Component fatty acids of marine fish liver oils

Summary 1. Two liver oils (Elasmobranch) fromCarcharias melanopterus andPristis cuspidatus, caught off the Madras coast are studied, and their component fatty acids are reported. 2. The mixed acids were separated into three groups (varying unsaturation) of acids, and their methylesters were fractionated. 3. The liver oils are found to belong to the fourth group of Tsujimoto’s classification of Elasmobranch fish liver oils.Carcharias melanopterus liver oil contains 31.1% unsaturated acids (myristic 3.1, palmitic 18.4, stearic 9.5, and 0.1% arachidic) and 68.9% unsaturated acids (C₁₆ 10.8, C₁₈ 19.7, C₂₀ 15.2, C₂₂ 17.1, C₂₄ 5.3%, and traces of C₁₄ monoethenoid).Pristis cuspidatus liver oil contains 36.9% saturated acids (myristic 1.2, palmitic 22.9, stearic 12.7, and arachidic 0.1%) and 67.1% unsaturated acids (C₁₆ 8.2, C₁₈ 28.5, C₂₀ 16.4, C₂₂ 5.2, C₂₄ 4.6%, and traces of C₁₄ monoethenoid). The unsaturations of the different groups of acids are almost of the same order. 4. The abnormal content of saturated acids can be explained by the process of bio-hydrogenation. The relatively less amount of saturated acids inCarcharias melanopterus liver oil along with its higher content of polyethylenic acids (C₂₀ and above) points strongly to the possible presence of intermediate types of fats among the four groups of Elasmobranch oils.     

Marine-derived fatty acids of fish oils as raw materials for fatty acids manufacture

Fish oils, often an abundant source of C₂₀ and C₂₂ fatty acids, could supplement rapessed oil in the manufacture of long chain saturated fatty acids. Herring oil, traditionally the fish oil of choice, is in very short supply due to depletion of fishery stocks. Menhaden oil, when made from fish caught in the Atlantic, could furnish a steady supply with long chain acids at about the 30% level. Oil made from other species such as anchovy or pilchard need further data on fatty acid content and variability. Manufacture of polyunsaturated fatty acids from fish oils is hampered by lack of suitable procedures. Potential markets for fish oil polyunsaturates especially in the pharmaceutical field seem promising.     

Kamlolenic acid and other conjugated fatty acids in certain seed oils

The major fatty acid of the seed oil ofTrewia nudiflora is shown to be α-kamlolenic acid, not α-eleostearic acid as believed earlier. Other conjugated acids were found and identified in seed oils not previously studied, viz., α-eleostearic acid inParinari insularum andRicinodendron rautanenii; trans,8-trans,10-cis,12-octadecatrienoic acid inCalendula stellata. The identity of the conjugated acids in four other seed oils was established, viz., α-eleostearic acid inPrunus yedoensis andValeriana officinalis; punicic acid inCucurbita digitata andC. palmata. Issued as N.R.C. No. 9063.     

Identity and configuration of conjugated fatty acids in certain seed oils

Punicic acid was found in the seed oils ofCayaponia grandifolia, Trichosanthes cordata andT. cucumerina. α-Eleostearic acid was found inMomordica cochinchinensis, M. cochinchinesis varietymixta andM. cymbalaria. The identity of the conjugated triene acid ofAleurites trisperma, Garcia nutans andCyclandrophora laurina was confirmed as α-eleostearic acid (cis, trans, trans configuration). The configuration of kamlolenic acid was proved to becis-9,trans-11,trans-13. The oils ofAleurites remyi andLicania platypus did not contain any conjugated acid. Issued as N.R.C. No. 10589.     

Cyclopropenoid fatty acids in leguminosae oils

Seed oils ofCassia grandis, Linn andDelonix elata, Gamble, Syn.Poinciana elata, Linn, belonging to the Leguminosae family contain small amounts of sterculic and malvalic acids as determined by conversion of esters with AgNO₃/MeOH, NMR and IR.     

