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1.
Folahan O. Ayorinde Erick Y. Nana Pete D. Nicely Anthony S. Woods Elvis O. Price Chukwuma P. Nwaonicha 《Journal of the American Oil Chemists' Society》1997,74(5):531-538
12-Aminododecanoic acid and 11-aminoundecanoic acid, monomer precursors for nylon-12 and nylon-11, respectively, have been
synthesized from vernolic (cis-12,13-epoxy-cis-9-octadecenoic) acid via a reaction sequence that includes the formation of 12-oxododecanoic acid oxime. Saponification of vernonia oil, followed
by a low-temperature recrystallization at −20°C, gave 51% vernolic acid (97% purity, m.p. 23–25°C). Hydrogenation afforded
cis-12,13-epoxystearic acid (m.p. 52–54°C, lit. m.p. 52–54°C), which upon oxidation with periodic acid in tertiary butyl alcohol
gave 12-oxododecanoic acid with an isolated yield of 71.0%. Reaction of the oxoacid with hydroxylamine hydrochloride gave
12-oxododecanoic acid oxime, which was catalytically reduced to give 12-aminododecanoic acid with a yield greater than 85%
and a melting point of 184–186°C (lit. m.p. 185–187°C). 11-Aminoundecanoic acid was prepared from the 12-oxododecanoic acid
oxime via a three-step reaction sequence that involved a Beckmann rearrangement, Hofmann degradation, and hydrolysis. Thus, the aldoxime
acid was hydrolyzed in the presence of nickel acetate tetrahydrate to give 11-carbamoylundecanoic acid (48% yield, m.p. 129–131°C,
lit. m.p. 129–130°C). The amide was then treated with a solution of sodium methoxide and bromine at 70–80°C to give 11-(methoxycarbonylamino)undecanoic
acid at 75% yield (m.p. 84–86°C; elemental analysis, calculated for C13H25NO4: C, 60.19; H, 9.73; N, 5.40; O, 24.68%; found C, 60.02; H, 9.81; N, 5.26; O, 24.91%), which upon alkaline hydrolysis and
subsequent neutralization gave 11-aminoundecanoic acid at 34% yield (m.p. 189–192°C, lit. m.p. 190°C). Mass spectrometric
and 13C nuclear magnetic resonance data of the previously unreported 11-(methoxycarbonylamino)undecanoic acid is provided. 相似文献
2.
Navdeep B. Malkar Ashish A. Vaidya V. G. Kumar 《Journal of the American Oil Chemists' Society》2000,77(10):1101-1106
We report synthesis and characterization of dimer and oligomer acids from chaulmoogra oil. (R)-Methyl hydnocarpate (methyl ester of the major fatty acid component of chaulmoogra oil) was brominated to give threo-2,3-dibromocyclopentane-1-methyl undecanoate. Formation of two diastereoisomers, viz., threo-2(R),3(R)-dibromocyclopentane-1(R)-methyl undecanoate and threo-2(S),3(S)-dibromocyclopentane-(R)-1-methyl undecanoate, was observed. Dehydrobromination of bromo derivatives using alcoholic KOH gave a cyclopentadiene derivative
as intermediate, which underwent Diels-Alder reaction to give dimer and oligomer fatty acids. The products were characterized
by ultraviolet, direct exposure probe-mass spectroscopy, 1H nuclear magnetic resonance (NMR), and 13C NMR spectroscopic techniques. 相似文献
3.
A. S. Charvet L. C. Comeau E. M. Gaydou 《Journal of the American Oil Chemists' Society》1991,68(8):604-607
Pure petroselinic acid (cis-6-octadecenoic acid) has been isolated from fennel oil by acid soap crystallization at 4°C in methanol, followed by two urea
segregations at room temperature and crystallization at −30°C in acetone. The purity control of petroselinic acid was effected
by combined gas chromatography, and13C nuclear magnetic resonance. This petroselinic acid preparation was compared to other previous crystallization or enzymatic
methods, showing that this method is both short (four steps) and easy to apply. 相似文献
4.
Barry F. Herron Marvin O. Bagby Terry A. Isbell Wm. Craig Byrdwell Ron Plattner David Weisleder 《Journal of the American Oil Chemists' Society》1997,74(3):229-234
Allylic amination of methyl oleate with bis(N-p-toluenesulfonyl) sulfodiimide results in a mixture of methyl 11-amino-(N-p-toluenesulfonyl)-9-E-octadecenoate and methyl 8-amino-(N-p-toluenesulfonyl)-9-E-octadecenoate in 58% yield. These novel products were isolated and characterized by nuclear magnetic resonance, infrared
spectroscopy, mass spectrometry, and melting point. The reaction was analyzed by highperformance liquid chromatography and
thin-layer chromatography. 相似文献
5.
