bluuebunny/crossref_metadata_2025_split huggingface dataset:
A new ceramide from the basidiomycete Russula cyanoxantha
Authors: Gao Jin‐Ming , Dong Ze‐Jun , Liu Ji‐Kai 
Published: November 2006

AbstractA new phytosphingosine‐type ceramide (1) was isolated along with nine other compounds—5α,8α‐epidioxy‐(22E,24R)‐ergosta‐6,22‐dien‐3β‐ol, 5α,8α‐epidioxy‐(24S)‐ergosta‐6‐en‐3β‐ol, (24S)‐ergosta‐7‐ene‐3β,5α,6β‐triol,(22E,24R)‐ergosta‐7, 22‐dien‐3β,5α,6β‐triol, inosine, adenine, l‐pyroglutamic acid, fumaric acid, and d‐allitol from the ethanol and chloroform/methanol extract of the fruiting bodies of the basidiomycete Russula cyanoxanotha (Schaeff.) Fr. The structure of (1) was established as (2S,3S,4R,2′R)‐2‐(2′‐hydroxytetracosanoylamino) octadecane‐1,3,4‐triol by means of spectroscopic and chemical methods.
Ab initio and density functional theory studies for the explanation of the antioxidant activity of certain phenolic acids
Authors: Bakalbassis Evangelos G. , Chatzopoulou Argero , Melissas Vasilios S. , Tsimidou Maria , Tsolaki Matina , Vafiadis Anastasios 
Published: November 2006

AbstractAb initio and density functional theory molecular orbital calculations were carried out at both the HF/6‐31+G(d) and B3LYP/6‐31+G(d) levels for the four antioxidants, p‐hydroxycinnamic acid derivatives, namely, the p‐coumaric, caffeic, ferulic, and sinapinic acid and the corresponding radicals, in an attempt to explain the structural dependency of the antioxidant activity of these compounds. Optimized resulting geometries, vibrational frequencies, absolute infrared intensities, and electron‐donating ability are discussed. Both the high degree of conjugation and the extended spin delocalization in the phenoxyl radicals offer explanation for the scavenging activity of the four acids. In structurally related compounds, the calculated heat of formation value in radical formation appears as a meaningful molecular descriptor of antioxidant activity in accordance with experimental data. This becomes more clear at the B3LYP level.
Formation of cleavage products by autoxidation of lycopene
Authors: Kim Seon‐Jae , Nara Eiichi , Kobayashi Hidetaka , Terao Junji , Nagao Akihiko 
Published: November 2006

AbstractThe cleavage products formed by autoxidation of lycopene were evaluated in order to elucidate possible oxidation products of lycopene in biological tissues. Lycopene solubilized at 50 μM in toluene, aqueous Tween 40, or liposomal suspension was oxidized by incubating at 37°C for 72 h. Among a number of oxidation products formed, eight products in the carbonyl compound fraction were identified as 3,7,11‐trimethyl‐2,4,6,10‐dodecatetraen‐1‐al, 6,10,14‐trimethyl‐3,5,7,9,13‐pentadecapentaen‐2‐one, acycloretinal, apo‐14′‐lycopenal, apo‐12′‐lycopenal, apo‐10′‐lycopenal, apo‐8′‐lycopenal, and apo‐6′‐lycopenal. These correspond to a series of products formed by cleavage in the respective 11 conjugated double bonds of lycopene. The maximal formation of acycloretinal was 135 nM in toluene, 49 nM in aqueous Tween 40, and 64 nM in liposomal suspension. Acycloretinoic acid was also formed by autoxidation of lycopene, although its formation was lower in the aqueous media than in toluene. The pig liver homogenate had the ability to convert acycloretinal to acycloretinoic acid, comparable to the conversion of all‐trans‐retinal to all‐trans‐retinoic acid. These results suggest that lycopene might be cleaved to a series of apolycopenals and short‐chain carbonyl compounds under the oxidative conditions in biological tissues and that acycloretinal is further enzymatically converted to acycloretinoic acid.
The effect of conjugated linoleic acid on platelet function, platelet fatty acid composition, and blood coagulation in humans
Authors: Benito P. , Nelson G. J. , Kelley D. S. , Bartolini G. , Schmidt P. C. , Simon V. 
Published: November 2006

