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1.
Selective Synthesis of Dimer Fatty Acids Dimer fatty acids are aliphatic C36-dicarboxylic acids, and are important raw materials for the manufacture of polyamides, polyesters, heavy duty lubrication oils and plasticizers. They are made by condensation of two unsaturated fatty acids in the presence of a catalyst. Because of the complicated reaction mechanism a complex mixture is obtained. Therefore only insufficient information in regard to the structure has been obtained. We report the synthesis of single isomers of linear and branched C36-dicarboxylic acids. Characteristic spectroscopic and GC-data of the structural types are reported. 相似文献
2.
The lipids of the common house cricket,Acheta domesticus L., have been examined with the following results. The fatty acids associated with the lipid extracts do not change significantly
from the third through the eleventh week of the crickets' postembryonic life. The major fatty acids are linoleic (30–40%),
oleic (23–27%), palmitic (24–30%), and stearic acids (7–11%). There are smaller amounts of palmitoleic (3–4%), myristic (∼1%),
and linolenic acids (<1%). The fatty acid composition of the cricket lipids reflects but is not identical to the fatty acids
of the dietary lipids: linoleic (53%), oleic (24%), palmitic (15%), stearic (3%), myristic (2%), and linolenic acid (2%).
The amount of triglycerides present in the crickets increases steadily from the second through the seventh or eighth week
of postembryonic life, then drops sharply. Other lipid classes, such as hydrocarbons, simple esters, diglycerides, monoglycerides,
sterols, and free fatty acids remain about constant. The composition of the fatty acids associated with the tri-, di-, and
monoglycerides and the free fatty acid fraction are all about the same. The fatty acids associated with the simple esters
are high in stearic acid.
Postdoctoral Research Associate, Department of Chemistry, University of Michigan, 1965–1967. 相似文献
3.
Melissa S. Mund Terry A. Isbell 《Journal of the American Oil Chemists' Society》1999,76(10):1189-1200
Chloroalkoxy substituted C20 and C22 fatty acids can be synthesized from the unsaturated fatty acids in meadow-foam oil by reaction of the fatty acids with primary
or secondary alcohols and an aqueous sodium hypochlorite solution (commercial bleach). The reactions are conducted at room
temperature for 3 h. Chlorohydroxy fatty acid derivatives are formed as by-products owing to the presence of water in the
reaction mixture. Chlorinated δ-lactones are also produced by direct reaction of sodium hypochlorite with the Δ5 unsaturated
fatty acids present in meadowfoam or by ring closure of the 6-chloro-5-hydroxy fatty acids. The product yield of chloroalkoxy
fatty acids is dependent on the nature and volume of the alcohol used in the reaction, as well as the concentration and pH
of the sodium hypochlorite solution. Primary alcohols such as methanol and butanol produce maximal yields (50–60%) of chloroalkoxy
fatty acids whereas the secondary alcohol 2-propanol gives a 30% yield. Chloroalkoxy fatty acid yields can be increased to
75–80% by elimination of water from the reaction mixture through a procedure that partitions sodium hypochlorite from water
into hexane/ethyl acetate mixtures. All of the reaction products were fully characterized using nuclear magnetic resonance
and gas chromatography-mass spectrometry. 相似文献
4.
Charles G. Goebel 《Journal of the American Oil Chemists' Society》1947,24(3):65-68
Summary A method is proposed for the preparation of polybasic fat acids or “dimer” acids directly from fatty acids which is readily
adaptable to commercial use. The presence of moisture maintained in the reaction vessel by steam pressure substantially prevents
decomposition and decarboxylation of the fatty acids. By this method a larger percentage of dibasic acids, as compared to
tribasic acids, is produced than by the previously described methods. The method of high temperature polymerization of fatty
acids in the presence of moisture is also used to remove polyunsaturated fatty acids from commercial oleic acid.
Presented at 20th fall meeting, American Oil Chemists’ Society, Chicago, Ill., Oct. 30–Nov. 1, 1946. 相似文献
5.
