi Sakae , Oishi Kunio 
Published: November 2006

AbstractFifty‐five triterpenoids consisting of 19 tetracyclic, 32 pentacyclic, and 4 incompletely cyclized triterpenoids, and 2 sterols, mostly isolated from various plant and fungal materials, were examined for their inhibitory effects on a purified human immunodeficiency virus type 1 (HIV‐1) reverse transcriptase. Twenty triterpenoids and one sterol showed inhibitory effects with 50% inhibition concentration (IC50) values less than 5.0 μM. Among these cycloartenol ferulate (IC50=2.2 μM), 24‐methylenecycloartanol ferulate (1.9 μM), lupenone (2.1 μM), betulin diacetate (1.4 μM), and karounidiol 29‐benzoate (2.2 μM) inhibited most effectively. Some of the triterpenoids and sterols may be potential new lead compounds to find still more potent HIV‐1 reverse transcriptase inhibitors.
New glycosphingolipid containing an unusual sphingoid base from the basidiomycete Polyporus ellisii
Authors: Gao Jin‐Ming , Hu Lin , Dong Ze‐Jun , Liu Ji‐Kai 
Published: November 2006

AbstractA new 9‐methyl‐sphinga‐4,8‐dienine‐containing glucocerebroside (1), together with two additional known analogs, cerebrosides B and D, was isolated from the chloroform‐soluble lipid fraction of the ethanol and chloroform/methanol extract of the fruiting bodies of the basidiomycete Polyporus ellisli Berk. and characterized. The structure and relative stereochemistry of the new compound were identified as (2S,3R,4E,8E)‐1‐(β‐d‐glucopyranosyl)‐3‐hydroxy‐2‐[(R)‐2′‐hydroxyheptadecanoyl]amino‐9‐methyl‐4,8‐octadecadiene by means of spectroscopic (1H, 13C, and two‐dimensional nuclear magnetic resonance; mass spectrometry) and chemical methods.
Interaction between dietary protein and fat in triglyceride metabolism in the rat: Effects of soy protein and menhaden oil
Authors: Demonty Isabelle , Deshaies Yves , Lamarche Benoît , Jacques Hélène 
Published: November 2006

AbstractThe objective of the present study was to determine the mechanisms by which dietary proteins interact with dietary lipids in the regulation of triglyceridemia in rats. Male Sprague‐Dawley rats (n=56) were subjected to 28‐d experimental diets containing different combinations of proteins (20% w/w) and lipid sources (14% w/w): (i) casein‐menhaden oil, (ii) casein‐beef tallow, (iii) soy protein‐menhaden oil, and (iv) soy protein‐beef tallow. Significant protein‐lipid interactions were observed on triglyceridemia and hepatic cholesterol in fasted rats. The combination of casein and beef tallow was associated with high plasma TG and hepatic cholesterol concentrations, which were reduced by substitution either of soy for casein or of menhaden oil for beef tallow. Therefore, triglyceridemia and liver cholesterol remained low with soy protein feeding, independently of the lipid source, as well as with menhaden oil feeding, regardless of the protein source. The menhaden oil diets reduced plasma cholesterol, hepatic TG, and TG secretion compared with beef tallow diets independently of the dietary protein source. Modifying the source of dietary proteins and lipids had no effect on post‐heparin plasma lipoprotein lipase activity. These results demonstrate that soy protein can lower rat triglyceridemia relative to casein when associated with beef tallow consumption, whereas menhaden oil can attenuate hypertriglyceridemia when rats are fed casein. The data further suggest that part of the hypotriglyceridemic effect of soy protein in the rat may be mediated by reduced hepatic lipid synthesis, as is the case for menhaden oil.
Similar effects of c9, t11‐CLA and t10,c12‐CLA on immune cell functions in mice
Authors: Kelley D. S. , Warren J. M. , Simon V. A. , Bartolini G. , Mackey B. E. , Erickson K. L. 
Published: November 2006

