bluuebunny/crossref_metadata_2025 huggingface dataset:
The distribution of dietary plant sterols in serum lipoproteins and liver subcellular fractions of rats
Authors: Sugano Michihiro , Morioka Hidekazu , Kida Yoshitaka , Ikeda Ikuo
Published: November 2006

Rats were fed plant sterols containing campesterol and β‐sitosterol in the different proportions, and their distribution in serum lipoproteins and in liver subcellular fractions was determined. In serum lipoproteins, the percentage as well as the concentration of plant sterols increased with the increase in the density of lipoproteins. Thus, high density lipoprotein (HDL) contained the highest and very low density lipoprotein (VLDL), the lowest. Also, there were distinct differences in the ratio of campesterol to sitosterol among lipoproteins, it was the highest in VLDL and lowest in HDL. Quantitatively, more than 75% of campesterol and 80% of sitosterol were carried in HDL; the values were significantly different from those of cholesterol (ca. 70%) in relation to total cholesterol. The distribution of plant sterols in liver subcellular fractions was virtually the same with that of cholesterol. Both nuclei and microsomes contained approximately 40% of total plant stetols.
The terpenyl pyrophosphates of wild type and tetraterpene mutants ofNeurospora crassa
Authors: Kushwaha S. C. , Kates M. , Renaud R. L. , Subden R. E.
Published: November 2006

Mutations to two albino loci ofNeurospora (al‐2 andal‐3) are known to block tetraterpene synthesis prior to phytoene but after farnesyl pyrophosphate. Analysis of the terpenyl pyrophosphates labeled with [214C] mevalonic acid revealed the presence of radioactive prephytoene, pyrophosphate in both albino mutants and in the corresponding wild type strain. Theal‐2 andal‐3 mutations are thus associated with lesions between prephytoene pyrophosphate and phytoene.
The effect of arylsulfonate esters on cholesterol‐aggravated atherosclerosis in white carneau pigeons
Authors: Macnintch John E. , Clair Richard W. St. , Lofland Hugh B. , Clarkson Thomas B.
Published: November 2006

The arylsulfonate esters of linoleyl, stearyl, and decyl alcohols were found to reduce significantly the accumulation of cholesterol in the plasma and livers of White Carneau pigeons subjected to a diet of Purina pigeon pellets coated with 0.25% cholesterol and 10% lard when fed for periods ranging from 9–12 months; no effects were observed in normocholesterolemic pigeons. These compounds produced no toxic side effects and were found to significantly attenuate the development of aortic atherosclerosis. The effect on aortic atherosclerosis was most likely the result of the lowering of plasma cholesterol concentrations. Linoleyl p‐toluenesulfonate appeared to be the most effective of the three arylsulfonates tested, both with respect to the reduction of plasma and liver cholesterol accumulation and attenuation of the atherosclerotic process.
Bile acid composition of rainbow trout,Salmo gairdneri
Authors: Denton J. E. , Yousef M. K. , Yousef I. M. , Kuksis A.
Published: November 2006

The bile acid composition and metabolism of rainbow troutSalmo gairdneri has been investigated by thin layer chromatography, gas liquid chromatography, and radio gas liquid chromatography methods. For this purpose gallbladder bile was collected from fed fish at 6 and 13 months and from starved fish at 12 months of age. Cholic acid was found to be the main component and constituted over 85% of total. Chenodeoxycholic acid accounted for 14% or less and the 3α, 12α‐7‐keto‐ and 7α, 12α‐3‐keto‐5β‐cholanoates for 1% or less of total. The bile acids were conjugated mainly with taurine, only small amounts of glycocholic acid being detected. Ca. 5% of the taurocholate was sulfated, as were trace amounts of cholic and glycocholic acids. The size of the bile acid pool was found to increase in the older fish and to decrease in starved fish. Unlike mammalian livers, the livers of the trout converted radioactive chenodeoxycholic acid into cholic acid.
Liver and serum lipids and lipoproteins of rats fed 5% L‐lysine
Authors: Hevia P. , Visek W. J.
Published: November 2006

Soybean protein and casein supplemented with 1% Arg were compared for their ability to prevent fatty livers caused by excess dietary Lys. The concentrations of serum lipids and lipoproteins of rats fed 5% Lys and having vatty livers were also compared with those of rats fed the identical diet but lacking fatty livers when killed. The total liver lipids, triglycerides and cholesterol of rats fed 15% casein +5% Lys were 3.9, 12.4 and 2 times control values, respectively. Rats fed 5% Lys +1% Arg or 5% Lys with 15% soybean protein had liver lipid concentrations similar to controls fed no supplemental Lys. Serum total lipids, triglycerides, cholesterol, phospholipids and free fatty acids also did not change, and serum ketone bodies were slightly elevated with Lys feeding whether the rats had fatty livers or not. The concentrations of circulating HDL were slightly depressed in all rats fed 5% Lys while LDL were significantly elevated, particularly in rats without fatty livers. Serum VLDL did not change with 5% dietary Lys. Overall, excessive dietary Lys caused fatty livers which were prevented by varying the diet or length of feeding. Excess Lys feeding altered lipoprotein metabolism shown by decreased serum HDL and a substantial elevation in LDL. The latter was more apparent when the fat accumulation in liver was less severe or absent. The data suggest that the fatty liver from Lys excess is probably unrelated to increased fat mobilization from storage, decreased fat oxidation or to a major block in the transport of triglycerides from the liver to the circulation.
Lipid composition of SV40‐induced transplantable hamster tumor
Authors: Fallani A. , Ruggieri S.
Published: November 2006

