bluuebunny/crossref_metadata_2025_split huggingface dataset:
Polyunsaturated monoglycerides and a pregnadiene in defensive glands of the water beetleAgabus affinis
Authors: Schaaf Otmar , Dettner Konrad 
Published: November 2006

AbstractIn addition to the C21steroid 15α‐hydroxypregna‐4,6‐dien‐3,20‐dione, four 1‐ or 2‐acylated polyunsaturated monoglycerides, 1‐ or 2‐(cis‐5,8,11,14‐eicosatetraenoyl)‐glycerol and 1‐ or 2‐(cis‐5,8,11,14,17‐eicosapentaenoyl)glycerol were identified as constituents of the prothoracic defensive gland secretion of the dytiscid beetleAgabus affinisby gas chromatography‐mass spectrometry of trimethylsilylated gland extracts. In a feeding assay with minnows, synthetic samples of the two 2‐acylated monoglycerides showed only a weak activity as a feeding deterrent. For that reason, other possible functions of the monoglycerides are discussed, such as roles as emulsifiers of cannabimimetics.
Blood fatty acid composition of pregnant and nonpregnant Korean women: Red cells may act as a reservoir of arachidonic acid and docosahexaenoic acid for utilization by the developing fetus
Authors: Ghebremeskel K. , Min Y. , Crawford M. A. , Nam Joo‐Hyun , Kim Ahm , Koo Ja‐Nam , Suzuki Hiramitsu 
Published: November 2006

AbstractRelative fatty acid composition of plasma and red blood cell (RBC) choline phosphoglycerides (CPG), and RBC ethanolamine phosphoglycerides (EPG) of pregnant (n=40) and nonpregnant, nonlactating (n=40), healthy Korean women was compared. The two groups were of the same ethnic origin and comparable in age and parity. Levels of arachidonic (AA) and docosahexaenoic (DHA) acids were lower (P<0.05) and palmitic and oleic acids higher (P<0.0001) in plasma CPG of the pregnant women. Similarly, the RBC CPG and EPG of the pregnant women had lower AA and DHA (P<0.05) and higher palmitic and oleic acids (P<0.01). The reduction in DHA and total n−3 fatty acids in plasma CPG of the pregnant women was paralleled by an increase in docosatetraenoic (DTA) and docosapentaenoic (DPA) acids of the n−6 series and in DPA/DTA ratio. In the RBC phospholipids (CPG and EPG) of the pregnant women, DTA and DPA acids of the n−6 series and DPA/DTA ratio did not increase with the decrease of the n−3 metabolites (eicosapentaenoic acid, DPA, and DHA) and total n−3. Since pregnancy was the main identifiable variable between the two groups, the lower levels of AA and DHA in RBC CPG and EPG of the pregnant women suggest that the mothers were mobilizing membrane AA and DHA to meet the high fetal requirement for these nutrients. It may also suggest that RBC play a role as a potential store of AA and DHA and as a vehicle for the transport of these fatty acids from maternal circulation to the placenta to be utilized by the developing fetus.
Simultaneous derivatization of acyl and S‐alkyl moieties of acyl thioesters by using trimethylsulfonium hydroxide for gas chromatographic analysis
Authors: Klein Erika , Weber Nikolaus 
Published: November 2006

AbstractThe reaction of long‐chain acyl thioesters, viz. lauric acid dodecyl thioester, 1,8‐di‐S‐palmitoyl octanedithiol, and tristearoyl α‐monothioglycerol, with trimethylsulfonium hydroxide in the presence of methanol leads to simultaneous derivatization of acyl moieties and S‐alkyl moieties of acyl thioesters to the corresponding fatty acid methyl esters and methyl alkylsulfides, respectively. These derivatized products were analyzed by gas chromatographic technique.
The composition of saturated fatty acids in plasma phospholipids changes in a way to counteract changes in the mean melting point during pregnancy
Authors: De Vrieses S. R. , v. Houwelingen A. C. , Hornstra G. , Dhont M. , Christophe A. B. 
Published: November 2006