AbstractPublished results regarding the effects of CLA on immune cell functions have ranged from stimulation to inhibition. In those studies, a mixture of CLA isomers were used, and food intake was not controlled. We have examined whether the discrepancies in the results of earlier studies may be due to the lack of controlled feeding and whether the two isomers of CLA may differ in their effects on immune cell functions. Three groups of C57BL/6 female mice were fed either a control, c9,t11‐CLA‐, or t10, c12‐CLA (0.5 wt%)‐supplemented diet, 5 g/d, for 56 d. At the end of the study, the number of immune cells in spleens, bone marrows, or in circulation; proliferation of splenocytes in response to T and B cell mitogens; and prosta‐glandin secretion in vitro did not differ among the three groups. Both CLA isomers significantly‐increased in vitro tumor necrosis factor α and interleukin (IL)‐6 secretion and decreased IL‐4 secretion by splenocytes compared to those in the control group. Thus, the two CLA isomers had similar effects on all response variables tested. The discrepancies among the results from previous studies did not seem to be caused by the differences in the isomer composition of CLA used.
Evidence for multiple sterol methyl transferase pathways in Pneumocystis carinii
Authors: Zhou Wenxu , Nguyen Thi Thuy Minh , Collins Margaret S. , Cushion Melanie T. , Nes W. David 
Published: November 2006

AbstractThe sterol composition of Pneumocystis carinii, an opportunistic pathogen responsible for life‐threatening pneumonia in immunocompromised patients, was determined. Our purpose was to identify pathway‐specific enzymes to impair using sterol biosynthesis inhibitors. Prior to this study, cholesterol 15 (ca. 80% of total sterols), lanosterol 1, and several phytosterols common to plants (sitosterol 31, 24α‐ethyl and campesterol, 24α‐methyl 30) were demonstrated in the fungus. In this investigation, we isolated all the previous sterols and many new compounds from P. carinii by culturing the microorganism in steroid‐immunosuppressed rats. Thirty‐one sterols were identified from the fungus (total sterol=100 fg/cell), and seven sterols were identified from rat chow. Unusual sterols in the fungus not present in the diet included, 24(28)‐methylenelanosterol 2; 24(28)E‐ethylidene lanosterol 3; 24(28)Z‐ethylidene lanosterol 4; 24β‐ethyllanosta‐25(27)‐dienol 5; 24β‐ethylcholest‐7‐enol 6; 24β‐ethylcholesterol 7; 24β‐ethylcholesta‐5,25(27)‐dienol 8; 24‐methyllanosta‐7‐enol 9; 24‐methyldesmosterol 10; 24(28)‐methylenecholest‐7‐enol 11; 24β‐methylcholest‐7‐enol 12; and 24β‐methylcholesterol 13. The structural relationships of the 24‐alkyl groups in the sterol side chain were demonstrated chromatographically relative to authentic specimens, by MS and high‐resolution 1H NMR. The hypothetical order of these compounds poses multiple phytosterol pathways that diverge from a common intermediate to generate 24β‐methyl sterols: route 1, 1→2→11→12→13; route 2, 1→2→9→10→13; or 24β‐ethyl sterols: route 3, 1→2→4→6→7; route 4, 1→2→5→8→7. Formation of 3 is considered to form an interrupted sterol pathway. Taken together, operation of distinct sterol methyl transferase (SMT) pathways that generate 24β‐alkyl sterols in P. carinii with no counterpart in human biochemistry suggests a close taxonomic affinity with fungi and provides a basis for mechanism‐based inactivation of SMI enzyme to treat Pneumocystis pneumonia.
Supplementation with CLA: Isomer incorporation into serum lipids and effect on body fat of women
Authors: Petridou Anatoli , Mougios Vassilis , Sagredos Angelos 
Published: November 2006

AbstractAnimal studies have suggested that CLA, a natural component of meat and dairy products, may confer beneficial effects on health. However, human studies using supplementation with CLA have produced contradictory results. The aim of the present study was to further investigate the effect of CLA supplementation on human body fat, serum leptin, and serum lipids, as well as the incorporation of CLA isomers into serum lipids classes. Sixteen young healthy nonobese sedentary women received 2.1 g of CLA (divided equally between the cis,trans‐9,11 and trans,cis‐10,12 isomers) daily for 45 d and placebo for 45 d in a randomized double‐blind crossover design. Body fat was estimated (by measurement of skinfold thickness at 10 sites), and blood was sampled at the beginning, middle, and end of the entire intervention period; an additional blood sample was obtained 2 wk thereafer. No significant differences in energy, carbohydrate, lipid, or protein intake existed between the CLA and placebo intake periods. No significant differences were found in body fat or serum leptin, TAG, total cholesterol, HDL‐cholesterol, and alanine aminotransferase between CLA and placebo. The CLA isomer content of serum TAG, phospholipids, and total lipids increased 2–5 times with CLA supplementation (P<0.05). In contrast, the CLA content of cholesteryl esters did not change significantly. The period of 2 wk after the end of CLA supplementation was sufficient for its washout from serum lipids. These data indicate that supplementation with 2.1 g of CLA daily for 45 d increased its levels in blood but had no effect on body composition or the lipidemic profile of nonobese women.
A sardine oil‐rich diet increases iron absorption but does not compensate the hypoferremia associated with inflammation
Authors: Rodríguez María C. , Sáiz María P. , Mitjavila María T. 
Published: November 2006