AbstractDespite extensive research on conjugated linoleic acid (CLA) showing multiple beneficial effects in animal models, little is known about the role of dietary CLA in human health. To investigate if the beneficial effects of CLA seen in animal models are relevant to humans, we conducted a study with 17 healthy female volunteers who lived in the Metabolic Research Unit of the Western Human Nutrition Research Center for 93 d. This paper reports only the results from this study that are related to the effects of CLA supplementation on blood coagulation, platelet function, and platelet fatty acid composition. Throughout the study, the subjects were fed a low‐fat diet (30 en% fat, 19 en% protein, and 51 en% carbohydrate) consisting of natural foods with the recommended dietary allowances for all known nutrients. After a 30‐d stabilization period, subjects were randomly assigned to either an intervention group (n=10) whose diet was supplemented with 3.9 g/d of CLA or a control group (n=7) who received an equivalent amount of sunflower oil consisting of 72.6% linoleic acid with no detectable CLA. Platelet aggregation was measured in platelet‐rich plasma using adenosine diphosphate, collagen, and arachidonic acid agonists. No statistical difference was detected between the amount of agonist required to produce 50% aggregation of platelet‐rich plasma before and after the subjects consumed the CLA, with the exception of a decrease in response to collagen. This decrease was found in both control and intervention groups with no significant difference between the groups, suggesting that both linoleic acid (sunflower oil) and CLA might have similar effects on platelet function. The prothrombin time, activated partial thromboplastin time, and the antithrombin III levels in the subjects were determined. Again, there was no statistically significant difference in these three parameters when pre‐and post‐CLA consumption values were compared. The in vivo bleeding times were also unaffected by CLA supplementation (10.4+2.8 min pre‐ and 10.2+1.6 min postconsumption). Platelet fatty acid composition was not markedly influenced by the consumption of dietary CLA, although there was a small increase in the amount of the 9 cis, 11 trans‐18∶2 isomer normally present in platelets after feeding CLA for 63 days. In addition, small amounts of the 8 trans, 10 cis‐18∶2 and the 10 trans, 12 cis‐18∶2 isomers were detected in the platelets along with traces of some of the other isomers. Thus, when compared to sunflower
The effect of conjugated linoleic acid on plasma lipoproteins and tissue fatty acid composition in humans
Authors: Benito P. , Nelson G. J. , Kelley D. S. , Bartolini G. , Schmidt P. C. , Simon V. 
Published: November 2006