The analysis of the lipid composition of the SV40‐induced transplantable hamster tumor has shown that: (a) the total phospholipid content in the tumor is lower than that usually found in normal tissues and similar to that reported for other neoplasms; (b) except for a lower percentage of diphosphatidylglycerol, the phospholipid composition is comparable with that reported for normal tissues; (c) the fatty acid profiles of the various glycerophospholipid classes are characterized by high proportions of oleic acid; and (d) phosphatidylethanolamine contains proportions of alkenyl side chains which are consistent with the amounts of plasmalogenic phospholipids found in other neoplasms.
Cholesterol interaction with recombinant human sterol carrier protein‐2
Authors: Colles S. M. , Woodford J. K. , Moncecchi D. , Myers‐Payne S. C. , McLean L. R. , Billheimer J. T. , Schroeder F.
Published: November 2006

The interaction of human recombinant sterol carrier protein‐2 (SCP‐2) with sterols was examined. Two independent ligand binding methods, Lipidex 1000 binding of [3H]cholesterol and a fluorescent dehydroergosterol binding assay, were used to determine the affinity of SCP‐2 for sterols. Binding analysis indicated SCP‐2 bound [3H]cholesterol and dehydroergosterol with aKd of 0.3 and 1.7 μM, respectively, and suggested the presence of a single binding site. Phase fluorometry and circular dichroism were used to characterize the SCP‐2 sterol binding site. Alterations in dehydroergosterol lifetime, SCP‐2 tryptophan lifetime, and SCP‐2 tryptophan quenching by acrylamide upon cholesterol binding demonstrated a shielding of the SCP‐2 tryptophan from the aqueous solvent by bound sterol. Differential polarized phase fluorometry revealed decreased SCP‐2 tryptophan rotational correlation time upon cholesterol binding. Circular dichroism of SCP‐2 indicated that cholesterol elicited a small decrease in SCP‐2 alpha helical content. The data suggest that SCP‐2 binds sterols with affinity consistent with a lipid transfer protein that may act either as an aqueous carrier or at a membrane surface to enhance sterol desorption.
Resistant starch is more effective than cholestyramine as a lipid‐lowering agent in the rat
Authors: Younes Hassan , Levrat Marie‐Anne , Demigné Christian , Rémésy Christian
Published: November 2006

Amylase‐resistant starch (RS) represents a substrate for the bacterial flora of the colon, and the question arises as whether RS shares with soluble fibers common mechanisms for their lipid‐lowering effects. It is uncertain whether a cholesterol‐lowering effect depends basically on an enhanced rate of steroid excretion or whether colonic fermentations also play a role in this effect. In the present study, the effect of RS (25% raw potato starch), of a steroid sequestrant (0.8% cholestyramine), or both were compared on bile acid excretion and lipid metabolism in rats fed semipurified diets. RS diets led to a marked rise in cecal size and the cecal pool of short‐chain fatty acids (SCFA), as well as SCFA absorption; cholestyramine did not noticeably affect cecal fermentation. Whereas cholestyramine was particularly effective at enhancing bile acid excretion, RS was more effective in lowering plasma cholesterol (−32%) and triglycerides (−29%). The activity of 3‐hydroxy‐3‐methylglutaryl‐CoA reductase was increased fivefold by cholestyramine and twofold by RS. This induction in rats fed RS diets was concomittant to a depressed fatty acid synthase activity. In rats fed the RS diet, there was a lower concentration of cholesterol in all lipoprotein fractions, especially the (d=1.040−1.080) fraction high‐density lipoprotein (HDL1), while those fed cholestyramine had only a significant reduction of HDL1cholesterol. In contrast to cholestyramine, RS also depressed the concentration of triglycerides in the triglyceride‐rich lipoprotein fraction. There was no noticeable synergy between the effects of RS and cholestyramine when both were present in the diet. This suggests that the cholesterol‐lowering effect of RS is not limited to its capacity to enhance bile acids excretion. The difference between RS and cholestyramine could relate to the capacity of fermentation end‐products to counteract the upregulation of cholesterol and bile acid biosynthesis. Thus, in the absence of fermentation in the large intestine, a high rate of bile acids excretion is not always sufficient to elicit a cholesterol‐lowering effect.
Lipid oxidation: Biologic effects and antioxidants—A review
Authors: Logani M. K. , Davies R. E.
Published: November 2006

The detection and measurement of lipid oxidation in biological systems and some biologic effects of this oxidation are reviewed. The role of lipid oxidation in the process of photocarcinogenesis and the protective effect of antioxidants against this process also are discussed. The mechanism of such protection is unknown and studies directed at elucidating the mechanism of antioxidant effect in photocarcinogenesis and in some other pathological conditions believed to involve, lipid oxidation are needed. In addition to this, epoxidation of lipids observed in monolayer studies requires further investigation, particularly in the presence of some other unsaturated molecules. The possible significance of such a study—particularly in the presence of polycyclic aromatic hydrocarbon carcinogens, where formation of epoxides is generally accepted as active intermediates‐is also discussed. In addition, present knowledge on the role of lipid peroxides in the destruction of proteins and biomembranes, in chemically induced toxicity and in generation of singlet oxygen is presented.
Dealkylation of 24‐ethylsterols byTetrahymena pyriformis
Authors: Nes William R. , Alcaide Antonio , Mallory Frank B. , Landrey Josephine R. , Conner Robert L.
Published: November 2006

WhenTetrahymena pyriformis was incubated with sitosterol ([24R]‐24‐ethylcholest‐5‐en‐3β‐ol]) or itstrans‐Δ22‐derivative (stigmasterol), the C‐24‐dealkylated product, cholesta‐5,7,trans‐22‐trien‐3β‐ol, was obtained in both cases. 24(S)‐24‐Ethylcholesta‐5,7,trans‐22‐trien‐3β‐ol also was found to be a metabolite. When sitosterol was the substrate, 24(R)‐24‐ethylcholesta‐5,7‐dien‐3β‐ol was obtained as a third product. Identifications were made by mass spectroscopy, quantitative chromatography, labeling with14C, and by other means. The dealkylated product (cholestratrienol) represented 30% of the sterols isolable after incubation. The administration of sterols to this organism did not induce sterol biosynthesis, since 2‐14C‐mevalonate failed to yield radioactive sterol in the presence of added stigmasterol.
New application of high pressure reversed‐phase liquid chromatography in lipids
Authors: Pei Patrick T‐S. , Henly Robert S. , Ramachandran S.
Published: November 2006

