Monoethylenic fatty acids of a partially hydrogenated herring oil

A Canadian Atlantic herring oil hydrogenated for margarine use to an iodine value of 76 and melting point of 32.5 C was found to have 30% saturated acids and 66% monounsaturated fatty acids. The monounsaturated fatty acids could be analytically determined ascis andtrans isomers by open tubular gas liquid chromatography.Trans acids were 33% of the C₁₆ and C₁₈ monounsaturated acids, and 32 and 28%, respectively, of the C₂₀ and C₂₂ monounsaturated acids. After separation of geometric isomers by Florisil-silver nitrate chromatography the positional isomers in each class were determined by oxidative fission. The double bond positions of the originalcis fatty acids were largely retained in bothcis andtrans isomers, but additional isomers were observed, especially in thetrans fatty acids.     

Monoethylenic isomers in cardiac lipids of rats fed partially hydrogenated herring oil

Compositional studies have been carried out to compare the monoethylenic fatty acid isomers of a partially hydrogenated herring oil with those found in the cardiac lipid of young rats fed this oil for 1 or 16 weeks. In general, all geometrical and positional isomers with chain lengths C₁₆, C₁₈, C₂₀ and C₂₂ found in the hydrogenated oil were also observed in cardiac lipid. Evidence was also obtained for the occurrence of β-oxidation in the catabolism of thecis andtrans isomers of these long chain acids. Presented at the AOCS Meeting, Ottawa, September 1972.     

Essential fatty acid-deficient rats: II. On the fatty acid composition of partially hydrogenated arachis,soybean and herring oils and of normal,refined arachis oil

The fatty acid composition of partially hydrogenated arachis (HAO), partially hydrogenated soybean (HSO) and partially hydrogenated herring (HHO) oils and of a normal, refined arachis oil (AO) was studied in detail by means of direct gas liquid chromatography, ultraviolet and infrared spectrophotometry and by thin layer chromatography fractionation on silver nitrate-silica gel plates followed by gas liquid chromatography. It was shown that the partially hydrogenated oils all contained fatty acids withtrans double bonds. In the plant oils, thetrans acids were present mainly as elaidic acid. The HHO showed an almost equal distribution betweentrans 18∶1 ω9,trans 20∶1 ω>9 andtrans 22∶1 ω>9. Sometrans configuration was also found in the C₂₀-and C₂₂-dienes and trienes of the HHO. In all the oils, conjugated fatty acids were present in minor amounts only (<0.5%). Special attention was given to the ω-acids known to be of specific nutritional value. The HSO contained about 32% linoleic acid, whereas the content ofcis, trans+trans, cis andtrans, trans octadecadienoic isomers was 1.7% and 0.5%, respectively. The amount of linoleic acid in the HSO was even higher than that of AO (29%). The HAO contained only 0.8% 18∶2 ω6 (linoleic acid). Further, two 18∶2 fatty acids with ω>6, acis, cis and atrans, trans isomer, were present in small amounts. The HHO contained 0.5% 18∶2 ω6 (linoleic acid). Isomers of 18∶2 ω>6 were also found in the HHO. They may be hydrogenation products of higher unsaturated C₁₈-acids orginally present. All the C₂₀- and C₂₂-dienes and trienes were shown to have an ω-chain greater than 6. Fatty acids with ω6-structure were not formed during partial hydrogenation of the oils studied.     

The effects of partially hydrogenated marine oils on the mitochondrial function and membrane phospholipid fatty acids in rat heart