AbstractConjugated linoleic acid (CLA) has been suggested by some animal studies to possess antiatherogenic properties. To determine, in humans, the effect of dietary CLA on blood lipids, lipoproteins, and tissue fatty acid composition, we conducted a 93‐d study with 17 healthy female volunteers at the Metabolic Research Unit of the Western Human Nutrition Research Center. Throughout the study, subjects were fed a low‐fat diet [30 energy percent (en%) fat, 19 en% protein, and 51 en% carbohydrate] that consisted of natural foods with the recommended dietary allowances for all known nutrients. After a 30‐d stabilization period, subjects were randomly assigned to either an intervention group (n=10) supplemented daily with capsules containing 3.9 g of CLA or a control group (n=7) that received an equivalent amount of sunflower oil. The CIA capsules (CLA 65%) contained four major cis/trans geometric isomers (11.4% 9 cis‐,11 trans‐18∶2; 10.8% 8 trans‐,10 cis‐18∶2; 15.3% 11 cis‐,13 trans‐18∶2; and 14.7% 10 trans‐, 12 cis‐18∶2) and their corresponding cis/cis (6.74% total) and trans/trans (5.99% total) varieties in smaller amounts. Fasting blood was drawn on study days 30 (end of the stabilization period), 60 (midpoint of the intervention period), and 93 (end of the intervention period). Adipose tissue samples were taken on days 30 and 93. CLA supplementation for 63 d did not change the levels of plasma cholesterol, low density lipoprotein cholesterol, high density lipoprotein cholesterol, and triglycerides. The weight percentage of CLA in plasma increased from 0.28±0.06 to 1.09±0.31 (n=10, P<0.05) after the supplementation. The 9 cis‐,11 trans‐isomer was the most prominent variety followed by the 11 cis‐,13 trans‐ and 10 trans‐,12 cis‐isomers in lesser amounts. CLA in adipose tissue was not influenced by the supplementation (0.79±0.18 to 0.83±0.19 wt%) (n=10) and the 9 cis‐,11 trans‐variety was the only isomer present. Thus, contrary to findings from some animal studies, CLA does not seem to offer health benefits, in the short term, regarding the prevention of atherosclerosis in humans. CLA supplementation for 2 mon did not alter the blood cholesterol or lipoprotein levels of healthy, normolipidemic subjects. The supplementation did increase CLA in the plasma but only 4.23% of the ingested CLA was present in the plasma at any given time. No adverse effect of CLA supplementation was detected in this study.
Unique phospholipid metabolism in mouse heart in response to dietary docosahexaenoic or α‐linolenic acids
Authors: Watkins S. M. , Lin T. Y. , Davis R. M. , Ching J. R. , DePeters E. J. , Halpern G. M. , Walzem R. L. , German J. B. 
Published: November 2006

AbstractDiet and fatty acid metabolism interact in yet unknown ways to modulate membrane fatty acid composition and certain cellular functions. For example, dietary precursors or metabolic products of n‐3 fatty acid metabolism differ in their ability to modify specific membrane components. In the present study, the effect of dietary 22∶6n−3 or its metabolic precursor, 18∶3n−3, on the selective accumulation of 22∶6n−3 by heart was investigated. The mass and fatty acid compositions of individual phospholipids (PL) in heart and liver were quantified in mice fed either 22∶6n−3 (from crocodile oil) or 18∶3n−3 (from soybean oil) for 13 wk. This study was conducted to determine if the selective accumulation of 22∶6n−3 in heart was due to the incorporation of 22∶6n−3 into cardiolipin (CL), a PL most prevalent in heart and known to accumulate 22∶6n−3. Although heart was significantly enriched with 22∶6n−3 relative to liver, the accumulation of 22∶6n−3 by CL in heart could not quantitatively account for this difference. CL from heart did accumulate 22∶6n−3, but only in mice fed preformed 22∶6n−3. Diets rich in non‐22∶6n−3 fatty acids result in a fatty acid composition of phosphatidylcholine (PC) in heart that is unusually enriched with 22∶6n−3. In this study, the mass of PC in heart was positively correlated with the enrichment of 22∶6n−3 into PC. The increased mass of PC was coincident with a decrease in the mass of phosphatidylethanolamine, suggesting that 22∶6n−3 induced PC synthesis by increasing phosphatidylethanolamine‐N‐methyltransferase activity in the heart.
1‐14C‐Linoleic acid distribution in various tissue lipids of guinea pigs following an oral dose
Authors: Fu Zhong , Attar‐Bashi Nadia M. , Sinclair Andrew J. 
Published: November 2006