Bakery shortenings prepared by hydrogenation contain high levels of trans fatty acids, which are considered to be risk factors for cardiovascular disease. The shortenings prepared from maogo kernel
and mahua fats have no trans fatty acids. Mahua fat was fractionated by dry fractionation to obtain a high-melting fraction (10% yield, Mh1). Mango fat
was fractionated by two-stage solvent fractionation, separating about 15% high-melting fraction (Mk1) in the first stage,
followed by 40% stearin (Mk2) in the second stage. The formulation containing 80% Mh1 and 20% of mango middle stearin fraction
(Mk2) showed melting characteristics and onset and enthalpy of crystallization similar to those of commercial hydrogenated
shortenings designed for cakes and biscuits. The formulation suitable for puff pastry shortening was prepared by blending
50% mango 1st stearin (Mk1) and 50% mahua fat with addition of 5–7% of fully hydrogenated vegetable oil. The formulations
having melting characteristics similar to those of commercial cake and biscuit shortenings were also prepared by blending
40% mango fat and 60% mahua fat with 5–7% incorporation of fully hydrogenated peanut oil. However, these formulations showed
delayed transition to the stable forms compared to those of commercial samples. Fatty acid composition revealed that commercial
hydrogenated shortenings consisted of 18–29% trans oleic acid, whereas the formulations we prepared did not contain any trans acids. The iodine values of commercial samples were 57–58, whereas the value for the formulations prepared were 47–53. The
consistency of the prepared samples as measured by cone penetrometer was slightly harder than commercial samples. These studies
showed that it is possible to prepare bakery shortenings with no trans fatty acids by using mango and mahua fats and their fractions. 相似文献
6.
Physico-chemical characteristics of palm-based oil blends for the production of reduced fat spreads 总被引:1,自引:1,他引:0
Habi Mat Dian Noor Lida A. Rahim Md Ali 《Journal of the American Oil Chemists' Society》1998,75(11):1625-1631
The effect of blending and interesterification on the physicochemical characteristics of fat blends containing palm oil products
was studied. The characteristics of the palm-based blends were tailored to resemble oil blends extracted from commercial reduced
fat spreads (RFS). The commercial products were found to contain up to 20.4% trans fatty acids, whereas the palm-based blends were free of trans fatty acids. Slip melting point of the blends varied from 26.0–32.0°C for tub, and 30.0–33.0°C for block RFS. Solid fat content
at 5 and 10°C (refrigeration temperature), respectively, varied from 10.9–19.7% and 8.5–17.6% for tub, and 28.2–38.6% and
20.8–33.5% for block RFS. Melting enthalpy of the tub RFS varied from 35.0–54.3 J/g and that of block RFS varied from 58.0–75.4
J/g. To produce block RFS, 65% palm oil (PO) and 18% palm kernel olein (PKOo) could be added in a ternary blend with sunflower
oil (SFO), but only 47% PO and 10% PKOo are suggested for tub RFS. Higher proportion of PO, i.e., 72% for block RFS and 65%
for tub RFS, could be used after the ternary blend was interesterified. Although a ternary blend of palm olein (POo)/SFO/PKOo
was not suitable for RFS formulation, after interesterification as much as 90% POo and 26% PKOo could be used in the block
RFS formulation. For tub RFS a maximum of 30% POo was found suitable. 相似文献
7.
The suitability of the selenium dioxide/tert.-butyl-hydroperoxide system for obtaining allylic mono- and dihydroxy fatty compounds has recently been reported. The surface
tension of some selected products was determined in 1N NaOH and compared to that of some known materials, such as ricinoleic
acid. The surface properties of the novel monohydroxy fatty acids are comparable or better than those of the reference materials.
The critical micelle concentrations of the novel monohydroxy acids are in the range 10−4–10−3 mol/L, depending on their structure. Furthermore, the monohydroxy acids were more effective when the hydroxy group was closer
to the functional group at C1. Allylic dihydroxy acids also lowered the surface tension but less so than the monohydroxy compounds.
