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1.
J. G. Endres V. R. Bhalerao F. A. Kummerow 《Journal of the American Oil Chemists' Society》1962,39(2):118-121
Tripalmitin, 1- and 2-lauryl dipalmitin and 1- and 2-oleyl dipalmitin were subjected to thermal oxidation at 200C in the presence
of air for various lengths of time. The triglycerides showed a loss in weight, and an increase in carbonyl hydroxyl and acid
values. The I.V. increased in the case of saturated triglycerides and decreased in the case of unsaturated triglycerides.
Hydrolysis of the ester linkage between glycerol and fatty acid was found to occur during thermal oxidation of the type and
position of the fatty acid in the triglyceride molecule. The fatty acids released from the triglyceride by hydrolysis were
found either to be oxidized further to short chain fatty acids, or were oxygenated with the introduction of a carbonyl or
hydroxyl group in the molecule. Moreover, the unsaturated fatty acid in the triglyceride molecule was found to be oxidized
more readily than the saturated fatty acid.
A hydroxy fatty acid with a carbon number of 13.5 on a diethylene glycol succinate column was isolated from oxidized tripalmitin
and was also found to occur in the free fatty acid fraction of oxidized tripalmitin, 1-lauryl, 2–3 dipalmitin, and 1-oleyl,
2–3 dipalmitin. The presence of laurie or oleic acid in the 2-position of the triglyceride prevented the formation of this
acid, which suggested that it is an oxidation product of palmitic acid.
Portion of a thesis presented by J. G. Endres as partial fulfillment of the requirements for the degree of Ph.D. in food technology.
Funds for partial support of these studies were made available by the National Institute of Health, Grant A-1671. 相似文献
2.
E. Selke W. K. Rohwedder H. J. Dutton 《Journal of the American Oil Chemists' Society》1975,52(7):232-235
Tristearin was heated to 192 C in air, and its volatile oxidation products were collected directly on a cooled (−60 C) gas
liquid chromatography column. Subsequently, the volatile products were separated by temperature programing up to 250 C and
identified by mass spectrometry. Methyl ketones and aldehydes were the major degradation products along with minor amounts
of monobasic acids, n-hydrocarbons, primary alcohols, and γ-lactones. Qualitative results indicated all the fatty acid methylene
carbon atoms are susceptible to oxidation. Quantities of aldehydes and ketones were found to be in excess of their taste threshold
concentrations, suggesting thermally oxidized saturated fatty acids may be precursors of some odors and flavors associated
with heated lipids.
Presented at the AOCS Fall Meeting, Philadelphia, September 1974.
ARS, USDA. 相似文献
3.
S. B. El-Magoli N. Z. Hassanen M. M. Morad F. A. El-Wakeil 《Journal of the American Oil Chemists' Society》1982,59(3):146-148
Jasmine wax was fractionated using thin layer chromatography. Six fractions were isolated, purified and identified using combined
gas liquid chromatography and mass spectrometry. Infrared spectra were adopted for the chemical structure confirmation of
each fraction. The fractions were 49.44% hydrocarbons, 15.73% esters, 3.49% aldehydes and ketones, 7.91% primary fatty alcohols,
8.31% free fatty acids and 8.99% was considered origin. The hydrocarbon fraction was found to consist mainly of saturated
chains with C29, C31 and C27 the most predominant. The aldehyde fraction was characterized by straight chains with even numbers of carbon atoms ranging
between C10 and C28, whereas the ketone fraction was found to contain a longer chain structure, i.e., C36. However, the C = O was found to be at the C8 and C11 positions. Free primary alcohols were found to occur in short chains, indicating their existence in the liquid phase, whereas
the free fatty acids were found in long chains and were more likely in the solid phase. 相似文献
4.
Summary Organic soil that had gradually accumulated on cotton garments and was unremovable by normal washing procedures was analyzed
for free and combined fatty acids by gas-liquid chromatography.