AbstractA recent study on the metabolism of 1‐14C‐α‐linolenic acid in the guinea pig revealed that the fur had the highest specific activity of all tissues examined, 48 h after dosing. The present study investigated the pattern of tissue lipid labeling following an oral dose of 1‐14C‐linoleic acid after the animals had been dosed for the same time as above. Guinea pigs were fed one of two diets with a constant linoleic acid content (18% total fatty acids) and a different content of α‐linolenic acid (0.3 or 17.3%) from weaning for 3 wk and 1‐14C‐linoleic acid was given orally to each animal for 48 h prior to sacrifice. The most highly labeled tissues (dpm/mg of linoleic acid) were liver, followed by brain, lung and spleen, heart, kidney and adrenal and intestines, in both diet groups. The liver had almost a three‐fold higher specific activity than skin and fur which was more extensively labeled than the adipose and carcass. Approximately two‐thirds of the label in skin plus fur was found in the fur which, because of a low lipid mass, would indicate that the fur was highly labeled. All tissues derived from animals on the diet with the low α‐linolenic acid level were significantly more labeled than the tissues from the animals on the high α‐linolenic acid diet, by a factor of 1.5 to 3. The phospholipid fraction was the most highly labeled fraction in the liver, free fatty acids were the most labeled fraction in skin & fur, while triacyglycerols were the most labeled in the carcass and adipose tissue. In these tissues, more than 90% of the radioactivity was found in fatty acids with 2‐double bonds in the tissue lipids. These data indicate that the majority of label found in guinea pig tissues 48 h after dosing was still associated with a fatty acid fraction with 2‐double bonds, which suggests there was little metabolism of linoleic acid to more highly unsaturated fatty acids in this time frame. In this study, the labeling of guinea pig tissues with linoleic acid, 48 h after dosing, was quite different from the labeling with α‐linolenic acid reported previously. The retention of the administered radioactivity from 14C‐linoleic acid in the whole body lipids was 1.6 times higher in the group fed the low α‐linolenic acid diet (diet contained a total of 1.8 g PUFA/100 g diet)compared with the group fed the high α‐linolenic acid diet (diet contained 3.6 g PUFA/100 g diet). The lack of retention of 14C‐labeled lipids in the whole body would be consistent with an increased rate of β‐oxidation of the labeled fatty acid on the diet rich in PUFA, a result supported by other studies using direct measurement of labeled carbon dioxide.
Effects of diets enriched in n−6 or n−3 fatty acids on cholesterol metabolism in older rats chronically fed a cholesterol‐enriched diet
Authors: Fukushima Michihiro , Ohhashi Tetsu , Ohno Syugo , Saitoh Hidetoshi , Sonoyama Kei , Shimada Ken‐ichiro , Sekikawa Mitsuo , Nakano Masuo 
Published: November 2006

AbstractHypocholesterolemic effects in older animals after long‐term feeding are unknown. Therefore, aged rats (24 wk of age) fed a conventional diet were shifted to diets containing 10% perilla oil [PEO; oleic acid+linoleic acid+α‐linolenic acid; n−6/n−3, 0.3; polyunsaturated fatty acid/saturated fatty acid (P/S), 9.6], borage oil [oleic acid+linoleic acid+α‐linolenic acid; n−6/n−3, 15.1; P/S, 5.3], evening primrose oil (FPO; linoleic acid+γ‐linolenic acid; P/S, 10.5), mixed oil (MIO; oleic acid+linoleic acid+γ‐linolenic acid+α‐linolenic acid; n−6/n−3, 1.7; P/S, 6.7), or palm oil (PLO; palmitic acid+oleic acid+linoleic acid; n−6/n−3, 25.3; P/S, 0.2) with 0.5% cholesterol for 15 wk in this experiment. There were no significant differences in the food intake and body weight gain among the groups. The liver weight in the PEO (n−6/n−3, 0.3) group was significantly higher than those of other groups in aged rats. The serum total cholesterol and very low density lipoprotein (VLDL) +intermediate density lipoprotein (IDL)+low density lipoprotein (LDL)‐cholesterol concentrations of the PLO (25.3) group were consistently higher than those in the other groups. The serum high density lipoprotein cholesterol concentrations of the PEO (0.3) and EPO groups were significantly lower than in the other groups at the end of the 15‐wk feeding period. The liver cholesterol concentration of the PLO (25.3) group was significantly higher than those of other groups. There were no significant differences in the hepatic LDL receptor mRNA level among the groups. Hepatic apolipoprotein (apo) B mRNA levels were not affected by the experimental conditions. The fecal neutral steroid excretion of the PLO (25.3) group tended to be low compared to the other groups. The results of this study demonstrate that both n\t‐6 fatty acid and n\t‐3 fatty acids such as \gg‐linolenic acid and \ga‐linolenic acid inhibit the increase of serum total cholesterol and VLDL+IDL+LDL‐cholesterol concentrations of aged rats in the presence of excess cholesterol in the diet compared with dietary saturated fatty acid.
Acute effect of ethanol on 7‐hydroperoxycholesterol in muscle and liver
Authors: Adachi Junko , Asano Migiwa , Ueno Yasuhiro , Marway Jaspaul S. , Camilleri Peter M. , Peters Timothy J. , Preedy Victor R. 
Published: November 2006