AbstractInflammatory disorders are associated with a decrease in iron absorption because of the blockade of iron in storage organs. Fish oils, rich in n−3 PUFA, are used to prevent and treat inflammatory disorders and increase iron absorption in non‐inflamed rats. Here we examine whether n−3 PUFA prevent inflammation‐related hypoferremia. Two groups of rats were fed isoenergetic semipurified diets (a standard diet and a sardine oilrich diet). A carrageenan granuloma was induced in half of the rats of each dietary group. Ferrokinetic studies using 59Fe, hematological analyses, and iron store evaluation were performed in noninflamed and inflamed rats. Although dietary n−3 PUFA increased 59Fe absorption in carageenan‐treated rats, they did not restore the hypoferremia associated with inflammation, which is due to several mechanisms. Among these mechanisms, the blockade of iron in storage organs is relevant. However, this blockade was less evident in the spleen of inflamed rats fed the sardine oil diet.
Stability of fatty acyl‐coenzyme a thioester ligands of hepatocyte nuclear factor‐4α and peroxisome proliferator‐activated receptor‐α
Authors: Schroeder Friedhelm , Huang Huan , Hostetler Heather A. , Petrescu Anca D. , Hertz Rachel , Bar‐Tana Jacob , Kier Ann B. 
Published: November 2006

AbstractAlthough long‐chain fatty acyl‐coenzyme A (LCFA‐CoA) thioesters are specific high‐affinity ligands for hepatocyte nuclear factor‐4α (HNF‐4α) and peroxisome proliferator‐activated receptor‐α (PPARα), X‐ray crystals of the respective purified recombinant ligand‐binding domains (LBD) do not contain LCFA‐CoA, but instead exhibit bound LCFA or have lost all ligands during the purification process, respectively. As shown herein: (i) The acyl chain composition of LCFA bound to recombinant HNF‐4α reflected that of the bacterial LCFA‐CoA pool, rather than the bacterial LCFA pool. (ii) Bacteria used to produce the respective HNF‐4α and PPARα contained nearly 100‐fold less LCFA‐CoA than LCFA. (iii) Under conditions used to crystallize LBD (at least 3 wk at room temperature in aqueous buffer), 16∶1‐CoA was very unstable in buffer alone. (iv) In the presence of the respective nuclear receptor (i.e., HNF‐4α and PPARα), LBD 70–75% of 16∶1‐CoA was degraded after 1 d at room temperature in the crystallization buffer, whereas as much as 94–97% of 16∶1‐CoA was degraded by 3 wk. (v) Cytoplasmic LCFA‐CoA binding proteins such as acyl‐CoA binding protein, sterol carrier protein‐2, and liver‐FA binding protein slowed the process of 16∶1‐CoA degradation proportional to their respective affinities for this ligand. Taken together, these data for the first time indicated that the absence of LCFA‐CoA in the crystallized HNF‐4α and PPARα was due to the paucity of LCFA‐CoA in bacteria as well as to the instability of LCFA‐CoA in aqueous buffers and the conditions used for LBD crystallization. Furthermore, instead of protecting bound LCFA‐CoA from autohydrolysis like several cytoplasmic LCFA‐CoA binding proteins, these nuclear receptors facilitated LCFA‐CoA degradation.
Maternal dietary alpine butter intake affects human milk: Fatty acids and conjugated linoleic acid isomers
Authors: Bertschi Isabelle , Collomb Marius , Rist Lukas , Eberhard Pius , Sieber Robert , Bütikofer Ulrich , Wechsler Daniel , Folkers Gerd , von Mandach Ursula 
Published: November 2006