Theerythro andthreo diastereomers of the allylic dihydroxy acids can be distinguished by surface tension, with thethreo diastereomers possessing better surfactant properties. Mixtures of the novel hydroxy fatty acids are also effective, thus
obviating the need for complete purification of the products. Side products such as enones, which are formed during the allylic
hydroxylations, also lower the surface tension. The products may be suitable for use in microemulsions or as additives in
various commercial products.
Presented in part at the Symposium “Industrial Uses for Agricultural Products,” 84th AOCS Annual Meeting, Anaheim, California,
April 1993. 相似文献
8.
The fatty acid composition of oyster larvae at various stages, as well as of the algal diet, were determined by gas liquid
chromatography (GC). Saturated fatty acids are the major fatty acid components in all larval stages and account for 34–62%,
30–35% and 35–81% of the neutral, polar and total lipids of algal-fed larvae respectively. Weight percentage of saturated
fatty acid in “starved” larvae was consistently higher (63–81%) during the whole period. The total polyunsaturated fatty acids
were higher in the polar lipids than in the neutral lipids. The concentration of the ω3 fatty acids also was comparatively
higher in the polar lipids than in the neutral lipids. In the total and neutral lipid fractions, the weight percentage of
polyunsaturated and ω3 fatty acids was higher in the eyed than in the pre-eyed (pediveliger) larvae. Eicosapentaenoic acid
(20∶5ω3) and 22∶6ω3 were not detected in lipids of “starved” and young larvae. There was an accumulation of 20∶5ω3, 22∶6ω3,
and total ω3 fatty acids in the older larvae. Lipid classes were separated by thin layer chromatography (TLC). There was no
qualitative change in lipid composition during larval development, but a marked increased of triacylglycerol in larvae up
to the stage of maturation in algae-fed larvae.
Contribution number 1195 of the Virginia Institute of Marine Science, Gloucester Point, VA 23062 相似文献
9.
A new aromatic diamine with a trifluoromethyl pendent group, 1,4-bis((4-amino-2-(trifluoromethyl)phenoxy)methyl)cyclohexane,
was successfully synthesized in two steps from 1,4-cyclohexanedimethanol and 2-chloro-5-nitrobenzotrifluoride as starting
materials. And the newly obtained diamine with various aromatic dicarboxylic acids, including isophthalic acid (IPA), 2,2-bis(4-carboxy-phenyl)hexafluoropropane
(6FA) and 4,4′-oxydibenzoic acid (OBA), were polymerized, respectively via the usual Yamazaki reaction to prepare a series
of fluorinated polyamides. The resulting polymers had inherent viscosities ranging from 1.85 to 2.36 dL/g. All the polymers
showed outstanding solubility and could be easily dissolved in amide-type polar aprotic solvents [e.g., N-methyl-2-pyrrolidone (NMP), DMAc, and DMF] and even dissolved in less polar solvents (e.g., pyridine, and tetrahydrofuran).
These polymers could also be easily be cast into transparent, tough and flexible films with tensile strengths of 76.5–82.3 MPa,
Young’s moduli of 1.64–1.85 GPa, and elongations at break of 10–12%. In addition, these polyamides films exhibited low dielectric
constants of 2.37–2.53 at 100 MHz, low water absorptions in the range of 1.54–2.13%, and high transparency with an ultraviolet–visible
absorption cut-off wavelength in the 326–333 nm range. Furthermore these polyamides still retained good thermal stability.
These combined outstanding features make these obtained polyamides competitive for advanced microelectronic applications. 相似文献
10.
Incorporation of alpha-linolenic acid and linoleic acid into human respiratory epithelial cell lines
Animal and human studies designed to examine the effects of α-linolenic acid (ALA) and linoleic acid (LA) supplementation
on the fatty acid composition of plasma and tissues have demonstrated a marked difference in incorporation into phospholipids
of these 18-carbon precursors of the long-chain polyunsaturates. Whereas tissue phospholipid levels are linearly related to
dietary ALA and LA, the levels of tissue LA can be 10-fold higher than tissue ALA even when dietary levels are equivalent.