AbstractWe tested the hypotheses that ethanol sensitivities of muscle and liver can be discerned in the initial periods of ethanol exposure, especially when acetaldehyde levels are markedly raised with cyanamide, an aldehyde dehydrogenase inhibitor. To test this, we measured cholesterol hydroperoxides in soleus (Type I) and plantaris (Type II) muscle in four groups of rats acutely (i.e., 2.5 h) exposed to: [S] saline (control), [Cy] cyanamide, [EtOH] ethanol, or [Cy+EtOH] cyanamide+ ethanol. Comparative reference was also made to the response of the liver. After 2.5 h, ethanol alone significantly increased 7α‐hydroperoxycholest‐5‐en‐3β‐ol (7α‐OOH) and 7β‐hydroperoxycholest‐5‐en‐3β‐ol (7β‐OOH) levels in plantaris muscle. Identical qualitative effects were seen in rats treated with cyanamide+ethanol, but there was no discernible difference between groups [LtOH] and [Cy+EtOH]. In both the soleus muscle and liver, none of the treatments with either ethanol or cyanamide+ethanol had any effect on any of the measured parameters. This is the first report of a differential response of 7α‐OOH and 7β‐OOH in Type II, compared to Type I predominant muscles, and the first time that muscle has been shown to be more sensitive than the liver in terms of its lipid marker response to oxidative stress. Perturbations in the muscle membrane lipid domain may contribute to impaiment of muscle in alcoholism.
Purification and characterization of an extracellular lipase from Penicillium candidum
Authors: Ruiz Beatriz , Farrés Amelia , Langley Elizabeth , Masso Felipe , Sánchez Sergio 
Published: November 2006

AbstractPenicillium candidum produces and secretes a single extracellular lipase with a monomer molecular weight of 29 kDa. However, this enzyme forms dimers and higher molecular weight aggregates under nondenaturing conditions. The lipase from P. candidum was purified 37‐fold using Octyl‐Sepharose CL‐4B and DEAE‐Sephadex columns. The optimal assay conditions for lipase activity were 35°C and pH 9. The lipase was stable in the pH range of 5–6 with a pl of 5.5, but rapid loss of the enzyme activity was observed above 25°C. Tributyrin was found to be the best substrate for the P. candidum lipase, among those tested. Metal ions such as Fe2+ and Cu2+ inhibited enzymatic activity and only Ca2+ was able to slightly enhance lipase activity. Ionic detergents inhibited the activity of the enzyme, whereas nonionic detergents stimulated lipase activity.
Comparative investigation of human stratum corneum ceramides
Authors: Vietzke Jens‐Peter , Brandt Oliver , Abeck Dietrich , Rapp Claudius , Strassner Manfred , Schreiner Volker , Hintze Ulrich 
Published: November 2006