The influence of dietary partially hydrogenated marine oils containing docosenoic acid on rat heart mitochondrial membrane phospholipid fatty acid composition was studied with particular reference to cardiolipin and oxidative phosphorylation. Five groups of male weanling rats were fed diets containing 20% (w/w) peanut oil (PO), partially hydrogenated peanut oil (HPO), partially hydrogenated Norwegian capelin oil (HCO), partially hydrogenated herring oil (HHO), and rapeseed oil (RSO) for 10 weeks. All the cardiac phospholipids investigated were influenced by the experimental diets. An increased amount of arachidonic acid observed in phosphatidylethanolamine (PE) after feeding partially hydrogenated oils suggests a changed regulation of the arachidonic acid metabolism in comparison with PO treatment. 22∶1 originating from the dietary oils was incorporated only to a small extent into phosphatidylcholine (PC) and PE. A selective incorporation of 18∶1 isomers into the 1- and 2-positions of PC and PE with respect to geometry and position of the double bond was observed. Large amounts of 18∶1trans were incorporated into the 1-position of PC and PE, irrespective of the amount of 18∶2 supplemented to the diets, replacing a considerable proportion of stearic acid in this position. After feeding HHO and RSO, the content of 22∶1 in mitochondrial cardiolipin of rat heart was found to be 3% (mainly cetoleic acid) and 10% (mainly erucic acid), respectively, indicating a high affinity forcis isomers of 22∶1, but also a considerable resistance against incorporation oftrans isomers was observed. The ability of rat cardiac mitochondria to oxidize palmitoylcarnitine and to synthesize ATP was depressed after feeding HHO and RSO. Dietarycis isomers of 22∶1 seem to have a specific ability to interfere with cardiac ATP synthesis and also to alter the fatty acid composition of cardiolipin of rat heart.     

Quantitative analysis of long-chain trans-monoenes originating from hydrogenated marine oil

Gas chromatography (GC) is used for the analysis of trans-fatty acids in partially hydrogenated vegetable oils. Although trans-isomers of C₁₈ carbon length predominate in partially hydrogenated vegetable oils, trans-isomers of C₂₀ and C₂₂ carbon length occur in partially hydrogenated fish oil. We report a simple silver ion chromatographic combined with capillary GC technique for quantitative analysis of trans-monoenes derived from partially hydrogenated fish oil. Silver nitrate thinlayer chromatographic (TLC) plates are developed in toluene/hexane (50∶50, vol/vol). Fatty acid methyl esters are separated into saturates (R _f 0.79), trans-monoenes (R _f 0.49), cis-monoenes (R _f, 0.27), dienes (R _f, 0.10), and polyunsaturated fatty acids with three or more double bonds remaining at the origin. The isolated trans-monoenes are quantitatively analyzed by capillary GC. The technique of argentation TLC with GC analysis of isolated methyl esters is highly reproducible with 4.8% variation (i.e., coefficient of variation, CV%) in R _f values and 4.3 and 6.9% CV% in quantification within batch and between batch, respectively. Furthermore, the combined technique revealed that direct GC analysis underestimated the trans-content of margarines by at least 30%. In this study, C₂₀ and C₂₂ trans-monoenes were found in relatively large quantities; 13.9% (range 10.3–19.6%) and 7.5% (range 5.3–11.5%), respectively, in margarine purchased in 1995, but these C₂₀ and C₂₂ trans-monoenes were much reduced (0.1%) in a fresh selection of margarine purchased in 1998. Compositional data from labels underestimated the trans-content of margarines, especially those dervied from hydrogenated marine oil. Low levels of C₂₀ trans-monoenes (range 0.1–0.3%) and C₂₂ trans-monoenes (range 0.0–0.1%) were identified in adipose tissue obtained from healthy volunteers in 1995, presumably indicating consumption of partially hydrogenated fish oil.     

The effect of dietary partially hydrogenated marine oils on desaturation of fatty acids in rat liver microsomes

The influence of dietary partially hydrogenated marine oils on distribution of phospholipid fatty acids in rat liver microsomes was studied with particular reference to the metabolism of linoleic acid. Five groups of weanling rats were fed diets containing 20% (w/w) peanut oil (PO), partially hydrogenated peanut oil (HPO), partially hydrogenated Norwegian capelin oil (HCO), partially hydrogenated herring oil (HHO), and rapeseed oil (RSO) for 10 weeks. The partially hydrogenated oils were supplemented with linoleic acid corresponding to 4.6 cal % in the diets. Accumulation of linoleic acid and reduced amount of total linoleic acid metabolites were observed in liver microsomal phospholipids from rats fed partially hydrogenated oils as compared to PO feeding. The most striking effects on the distribution of ω6-polyunsaturated fatty acids was obtained after feeding HHO, a marine oil with a moderate content oftrans fatty acids in comparison with HPO but rich in isomers of eicosenoic and docosenoic acids. Liver microsomal Δ⁶-as well as Δ⁶-desaturase activities as measured in vitro were reduced in rats kept on HHO as compared to PO dietary treatment. The results obtained suggest that the dietary influence of partially hydrogenated marine oils on the metabolism of linoleic acid might be better related to the intake of isomeric eicosenoic and docosenoic acids than to the total intake oftrans fatty acids.     