AbstractIt has been demonstrated that in pathological conditions with an increase in the calculated mean melting point (MMP) of phospholipid (PL) fatty acids (FA) there are changes in the composition of the saturated FA (SFA), which partially counteract this effect: shorter‐chain SFA with lower melting points are increased, while longer‐chain less fluid SFA are suppressed. The aim of this study was to determine whether there are differences in MMP during pregnancy and in the newborn and, if so, whether similar adaptive changes occur in the composition of the SFA The FA composition of plasma PL was determined in healthy women (n‐16) twice during pregnancy (15–24 wk and 29–36 wk) and at delivery and in umbilical venous blood obtained at birth. The MMP of maternal PL was significantly higher at delivery compared to mid‐gestation, due to a loss of highly unsaturated FA (HUFA) which were replaced by SFA. In addition, changes in the SFA occurred; 16∶0 with lower melting point was higher while 18∶0 with higher melting point was lower at delivery. MMP of PL FA in umbilical plasma was lower than in maternal plasma at delivery, which was due to higher HUFA content. In contrast to maternal plasma, 16∶0 was lower while 18∶0, 20∶0 and 24∶0 were higher in umbilical plasma resulting in a higher MMP of SFA, tending to raise the overall MMP. It can be concluded that, during pregnancy and in the newborn, the FA composition of SFA changes in a way to counteract changes in MMP induced by reduced and increased HUFA, respectively.
Influence of fatty alcohol and other fatty acid derivatives on fatty acid uptake into rat intestinal epithelial cells
Authors: Murota Kaeko , Matsui Noriko , Kawada Teruo , Takahashi Nobuyuki , Shintani Takafumi , Sasaki Kahori , Fushiki Tohru 
Published: November 2006

AbstractWe investigated the influence of various substrates on the uptake of long‐chain fatty acid into IEC‐6, rat intestinal epithelial cell line. The uptake of [3H]oleic acid into IEC‐6 cells was a saturable function of the oleic acid concentration. Long‐chain fatty acids significantly inhibited the oleic acid uptake into IEC‐6 cells and shorter‐chain fatty acids had little or no effect. Various fatty acid esters suppressed the oleic acid uptake into IEC‐6. Fatty alcohols also inhibited oleic acid uptake into IEC‐6 and the length of the carbon chain played an important role. These results suggest that long‐chain fatty acid uptake was inhibited by the substrates which had a structure similar to long‐chain fatty acids, especially those with a long carbon chain. At least two molecules, fatty acid translocase and fatty acid transport protein type 4, which are considered to be involved in the long‐chain fatty acid transport into the cell, were expressed on IEC‐6 cells, supporting the existence of the carrier‐mediated system of long‐chain fatty acid transport on IEC‐6 cells.
In vitro behavior of marine lipid‐based liposomes. Influence of pH, temperature, bile salts, and phospholipase A2
Authors: Nacka Fabienne , Cansell Maud , Entressangles Bernard 
Published: November 2006

AbstractTo deliver polyunsaturated fatty acids (PUFA) by the oral route, liposomes based on a natural mixture of marine lipids were prepared by filtration and characterized in media that mimic gastrointestinal fluids. First the influence of large pH variations from 1.5–2.5 (stomach) to 7.4 (intestine) at the physiological temperature (37°C) was investigated. Acidification of liposome suspensions induced instantaneous vesicle aggregation, which was partially reversible when the external medium was further neutralized. Simultaneously, complex morphological bilayer rearrangements occurred, leading to the formation of small aggregates. These pH‐ and temperature‐dependent structural changes were interpreted in terms of osmotic shock and lipid chemical alterations, i.e., oxidation and hydrolysis, especially in the first hours of storage. Besides, oxidative stability was closely related to the state of liposome aggregation and the supramolecular organization (vesicles or mixed micelles). The effects of bile salts and phospholipase A2 (PLA2) on the liposome structures were also studied. Membrane solubilization by bile salts was favored by preliminary liposome incubation in acid conditions. PLA2 showed a better activity on liposome structures than on the corresponding mixed lipid‐bile salt micelles. As a whole, in spite of slight morphological modifications, vesicle structures were preserved after an acid stress and no lipid oxidation products were detected during the first 5 h of incubation. Thus, marine lipids constituted an attractive material for the development of liposomes as potential oral PUFA supplements.
Mechanisms of dimer and trimer formation from ultraviolet‐irradiated α‐tocopherol
Authors: Krol Ed S. , Escalante Daniel D. J. , Liebler Daniel C. 
Published: November 2006