AbstractThe stratum corneum (SC) requires ceramides, cholesterol, and fatty acids to provide the cutaneous permeability barrier. SC lipids can be analyzed by normal‐phase high‐performance thin‐layer chromatography (HPTLC). However, without further analysis, some uncertainty remains about the molecular composition of lipids represented by every TLC band of an unknown sample. We therefore analyzed each ceramide band further by subjecting the isolated lipids to a direct coupling of reversed‐phase high‐performance liquid chromatography and electrospray ionization‐mass spectrometry (HPLC/ESI‐MS, or IC/MS). IC/MS analysis and ESI‐MS/MS negative ion and collision‐induced dissociation experiments revealed that ceramide band 4 contained not only N‐(ω‐OH‐acyl)acyl‐6‐OH‐sphingosine, Cer(EOH), but also N‐(α‐OH‐acyl)‐sphingosine. Band 5 exclusively contained N‐acyl‐6‐OH‐sphingosine. Our results demonstrate the benefit of LC/MS analysis for selective identification of human SC ceramides. Moreover, the combination of HPTLC for pre‐separation and LC/MS for identification of lipids is an even more powerful tool for detailed ceramide analysis.
Changes in conjugated linolenic acid composition within samples obtained from a single source
Authors: Adlof R. O. , Copes L. C. , Walter E. L. 
Published: November 2006

AbstractConjugated linoleic acid (CLA; 9c, 11t‐18∶2) and CLA isomers have been reported, in animals, to exhibit a variety of health‐related benefits. Silver ion high‐performance liquid chromatography (Ag‐HPLC) was found to provide better resolution of the isomes than gas chromatography. Most commercially available samples of CLA, prepared by base‐catalyzed isomerization of linoleic acid (9c, 12c‐18∶2), are conposed of mixtures of four major isomers. While these isomers have been characterized, we found significant changes in CLA isomer ratios within samples obtained from the same producer/commercial supplier over a period of 1.5 yr. In the first sample, the four cis/trans isomers (8t, 10c‐18∶2, 9c, 11t‐18∶2, 10t, 12c‐18∶2 and 11c, 13t‐18∶2) were present in a ratio of approximately 1∶2∶2∶1, while in the second sample they were present in almost equal proportions. If indeed certain daily levels of CLA intake are required to produce suggested health benefits in humans, changes in concentrations of specific CLA isomers could significantly impact these effects. Care must be taken to analyze the CLA used in human and animal studies.
A new Δ7‐polyunsaturated fatty acid in taxus spp. Seed lipids, dihomotaxoleic (7,11–20∶2) acid
Authors: Destaillats Frédéric , Wolff Robert L. , Angers Paul 
Published: November 2006

AbstractA previously undescribed fatty acid, all‐cis 7, 11–20∶2 (dihomotaxoleic acid, DHT), has been characterized by gas chromatography‐mass spectrometry as being present (approximately 0.1%) in seed oils of two Taxaceae containing high levels (11–16%) of taxoleic acid (all‐cis 5,9–18∶2). This compound was absent from oils of 10 other conifer genera, as well as from one member of Taxaceae containing very low amounts of taxoleic acid, suggesting that DHT is a taxoleic acid elongation product.
Oxidative catabolism of α‐tocopherol in rat liver microsomes
Authors: Van Houte Hilde , de Hoffmann Edmond , Van Veldhoven Paul P. , Mannaerts Guy P. , Carchon Hubert , Baes Myriam I. , Declercq Peter E. 
Published: November 2006

AbstractThe goal of this study was to clarify the mechanism responsible for the catabolism of α‐tocopherol. The vitamin, bound to albumin, was incubated with rat liver microsomes and appeared to be broken down. Optimal production of the metabolite was obtained when 1 mg of microsomal protein was incubated with 36 μM of α‐tocopherol in the presence of 1.5 mM of NADPH. Chromatographic and mass spectrometric analyses of the metabolite led to the conclusion that it consists of an ω‐acid with an opened chroman ring, although we could not perform nuclear magnetic resonance analysis to confirm this. Our data show that α‐tocopherol is ω‐oxidized to a carboxylic acid and that this process can occur in rat liver microsomes in the presence of NADPH and O2. The oxidation to the quinone structure appears to be a subsequent event that may be artifactual and/or catalyzed by a microsomal enzyme(s).