High pressure reverse‐phase liquid chromatography has been used to separate saturated fatty acids, their methyl esters, polyunsaturated fatty acids, and triglycerides. Rapid separation of fatty acids differing in chain length and number of double bonds has been accomplished. Analysis time was less than 10 min in most cases. The high pressure reverse chromatography resulted in better separations of polyenoic acids than can be accomplished by conventional argentation silicic acid column chromatography. The analyses were carried out on a chemically bonded reverse phase packing, VYDAC reverse phase.
Comparative studies of triacylglycerol structure of very low density lipoproteins and chylomicrons of normolipemic subjects and patients with type II hyperlipoproteinemia
Authors: Myher J. J. , Kuksis A. , Breckenridge W. C. , McGuire V. , Little J. A.
Published: November 2006

The triacylglycerols of very low density lipoproteins (VLDL) and of chylomicrons were analyzed in the fasting and postabsorptive states from normolipemic subjects and patients with Frederickson's Type II hyperlipoproteinemia, who subsisted on free choice diets, standard diets excluding lard, or were given a breakfast enriched in lard. The VLDL and chylomicrons were obtained by conventional ultracentrifugation, and the triacylglycerols were isolated by thin‐layer chromatography (TLC). Representative sn‐1,2, 2n‐2‐3‐ and sn‐1,3‐diacylglycerols were generated by partial Grignard degradation of the triacylglycerols and a stereospecific hydrolysis by phospholipase C of the mixed sn‐1,2(2,3)‐diacyl phosphatidylcholines prepared as intermediates. Representative sn‐2‐acylglycerols were obtained by hydrolysis with pancreatic lipase. Positional distribution of the fatty acids was established by subtracting in turn the fatty acid composition of the sn‐2‐position from the fatty acid composition of the sn‐1,2‐ and sn‐2,3‐diacylglycerols. The molecular association of the fatty acids in the diacylglycerol moieties was determined by gas‐liquid chromatography with mass spectrometry (GC/MS) of the tertiary‐butyldimethylsilyl (t‐BDMS) ethers. The molecular association of the fatty acids in the triacylglycerols was determined by 1‐random 2‐random 3‐random calculation following experimental validation of the distribution. The results confirm a marked asymmetry in the positional distribution of the fatty acids in all triacylglycerol samples, with the palmitic acid predominantly in the sn‐1‐position, the unsaturated acids about equally divided between the sn‐2‐and sn‐3‐positions, and the stearic acid divided about equally between the sn‐1‐ and sn‐3‐positions. The overall structure of the VLDL and chylomicron triacylglycerols from patients and control subjects was characterized by a noncorrelative distribution of fatty acids under all dietary conditions.
Determination of the amounts of free arachidonic acid in resident and activated rabbit alveolar macrophages by fluorometric high performance liquid chromatography
Authors: Nakagawa Yasuhito , Waku Keizo
Published: November 2006

An improved method of high performance liquid chromatography (HPLC) has been developed for the separation and quantitation of low levels of free fatty acids as they occur in mammalian tissues. The fatty acid analysis is based on the esterification of the carboxylic group with 9‐anthryldiazomethane (ADAM). HPLC separation and fluorescence measurement of fatty acid ADAM esters allow the determination of pmole amounts of fatty acids.

The amounts of free fatty acids of resident and activated alveolar macrophages were determined by the fluorometric HPLC method. There were approximately 2 μg/106 cells of free fatty acids. In resident macrophages, free 20∶4 was a minor component (0.8% of total free fatty acids), while significant amounts of 20∶4 were found in the total glycerophospholipids, representing 16.6% of the total fatty acids. A marked increase in amounts of 20∶4 (8 times) occurred in activated macrophages stimulated for 1 hr with opsonized zymosan. Small but significant increases (1.5 times) also occurred in other fatty acids. These results show that the release reaction of fatty acids was not selective for 20∶4 in alveolar macrophages after the challenge with opsonized zymosan.
Phosphorylation of chloroform soluble compounds in plasma membranes of human epidermoid carcinoma A431 cells
Authors: Brautigan David L. , Randazzo Paul , Shriner Carol , Fain John N.
Published: November 2006

This study investigated a possible role for the epidermal growth factor (EGF) receptor protein tyrosine kinase in phosphoinositide metabolism with plasma membrane vesicles from human epidermoid carcinoma (A431) cells. We found a novel chloroform‐soluble product radiolabeled with [gamma‐32P] ATP that did not migrate from the origin in the thin layer system designed to separate the phosphoinositides, appeared as a single band of Mr=3500 on polyacrylamide gels in the presence of dodecyl sulfate, had an ultraviolet absorbance spectrum with a maximum at 275 nm and stained with Coomassie dye. Based on these properties this phosphorylation product is referred to as a proteolipid. The32P label was not detected in phosphotyrosine [Tyr(P)], phosphoserine [Ser(P)] or phosphothreonine [Thr(P)] and was lost during acid or base hydrolysis. Phosphorylation of proteolipid was increased significantly by EGF, whereas phosphorylation of phosphatidic acid was decreased and labeling of phosphoinositides was unaffected. Thus, it appears that in A431 membranes the EGF receptor/ kinase does not utilize phosphatidylinositol as a substrate, but does phosphorylate a membrane proteolipid.
Biosynthesis and isomerization of 11‐hydroperoxylinoleates by manganese‐ and iron‐dependent lipoxygenases
Authors: Oliw Ernst H. , Cristea Mirela , Hamberg Mats
Published: November 2006