There is some dispute whether this disparity is due to ALA being more rapidly metabolized to its products or substantially
oxidized by the liver, or whether LA but not ALA is readily incorporated into cellular phospholipids. We examined the level
of incorporation of polyunsaturated fatty acids into human respiratory epithelial cell lines (A549, 16HBE) by determining
the dose-dependent incorporation of ALA and LA as free fatty acid (5–150 μg FFA/mL). Cell membrane phospholipid ALA and LA
were both increased up to ∼20–30% total fatty acids, with a concomitant decrease predominantly in monounsaturated membrane
fatty acids, before significant toxicity was observed (50 μg/mL). Our data support the concept that rather than any inherent
inability by human cells to incorporate ALA into membrane phospholipids, the lack of ALA content in human and animal tissues
in vivo is due to the rapid metabolism or oxidation of this fatty acid in the liver. 相似文献
11.
M. R. Sahasrabudhe V. R. Bhalerao 《Journal of the American Oil Chemists' Society》1963,40(12):711-712
A method is described for the isolation of polymerized products in frying fats as a urea non-inclusion fraction (NAF). Analysis
of fats used in commercial frying operations and of fats extracted from some fried foods is reported. Amount of NAF obtained
by the method appears to be in direct relation to the duration of heating. Oils heated at 200C for 24 hr yield 15–18% of NAF
having molecular weights of 500–550. Some of the fats extracted from fried foods yielded up to 2.5% of the polymeric fatty
acids. 相似文献
12.
Open-tubular gas chromatographic analysis of fatty acids in the lipids from the seeds of 20 species of Gymnospermae showed
that they all contained nonmethylene-interrupted polyenoic (NMIP) acids as minor components and palmitic, oleic, linoleic
and α-linolenic acids as major components. The NMIP acids have an additional 5,6-ethylenic bond in ordinary plant unsaturated
fatty acids and the following C2 elongation acids:cis-5,cis-9-octadecadienoic acid (5,9–18∶2) (I); 5,9,12–18∶3 (II); 5,9,12,15–18∶4, 5,11–20∶2, 5,11,14–20∶3 (III); and 5,11,14,17–20∶4
(IV). The main NMIP acids found in neutral lipids are I in two species ofTaxus, II in seven species of Pinaceae, III in two species of Podocarpaceae,Torreya nucifera, Cycas revoluta, andGinkgo biloba, and III and IV in each of three species of Taxodiaceae, and Cupressaceae. The polar lipids constitute the minor fraction
of seed lipids in general. The content and composition of NMIP acids in these lipids differe considerably from those in neutral
lipids. Analysis of the partial cleavage products of triacylglycerols showed that the NMIP acids distribute mainly in the
1,3-position. 相似文献
13.
R. A. Gibson 《Lipids》1983,18(11):743-752
The fatty acid methyl esters obtained by the esterification of total lipids extracted from 24 species of fin fish and 4 species
of invertebrates caught in the rivers and coastal waters of southern Australia were analyzed by gas chromatography. The lipids
of most species contained significant levels of arachidonic acid (0.7–15.8%) as well as the more common marine polyunsaturate,
eicosapentaenoic acid (0.7–15.9%). The major ω6 fatty acid present in most species was 20∶4; however, other fatty acids of
this series, including 18∶2, 22∶4 and 22∶5, were present. The level of total ω6 fatty acids ranged from 3.9 to 22.3% of the
total lipid. In general, the level of total ω3 polyunsaturates was higher than the total ω6 fatty acids with levels of ω3
fatty acids ranging from 9.6 to 48.2%. Only 2 fish (barramundi and gurnard perch) had ω6/ω3 ratios greater than 1.0. Most
of the Australian species examined contained low levels of fat (0.5–7.8% of fresh weight). Two species examined, callop (freshwater)
and blue groper (marine) contained sufficient quantities of both fat (7.7 and 7.8%) and arachidonic acid (4.8 and 9.3%) to
warrant consideration for commercial exploitation. 相似文献
14.