AbstractConsumption of CLA by lactating women affects the composition of their milk, but the pattern of the different CLA isomers is still unknown. We determined the effects of short maternal supplementation with CLA‐rich Alpine butter on the occurrence of FA and CLA isomers in human milk. In an open randomized controlled study with a two‐period cross‐over design, milk FA and CLA isomer concentrations were measured on postpartum days >‐20 in two parallel groups of lactating women before, during, and after consumption of defined quantities of Alpine butter or margarine with comparable fat content (10 d of butter followed by 10 d of margarine for one group, and vice versa in the other). In the 16 women who completed the study (8/group), Alpine butter supplementation, increased the C16 and C18 FA, the sum of saturated FA, the 18∶1 trans FA, and the trans FA with CLA. The CLA isomer 18∶2 c9, t11 increased by 19.7%. Significant increases were also found for the isomers t9,t111, t7,c9,t11,c13, and t8,c10 18∶2. The remaining nine of the total 14 detectable isomers showed no changes, and concentrations were <5 mg/100g fat. A breastfeeding mother can therefore modulate the FA/CLA supply of her child by consuming Alpine butter. Further studies will show whether human milk containing this FA and CLA isomer pattern acts as a functional food for newborns.
Paradoxical effect of n−3‐containing vegetable oils on long‐chain n−3 fatty acids in rat heart
Authors: Cleland Leslie G. , Gibson Robert A. , Pedler Janet , James Michael J. 
Published: November 2006

AbstractFlaxseed, echium, and canola oils contain α‐linolenic acid (18∶3n−3, ALA) in a range of concentrations. To examine their effect on elevating cardiac levels of long‐chain n−3 FA, diets based on these n−3‐containing vegetable oils were fed to rats for 4 wk. Sunflower oil, which contains little ALA, was a comparator. Despite canola oil having the lowest ALA content of the three n−3‐containing vegetable oils, it was the most potent for elevating DHA (22∶6n−3) levels in rat hearts and plasma. However, the relative potencies of the dietary oils for elevation of EPA (20∶5n−3) in heart and plasma followed the same rank order as their ALA content, i.e., flaxseed>echium>canola>sunflower oil. This paradox may be explained by lower ALA intake leading to decreased competition for Δ6 desaturase activity between ALA and the 24∶5n−3 FA precursor to DHA formation.
A molecular dynamics study of an archaeal tetraether lipid membrane: Comparison with a dipalmitoylphosphatidylcholine lipid bilayer
Authors: Nicolas J. P. 
Published: November 2006

AbstractMolecular dynamics simulations of an archaeal membrane made up of bipolar tetraether lipids and a dipalmitoylphosphatidylcholine (DPPC) lipid membrane were performed and compared for the first time. The simulated archaeal membrane consists of a pure monolayer of asymmetrical lipids, analogous to the main polar lipid [MPL; Swain, M., Brisson, J.‐R., Sprott, G.D., Cooper, F.P., and Patel, G.B., (1997) Identification of β‐1‐Gulose as the Sugar moiety of the Main Polar Lipid of Thermoplasma acidophilum, Biochim. Biophys. Acta 1345, 56–64] found in T. acidophilum, an extremophile archaeal organism. This simulated membrane lipid contains two cyclopentane rings located on one of the two aliphatic chains of the lipid. The archaeal membrane is simulated at 62°C, slightly above the optimal growth temperature of T. acidophilum. We compared the organization of this tetraether lipid monolayer with a DPPC bilayer simulated at 50°C, both of them being modeled in a partially hydrated state. Our results assess the singularity of the tetrather lipid organization, in particular the influence of the spanning structure on the molecular ordering within the archaeal membrane.
Dietary stearic acid and risk of cardiovascular disease: Intake, sources, digestion, and absorption
Authors: Kris‐Etherton Penny M. , Griel Amy E. , Psota Tricia L. , Gebauer Sarah K. , Zhang Jun , Etherton Terry D. 
Published: November 2006

AbstractIndividual FA have diverse biological effects, some of which affect the risk of cardiovascular disease (CVD). In the context of food‐based dietary guidance designed to reduce CVD risk, fat and FA recommendations focus on reducing saturated FA (SFA) and trans FA (TFA), and ensuring an adequate intake of unsaturated FA. Because stearic acid shares many physical properties with the other long‐chain SFA but has different physiological effects, it is being evaluated as a substitute for TFA in food manufacturing. For stearic acid to become the primary replacement for TFA, it is essential that its physical properties and biological effects be well understood.