The fatty acid composition of this material was similar to sebum and hair fat and was remarkably uniform although from several
different sources and geographical locations. The predominant fatty acids were C15, C16, and C18 straight-chain acids. More than 30% of the total fatty acid was palmitic acid. The amount of oleic acid was considerably
less than is reported for hair and skin fat. No linoleic acid or linolenic acid was detected. The small amount of unsaturated
acids is probably the result of their oxidation to polymers and other oxidation products. The amount of free fatty acids was
very small because they were converted to insoluble heavy metal soaps. Most of the combined fatty acids were present as esters,i.e., triglycerides. 相似文献
5.
Fatty acid α-hydroxylase from Sphingomonas paucimobilis is an unusual cytochrome P450 enzyme that hydroxylates the α-carbon of fatty acids in the presence of H2O2. Herein, we describe our investigation concerning the utilization of various substrates and the optical configuration of
the α-hydroxyl product using a recombinant form of this enzyme. This enzyme can metabolize saturated fatty acids with carbon
chain lengths of more than 10. The K
m value for pentadecanoic acid (C15) was the smallest among the saturated fatty acids tested (C10–C18) and that for myristic acid (C14) showed similar enzyme kinetics to those seen for C15. As shorter or longer carbon chain lengths were used, K
m values increased. The turnover numbers for fatty acids with carbon chain lengths of more than 11 were of the same order of
magnitude (103 min−1), but the turnover number for undecanoic acid (C11) was less. Dicarboxylic fatty acids and methyl myristate were not metabolized, but monomethyl hexadecanedioate and ω-hydroxypalmitic
acid were metabolized, though with lower turnover values. Arachidonic acid was a good substrate, comparable to C14 or C15. The metabolite of arachidonic acid was only α-hydroxyarachidonic acid. Alkanes, fatty alcohols, and fatty aldehydes were
not utilized as substrates. Analysis of the optical configurations of the α-hydroxylated products demonstrated that the products
were S-enantiomers (more than 98% enantiomerically pure). These results suggested that this P450 enzyme is strictly responsible
for fatty acids and catalyzes highly stereo- and regioselective hydroxylation, where structure of ω-carbon and carboxyl carbon
as well as carbon chain length of fatty acids are important for substrate-enzyme interaction. 相似文献
6.
D. F. Kuemmel 《Journal of the American Oil Chemists' Society》1958,35(1):41-45
Summary A direct gravimetric method has been developed for the determination of saturated fatty acids in fats, oils, and methyl esters.
The procedure involves methanolysis of the triglycerides to produce methyl esters, followed by oxidation of the unsaturated
methyl esters by potassium permanganate. The undesired, acidic oxidation products are removed by alkaline washing and the
saturated methyl esters thus isolated are weighed directly.
The method is intended for the determination of saturated fatty acids having C16 or longer carbon chains. Small quantities of C14 saturated acids will be included in the determination if present with other higher saturated acids. The method is applicable
to both natural and hydrogenated vegetable oils. It is not applicable to oils containing large amounts of C14 and lower saturated acids.
Concentrations of saturated acids ranging from 3 to 90% in known glyceride mixtures and from 0.3 to 95% in mixtures of methyl
esters were determined with an average difference from the calculated value of 0.8%. Replicate determinations on samples in
the 10 to 30% saturates range gave a standard deviation of 0.3 to 0.4%.
Presented at the spring meeting, American Oil Chemists’ Society, New Orleans, La., April 28 to May 1, 1957 相似文献
7.