Abstractα‐Tocopherol (α‐TH) undergoes ultraviolet (UV)‐induced photooxidation on the surface of mouse skin to produce a dihydroxydimer, a spirodimer, and trimers as the major products. To study the photochemistry involved, we UV‐irradiated α‐TH in a thin film on a glass petri dish. Photooxidation yielded a mixture of dihydroxydimer, spirodimer, and trimers. In the time‐course studies, the dihydroxydimer accumulated and then was further oxidized, whereas the spirodimer and trimers accumulated more gradually. Reaction of two tocopheroxyl radicals forms the dihydroxydimer, whereas the spirodimer may be formed either by photooxidation of α‐TH to an orthoquinone methide (o‐QM) followed by a Diels‐Alder reaction or by photooxidation of α‐TH to the dihydroxydimer, followed by two‐electron oxidation. Irradiation of a mixture of d10‐labeled and unlabeled (d0) dihydroxydimer produced a mixture of labeled and unlabeled spirodimers as detected by positive atmospheric pressure chemical ionization‐mass spectrometry. The absence of mixed label spirodimers among products indicated that direct oxidation of the dihydroxydimer is a facile route to the spirodimer and is probably the major spirodimer‐forming reaction in α‐TH photooxidations. Trimer formation from the dihydroxydimer and the spirodimer was observed, however, and requires an o‐QM intermediate. Photooxidation of d10‐labeled and unlabeled (d0) dihydroxydimers yielded mixed isotopomers of the trimer products, thus demonstrating that the dihydroxydimer and spirodimers underwent conversion to o‐QM intermediates. Photochemical conversion of α‐TH to UV‐absorbing dimer and trimer products may contribute to photoprotection by topically applied α‐TH.
Effects of ascorbate on membrane phospholipids and tocopherols of intact erythrocytes during peroxidation by t‐butylhydroperoxide: Comparison with effects of dithiothreitol
Authors: Mawatari Shiro , Murakami Kaori 
Published: November 2006

AbstractPeroxidation of intact human erythrocytes by t‐butylhydroperoxide (tBHP) was studied. By incubation of the erythrocytes with 1 mM tBHP, reduced glutathione (GSH) was exhausted within 1 min, and tocopherols (Toc) and phospholipids (PL) decreased to nearly their lowest levels (in this study) within 5 min. The rate of decrease of α‐Toc was faster than that of γ‐Toc, but α‐Toc was never exhausted. The rates of decrease of Toc were faster than that of PL. Malondialdehyde increased slowly to reach a maximal value at 30 min. Methemoglobin (metHB) reached a maximum at 15 min. The maximal levels of these substances were maintained until 90 min incubation, which indicated that the peroxidation by tBHP had stopped spontaneously until at least 90 min. By the incubation with tBHP for 30 min, phosphatidylethanolamine (PE) and α‐Toc decreased to about 70 and 30% of control levels, respectively, and γ‐Toc and GSH were almost exhausted. Ascorbate (0.1 mM) afforded protection of 92% to PF, 50% to α‐Toc, and 65% to γ‐Toc against peroxidation, but ascorbate had no preventive effect at all on the formation of metHB and the decrease of GSH. These results may indicate that ascorbate‐mediated protection of the membrane PL against the peroxidation depends primarily on Toc. On the other hand, dithiothreitol (DTT) (5 mM) almost completely prevented the formation of metHB, and DTT completely protected the PL and Toc against peroxidation, indicating the importance of sulfhydryl groups in erythrocytes.
Cacao liquor polyphenols reduce oxidative stress without maintaining α‐tocopherol levels in rats fed a vitamin E‐deficient diet
Authors: Yamagishi Megumi , Osakabe Naomi , Takizawa Toshio , Osawa Toshihiko 
Published: November 2006