High oleic oils by selective hydrogenation of soybean oil

High oleic (monoene) oils were obtained from soybean oil by selective hydrogenation with copper catalysts. A mixture of nickel and copper chromite catalyst had activity suitable for producing the high monoene oils. A new catalyst (copper-on-Cab-O-Sil) prepared in the Laboratory was more active than commercial copper catalysts. Hydrogenated oils contained 61–72% monoenoic and 14–24% dienoic acids, and there was essentially no increase in stearic acid. Thetrans-isomer content of these oils varied between 17% to 32%. Double bonds in the monoene were distributed along the molecule from C₆ to C₁₅, but were located preferentially in the C₉ position for thecis-monoene and in the C₁₀ and C₁₁ positions for thetrans-monoene. When the iodine value of these high monoene oils was about 90–95, they remained liquid above 28 C. Citric acid treatment reduced the copper content of hydrogenated oils to a level that was comparable to that of the original soybean oil. Presented at the AOCS Meeting, Chicago, October 1967. Food and Agricultural Organization representative from Rumania. No. Utiliz. Res. Dev. Div., ARS, USDA.     

Cardiac lipids in rats and gerbils fed oils containing C22 fatty acids

Docosenoic acid from rapeseed oil or herring oil in the diet of the young rat promoted an accumulation of cardiac lipid. The triglyceride fraction accounted for most of the deposited fat and contained a high concentration of the docosenoic acid. Liquid rapeseed oil, partially hydrogenated rapeseed oil or partially hydrogenated herring oil increased the amount of cardiac fatty acids at 1 week and led to the development of degenerative lesions at 16 weeks. Whale or seal oils low in C₂₂ fatty acids produced little effect on the amount of lipids in the heart of rats or gerbils. The latter species receiving 20% rapeseed oil in the diet showed a peak in cardiac lipid deposition at 4 days with similar levels of total fatty acids to that of rats, but with a lower concentration of erucic acid. Oil fromLimnanthes douglasii and hydrogenated herring oil also increased the amount of cardiac fatty acids in gerbils. A high intake of docosenoic acid was common to the animals displaying the cardiac alterations. Presented at the AOCS Meeting, Atlantic City, October 1971.     

Analysis of C18:1 cis and trans fatty acid isomers by the combination of gas-liquid chromatography of 4,4-dimethyloxazoline derivatives and methyl esters

Trans fatty acids in foods are usually analyzed by gas-liquid chromatography (GLC) of fatty acid methyl esters (FAME). However, this method may produce erroneously low values because of insufficient separation between cis and trans isomers. Separation can be optimized by preceding silver-ion thin-layer chromatography (Ag-TLC), but this is laborious. We have developed an efficient method for the separation of 18-carbon trans fatty acid isomers by combining GLC of FAME with GLC of fatty acid 4,4-dimethyloxazoline (DMOX) derivatives. We validated this method against conventional GLC of FAME, with and without preceding Ag-TLC. Fatty acid isomers were identified by comparison with standards, based on retention times and mass spectrometry. Analysis of DMOX derivatives allowed the 13t, 14t, and 15t isomers to be separated from the cis isomers. The combination of the GLC analyses of FAME and DMOX derivatives gave results comparable with those obtained by GLC of FAME after preceding Ag-TLC, while saving about 100 h of manpower per 25 samples. It allowed the identification and quantitation of 11 trans and 8 cis isomers and resulted in 25% higher values for total C_18:1 trans, compared with the analysis of FAME alone. The combination of DMOX and FAME analyses, as applied to the analysis of 14 foods that contained ruminant fat and partially hydrogenated vegetable and fish oils, indicated that the most common isomers were 11t in ruminant fats, 9t in partially hydrogenated fish fats, and either 9t or 10t in partially hydrogenated vegetable fats. The combination of GLC analyses of FAME and DMOX derivatives of fatty acids improves the quantitation of 18-carbon fatty acid isomers and may replace the laborious and time-consuming Ag-TLC.     