《Fuel》1987,66(5):587-593
Green River shale kerogen was degraded by a careful five-step oxidation with sodium dichromate in glacial acetic acid. Products isolated from each oxidation step were examined by capillary gas chromatography and combined gas chromatography-mass spectrometry. The analyses revealed the presence of several homologous series. Saturated normal monocarboxylic acids (C6C35) and saturated normal α,ω-dicarboxylic acids (C4C33) were the major constituent series, while isoprenoid acids (C14C21, except C18), iso and anteiso acids (C6C16), branched dicarboxylic acids (C20C29), triterpenoidal acids (C27C33), cyclic, and oxo-acids were the minor constituent series. Moreover, a few aromatic acids, branched ketones, heterocyclic compounds, as well as a series of (C25C30) n-alkanes were identified. The results were discussed in terms of the qualitative and quantitative variations of the products with duration of oxidation. The data corroborate the conclusion of a predominantly open chain crosslinked aliphatic structure for Green River kerogen, and indicate that aromatic structures are mainly in the form of isolated phenyl and tolyl groups. The results further confirm the presence of etioporphyrin as a significant constituent in the kerogen studied. 相似文献
8.
Results of oil-shale liquefaction experiments by conversion in aqueous solutions of sodium formate and sodium hydroxide are discussed. The study of the decomposition products shows that not only fatty acids, C14, C16 and C18, but also poly-unsaturated acids, C20, C22 and C24 took part in the formation of kukersite. Additional data are presented to confirm the assumption that polycarbonyl structures are present in kukersite. On thermal decomposition (semi-coking) kukersite yields a considerable amount of 5-alkyl resorcinols. On conversion in aqueous suspension, however, ketones are formed instead of alkyl resorcinols. Kukersite is a rare caustobiolith, distinguished by the presence of significant amounts of unchanged fragments of biological precursor material, mostly decarboxylated alkyl chains of fatty acids. 相似文献
9.
Position 1 of the phospholipid and triglyceride fractions isolated fromMycobacterium smegmatis andM. bovis BCG was esterified principally with C18 related fatty acids (18∶0, 18∶1 and 19Br). Position 2 was occupied principally by C16 fatty acids. The third position of the triglycerides was esterified with a preponderance of C20+fatty acids. Seventysix per cent of position 3 fatty acids in BCG and 43% inM. smegmatis triglycerides contained fatty acids of greater than 20 carbon atoms. 相似文献
10.
P. J. Holloway 《Journal of the American Oil Chemists' Society》1969,46(4):189-190
The alkyl esters of beeswax, after isolation from the unhydrolyzed wax by preparative layer chromatography (PLC), have been
analyzed directly by high temperature GLC using 1.5% OV1 as liquid phase. In two commercial wax samples examined the ester
homologues are predominantly even carbon numbered ranging from C36 to C54. The principal alkyl esters are C40, C42, C44, C46 and C48. The GLC analysis of the ester hydrolysis products revealed that the variations in ester chain length are produced by variations
in the esterified primary alcohol chain lengths. The esterified fatty acid is chiefly hexadecanoic acid. The esterified fatty
acids differ in composition from the free fatty acids which are also present in the wax. 相似文献
11.
Severe economic challenges and stringent environmental regulations have made it necessary to devise new higher fatty alcohol
synthesis technologies in order to replace the existing processes, which produce large amounts of waste, or to eliminate or
considerably lessen their drawbacks. Processes using hydrogen peroxide, an environmentally friendly oxidizer, are of great
interest in this respect. Here we report the effect of process conditions (the initial molar ratio of reactants and temperature)
on the proportions of the products (alcohols and ketones) of the liquid-phase oxidation of normal C10–C13 hydrocarbons on a heterogeneous titanium-containing silicalite catalyst (TS-1). The main products of the reaction are alcohols
and ketones, and the proportion of the alcohols in the reaction mixture decreases as the temperature is raised and as the
hydrocarbon-to-hydrogen peroxide molar ratio is decreased. 相似文献
12.
Distribution of the individual fatty acids in the triglycerides of lard was determined by fractional crystallization, partial
enzymatic hydrolysis with steapsin, and fatty acid analyses by GLC. It was found that none of the individual fatty acids corresponded
to a random distribution in the crystallization fractions, but that the distribution of the total saturated and total unsaturated
acids was very nearly random. The short chain fatty acids, C14 and C16, both saturated and unsaturated, were found to be more predominant in the 2-position than in the 1- and 3-positions of the
lard triglycerides. All of the C18 fatty acids were found to be more predominant in the 1- and 3-positions. 相似文献
13.