由直链不饱和脂肪酸异构制备支链脂肪酸的研究进展

介绍了直链不饱和脂肪酸制备支链脂肪酸的研究现状,综述了脂肪酸异构机理,异构催化剂如白土催化剂、沸石催化剂,催化剂的筛选原则,着重讨论了各种常用沸石对于脂肪酸异构反应不同的影响以及现有的合成工艺。分析了脂肪酸的分离技术,包括精馏分离法、溶剂结晶法、尿素包结法、超临界流体萃取法的优缺点,指出沸石催化生产支链饱和脂肪酸的关键问题是需要解决混合脂肪酸作为原料反应的选择性问题,其相关的基础性工作,如更明确的反应机理和催化剂结构参数对反应的影响,仍是将来的研究方向。     

Production of branched-chain fatty acids from sterculia oil

Methyl sterculate was rearranged by use of 0.5% of rhodium catalyst to isomeric conjugated diene fatty acid methyl esters containing both methylene-and methyl-branched isomers. The rearanged products were hydrogenated directly to saturated, methyl-substituted, branched-chain fatty acid methyl esters with the methyl substituent at one of the positions formerly occupied by the cyclopropenoid ring. The crude branched-chain fatty acids from these esters were purified by recrystallization from a mixed solvent of ethanol and water (80:20, v/v) and flash distillation; the product contained about 90% of branched-chain fatty acids (C₁₉:80%, C₁₈:10%). Esters of the branched-chain fatty acid were prepared with 2-ethylhexyl alcohol or trimethylolpropane, and the characteristic properties of these esters were investigated. The branched-chain fatty esters appear to have potential utility in lubricants; other uses may be possible. Presented at the AOCS meeting in New Orleans, May 1981.     

Resistance of certain long-chain polyunsaturated fatty acids of marine oils to pancreatic lipase hydrolysis

When whale oil triglycerides were subjected to pancreatic lipase hydrolysis, eicosapentaenoic and docosahexaenoic acids were found mainly in the di- and triglyceride products, suggesting that they are in the 1,3-positions but resistant to the action of the lipase. Their presence in the 1,3-positions was confirmed. Their resistance to pancreatic lipase hydrolysis was demonstrated by analysis of the products of the enzyme action on: (a) a concentrate of highly unsaturated whale oil triglycerides; (b) the latter after randomization; and (c) synthetic 1,2-di-octadecenoyl-3-eicosapentaenoyl glycerol. Docosapentaenoic acid was also shown to be present in the 1,3-position of whale oil triglycerides but was not lipase resistant. It is postulated that the presence of a double bond near the carboxyl group exercises an inhibitory effect, or that the location of the double bonds in the resistant acids places their terminal methyl groups close to the carboxyl, producing a steric hindrance effect.     

New process for the production of branched-chain fatty acids

Fatty acids are the primary natural starting materials for the production of surfactant and detergent molecules. Derived from vegetable (oil) and animal (fat) triglyceride sources, the fatty acids are linear aliphatic carboxylic acids. Industrial interest in branched-chain fatty acids is driven by the needs for products with enhanced performance benefits including higher solubility, ease of handling, better hard water tolerance, and improved oxidative stability. Therefore, catalytic processes have been developed for the conversion of linear fatty acids to branched ones. High yields of branched acids are obtained from unsaturated fatty acids over acidic zeolites, particularly those with large pores. Fatty esters also are readily isomerized to branched ones by means of the same catalyst and process. It is postulated that the isomerization of fatty acids proceeds through three- and four-membered ring carbocation intermediates formed inside the largepore zeolites. This is supported by evidence of methyl and ethyl branching in the primary and final products. The total number of carbon atoms in the fatty acid molecule is unchanged. Surfactants derived from branched fatty acids show favorable physical properties, including a lower viscosity and improved handling, even as intended performance characteristics are maintained.     

Bactericidal activity of certain fatty acids

Fatty acids in the C₉ to C₁₂ range are bactericidal to a number of different organisms, and this activity is markedly enhanced with increasing acidity. Optimum bactericidal activity toStaphylococcus aureus was exhibited by undecylic acid. Since the activity is of the same order as that of the quaternary ammonium germicides in alkaline solution, an explanation for both types of germicidal activity is presented in which the bacteria or some protein essential to the bacteria are considered to be “suffocated” by a “coating” of fatty groups in chemical combination with the protein. The application of these findings to bactericidal activity encountered in rancid fats is discussed briefly in connection with the oxidative degradation of oleic acid derivatives to pelargonic acid. In addition, the possible usefulness of the bactericidal activity as a microbiological assay method for certain fatty acids is pointed out.     