Manganese lipoxygenase (Mn‐LO) oxygenates linoleic acid (LA) to a mixture of the hydroperoxides—11(S)‐hydroperoxy‐9Z,12Z‐octadecadienoic acid [11(S)‐HPODE] and 13(R)‐hydroperoxy‐9Z,11E‐octadecadienoic acid [13(R)‐HPODE]‐ and also catalyzes the conversion of 11(S)‐HPODE to 13(R)‐HPODE via oxygen‐centered (LOO•) and carbon‐centered (L•) radicals [Hamberg, M., Su, C., and Oliw, E. (1998) Manganese Lipoxygenase. Discovery of a Bis‐allylic Hydroperoxide as Product and Intermediate in a Lipoxygenase Reaction, J. Biol. Chem. 273, 13080–13088]. The aims of the present work were to investigate whether 11‐HPODE can also be produced by iron‐dependent lipoxygenases and to determine the enzymatic transformations of stereoisomers of 11‐HPODE by lipoxygenases. Rice leaf pathogen‐inducible lipoxygenase, but not soybean lipoxygenase‐1 (sLO‐1), generated a low level of 11‐HPODE (0.4%) besides its main hydroperoxide, 13(S)‐HPODE, on incubation with LA. Steric analysis revealed that 11‐HPODE was enriched with respect to the R enantiomer [74% 11(R)]. In agreement with previous results, 11(S)‐HPODE incubated with Mn‐LO provided 13(R)‐HPODE, and the same conversion also took place with the methyl ester of 11(S)‐HPODE. 11(R,S)‐HPODE was metabolized biphasically in the presence of Mn‐LO, i.e., by a rapid phase during which the 11(S)‐enantiomer was converted into 13(R)‐HPODE and a slow phase during which the 11(R)‐enantiomer was converted into 9(R)‐HPODE. sLO‐1 catalyzed a slow conversion of 11(S)‐HPODE into a mixture of 13(R)‐HPODE (75%), 9(S)‐HPODE (10%), and 13(S)‐HPODE (10%), whereas 11(R,S)‐HPODE produced a mixture of nearly racemic 13‐HPODE (≈70%) and 9‐HPODE (≈30%). The results showed that 11‐HPODE can also be produced by an iron‐dependent LO and suggested that the previously established mechanism of isomerization of 11(S)‐HPODE involving suprafacial migration of O2 is valid also for the isomerizations of 11(R)‐HPODE by Mn‐LO and of 11(S)‐HPODE by sLO‐1.
Type 1 diabetes compromises plasma arachidonic and docosahexaenoic acids in newborn babies
Authors: Ghebremeskel Kebreab , Thomas Beverley , Lowy Clara , Min Yoeju , Crawford Michael A.
Published: November 2006

The activity of Δ6‐ and Δ5‐desaturase, enzymes required for the synthesis of AA and DHA, are impaired in human and experimental diabetes. We have investigated whether neonates of type 1 diabetic women have compromised plasma AA and DHA at birth. Cord blood was obtained from healthy babies born to mothers with (n=31) and without (n=59) type 1 diabetes. FA composition of plasma choline phosphoglycerides (CPG), TG, and cholesterol esters (CE) was assayed. The neonates of the diabetics had lower levels of AA (20∶4n−6, P<0.0001), adrenic acid (22∶4n−6, P<0.01), Σn−6 metabolites (P<0.0001), docosapentaenoic acid (22∶5n−3, P<0.0001), DHA (22∶6n−3, P<0.0001), Σn−3 (P<0.0001), and Σn−3 metabolites (P<0.0001) in CPG compared with the corresponding babies of the nondiabetic mothers. Similarly, they had lower levels of AA (P<0.05), Σn−6 metabolites (P<0.05), DHA (P<0.0001), and Σn−3 metabolites (P<0.01) in plasma CE. There was also a nonsignificant reduction of AA and DHA in TG in the babies of the diabetic group. The current investigation indicates that healthy neonates born to mothers with type 1 diabetes have highly compromised levels of AA and DHA. These nutrients are of critical importance for neurovisual and vascular system development. In poorly controlled maternal diabetes, it is conceivable that the relative “insufficiency” of AA and DHA may exacerbate speech and reading impairments, behavioral disorders, suboptimal performance on developmental tests, and lower IQ, which have been reported in some children born to mothers with type 1 diabetes mellitus. Further studies are needed to understand the underlying mechanism for this biochemical abnormality and its implications for fetal and infant development.
CLA isomers in milk fat from cows fed diets with high levels of unsaturated fatty acids
Authors: Collomb Marius , Sieber Robert , Bütikofer Ueli
Published: November 2006

The concentrations of CLA isomers were determined by Ag+‐HPLC in the milk fat of cows fed a control diet consisting of hay ad libitum and 15 kg of fodder beets or this diet supplemented with oilseeds containing either high levels of oleic acid (rapeseed), linoleic acid (sunflower seed), or α‐linolenic acid (linseed). Highly significant (P≤0.001) correlations were found between the daily intakes of oleic acid and the concentration of the CLA isomer trans‐7,cis‐9 in milk fat; of linoleic acid and the CLA isomers trans‐10,trans‐12, trans‐9,trans‐11, trans‐8,trans‐10, trans‐7,trans‐9, trans‐10,cis‐12, cis‐9,trans‐11, trans‐8,cis‐10, and trans‐7,cis‐9; and of α‐linolenic acid and the CLA isomers trans‐12,trans‐14, trans‐11,trans‐13, cis,trans/trans,cis‐12,14, trans‐11,cis‐13, and cis‐11,trans‐13. CLA concentrations were also determined in the milk fat of cows grazing in the lowlands (600–650 m), the mountains (900–1210 m), and the highlands (1275–2120 m). The concentrations of many isomers were highest in milk fat from the highlands, but only three CLA isomers (cis‐9,trans‐11, trans‐11,cis‐13, and trans‐8,cis‐10) showed a nearly linear increase with elevation. Therefore, these three CLA isomers, and particularly the CLA isomer trans‐11,cis‐13, the second‐most important CLA in milk fat from cows grazing at the three altitudes, could be useful indicators of milk products of Alpine origin.
Selective increase in pinolenic acid (all‐cis‐5,9,12–18∶3) in Korean pine nut oil by crystallization and its effect on LDL‐receptor activity
Authors: Lee Jin‐Won , Lee Kwang‐Won , Lee Seog‐Won , Kim In‐Hwan , Rhee Chul
Published: November 2006