The aim of the present study was to investigate the hepatic regulation and β-oxidation of long-chain fatty acids in peroxisomes
and mitochondria, after 3-thia- tetradecylthioacetic acid (C14-S-acetic acid) treatment. When palmitoyl-CoA and palmitoyl-l-carnitine were used as substrates, hepatic formation of acid-soluble products was significantly increased in C14-S-acetic acid treated rats. Administration of C14-S-acetic acid resulted in increased enzyme activity and mRNA levels of hepatic mitochondrial carnitine palmitoyltransferase
(CPT)-II. CPT-II activity correlated with both palmitoyl-CoA and palmitoyl-l-carnitine oxidation in rats treated with different chain-length 3-thia fatty acids. CPT-I activity and mRNA levels were,
however, marginally affected. The hepatic CPT-II activity was mainly localized in the mitochondrial fraction, whereas the
CPT-I activity was enriched in the mitochondrial, peroxisomal, and microsomal fractions. In C14-S-acetic acid-treated rats, the specific activity of peroxisomal and microsomal CPT-I increased, whereas the mitochondrial
activity tended to decrease. C14-S-Acetyl-CoA inhibited CPT-I activity in vitro. The sensitivity of CPT-I to malonyl-CoA was unchanged, and the hepatic malonyl-CoA concentration increased after C14-S-acetic acid treatment. The mRNA levels of acetyl-CoA carboxylase increased. In hepatocytes cultured from palmitic acid-
and C14-S-acetic acid-treated rats, the CPT-I inhibitor etomoxir inhibited the formation of acid-soluble products 91 and 21%, respectively.
In contrast to 3-thia fatty acid treatment, eicosapentaenoic acid treatment and starvation increased the mitochondrial CPT-I
activity and reduced its malonyl-CoA sensitivity. Palmitoyl-l-carnitine oxidation and CPT-II activity were, however, unchanged after either EPA treatment or starvation. The results from
this study open the possibility that the rate control of mitochondrial β-oxidation under mitochondrion and peroxisome proliferation
is distributed between an enzyme or enzymes of the pathway beyond the CPT-I site after 3-thia fatty acid treatment. It is
suggested that fatty acids are partly oxidized in the peroxisomes before entering the mitochondria as acylcarnitines for further
oxidation. 相似文献
14.
A cyclic compound was isolated from the radiolytic products of each of the simple triglycerides containing C6, C8, C10, C12, C14, C16 and C18 fatty acids. In each case the compound was identified as the 2-alkylcyclobutanone of the same carbon number as the precursor
fatty acid. A mechanism is proposed for the production of these compounds which involves the formation of a six-membered ring
intermediate, cyclization and cleavage at the acyl-oxy bond. 相似文献
15.
Reduction of NO by propene in the presence of oxygen and water was studied on a Pt/Al2O3 catalyst in the following conditions (ppm (v)): NO/C3H6/O2/H2O = 800/500/50000/50000. The organic products accompanying N2, N2O and NO2 formation were trapped and analyzed by GC-MS. These analyses revealed the presence in small quantities of products of propene partial oxidation such as ketones or acids, nitrogen derivatives such as nitriles or/and nitro and nitroso compounds. The transformation of some nitrogen-containing derivatives were studied under reaction conditions to explain the formation of the by-products and of N2O. 相似文献
16.