Fatty acid content of marine oil capsules 总被引:2,自引:0,他引:2
Kew M. Chee Jun Xian Gong Deirdre M. Good Rees Mohsen Meydanl Lynne Ausman Julia Johnson Edward N. Siguel Ernst J. Schaefer 《Lipids》1990,25(9):523-528
The use of dietary ω3 fatty acid capsules has been associated with a decrease in plasma triglyceride levels. In addition,
populations consuming diets rich in fish appear to have a decreased incidence of cardiovascular disease. Eicosapentaenoic
acid (EPA, 20∶5ω3) and docosahexaenoic acid (DHA, 22∶6ω3) are major fatty acids in fish oils. It is believed that fish oils
exert their biolotic effect through these fatty acids. Many individuals are currently taking fish oil capsules to lower lipids,
increase bleeding time, and possibly decrease cardiovascular risk. These capsules also have been classified as food additives
with less stringent controls on content. We assessed the fatty acid, cholesterol, and vitamin A and E content of eight commercially
available capcules along with cod liver oil. The content of EPA was found to range from 8.7–26.4% (wt%) with a mean of 17.3%
(82.4% of labeled content), and that of DHA from 8.9–17.4% with a mean of 11.5% (90.0% of labeled content) as assessed by
capillary column gas-liquid chromatography. The mean content of the polyunsaturated ω3 fatty acids was 31.9%, and that of
the ω6 fatty acids was 1.4%. The content of saturated fatty acids was 32,0%, and that of monounsaturated fatty acids was 25.1%.
Cholesterol content was low, with a range of 0.7–8.3 mg/g, the α-tocopherol range was 0.62–2.24 mg/g, and the range of retinyl
esters was 0.4–298.4 μg/g. Cod liver oil had substantially more retinyl esters (2450.1 μg/g) than did fish oil capsules. Our
data serve as an independent guide to fish oil capsule fatty acid content upon single lot analysis, and indicate that these
capsules contain as much saturated fat as they contain ω3 fatty acids. 相似文献
15.
The fatty acid composition of 10 species of fish caught off the northwest coast of Australia (latitude 17°S) was examined.
All species contained high levels of ω6 fatty acids (9.6–23.1% of total fatty acids) with arachidonic acid being the major
ω6 fatty acid (5.9–14.8% of fatty acids). Docosatetraenoic and docosapentaenoic acids of the ω6 series accounted for 3–8%
of the total fatty acids. The ratio of ω6 to ω3 fatty acids in these fish varied from 0.38 to 0.93, compared with an average
ratio of 0.16 for fish from the northern hemisphere (latitude >30°N). The present data and figures from the literature indicate
that the marine food chain in the southern hemisphere contains significant quantities of ω6 fatty acids. 相似文献
16.
Aftab Kandhro S. T. H. Sherazi S. A. Mahesar M. I. Bhanger M. Younis Talpur Sarfraz Arain 《Journal of the American Oil Chemists' Society》2008,85(11):1057-1061
The fat contents of 12 brands of biscuits were extracted and evaluated for free fatty acids (FFA) and their fatty acid composition
(FAC). The oil content and FFA varied from 13.7 to 27.6% and 0.2 to 1.0%, respectively. The FAC was analyzed by gas chromatography–mass
spectroscopy with particular emphasis on trans fatty acids (TFA). Total saturated, unsaturated, cis-monounsaturated and polyunsaturated fatty acids were determined in the range of 37.9–46.9, 53.0–62.0, 12.3–43.7 and 0.1–9.2%,
respectively. The high amount of TFA was observed in all biscuit samples and varied from 9.3 to 34.9%. The quantity and quality
of the lipid fraction of the biscuits indicated that the all analyzed biscuits are a rich source of fat, saturated fatty acids
and trans fatty acids, consequently not suitable for the health of consumers. The high content of trans fatty acids and palmitic acid also indicated that blends of RBD palm oil and partially hydrogenated oil had been used in
the biscuit manufacturing. 相似文献
17.