The aims of this study were to obtain concentrated pinolenic acid (5,9,12–18∶3) from dietary Korean pine (Pinus koraiensis) nut oil by urea complexation and to investigate its cholesteroi‐lowering effect on the LDL‐receptor activity of human hepatoma HepG2 cells. Pine nut oil was hydrolyzed to provide a low‐pinolenic acid‐containing FA extract (LPAFAE), followed by crystallization with different ratios of urea in ethanol (EtOH) or methanol (MeOH) as a solvent to produce a high‐pinolenic acid‐containing FA extract (HPAFAE). The profiles of HPAFAE obtained by urea complexation showed different FA compositions compared with LPAFAE. The long‐chain saturated FA palmitic acid (16∶0) and stearic acid (18∶0) were decreased with urea/FA ratios (UFR) of 1∶1 (UFR1), 2∶1 (UFR2), and 3∶1 (UFR3). Linoleic acid (9,12–18∶2) was increased 1.3 times with UFR2 in EtOH, and linolenic acid (9,12,15–18∶3) was increased 1.5 times with UFR3 in MeOH after crystallization. The crystallization with UFR3 in EtOH provided the highest concentration of pinolenic acid, which was elevated by 3.2‐fold from 14.1 to 45.1%, whereas that of linoleic acid (9,12–18∶2) was not changed, and that of oleic acid (9–18∶1) was decreased 7.2‐fold. Treatment of HepG2 cells with HPAFE resulted in significantly higher internalization of 3,3′‐dioctadecylindocarbocyanine‐LDL (47.0±0.15) as compared with treatment with LPAFAE (25.6±0.36) (P<0.05). Thus, we demonstrate a method for the concentration of pinolenic acid and suggest that this concentrate may have LDL‐lowering properties by enhancing hepatic LDL uptake.
Lipid components of borage (Borago officinalis L.) seeds and their changes during germination
Authors: Namal Senanayake S. P. J. , Shahidi Fereidoon
Published: November 2006

The changes in composition of total and neutral lipids (NL) as well as glycolipids (GL) and phospholipids (PL) of borage (Borago officinalis L.) seeds, germinated in the dark at 25°C for 10 d, were studied. Total lipids constituted 34.0% of the dry matter of borage seeds. During germination, the content of total lipids was decreased by 95%. NL accounted for 95.7% of total lipids prior to germination and were composed of triacylglycerols (TAG; 99.1%), diacylglycerols (DAG; 0.06%), monoacylglycerols (MAG;0.02%), free fatty acids (FFA;0.91%), and sterols (0.02%). The content of TAG was significantly (P≤0.05) decreased, while that of other components, such as MAG and FFA, significantly (P≤0.05) increased during germination. However, the content of DAG did not change. GL and PL accounted for 2.0 and 2.3% of total lipids, respectively, and their contents significantly (P≤0.05) increased as germination proceeded. The thin layer chromatography‐flame‐ionization detection studies showed that phosphatidylcholine (PC; 69.7%) was the major PL present. The total content of phosphatidylserine (PS) and phosphatidylethanolamine (PE), which were coeluted, was 18.2%; phosphatidic acid (PA) was present at 11.2% of the total PL fraction. Lysophosphatidylcholine was detected at 0.9%. The proportion of PC, PS, and PE significantly (P≤0.05) decreased during germination, but that of PA increased (P≤0.05) markedly. The fatty acid composition of lipid fractions changed as germination proceeded. The predominant fatty acids of total lipids, NL, and GL were linoleic and linolenic acids, while those of PL were linoleic and palmitic acids. The present study demonstrated that the overall changes of lipids seen in borage seeds during germination agree well with results for other oilseeds. Changes in lipid compositions during germination result from the formation of tissues and metabolic interconversion of lipid classes. Rapid changes in lipid composition during seed germination may enhance the nutritional value of the sprouts.
Partition coefficient calculation of selected terpenes and low molecular weight solvents between tall oil fatty acid and air and polydimethyl siloxane oil and air
Authors: Bir David
Published: November 2006

Headspace gas chromatography‐mass spectrometry (GC‐MS) has been applied to the analysis of the temperature‐dependent tall oil fatty acid (TOFA)/air partition coefficient (k1) and the polydimethyl siloxane oil/air partition coefficient (k2) of selected terpenes and low molecular weight solvents. As expected, both the TOFA and the silicone oil are effective trapping media for the nonpolar terpenes, but they are also efficient traps for acetone, methanol, n‐propanol, and n‐butanol. However, several species of low and moderate molecular weight (less than 150 amu) aldehydes, ketones, and organic acids that might adversely affect its trapping capacity were detected in the TOFA. This article will report the empirically gathered data and the subsequent calculation of the partition coefficients for the terpenes: α‐ and β‐pinene, limonene, and α‐terpineol and the solvents: acetone, methanol, n‐propanol, and n‐butanol between 50 and 130°C.
Crossflow filtration of oils on metal oxides. Influence of chemical composition of the layer
Authors: El’Ama Claude , Fanni Jacques , Parmentier Michel
Published: November 2006

A new technique of fat fractionation was described in which butter oil and a formulated oil (olive, grapestone, coconut, and linseed) have been submitted to crossflow percolation at 45°C on different metal oxides layers (Al2O3, TiO2, ZrO2) of various thickness. The metal oxides layers were used in order to highlight the interaction between triglycerides (TG) and filtering materials. Experiments have been checked by high‐performance liquid chromatography and by differential scanning calorimetry. Partition number was used to take the double bonds into account, and nonpolarity index was used to estimate the relative hydrophobicity of TG molecules. Results point out a two‐step complex partition phenomenon: The filtering layer that is initially hydrophilic is coated by less hydrophobic TG acting as a second interface with hydrophobic characteristics. The three tested metal oxides did not provide comparable patterns. The specific property of aluminum oxide is related to a better polarizability of the Al−O bond.
Modification of fish oil aroma using a macroalgal lipoxygenase
Authors: Hu Seng‐Pei , Pan Bonnie Sun
Published: November 2006