1H NMR spectroscopy as tool to follow changes in the fatty acids of fish oils

High‐resolution NMR spectroscopy is a fast and accurate tool to measure the content of n‐3 PUFA in unoxidised oils. Four types of fish oils with a high amount of n‐3 PUFA were oxidised under different conditions, and the changes in their fatty acid pattern were monitored with NMR spectroscopy and compared with traditional analytical methods, especially GC. Good compliances were obtained for unoxidised oils and for oils at the early oxidation stages. Distinct changes in signals or signal ratio intensities arose only in higher‐oxidised oils that were irradiated or heated in the presence of oxygen over several days. Slight differences between values obtained by GC and NMR at this point were likely caused by accumulation of oxidation products. Detection of the terminal lipid oxidation products propanal and 2‐propenal was only possible at late oxidation stages.     

Cardiac fatty acids in rats fed marine oils

Cardiac fatty acids were studied in young rats fed marine oils for 1 week. When the diet contained 0, 0.5, 1, 2, 4, 8 or 16% by weight of partially hydrogenated oil from Norwegian capelin, the concentration of fatty acids in the cardiac tissue was elevated only at the highest level. The amount of the lipid and the content of docosenoic acid in the heart were less than those observed with 15% partially hydrogenated oil from Canadian herring. Nonhydrogenated Peruvian anchovy oil lacking docosenoic acid produced no change in the amount of fat deposited. The extent of fatty acid accumulation in the heart was related to the dietary C₂₂ acids.     

The fungicidal activity of the unsaturated fatty acids and quaternary salts prepared from fish oils

Summary Saturated and unsaturated fatty acids and 10 unsaturated fatty acid fractions and ethyl esters of unsaturated fatty acid fractions prepared from fish oils were tested on their inhibitory activity againstCandida albicans. Oxidation of highly unsaturated fractions from fish oil and ethyl esters of unsaturated fatty acid fractions of menhaden, pilchard, and cod liver oils increases their antifungal activity. Saturated and unsaturated quaternaries were tested for their antifungal activity. Hexadecyltriethylammonium bromide and hexadecylpyridinium bromide showed the highest activity againstCandida albicans, Aspergillus niger, andRhyzopus nigricans. Any lengthening of the carbon chain more than C₁₆ weakened the activity of both saturated triethylammonium bromide and pyridinium bromide. An increase of unsaturation enhanced it. The antifungal activity of quaternaries prepared from fish oils was about 4,000 times stronger than that of oxidized highly unsaturated fatty acid fractions prepared from fish oils. The decisive factor in the highly inhibitory activity of quaternaries against fungi might depend on their positively charged portion since the surface of microorganisms is, as a rule, negatively charged. Aided by a grant from the Collett-Week Company, Ossining, N. Y.     

Densities of vegetable oils and fatty acids

Complete data for density as a function of temperature have been measured for a number of vegetable oils (crambe, rapeseed, corn, soybean, milkweed, coconut, lesquerella), as well as eight fatty acids in the range C₉ to C₂₂ at temperatures from above their melting points to 110°C (230°F). The specific gravity and density measurements were performed according to American Society for Testing and Materials (ASTM) standard test methods D 368, D 891 and D 1298 for hydrometers and a modified ASTM D 369 and D 891 for pycnometers. Correlation constants, based on the experimental data, are presented for calculating the density of fatty acids and vegetable oils in the range of temperature from 24°C (75°F) or the melting point of the substance, to 110°C (230°F). The constants are valuable for designing or evaluating such chemical process equipment as heat exchangers, reactors, process piping and storage tanks. Estimated density of fatty acids by a modified Rackett equation is also presented.     

Viscosities of vegetable oils and fatty acids

Data for viscosity as a function of temperature from 24 to 110°C (75 to 230°F) have been measured for a number of vegetable oils (crambe, rapeseed, corn, soybean, milk-weed, coconut, lesquerella) and eight fatty acids in the range from C₉ to C₂₂. The viscosity measurements were performed according to ASTM test methods D 445 and D 446. Several correlations were fitted to the experimental data. Correlation constants for the best fit are presented. The range of temperature in which the correlations are valid is from 24°C (75°F), or the melting point of the substance, to 110°C (230°F). The correlation constants are valuable for designing or evaluating such chemical process equipment as heat exchangers, reactors, distillation columns, mixing vessels and process piping.     