AbstractThe effect of crude polyphenols (CLP) from cacao liquor on vitamin F‐deficient rats was examined. The CLP fraction contained 49.8% antioxidative polyphenols such as catechins and their oligomers. Supplementation of the vitamin E‐deficient diet with CLP for 7 wk did not prevent the decrease in α‐tocopherol levels in the liver, kidney, heart, brain, and plasma. The lipid peroxide levels in these tissues increased in the group fed the vitamin F‐deficient diet compared with the control group. However, these changes were inhibited in a dose‐dependent manner as a result of supplementation of the vitamin E‐deficient diet with 0.25, 0.5, or 1.0% CLP. The lipid peroxide levels in plasma increased in the group fed the vitamin E‐deficient diet. This change tended to be suppressed as a result of supplementation of the diet with CLP, but the difference was not significant. There was no evidence of absorption and distribution of CLP to the tissues; however, CLP intake resulted in a decrease in oxidative stress without maintaining vitamin E levels in the plasma and the tissues.
The first naturally occurring α‐methoxylated branched‐chain fatty acids from the phospholipids of Amphimedon complanata
Authors: Carballeira Néstor M. , Alicea Johanna 
Published: November 2006

AbstractThe phospholipid fatty acid composition of the sponge Amphimedon complanata was reinvestigated, and the 2‐methoxy‐13‐methyltetradecanoic acid, 2‐methoxy‐14‐methylpentadecanoic acid, and 2‐methoxy‐13‐methylpentadecanoic acid were identified for the first time in nature. Structure characterization was accomplished by means of gas chromatographic retention times and gas chromatography‐mass spectrometry. These acids could have originated from bacteria in symbiosis with the sponge.
A Fast and reliable spectroscopic method for the determination of membrane‐water partition coefficients of organic compounds
Authors: de Castro Baltazar , Gameiro Paula , Lima José L. F. C. , Matos Carla , Reis Salette 
Published: November 2006

AbstractPartition coefficients (Kp) between egg yolk phosphatidylcholine multilamellar vesicles and water were determined for two nonsteroidal anti‐inflammatory drugs (indomethacin and acemetacin) using two independent methodologies: derivative spectrophotometry and variation of the experimental acidity constant in the presence of increasing vesicle concentration. Second‐derivative spectrophotometry allowed for total elimination of background signal effects arising from lipid vesicles, without the need for separation techniques that may disturb equilibrium states. By using a model based on a simple partition, the values of KpT can be obtained directly; furthermore, by performing determinations at two different pH values it is possible to calculate partition coefficients for the neutral and negatively charged forms of the drugs (KpAH and KpA). In the other methodology, values of apparent acidity constants (Kapp) were determined by spectrophotometry at different pH values and different lipid concentrations, and an increase in Kapp with decreasing lipid concentration was observed for both drugs, and from this dependence it was possible to calculate KpAH and KpA‐ for each drug. These values were used as a check for those obtained by derivative spectroscopy, which has proven to be a reliable and more expeditious method to obtain KpAH and KpA‐.
A novel assay method for glycosphingolipid deacylase by enzyme‐linked immunochemical detection of lysoglycosphingolipid
Authors: Izumi Kazuo , Sawada Michiko Takagi 
Published: November 2006