E. Buddecke I. Filipovi B. Wortberg A. Seher 《European Journal of Lipid Science and Technology》1976,78(5):196-200
Mechanism of Long Chain Monoenoic Fatty Acids Acting on the Energy Metabolism of Heart The oxidation of 1-14C-erucic (C22:1) and 1-14C-nervonic (C24:1) acids was studied in comparison to 1-14C-palmitic and -oleic acids in isolated rat and pig heart mitochondria. After mitochondrial incubation with the albumin-bound fatty acids only small amounts of 14CO2 developed from the oxidation of the long chain monoenoic acids as compared to palmitic or oleic acid. The slow down of the oxidation rate was more pronounced in rat than in pig heart mitochondria. The oxidation of palmitic or oleic acid was not found to be inhibited by the C20–C24-monoenoic acids, whereas palmitic or oleic acid inhibited the oxidation of erucic acid competitively. From present findings an idea may be developed of the interference on fatty acid metabolism in heart muscle by erucic and other long chain monoenoic acids. 相似文献
17.
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
18.
Stavros Lalas Olga Gortzi Vasilios Athanasiadis Eftalia Dourtoglou Vassilis Dourtoglou 《Journal of the American Oil Chemists' Society》2012,89(12):2253-2258
This work was dedicated to reporting the full chemical and physical characterisation of Crambe abyssinica Hochst. seed oil. The oil from the seeds was extracted using n-hexane. The seeds contain about 30?% oil. Density, refractive index, colour, smoke point, viscosity, acidity, saponification value, iodine value, fatty acid methyl esters, the relative position of fatty acids in C1 and C3 carbon glycerol, sterols, tocopherols, peroxide value, $ \mathop E\nolimits_{{1{\text{cm}}}}^{1\,\% } $ at 232?nm, and the susceptibility to oxidation measured by the Rancimat method were determined. The oil was found to contain high levels of unsaturated fatty acids, especially C22:1 (63.77?%). The dominant saturated acid was C22:0 (2.14?%). The oil was also found to contain high levels of β-sitosterol (51.93?%), campestanol (21.98?%), and brassicasterol (12.35?%). α-, γ-, and δ-Tocopherols were detected up to levels of 7.67, 125.04, and 3.99?mg/kg, respectively. The induction period (at 110?°C and 20?l/h) of the oil was 8.83?h. The relative position of fatty acids in C1 and C3 position was as follows: linoleic 0.45?%, oleic 8.84?%, and erucic 90.72?%. The thermal profile of the oil presented a single peak at ?20.94?°C. 相似文献
19.
Thirty percent of the fatty acids fromHeliophila amplexicaulis seed oil are hydroxy acids, primarily lesquerolic acid (14-hydroxy-cis-11-eicosenoic acid) with a trace of a new fatty acid, 16-hydroxy-cis-13-docosenoic acid. The hydroxy acids in the oil are found exclusively in the 1 and/or 3 positions of the triglycerides and
are completely acylated with C20 or C22 saturated or monoenoic acids.
The mention of firm names or trade products does not imply that they are endorsed or recommended by the U.S. Department of
Agriculture over other firms or similar products not mentioned. 相似文献
20.
Normal fatty acids ranging from C14 to C36 were found to account for a maximal 0.10% of the dry ash-free weight of a water soluble soil fulvic acid. Only 10.0% of the total fatty acids could be extracted by organic solvents from untreated fulvic acid. The remaining 90.0% was extractable only after methylation of the fulvic acid and adsorption on neutral aluminum oxide. While the nature of the molecular forces that hold the fatty acids to the fulvic acid is still a matter of conjecture, evidence was obtained that reduction of hydrogen bonding by methylation was related to the release of fatty acids by the fulvic acid. Ninety-five percent of the acids that were isolated were saturated, the remaining 5.0% were unsaturated and branched-cyclic. The C24 acid was the major component. The overall C-even to C-odd carbon atom ratio for all acids was 2.3. The results suggested two different origins for the fatty acids: the C14 to C26 acids may be of microbiological origin, whereas the C27 to C36 acids may have arisen from plants. Weight distribution plots of fatty acids and n-alkanes extracted from the fulvic acid showed an inverse concentration relationship between the two components with identical carbon numbers. The data reported herein suggest that fulvic acid may act as a vehicle for the mobilization, transport and immobilization of water-insoluble organic compounds—some of which may be serious pollutants—in an aquatic environment. 相似文献