The effect of feeding fish oils,vegetable oils and clofibrate on the ketogenesis from long chain fatty acids in hepatocytes

Groups of rats were fed diets containing 25% fish oil (FO), 25% soybean oil, 25% partially hydrogenated fish oil (PHFO), 25% partially hydrogenated soybean oil (PHSO), 25% partially hydrogenated coconut oil or 0.3% clofibrate for 3 wk. After the animals were fasted for 24 hr, hepatocytes were isolated and ketogenesis from added palmitate, linoleatecis andtrans, arachidonate and docosahexaenoate was measured. Ketogenesis after oil feeding was significantly stimulated (two-to threefold) only in cells from the PHFO-and PHSO-fed rats. The stimulation was most apparent with the long chain unsaturated fatty acids as substrates. These fatty acids were relatively poor ketone body precursors in control hepatocytes. Essential fatty acid deficiency did not seem to be the reason for this stimulation. Clofibrate also stimulated ketogenesis significantly (1.5- to 3-fold). The degree of stimulation increased with chain length and degree of unsaturation of the substrate. The activity of the enzyme 2,4-dienoyl-CoA reductase was also studied in the same groups. Its activity was stimulated about fourfold in the clofibrate-treated rats and to a lesser extent by the PHFO, PHSO and FO diets. The activity showed no correlation with the content of unsaturated fatty acids in the diet or their oxidation in isolated hepatocytes. The 2,4-dienoyl-CoA reductase, therefore, does not seem to be a regulatory enzyme in the metabolism of dietary polyunsaturated fatty acids. It is concluded that an induction of the peroxisomal β-oxidation system most likely is involved in the reported increases in ketogenesis from very long chain polyunsaturated fatty acids.     

Some minor fatty acids of rapeseed oils

A number of minor unsaturated fatty acids of rapeseed oil (fromBrassica napus orcampestris) have been isolated by combinations of distillation preparatve gas liquid chromatography and silver nitrate thin layer chromatography, and were further identified by oxidative fission in BF₃-MeOH. Among the shorter chain, all-cis polyunsaturated fatty acids described are 16:3ω3, 16:2ω6 and 14:2ω6. A ubiquitous minor component inunproceessed oils was found to becis-9, cis-12, trans-15-octadecatrienoic acid, with lesser proportions of thetrans-9, cis-12, cis-15 isomer. Among others identified werecis-14:1ω9 and 15:1ω10, the latter accompanied by half as muchtrans-15:1ω10. Particular attention was paid to the proportions of the minor monoethylenic fatty acids of the ω7 series relative to the longer chain major ω9 monoethylenic fatty acids which have been reduced by plant breeding.     

Component fatty acids of some cruciferae oils

Summary The oils from yellow mustard seed (Brassica alba), black mustard seed (Brassica nigra) of Indian origin, and rapeseed (Brassica Compestris) of unknown origin have been analyzed for their fatty acid composition without preliminary resolution of fatty acids by lead-salt-alcohol or fractional crystallization methods. The results compare very favorably with those determined by other recently developed methods. It may be concluded therefore that this method can be favorably employed for the determination of fatty acid composition of fats containing higher unsaturated acids. Confirmatory evidence has been obtained for the presence of eicosenoic acid in rapeseed oil. The nature and amount of fatty acids of yellow mustard seed oil of Indian origin do not differ in any significant manner from those of other cruciferous seed oils. The present analysis of black mustard seed oil reveals a higher amount of linolenic acid, and the presence of a C₂₀ monoethenoid acid, not heretofore reported. Contribution No. 708 from the Department of Chemistry, University of Pittsburgh. Presented in part at the Spring meeting of the American Oil Chemists’ Society, held in New Orleans, La., May, 1948. Baliga and Hilditch’s paper. “The Component Acids of Rapeseed Oil” (J. Soc. Chem. Ind.67, 258–262 (1948).     

Accumulation of cardiac fatty acids in rats fed synthesized oils containing C22 fatty acids

Synthesized oils containing a high proportion of oleic, eicosenoic or docosenoic acid were fed to weanling rats as 20% w/w of the diet. After 1 week, a high intake of eicosenoate produced cardiac fat droplets detected histologically, whereas erucate (22∶1 Δ 13) or cetoleate (22∶1 Δ 11) caused an appreciably greater accumulation of cardiac lipid characterized by the dietary fatty acids.