AbstractLysoglycosphingolipids consist of a sphingoid long‐chain base and monosaccharide or complex sugar, and they lack the fatty acyl group present in native glycosphingolipids. Less than 1 pmol of lyso‐Forssman glycolipid and lysoganglioside GM1 were detected on a thin‐layer chromatogram by an enzyme‐linked immunochemical coloration method with anti‐Forssman glycolipid antibody (FOM‐1) and cholera toxin B subunit, respectively. Each spot between 1 and 100 pmol lyso‐Forssman glycolipid was immunostained as densely as that of the same amount of native Forssman glycolipid. The density of the lyso‐Forssman glycolipid spots increased proportionally with increment in the amount of lysoglycolipid. The density of spots of 0.2–100 pmol lysoganglioside GM1 was also proportional to the amount of each lyso‐GM1 spot. These results indicated that less than 1 to 100 pmol of deacylated glycosphingolipid was quantifiable by the immunochemical coloration method with sugar chain‐specific antibodies. Glycosphingolipid deacylase, which cleaved an amide bond between the sphingoid long‐chain base and fatty acyl chain in ceramide of glycosphingolipid, was assayed by detecting the lyso‐Forssman glycolipid produced. Lipophilic compounds, recovered from an aliquot of the reaction mixture of Forssman glycolipid and crude enzyme at appropriate times, were analyzed by thin‐layer chromatography. It was found that lyso‐Forssman glycolipid was produced in the first 1–2 h by the enzyme and production increased with incubation time. This coloration method is more sensitive and specific than the visualization method with a non‐specific reagent such as orcinol‐sulfuric acid reagent.
Measurement of human chylomicron triglyceride clearance with a labeled commercial lipid emulsion
Authors: Park Yongsoon , Damron Bart D. , Miles John M. , Harris William S. 
Published: November 2006

AbstractHuman chylomicron triglyceride (TG) kinetics has been difficult to determine directly owing to technical limitations. This report describes a new method for studying chylomicron metabolism. Healthy volunteers (n=10) sipped a drink providing 175 mg fat·kg−1·h−1 for 7.5 h to produce a steady‐state chylomicronemia. A commercial 10% intravenous lipid emulsion was labeled with [3H]triolein, purified by high‐performance liquid chromatography, and sterilized. A trace amount of labeled emulsion was injected intravenously 30 min before (i.e., in the fasting state) and 5, 6, and 7 h after sipping began (i.e., triplicate determinations in the fed state). Chylomicron half‐lives were calculated from the monoexponential decay curves, and apparent distribution volumes were estimated by back‐extrapolation to time zero. Plasma and estimated chylomicron TG concentrations increased from 89±13 and 0.8±0.3 to 263±43 and 91±39 mg/dL (mean±SEM), respectively, with feeding. Tracer‐determined chylomicron TG half‐lives were 5.34±0.58 and 6.51±0.58 min during the fasting and fed states, respectively (P<0.01). The apparent distribution volume during the fasting state was 24% greater than plasma volume (4515±308 vs. 3630±78 mL, P<0.02), consistent with significant margination of lipid emulsion particles to endothelial binding sites. Margination was reduced during the fed state, suggesting that native chylomicrons competed with lipid emulsion particles for endothelial lipoprotein lipase. The results indicate that a radiolabeled commercial lipid emulsion is metabolized in a fashion similar to native chylomicron TG, and thus can be used to study chylomicron TG kinetics.
Low density lipoprotein receptor mRNA in rat liver is affected by resistant starch of beans
Authors: Fukushima Michihiro , Ohashi Tetsu , Kojima Michiyuki , Ohba Kiyoshi , Shimizu Hideki , Sonoyama Kei , Nakano Masuo 
Published: November 2006