S-methyltetrafluoroborate salts of the thiophenic compounds (CH3-S+:BF4−) present in LCO petroleum fractions were obtained and analyzed by 1H and 13C NMR spectroscopy. The methylation of the samples was carried out using 99.5% 13C enriched methyl iodine, to improve the sensitivity of the technique. The amount of the methylated derivatives was determined by the internal standard method; using dioxane as a reference, 37 sulphur compounds were detected. Among them, benzo[b]thiophene, dibenzo[b,d]thiophene, and several isomers of methyl, dimethyl and trimethyl[b]benzothiophenes were the most abundant. With this research, it was demonstrated that NMR spectroscopy can be used to analyze thiophenic compounds from petroleum medium fractions. 相似文献
6.
Rogers E. Harry-O kuru Terry A. Isbell David Weisleder 《Journal of the American Oil Chemists' Society》2001,78(3):219-223
Oleic acid (cis-9-octadecenoic acid) was converted in excellent yield to the estolide, which was then esterified with 2,2-dimethypropan-1-ol
(neopentyl alcohol), cis-9-octadence-1-ol (oleyl alcohol), and 2-propanol to generate the corresponding estolide esters. Higher-formula mass estolide
esters were synthesized by reaction of the parent estolide with 1,3-propanediol, 2,2-dimethyl-1,3-propanediol, and 1,5-pentanediol
to give the corresponding diesters of oleic estolide, thus doubling the molecular size of the parent estolide. Pour points
and viscosities were determined in order to evaluate these products for possible industrial application. 相似文献
7.
Giovanna Vlahov Adrian D. Shaw Douglas B. Kell 《Journal of the American Oil Chemists' Society》1999,76(10):1223-1231
Distortionless enhancement by polarization transfer (DEPT) pulse sequence was used to set up a quantitative high-resolution
13C nuclear magnetic resonance (NMR) method to discriminate olive oils by cultivars and geographical origin. DEPT pulse sequence
enhances the intensity of NMR signals from nuclei of low magnetogyric ratio. The nuclear spin polarization is transferred
from spins with large Boltzmann population differences (usually protons) to nuclear species characterized by low Boltzmann
factors, e.g., 13C. The signal enhancement of 13C spectra ensures the accuracy of resonance integration, which is a major task when the resonance intensities of different
spectra must be compared. The resonances of triglyceride acyl chains C
n:0, C18:1, C18:2, and C18:3, were also assigned. Multivariate analysis was carried out on the 35 carbon signals obtained. By using variable reduction
techniques, coupled with standard statistical methods—partial least squares and principal components analysis—it was largely
possible to separate the samples according to their variety and region of origin. With one problem variety removed, 100% prediction
of the three remaining varieties was achieved. Similarly, by using the three regions with greatest representation in the data,
all but one of a test set of 34 samples were correctly predicted. Thus, the composition of olive oils from different cultivars
and of different geographical origin were compared and successfully studied by multivariate analysis. These considerations
in conjunction with the structural elucidations of triglyceride molecules demonstrated that 13C NMR is among the most powerful techniques yet described for analysis of olive oils. 相似文献
8.
Marcel S. F. Lie Ken Jie M. S. K. Syed-Rahmatullah 《Journal of the American Oil Chemists' Society》1992,69(4):359-362
Reaction of 1-mesyloxynonane with methyl 8-aminooctanoate gives methyl 9-azastearate (I, 20%); treatment of methyl 9(10),10(9)-azidohydroxyoctadecanoate
and methyl 10-azido-12-hydroxyoctadecanoate with triphenylphosphine furnishes the corresponding aziridine derivative (II,
75%) and two geometric azetidine isomers (IIIa and IIIb, 37%), respectively. The aza function in compound I, the aziridine
nucleus in compound II and the azetidine system in compounds IIIa, IIIb were characterized by1H nuclear magnetic resonance (NMR) and13C NMR spectral analysis. The infrared spectral analyses of compounds (I), (II) and (IIIa,IIIb) showed characteristic absorption
bands at 3200–3300 cm−1 for the N-H stretching vibration. 相似文献
9.