Hydrogenation of a menhaden oil: I. Fatty acid and C20 monoethylenic isomer compositions as a function of the degree of hydrogenation

US menhaden oil is rich in long-chain polyethylenic fatty acids, chiefly C₂₀ (eicosapentaenoic) and C₂₂ (docosahexaenoic) fatty acids, unlike Canadian herring oil, which is rich in long-chain (C₂₀ and C₂₂) monoethylenic fatty acids. An examination of the product fatty acids from hydrogenation of menhaden oil therefore comple-ments studies previously published for herring oil. During a commer-cial hydrogenation of menhaden oil, iodine value (IV) 159.0, on nickel catalyst, samples were collected at IV 150.0, 140.0, 131.5, 120.5, 96.5, 90.0 and 84.5. The fatty acid compositions were deter-mined using a combination of mercuric adduct fractionation and gas liquid chromatographic (GLC) analyses, and the totaltrans content by infrared spectroscopy. The partial hydrogenation resulted in the disappearance of the pentaenoic and hexaenoic fatty acids, a de-crease in tetraenes, and a definite increase in trienes, 8.3% at IV 84.5 compared to 4.2% at IV 159.0. The dienoic fatty acids in-creased to 13.2% at IV 84.5 compared to 4.1% at IV 159.0, and the monoenoic fatty acids increased to 34.2% from 24.0%. No impor-tant changes in the saturated acids were observed, 43.8% at IV 84.5 compared to 41.6% at IV 159.0. The totaltrans content varied from 3.4% at IV 150.0 to 45.1% at an IV of 84.5. The isomer composi-tions of thecis andtrans C₂₀ monoethylenic fatty acids were deter-mined using a combination of preparative GLC, AgNO₃ thin layer chromatography and ozonolysis. Thecis 20:1 acids at IV 84.5 still retained 27.5% of the major isomer (All) originally present at 72%. The parent A5, A8, All, A14 and A17 bonds of the 20:5 originally present could be detected in thecis 20:1 isomers at IV 96.5 but not at IV 84.5. At IV 84.5, 58% of the 20:1was trans, the major isomer being All (9.4% of total 20.1), accompanied by important quanti-ties of Δ10 and Δ12, respectively, 6.9% and 6.6% of the total 20:1. Presented in part at the 73rd annual AOCS meeting, Toronto, 1982.     

Heart mitochondrial metabolism after feeding herring oil to rats and monkeys

Heart mitochondrial oxidation of palmityl CoA and pyruvic acid was studied in rats and in the monkeyMacaca fascicularis to determine the effects of feeding partially hydrogenated herring oil. Herring oil glycerides contain cetoleic acid (cis-11-docosenoic) which could have a similar effect to erucic acid (cis-13-docosenoic) in causing a rat cardiomyopathy. The initial rat heart mitochondrial response to dietary cetoleic acid (67%cis, 33%trans) was an in vitro decrease in palmityl CoA oxidation. Prolonged feeding of cetoleic acid mixture was associated with a significant metabolic adaptation, increasing pyruvate and palmityl CoA oxidation above control levels. In vitro addition of cetoleyl CoA (purecis isomer) stimulated pyruvate dehydrogenase activity, a possible response to decreased β-oxidation. There was no significant adaptive change in pyruvate or palmityl CoA use in monkeys after prolonged feeding of partially hydrogenated herring oil. Cetoleyl CoA was a good substrate for monkey heart carnitine acyl transferase even in the presence of palmityl CoA. These observations suggest that C₂₂ fatty acids may be matabolized more rapidly in monkey heart than in rat heart. Metabolic differences argue against using the rat as an experimental model for studying possible cardiotoxic effects of docosenoic acids in primates.     