AbstractThe effects of resistant starches of beans on serum cholesterol and hepatic low density lipoprotein (LDL) receptor mRNA in rats were investigated. Rats were fed a cholesterol‐free diet with 150 g/kg corn starch (CS), 150g/kg adzuki (Vigna angularis) starch (AS), 150 g/kg kintoki (Phaseolus vulgaris, variety) starch (KS), or 150 g/kg tebou (P. vulgaris, variety) starch (TS) for 4 wk. There were no significant differences in body weight among groups through the experimental period. The liver weight in the CS group was 1.1–1.2 times higher than that in the AS, KS, and TS groups. The cecum weight in the TS was 1.4 times higher than that in the CS group, and the cecal pH in the CS group was significantly higher than in the other groups. The serum total cholesterol, very low density lipoprotein + intermediate density lipoprotein +LDL‐cholesterol and high density lipoprotein (HDL)‐cholesterol concentrations in the bean starch groups were significantly lower than those in the CS group through the feeding period. The total cholesterol/HDL‐cholesterol ratio in the bean starch groups was also significantly lower than that in the CS group at the end of the 4‐wk feeding period. The hepatic cholesterol concentration in the TS group was significantly higher than in the CS group at the end of the 4‐wk feeding period. The relative quantity of hepatic apo B mRNA in the AS group was 1.2 times higher than that in the CS group, and the hepatic LDL receptor mRNA levels in the AS and TS groups were 1.8–2.0 times higher than that in the CS group. The results of this study demonstrate that AS, KS, and TS lowered the serum total cholesterol level by enhancing the hepatic LDL receptor mRNA level.
Cyclodehydration reactions of methyl 9,10‐; 10,12‐; and 9,12‐dioxostearates with 1,2‐diaminoethane under ultrasonic irradiation
Authors: Lie Ken Jie Marcel S. F. , Lau Maureen M. L. , Kalluri Prabhavathi 
Published: November 2006

AbstractReaction of methyl 9,10‐dioxostearate (1) and 9,12‐dioxostearate (2) with 1,2‐diaminoethane under concomitant ultrasonic irradiation (10–15 min, 60°C) in water furnished the corresponding 2,3‐dihydropyrazine (4, 79%) and 1,2,3,4‐tetrahydro‐1,4‐diazocine (5, 70%) derivatives, respectively. Reaction of methyl 10,12‐dioxostearate (3) with 1,2‐diaminoethane was successful only when glacial acetic acid was used instead of water under ultrasonic irradiation (4×10 min, 70°C) to give a 2,3‐dihydro‐1H‐1,4‐diazepine (6, 95%) derivative. The structures of these novel six‐membered (4), seven‐membered (6), and eight‐membered (5) N‐heterocyclic fatty ester derivatives were confirmed by a combination of infrared, nuclear magnetic resonance spectroscopic and mass spectral analyses.
Dialysis and gel filtration of isolated low density lipoproteins do not cause a significant loss of low density lipoprotein tocopherol and carotenoid concentration
Authors: Chopra Mridula , Fitzsimons Patricia , Hopkins Marie , Thurnham David I. 
Published: November 2006

AbstractThe resistance of isolated low density lipoprotein (LDL) to copper‐initiated oxidation is often used as a measure of effectiveness of an antioxidant intervention. Prior to oxidation excess salt and EDTA are removed via dialysis or gel filtration of the LDL sample. However, there is concern over whether the antioxidant content of dialyzed or gel‐filtered LDL is truly representative of native LDL extracted from a blood sample. Previously, the experiments done after the storage of native and dialyzed LDL at −80°C showed that the dialysis step can cause a loss of up to 60% in the tocopherol and carotenoid content of LDL. In the present study, a comparison of the micronutrient concentration in freshly prepared dialyzed and native LDL from 35 subjects showed that after the correction for cholesterol, only lycopene (13%, P<0.001) and to a lesser extent α‐carotene (8%, P<0.02) were significantly decreased, and the absolute fall in concentration was far smaller than previously reported. Other experiments done with smaller numbers of samples suggested that there were minimal micronutrient losses following gel filtration and that it was important to include 10 μmol/L EDTA in the dialysis and elution buffer; otherwise micronutrient losses did occur. In summary, immediate dialysis of freshly isolated LDL in the presence of 10 μmol/L. EDTA does not cause any major loss in the concentration of tocopherol and most carotenoids.