《Journal of Sulfur Chemistry》2013,34(3):281-292
Aluminum(III) is generally found in small amounts in living organisms where it interacts with several biomolecules. Low mass biomolecules can form complexes associated with absorption and distribution processes of this toxic ion. However, investigating aluminum(III) complexes in solution poses singular difficulties, because it is highly hydrolyzable. Amino acids constitute possible ligands for aluminum(III). Methionine, cysteine and homocysteine are found in healthy human body. Penicillamine is a drug used in several circumstances, such as in treating metal poisoning. These four biomolecules share similar donor atoms involved in complexation reactions: a carboxylate oxygen, an amine nitrogen and sulfur. In this study, four binary complexes formed by aluminum(III) and amino acids in solution at a metal-to-ligand ratio of 1:1 were analyzed through potentiometry and multinuclear magnetic resonance (13C and 27Al). Potentiometry data consistently demonstrated complexion formation. Distributions of species revealed the coexistence of several species in ample pH ranges and pointed out the preferable value to perform the NMR analyses. 13C NMR data were used to confirm complexion formation, while 27Al NMR data indicated the geometric arrangement adopted by the complexes. Structures were proposed for each complex. 相似文献
10.
Terry A. Isbell Steven C. Cermak 《Journal of the American Oil Chemists' Society》2002,79(12):1227-1233
Triglyceride (TG) estolides were synthesized from the hydroxy moieties of lesquerella and castor oils with oleic acid. Complete
esterification of the hydroxy oils was possible when a slight excess of oleic acid was employed (1 to 1.5 mole equivalents).
The estolides could be formed in the absence of catalyst at 175 to 250°C under vacuum or a nitrogen atmosphere. The optimal
reaction conditions were found to be under vacuum at 200°C for 12 h for lesquerella and 24 h for castor oil. The lesquerella
esterification reaction was completed in half the time of the for castor and with lower equivalents of oleic acid due to the
difunctional hydroxy nature of lesquerella TG compared to the trifunctional nature of castor TG. Interesterification or dehydration
of the resulting estolides to conjugated FA was not a significant side reaction, with only a slight amount of dehydration
occurring at the highest temperature studied, 250°C. Use of a mineral-or Lewis-acid catalyst increased the rate of TG-estolide
formation at 75°C but resulted in the formation of a dark oil, and the reaction did not go to completion in 24 h. Estolide
numbers (i.e., degree of estolide formation) for the reaction and characterization of the products were made by 1H NMR and 13C NMR. The decrease in the hydroxy methine signal at 3.55 ppm was used to quantify the degree of esterification by comparing
this integral to the integral of the alpha methylene protons on the glycerine at 4.28 and 4.13 ppm. 相似文献
11.
High-performance liquid chromatography and spectroscopic studies on fish oil oxidation products extracted from frozen atlantic mackerel 总被引:4,自引:0,他引:4
The formation of stable hydroxy derivatives from hydroperoxides produced during the oxidation of linoleic acid methyl ester
and fish oil were studied by reverse-phase high-performance liquid chromatography (HPLC), gas chromatography-mass spectrometry
(GC-MS) and 13C nuclear magnetic resonance (NMR) spectroscopy. The oxidation products identified were mixtures of four isomeric hydroxy
derivatives: 13-hydroxy-9-cis,11-trans-octadecadienoic, 13-hydroxy-9-trans,11-trans-octadecadienoic, 9-hydroxy-10-trans,12-cis-octadecadienoic, and 9-hydroxy-10-trans,12-trans-octadecadienoic acids. The presence of hydroxy compounds was confirmed by 13C NMR, which gave rise to a hydroxy carbon peak at 87 ppm, and by GC-MS, which showed three peaks corresponding to isomeric
mixtures of trimethylsilyl ethers of the oxidized linoleic acid methyl ester. The mass spectra scans of the three peaks showed
that they represent isomers of molecular weight 382 and are consistent with the molecular formula C22H42O3Si. In oil extracted from stored frozen mackerel, 13-hydroxy-9-cis,11-trans-octadecadienoic acid was more prominent compared to the model lipid systems. HPLC offered a sensitive means of detection
of hydroxy compounds produced both in the initiation and latter stages of oxidation. The effect of antioxidants added to the
fish mince prior to storage can also be monitored by HPLC. Thus, the monitoring of lipid oxidation hydroxy derivatives by
HPLC is of practical value in the efficient processing and quality control of fish, fish oils, and other fatty foodstuffs
in order to enhance the acceptability, nutritional, and safety aspects. 相似文献
12.