Summary Concentrates of natural linoleic acid (linoleic acid content, 85–95%) have been prepared in 50–72% yields from corn oil fatty
acids by preferential precipitation of the saturated and monounsaturated fatty acids at room temperature as their urea complexes.
By a similar procedure, concentrates of natural linolenic acid (linolenic acid content, 87–89%) have been prepared in 55–61%
yields from perilla oil fatty acids by preferential precipitation of the saturated, monounsaturated, and diunsaturated fatty
acids. Although concentrates of natural linolenic acid containing only 66–70% linolenic acid were obtained from linseed oil
fatty acids, yields were 87–90%.
A levelling-off effect has been observed in the use of the preferential precipitation technique in raising the purity of concentrates
of linoleic and linolenic acid. This parallels the experience in the purification of these acids by low-temperature crystallization.
The preceding papers in this series are references 12 and 13.
Presented at the Fall Meeting of the American Oil Chemists' Society, Cincinnati, O., Oct. 20–22, 1952.
One of the laboratories of the Bureau of Agricultural and Industrial Chemistry, Agricultural Research Administration, U. S.
Department of Agriculture. 相似文献
18.
Large genetic diversity is available in corn (Zea mays L.) for alteration of its lipid composition. Mass selection has produced strains ranging from 0.4–17% oil with genetic variability
still existing in the high oil version. High oil hybrids (7–8% oil) with yields equal to those of commercial hybrids (4% oil)
have recently been developed. In feeding trials at the University of Minnesota, pigs made more efficient gains on high oil
corn. Oleic and linoleic acids usually make up 80–90% of the fatty acids of corn oil. Screening of corn lines has revealed
a range for linoleic acid of 25–71% and for oleic acid of 20–60%. Although the genetics of fattya cid synthesis have not been
completely elucidated, breeding of corn with selected unsaturation should be possible. Fatty acid placement within the triglyceride
molecule also may be subject to genetic modification in corn. 相似文献
19.
Norman O. V. Sonntag 《Journal of the American Oil Chemists' Society》1969,46(1):4A-4A
New developments in synthetic fatty acids have occurred in the last few years in Russia, Japan, the United States and Canada.
In 1959 Russia decided to replace 40% of natural fatty acids in soaps with synthetic fatty acids. In 1966, 548 million pounds
of C5–C30 synthetic fatty acids were produced including 288 million pounds of C10–C20 fatty acids. Forty million pounds of fatty acids are converted directly to the fatty alcohols for detergent use. A conservative
estimate predicts that one billion pounds of synthetic fatty acids will be produced in Russia by the end of the current five-year
program. Reports say that the Japanese have been interested in the oxidation of not only paraffin hydrocarbons but naphthenic
petroleum hydrocarbons as well. Production of lower homology fatty acids up to butyric acid is being seriously considered
in Japan. In America the most likely syntheses aside from “oxo” syntheses being considered for the manufacture of products
like lauric acid is the carboxylation of the Ziegler intermediates prepared from ethylene polymerization. Some data on the
current and future coconut oil consumption by major end-use for Canada and the United States are presented. Synthetic lauric
acid is predicted for 1970 in the United States.
Prepared from an address given at a meeting of the Northeast Section, New York, June 1968. 相似文献
20.
S. H. Feairheller R. G. Bistline Jr. A. Bilyk R. L. Dudley M. F. Kozempel M. J. Haas 《Journal of the American Oil Chemists' Society》1994,71(8):863-866
A low-temperature synthesis of fatty alkanolamides, fatty diamides and fatty aralkylamides directly from triglycerides and
primary amines provides essentially quantitative yields of the various products. The reactions run to completion in 3–12 h
at temperatures of 50–60°C, approximately 100°C lower than employed in present conventional practice. The amines are used
in excess and serve as solvent, reagent and, perhaps, as catalyst. The amides were characterized by melting point and spectroscopic
(infrared and nuclear magnetic resonance) methods. If the mixed amides produced from the various natural triglyceride mixtures
of fats and oils are acceptable products, this synthetic method provides these products in satisfactory quality while conserving
energy and avoiding the intermediate production of free fatty acids or their esters. 相似文献