Biohydrogenation intermediates are differentially deposited between polar and neutral intramuscular lipids of lambs

The deposition of C₁₈ fatty acids (FA), especially in rumen biohydrogenation intermediates, was studied using 36 lambs fed four diets with graded proportions of sunflower oil (SO) and linseed oil (LO). Lambs were fed one of four diets consisting on dehydrated lucerne with either: 6% SO, 4% SO plus 2% LO, 2% SO plus 4% LO and 6% LO. The profile of C₁₈ FA was greatly affected by replacement of SO with LO in both lipid fractions. In PL, oil replacement led to an extensive substitution of 18:2n‐6 with 18:3n‐3 and cis‐9 18:1, resulting in a fairly constant degree of unsaturation of C₁₈ FA in membrane PL. C₁₈ FA were differentially incorporated in NL and PL. Cis‐isomers like cis‐11; cis‐12; cis‐15 18:1 and cis‐12, cis‐15 18:2 were preferentially incorporated in PL with the exception of cis‐9, cis‐15 18:2. Trans C₁₈ FA, including CLA isomers, were preferentially incorporated in NL with the exception of cis‐11, trans‐13 18:2. The preferential deposition of biohydrogenation derived trans C₁₈ FA, including CLA isomers in NL, suggests that their potential to change membrane FA composition and structure is low.     

Heat treatment of vegetable oils III. GC-MS characterization of cyclic fatty acid monomers in heated sunflower and linseed oils after total hydrogenation

Fractions of cyclic fatty acid monomers (CFAM) were isolated from linseed oil heated at 275°C for 12 hr under nitrogen, at 240°C for 10 hr under nitrogen and at 240°C for 10 hr under air. Cyclic fatty acid monomers fractions were also isolated from a sunflower oil heated at 275°C for 12 hr under nitrogen and at 200°C for 48 hr in a commercial fryer. The CFAM fractions were hydrogenated and their composition studied by gas liquid chromatography coupled with mass spectrometry (GC-MS). The CFAM in the fraction isolated from heated linseed oil samples were a mixture (1:1) ofcis andtrans cyclopentyl and cyclohexyl isomers, while the CFAM in the fractions isolated from heated sunflower oils were mostly cyclopentyl isomers. The major cyclopentyl isomers weretrans andcis methyl 7-(2′-hexylcyclopentyl) -heptanoate, methyl 9-(2′-butyl-cyclopentyl)-nonanoate and methyl 10-(2′-propylcyclo-pentyl)-decanoate. The major cyclohexyl isomers were thetrans andcis methyl 9-(2′-propylcyclohexyl)-nonanoate which represented about 50% of the CFAM isomers isolated from heated linseed oil samples. For part II in this series see Ref. 1.     

Conversion of polyunsaturates in vegetable oils tocis-monounsaturates by homogeneous hydrogenation catalyzed with chromium carbonyls

Chromium carbonyl complex catalysts were used to selectively hydrogenate polyunsaturates in vegetable oils into products retaining 90% to 95%cis configuration and their liquid properties. The product from soybean oil contained 42–69% monoene, 10–40% diene and 0–4% triene. The product from safflower oil contained 73–82% monoene and 8–17% diene. About 45–55% of the double bonds in monoenes from hydrogenated soybean oil remained in the C₉ position, and the rest was distributed between C₁₀, C₁₁, and C₁₂. Preliminary oxidative and flavor stability evaluations showed that these hydrogenated soybean oils compared favorably with a commercial sample of hydrogenated-winterized soybean oil. Liquid fatty acids prepared by saponification of hydrogenated soybean and safflower oils (IV 90–100) had analyses about the same as those of commercial oleic acid. Presented before the Division of Agricultural and Food Chemistry, 156th American Chemical Society National Meeting, Atlantic City, N.J., September 1968.     

Heat treatment of vegetable oils. II. GC-MS and GC-FTIR spectra of some isolated cyclic fatty acid monomers

Gas liquid chromatography coupled with mass spectrometry (GC-MS) showed that the cyclic fatty acid monomers (CFAM) isolated from a heated linseed oil have two ethylenic bonds, while the CFAM isolated from heated sunflower oils were saturated and monoethylenic isomers. GC-MS studies also showed the presence of cyclohexenic derivatives in the case of linseed oil. GLC coupled with Fourier transform infrared spectrometry (GC-FTIR) studies indicated that the CFAM isolated from linseed oil were ofcis (Z),trans (E) structures except two components which werecis,cis (Z,Z) dienoic acids. The unsaturated CFAM isolated from sunflower oils werecis (Z) andtrans (E) monoethylenic isomers. For sunflower oils, the major CFAM were isomers having acis (Z) ethylenic bond. The saturated CFAM isolated from a heated sunflower oil had molecular weights of 296 and 294. The latter could correspond to some bicyclic isomers.     