The odor of fish oil is the major factor limiting its application in food. In this study, the addition of butylated hydroxytoluene to fish oil did not significantly inhibit the generation of fishy and rancid odors. To reduce the undesirable odors, fish oil was treated with lipoxygenase (LOX) to produce volatile compounds via position‐specific cleavage of hydroperoxides. An extract of a green marine macroalga, Ulva conglobata, showed a high level of 13‐LOX activity and 9‐LOX to a lesser extent, and produced strong green, melon‐like, and fresh‐fish‐like flavor notes from fish oil. The LOX‐modified fish oil contained 99% of the highly unsaturated fatty acids (HUFA; containing three or more double bonds) originally present, total volatile compounds increased from 3477 to 3787 ppb after LOX treatment. Compounds with strong odors accounted for about 40% of the total volatiles. Increasing the level of LOX activity used to treat fish oil produced higher concentrations of the desirable unsaturated aldehydes, ketones, and alcohols, with odors resembling fresh fish, apple, citrus, melon, fruit, and oyster. These compounds were tentatively identified as E,Z‐2,6‐nonadienal E‐2‐hexenal, E,E‐2,4‐octadienal, E,E‐3‐5‐octadien‐2‐one, and alcohols E‐2‐pentenol and 2‐butoxyethanol. The LOX treatment also slightly increased the content of the undesirable volatile components, including sour and rancid odors, tentatively identified as acetic acid and E,Z‐ and E,E‐2,4‐decadienals
Lipase‐catalyzed alcoholysis of crambe oil and camelina oil for the preparation of long‐chain esters
Authors: Steinke Georg , Kirchhoff Rita , Mukherjee Kumar D.
Published: November 2006

Crambe oil and camelina oil were transesterified with oleyl alcohol, the alcohols derived from crambe and camelina oils, n‐octanol or isopropanol using Novozym 435 (immobilized lipase B from Candida antarctica), Lipozyme IM (immobilized lipase from Rhizomucor miehei), and papaya (Carica papaya) latex lipase as biocatalysts. The highest conversions to alkyl esters were obtained with Novozym 435 (up to 95%) in most cases, whereas Lipozyme IM and papaya latex lipase gave lower (40 to 50%) conversions. The conversions with long‐chain alcohols (oleyl alcohol, crambe alcohols, and camelina alcohols) were higher (40 to 95%) than with medium‐chain n‐octanol (30 to 85%). Isopropyl esters of crambe oil and camelina oil were obtained with rather low conversions using Novozym 435 (<40%) and Lipozyme IM (about 10%) as biocatalysts, whereas with papaya latex lipase no isopropyl esters were formed. The conversions of crambe oil and camelina oil to oleyl and n‐octyl esters using Novozym 435 as biocatalyst were hardly affected by the ratio of the substrates, but with Lipozyme IM the conversions to alkyl esters distinctly increased with an excess of alcohol substrate
Identification and quantification of important steryl esters in aspen wood
Authors: Serreqi Alessio N. , Leone Robert , Del Rio Luis F. , Mei Shirley , Fernandez Marc , Breuil Colette
Published: November 2006

Steryl esters make up a major portion of the total lipids in aspen wood, and contribute significantly to pitch deposit problems during pulping. Fungal treatment of aspen is an attractive method for removing these compounds because it is inexpensive and environmentally acceptable; however, the mechanism of steryl ester removal remains unclear. Identification of the steryl esters will lead to a better understanding of how they are removed by fungi. The steryl ester fraction from aspen wood was obtained by acetone extraction then further purified by silica gel column chromatography and argentation‐silica gel column chromatography. This led to the isolation of three major fractions: fraction I, fraction II, and fraction III. The major steryl esters of fractions I and II were identified by gas chromatography, gas chromatography‐mass spectroscopy, and proton nuclear magnetic resonance analysis of the intact fraction as well as sterol and fatty acid moieties obtained after base hydrolysis. Identification of the steryl esters was carried out by mass spectra comparisons with steryl ester standards synthesized in the laboratory and comparison with mass spectra libraries (Wiley and NIST) by mass fragmentography. Fraction I contained primarily the palmitate, stearate, and eicosanoate esters of α‐ and β‐amyrin. Fraction II consisted mainly of the palmitate, stearate, and eicosanoate esters of tirucalla‐7,24‐dien‐3β‐ol and lupeol.
Evaluation of the role of saturated fatty acids in sedimenting canola oils
Authors: Botha Ingrid , Mailer Rodney , Robards Kevin
Published: November 2006

Canola oil is generally a clear oil which does not require winterization. However, sediment formation has become an increasing problem in Australian canola oil. Canola oil stored at temperatures between −5 and 21°C formed sediment more rapidly at lower temperatures. The sediment and clear fractions of a group of sedimenting canola oils were analyzed and compared. Both fractions contained wax esters of carbon number C42–C52, the sediment fractions containing between 0.37 and 3.09 mg g−1 and clear fractions containing between 0.12 and 0.85 mg g−1. The triacylglycerol profiles of sediment fractions contained four compounds, PPO, PPP, PSO and PPS (where P is palmitoyl, O is oleoyl, and S stearoyl), that were not detected in clear fractions. The contents of palmitic acid and total saturated fatty acids were higher in the sediment fraction than the clear fraction. Added PPP clouded a clear oil as effectively as stearyl behanate and more than OOO or lauryl arachidate. Sedimentation may be linked to environmental conditions, as seed grown in 1997, a dry year, produced more problem oils than seed grown in previous years that had more nearly average rainfall.
Supercritical fluid extraction of oil from millet bran
Authors: Devittori C. , Gumy D. , Kusy A. , Colarow L. , Bertoli C. , Lambelet P.
Published: November 2006