Seppo Kaltia Jorma Matikainen Maija Ala-Peijari Tapio Hase 《Journal of the American Oil Chemists' Society》2008,85(6):561-565
Pinolenic acid (5Z,9Z,12Z-octadecatrienoic acid, 1a), one of the most abundant trienoic fatty acids in nature, is very difficult to obtain in quantity in a pure state from the
highly complex mixture of unsaturated tall oil fatty acids. For this reason its chemistry has been little studied when compared
to linolenic or linoleic acids. A simple synthesis of esters of 1a and of 12Z,15Z-octadecadienoic acid 3 using the one pot double Wittig procedure is described here. The products of double Wittig reactions were purified by argentation
chromatography, and their structural purity was established by 1H-, 13C-NMR and 2D-NMR spectroscopies.
相似文献
Tapio HaseEmail: |
13.
The triad-level sequence analysis of poly(ethylene/1,4-cyclohexanedimethylene terephthalate) copolymer was reported in a solvent system of o-chlorophenol/deuterated chloroform mixture (50/50 v/v) at 80 °C using 600 MHz 1H NMR. The well-resolved alcoholic CH2 proton peak of the glycol units was observed, which made the detailed sequence analysis possible. The peaks of the cis- and trans-forms of the 1,4-cyclohexanedimethylene glycol units were split into the triad sequence in the chain and could be assigned by a comparison of the spectra with those of homopolymers and by an additional two-dimensional heteronuclear multiple bond correlation observation. The triad sequence distributions centered on 1,4-cyclohexanedimethylene glycol units were determined, which was independent of the cis- and trans-forms of the units and controlled according to Bernoullian statistics. 相似文献
14.
S. M. Motshegwe J. Holmback S. O. Yeboah 《Journal of the American Oil Chemists' Society》1998,75(6):725-728
A preliminary investigation of the bulk properties of the oil from the edible mophane caterpillar (phane), Imbrasia belina, showed a significant difference in the iodine values of the oils from mature and young phane. Detailed analysis of the fatty
acid composition of the two oil samples was thus carried out by capillary gas chromatography (GC) and complemented with 1H and 13C nuclear magnetic resonance (NMR) studies to investigate the degree of unstauration in the two oil samples. While these studies
showed that the oil samples from the mature and young mophane caterpillar were much the same in fatty acid composition, the
data revealed a significant divergence from a literature report on phane oil. This earlier report puts the ratio of total
saturated to total unsaturated fatty acids at approximately 1:1 (48.2:48.8, in percentages) and estimates the fatty acid composition
for the major fatty acids as 16:0 (31.9%), 18:0 (15.2%), 18:1 (20.4%), 18:2 (9.9%), and 18:3 (19%). The data collected from
the present work, however, showed the fatty acid composition for total saturated and total unsaturated fatty acids to be 40.5
and 57.0%, respectively. This work estimated the fatty acid composition for the major fatty acids as 16:0 (27.2%), 18:0 (12.3%),
18:1 (16.1%), 18.2 (10.7%), and 18:3 (29.0%). Thus, linolenic acid was the most abundant fatty acid in the phane oil. The
GC results of the present analysis were largely corroborated by studies of the composition of fatty acid classes in the phane
oil estimated from integrals of 1H and 13C NMR signals. Oils from other edible Lepidoptera larvae are also known to be much richer in unsaturated than saturated fatty
acids. 相似文献
15.
M. Tóth H. R. Buser P. M. Guerin H. Arn F. Schmidt W. Francke G. Szöcs 《Journal of chemical ecology》1992,18(1):13-25
(3Z,6Z,9Z)-3,6,9-Heptadecatriene and (6Z,9Z)-6,9-cis-3,4-epoxyheptadecadiene have been identified in female sex pheromone gland extracts ofAbraxas grossulariata L. (Lepidoptera: Geometridae). The compounds were detected by gas chromatography with electroantennographic detection (GC-EAD) and identified by GC-mass spectrometry (GC-MS). The amounts of hydrocarbon and epoxide were 0.13 and 0.42 ng/female, respectively. These identifications were confirmed by synthesis; the absolute configuration of the epoxide remains to be determined. Another isomeric epoxide, (3Z,6Z)-3,6-cis-9,10-epoxyheptadecadiene, was tentatively identified in small amounts (0.04 ng/female). Racemic (6Z,9Z)-6,9-cis-3,4-epoxyheptadecadiene elicited the largest electroantennogram response within a series of heptadecadiene and nonadecadiene monoepoxides and the corresponding trienic hydrocarbons and, in field tests, attracted maleA. grossulariata into traps. Addition of 10% (3Z,6Z,9Z)-3,6,9-heptadecatriene to this epoxide enhanced attractiveness; addition of (3Z,6Z)-3,6-cis-9,10-epoxyheptadecadiene had no effect at low proportions while higher proportions caused a reduction in the numbers of males caught. 相似文献
16.