Positional and geometrical isomers of linoleic acid in partially hydrogenated oils

The geometrical and positional isomers of linoleic acid of a partially hydrogenated canola oil-based spread were isolated and identified. Through partial hydrazine reduction and mass spectral studies,cis-9,trans-13 octadecadienoic acid was identified as the major isomer. Other quantitatively important isomers characterized werecis-9,trans-12;trans-9,cis-12 andcis-9,cis-15. These four were also the major isomers in margarine based on common vegetable oils. A number of minor isomers were detected and some structures identified weretrans-9,trans-12;trans-8,cis-12;trans-8,cis-13;cis-8,cis-13;trans-9,cis-15;trans-10,cis-15 andcis-9,cis-13. The proportions of the various isomers are given for some margarines in the Canadian retail market. The amounts oftrans-9,trans-12 isomer in Canadian margarines were generally below 0.5% of the total fatty acids.     

Occurrence of 5c,8c,11c,15t-eicosatetraenoic acid and other unusual polyunsaturated fatty acids in rats fed partially hydrogenated calola oil

Uncommoncis andtrans fatty acids can be desaturated and elongated to produce unusual C₁₈ and C₂₀ polyunsaturated fatty acids in animal tissues. In the present study we examined the formation of such metabolites derived fromcis andtrans isomers of oleic and linoleic acids of partially hydrogenated vegetable oil origin in rats. For two months, aduut male rats were fed a partially hydrogenated canola oil diet containing moderately high levels oftrans fatty acids (9.6 energy%) and an adequate level of linoleic acid (1.46 energy%). Analysis of the phospholipid (PL) fatty acids of liver, heart, serum and brain showed no new C₁₈ polyunsaturated fatty acids, except for those uncommon 18∶2 isomers originating from the diet. However, minor levels (each <0.3% PL fatty acids) of six unusual C₂₀ polyunsaturated fatty acids were detected in the tissues examined, except in brain PL. Identification of their structures indicated that the dietary 9c,13t−18∶2 isomer, which is the majortrans polyunsaturated fatty acid in partially hydrogenated vegetable oils, was desaturated and elongated to 5c,8c,11c,15t−20∶4, possibly by the same pathway that is operative for linoleic acid. Furthermore, dietary 12c−18∶1 was converted to 8c,14c−20∶2 and 5c,8c,14c−20∶3; dietary 9c,12t−18∶2 metabolized to 11c,14t−20∶2 and 5c,8c,11c14t−20∶4, and dietary 9t,12c to 11t,14c−20∶2. These results suggested that of all the possible isomers of oleic and linoleic acids in partially hydrogenated vegetable oils, 12c−18∶1, 9c,13t−18∶2, 9c,12t−18∶2 and 9t,12c−18∶2 are the preferred substrates for desaturation and elongation in rats. However, their conversions to C₂₀ metabolites were not as efficient as that of oleic or linoleic acids.     

Influence of dietary partially hydrogenated vegetable and marine oils on membrane composition and function of liver microsomes and platelets in the rat