Proso millet bran [Panicum miliaceum (L.)], variety Dakota White, was extracted with supercritical carbon dioxide (SC‐CO2) to yield crude oil. The effects of operating parameters (pressure, temperature, and specific solvent flow) and of features of the raw material (moisture content and particle size) on oil extraction were investigated. Complete de‐oiling of ground millet bran pellets was achieved under 300 bar at 40°C with a specific solvent flow of 2–10 h−1 within 200 to 500 min. Solvent requirements were 20–30 kg CO2/kg raw material. Composition of crude SC‐CO2 oil extracted under optimal conditions, i.e., fatty acid profile, amount of unsaponifiables, tocopherols, free fatty acids, sterols, sterol esters, waxes, hydrocarbons, and phospholipids, was compared to that of crude oil obtained by petroleum ether extraction. These two oils were similar in terms of fatty acid profile and amount of free fatty acids, unsaponifiables, peroxides, and tocopherols. They differed in respect to phospholipids (present in petroleum etherextracted oil and absent in SC‐CO2 extracted oil), metals, and waxes (lower levels in SC‐CO2 extracted oil). The effects of extraction procedures on oxidative stability of crude SC‐CO2 oil were studied. Ensuring that all pieces of the extractor in contact with the oil were in stainless steel; cleaning the separator, i.e., washing with KOH, rinsing, purging with N2 and CO2, and heating; performing a couple of extractions before the main extraction; and achieving the extraction without interruption all positively influenced the oxidative stability of the oil. Conversely, increasing CO2 purity above 99.5% had no effect. Oxidative stability of the SC‐CO2 oil extracted under these conditions was only slightly lower than that of the oil extracted with petroleum ether.
Lipase‐mediated synthesis of dodecyl oleate and oleyl oleate in aqueous foams
Authors: Rao N. Madhusudhana , Shanmugam V. M.
Published: November 2006

Engineering media for optimal product yield in enzyme‐catalyzed reactions is an important strategy. We report here synthesis of dodecyl oleate and oleyl oleate by lipase (Candida rugosa) in solvent‐free substrate foams. Ester formation was characterized with respect to enzyme concentration, pH, temperature, and substrate concentration. The kinetics of ester formation suggest that the formation of ester was 80% complete in 2h. The pH and temperature optima of lipase suggest that the behavior of lipase in substrate foams was similar to its behavior in water or in organic solvents. The denaturing effect of foams on enzyme was evaluated. Rapid loss in activity (>70% in 1 h) was observed in the presence of oleic acid and dodecanol. The large surface areas generated in aqueous foams offer better accessibility of substrate to lipase for esterification.
Synthesis of dimer and oligomers from (R)‐methyl hydnocarpate
Authors: Malkar Navdeep B. , Vaidya Ashish A. , Kumar V. G.
Published: November 2006

We report synthesis and characterization of dimer and oligomer acids from chaulmoogra oil. (R)‐Methyl hydnocarpate (methyl ester of the major fatty acid component of chaulmoogra oil) was brominated to give threo‐2,3‐dibromocyclopentane‐1‐methyl undecanoate. Formation of two diastereoisomers, viz., threo‐2(R),3(R)‐dibromocyclopentane‐1(R)‐methyl undecanoate and threo‐2(S),3(S)‐dibromocyclopentane‐(R)‐1‐methyl undecanoate, was observed. Dehydrobromination of bromo derivatives using alcoholic KOH gave a cyclopentadiene derivative as intermediate, which underwent Diels‐Alder reaction to give dimer and oligomer fatty acids. The products were characterized by ultraviolet, direct exposure probe‐mass spectroscopy, 1H nuclear magnetic resonance (NMR), and 13C NMR spectroscopic techniques.
Thermophilic phospholipase A2 in the cytosolic fraction from the archaeon Pyrococcus horikoshii
Authors: Feng Yan , Joh Yong‐Goe , Ishikawa Kazuhiko , Ishida Hiroyasu , Ando Susumu , Yamagaki Tohru , Nakanishi Hiroshi , Cao Shugui , Matsui Ikuo , Kosugi Yoshitsugu
Published: November 2006

Hyperthermophilic archaeon Pyrococcus horikoshii produced phospholipase A2 in a cytosolic fraction. The enzyme displayed optimal activity at 90°C and pH 7 and preferentially hydrolyzed sn‐2 fatty acids in the following order: linoleoyl> oleoyl>arachidoyl phosphatidylcholine. Phospholipase A2 had similar activities toward l‐α‐1‐palmitoyl‐2‐arachidoyl derivatives of phosphatidylcholine and phosphatidylethanolamine. Phospholipase A2 activity was unaffected by the addition of 0.0001–1 mM calcium, but was inhibited slightly by the addition of 2–10 mM calcium. The activity was enhanced more than 5–18‐fold in the presence of 3–20% (vol/vol) glycerol. The activity was unaffected by the addition of 1–5 mM EDTA or 0.01–20 mM dithiothreitol. A caldarchaetidic acid derivative having a molecular weight of 1544 disappeared upon incubation of the cytosolic fraction with total lipid. The phospholipase A2 was difficult to purify by general chromatography because it existed as an aggregate. Electrophoresis was carried out using 10–15% polyacrylamide gels containing sodium dodecyl sulfate (SDS‐PAGE). No activity of phospholipase A2 activity was observed in the absence of proteins less than 19 kD in size, as fractionated by SDS‐PAGE.
Photochemical reactions of antioxidant sesamol in aqueous solution
Authors: Nakagawa Kouichi
Published: November 2006

Antioxidant intermediate radicals generated by continuous ultraviolet (UV) and pulsed UV laser irradiation of sesamol in aqueous solutions were investigated. Radical species with the intensity ratio of 1∶4∶6∶4∶1 were observed by using continuous wave electron paramagnetic resonance (EPR) with continuous UV irradiation. The radical was also observed after the irradiation. To observe the intermediate radical right after the excitation, Fourier transform EPR (FT EPR) was used. Trace amounts of the same radical were also detected by FT EPR with pulsed UV laser. Based on the hyperfine coupling constant (2.3 G) and g‐value (2.0048), together with FT EPR results, this radical was found to be a benzoquinone anion radical. The radical might have been produced via multistep reactions of the excited sesamol in aqueous solution, and it was stable for at least several minutes. In addition to the benzoquinone radical, the formation and dynamics of the sesamolyl radical were investigated by using FT EPR. FT EPR showed the detailed behavior of the radical. Characterization of the intermediate is important to evaluate the antioxidant sesamol.
Purification process for cod liver oil polyunsaturated fatty acids
Authors: Guil‐Guerrero J. L. , Belarbi El‐Hassan
Published: November 2006

The polyunsaturated fatty acids (PUFA) eicosapentaenoic acid (EPA, 20∶5n−3) and docosahexaenoic acid (DHA, 22∶6n−3), which have several pharmaceutical properties, have been purified from cod liver oil. The process consisted of four main steps: (i) saponification of the oil, (ii) use of urea inclusion adducts method to obtain PUFA, (iii) PUFA methylation, and (iv) argentation silica gel column chromatography of the methylated PUFA. Argentation silica gel chromatography yielded highly pure DHA in the process (100% purity, 64% yiild). For EPA, the recovery in the combined process was 29.6%, and the final purity was 90.6%, owing to the simultaneous elution of other polyunsaturated fatty esters. The recovery in the urea inclusion method was strongly enhanced by application of orbital agitation during the crystallization process, in which EPA yield increased from 60–70% without agitation to 90–97% at 800 rpm; stearidonic acid (18∶4n−3) yield ranged from 60–75% without agitation to 87–95% at 800 rpm, and DHA yield varied from 53–73% without agitation to 85–99% at 800 rpm
Lipase‐catalyzed incorporation of conjugated linoleic acid into tricaprylin
Authors: Kim In‐Hwan , Yoon Chil‐Surk , Cho Soo‐Hee , Lee Kwang‐Won , Chung Soo‐Hyun , Tae Beom‐Seok
Published: November 2006

Three commercially available immobilized lipases, Novozym 435 from Candida antarctica, Lipozyme IM from Rhizomucor miehei, and Lipase PS‐C from Pseudomonas cepacia, were used as biocatalysts for the interesterification of conjugated linoleic acid (CLA) ethyl ester and tricaprylin. The reactions were carried out in hexane, and the products were analyzed by gas‐liquid chromatography. The effects of molar ratio, enzyme load, incubation time, and temperature on CLA incorporation were investigated. Novozym 435, as compared to Lipozyme IM and Lipase PC‐C, showed the highest degree of CLA incorporation into tricaprylin. By hydrolysis with pancreatic lipase, it was found that Lipozyme IM and Lipase PS‐C exhibited high selectivity for the sn‐1,3 position of the triacylglycerol early in the interesterification, with small extents of incorporation of CLA into the sn‐2 position, probably due to acyl migration, at later reaction times. A small extent of sn‐1,3 selectivity during interesterification by Novozym 435 was observed.
Profile of polyunsaturated fatty acids produced by Thraustochytrium sp. KK17‐3
Authors: Huang Jianzhong , Aki Tsunehiro , Hachida Kazutaka , Yokochi Toshihiro , Kawamoto Seiji , Shigeta Seiko , Ono Kazuhisa , Suzuki Osamu
Published: November 2006

More than 300 strains of microorganisms producing polyunsaturated fatty acids (PUFA) were newly isolated from coastal seawater in the Seto Inland Sea and around Iriomote Island, Japan, by the baiting method. The profiles of PUFA from docosahexaenoic acid (DHA)‐producing strains could be classified into four types. A strain, named KK17‐3, was chosen for further study owing to its high DHA content (52.1% of total fatty acid) and wide range of PUFA (76.1%) including arachidonic, eicosapentaenoic, and docosapentaenoic acids as well as DHA. Glucose and tryptone were the optimal carbon and nitrogen sources, respectively, in a medium with salinity at 75% that of seawater. The PUFA contents in polar lipids (22.1% of total lipid), in which the DHA content was 39.3%, were higher than those in neutral lipids and glycolipids. Molecular phylogenetic analysis of 18S rRNA gene sequences showed KK17‐3 to be a thraustochytrid. It also was observed to possess a life cycle composed of vegetative cells without successive bipartition, zoosporangium, and zoospore stage. Classification by the chemotaxonomic criterion based on PUFA compositions also supported this assignment.
Kinetics of in situ epoxidation of soybean oil in bulk catalyzed by ion exchange resin
Authors: Sinadinović‐Fišer Snežana , Janković Milovan , Petrović Zoran S.
Published: November 2006

The kinetics of the epoxidation of soybean oil in bulk by peracetic acid formed in situ, in the presence of an ion exchange resin as the catalyst, was studied. The proposed kinetic model takes into consideration two side reactions of the epoxy ring opening involving the formation of hydroxy acetate and hydroxyl groups as well as the reactions of the formation of the peracid and epoxy groups. The catalytic reaction of the peracetic acid formation was characterized by adsorption of only acetic acid and peracetic acid on the active catalyst sites, and irreversible surface reaction was the overall rate‐determining step. Kinetic parameters were estimated by fitting experimental data using the Marquardt method. Good agreement between the calculated and experimental data indicated that the proposed kinetic model was correct. The effect of different reaction variables on epoxidation was also discussed. The conditions for obtaining optimal epoxide yield (91% conversion, 5.99% epoxide content in product) were found to be: 0.5 mole of glacial acetic acid and 1.1 mole of hydrogen peroxide (30% aqueous solution) per mole of ethylenic unsaturation, in the presence of 5 wt% of the ion exchange resin at 75°C, over the reaction period of 8 h.