The aim of the present study was to investigate the influence of partially hydrogenated vegetable and marine oils on membrane composition and function of liver microsomes and platelets with particular reference to the metabolism of linoleic acid and the production of arachidonic acid metabolites. Four groups of male weanling rats were fed linoleic acid supplemented diets containing 20% (w/w) of partially hydrogenated low erucic acid rapeseed oil (HLRSO), partially hydrogenated herring oil (HHO), olive oil (OO) and trierucin + triolein (TE) for 10 weeks. An additional two groups were fed partially hydrogenated low erucic acid rapeseed oil and partially hydrogenated herring oil without linoleic acid supplementation (HLRSO- and HHO-, respectively). Substantial amounts oftrans fatty acids were incorporated into liver microsomes (12.6% in group HLRSO) and platelets (7.0% in group HLRSO-). This incorporation was not dependent on the dietary linoleic acid level. Hepatic microsomal Δ⁵-desaturase activity was significantly increased after HLRSO feeding compared to OO feeding. Δ⁶-Desaturase activity did not vary in the linoleic acid supplemented groups. Both Δ⁵- and Δ⁶-desaturase activities were significantly increased in groups without linoleic acid supplementation. Docosenoic acid was incorporated into platelet phospholipids in contrast to liver microsomes. In the platelet, docosenoic acid seemed to have a special preference for phosphatidylserine. Very small amounts were incorporated into platelet phosphatidylinositol. Feeding diets HLRSO, HHO and OO did not influence rat platelet cyclooxygenase or 12-lipoxygenase activity. Platelets from rats fed TE, however, produced significantly less 12-hydroxy-5,8,10,14-eicosatetraenoic acid (12-HETE) than platelets from rats fed OO. Feeding of HLRSO- and HHO- resulted in a significantly diminished production of the arachidonic acid metabolites 12-HETE, 12-hydroxy-5,8,10-heptadecatrienoic acid (HHT) and 6-keto-prostaglandin F_1α in stimulated platelets and aorta. Thus, high dietary levels oftrans isomers of monoenoic acids do not interfere with platelet cyclooxygenase or lipoxygenase activity provided sufficient amounts of linoleic acid are available.     

Directed sequential synthesis of conjugated linoleic acid isomers from Δ7, 9 to Δ12, 14

Position and configuration isomers of conjugated linoleic acid (CLA), from 7, 9‐ through 12, 14‐C18:2, were synthesized by directed sequential isomerizations of a mixture of rumenic (cis‐9, trans‐11 C18:2) and trans‐10, cis‐12 C18:2 acids. Indeed, the synthesized conjugated fatty acids cover the range of unsaturated systems as found in milk fat CLA. The two‐step sequence consisted in initial sigmatropic rearrangement of cis/trans CLA isomers at 200 °C for 13 h under inert atmosphere (Helium, He), followed by selenium‐catalyzed geometrical isomerization of double bonds at 120 °C for 20 h under He. Product analysis was achieved by gas‐liquid chromatography using a 120 m polar capillary column coated with 70% cyanoalkylpolysiloxane equivalent polymer. Migration of conjugated systems was geometrically controlled as follows: the cis‐C_n, trans‐C_n+2 double bond system was rearranged through a pericyclic [1, 5] sigmatropic mechanism into a trans‐C_n‐1, cis‐C_n+1 unsaturated system, while the trans‐C_n, cis‐C_n+2 double bond system was rearranged through a similar pericyclic mechanism into a cis‐C_n+1, trans‐C_n+3 unsaturated system. Selenium‐catalyzed geometrical isomerization under mild conditions then allowed cis/trans double bond configuration transitions, resulting in the formation of all cis, all trans, cis‐trans and trans‐cis isomers. A sequential combination of the two reactions resulted in a facile controlled synthesis of CLA isomers, useful for the chromatographic identification of milk fat CLA, as well as for the preparation of CLA standard mixture.     

Oil from deep water fish species as a substitute for sperm whale and jojoba oils

The lipid fraction of the deep water fish species orange roughy (Hoplostetbus atlanticus), black oreo (Allocyttus sp.) and small spined oreo (Pseudocyttus maculatus) had wax esters with even carbon numbers over the range C₃₀ to C₄₆ as the major components. The component acids and alcohols of the wax ester fraction were analyzed by gas liquid chromatography and compared with those of jojoba and sperm whale oils. Orange roughy oil was refined and deodorized and its chemical, physical and mechanical properties were determined. Hydrogenation of orange roughy oil produced a range of white crystalline waxes with melting points between 34 and 66 C. The characteristics of these waxes were very similar to those of hydrogenated jojoba oil and spermaceti. Lubricant tests performed on sulfurized orange roughy oil indicated it is comparable to sulfurized jojoba and sperm whale oils as an extreme-pressure additive in lubricants. The results show a sound technical basis on which to consider an industry based on orange roughy oil and the oreo oils as replacements for sperm whale oil and as substitutes for jojoba oil. Applications for the oil could be in the cosmetic and high-grade lubricant fields, the waxes in the polish, textile, cosmetic and pharmaceutical industries and the sulfurized derivative of orange roughy oil in the lubricant industry.