Soon Ng 《Journal of the American Oil Chemists' Society》2000,77(7):749-755
The chemical shifts, spin-lattice relaxation times (T
1), and one-bond C−H coupling constants of the glycerol carbons of mono-, di-, and triacylglycerols in CDCI3 solution are presented and discussed. The glycerol carbons have low T
1 values (<1.0 s) and full nuclear Overhauser effect and also exhibit broader linewidths than the aliphatic carbons, suggesting
that the glycerol carbons are at or near the T
1 minimum for the dipole-dipole relaxation mechanism. Therefore, for quantitative measurement of the composition of partial
acylglycerols (relative to the triacylglycerols) in palm oil, the nuclear magnetic resonance (NMR) spectrum of the β-carbons,
which lie exclusively in the region δ68.3–72.1 ppm, should preferably be acquired at medium or low magnetic fields and at
an elevated temperature in order to ensure that the condition for extremely narrow spectral lines is satisfied. The chemical
shifts and spinlattice relaxation times of the aliphatic C-2 and C-3 carbons and of the carbonyl carbons (C-1) of acyl groups
present in palm oil are also presented and discussed. The presence of free fatty acid in the palm oil is easily detected and
quantified in the spectrum of the aliphatic carbons. The presence of partial acylglycerols in palm oil can also be detected
and/or quantified in the NMR spectra of the C-2 and the carbonyl carbons. The quantitative analysis of the glycerol carbons
of a known mixture of acylglycerols obtained by using this method is presented. 相似文献
17.
P. I. Svirskaya S. N. Maiti A. J. Jones B. Khouw C. C. Leznoff 《Journal of chemical ecology》1984,10(5):795-807
The title compounds were prepared by six different routes, and recommendations are given for the more convenient procedures in laboratory-scale syntheses. Modifications in the literature preparations of the 9E,11E and 9E,11Z isomers are described. Baseline separation of a prepared mixture of all four isomers of the (9Z, 11Z), (9E, 11E), (9E, 11Z), and (9Z, 11E)-9,11-hexadecadienals was achieved using GC methods with standard capillary columns. [13C]NMR spectroscopy of the alkene carbon atoms clearly differentiates between theZ,Z, E,E and eitherE,Z orZ,E isomers of the precursor dienols and thus of the dienals. 相似文献
18.
Sex attractants for the geometrid mothsEufidonia convergaria andCaripeta angustiorata, and the noctuid mothRivula propinqualis have been elucidated during field screening of a series of (3Z,6Z,9Z)-triene hydrocarbons (C17–22), and the racemic and enantiomerically enriched monoepoxydienes derived from those hydrocarbons. Biologically active compounds were identified by a combination of field testing of synthetic standards, electroantennography, and coupled gas chromatography-electroantennogram detection.E. convergaria males were optimally attracted by a 11 blend of (3Z,9Z)-(6S,7R)-epoxy-nonadecadiene (3Z,9Z-6S,7R-epoxy-19H); other abbreviations follow the same system) with (3Z,6Z,9Z)-nonadecatriene (3Z,6Z,9Z-19H). The 6R,7S enantiomer of the epoxide had no apparent biological activity, either as an attractant or as a behavioral antagonist. Male moths also were attracted to blends of the C18 and C20 homologs of the triene and the epoxide. 3Z,6Z,9Z-19H and 3Z,6Z-cis-6,7-epoxy-19H were identified inE. convergaria female pheromone gland extracts. Males of the geometrid moth speciesC. angustiorata were attracted by a 11 blend of 3Z,6Z,9Z-19H and enantiomerically enriched 3Z,9Z-6R,7S-epoxy-19H. Males of the noctuid mothR. propinqualis were attracted by an approximately 101 blend of 3Z,6Z,9Z-19H and enantiomerically enriched 3Z,9Z-6S, 7R-epoxy-19H. The components were synergistic, with neither being attractive alone. The blend ratio was quite specific, as the attractiveness of blends decreased sharply on either side of the optimum ratio.Issued as NRC No. 30266. 相似文献
19.
Pierre Blaise Marie Farines Jacques Soulier 《Journal of the American Oil Chemists' Society》1997,74(6):727-730
Gorlic, chaulmoogric and hydnocarpic fatty acids, specific to the seed oil of the genus Hydnocarpus sp. (Flacourtiaceae), are determined only with difficulty by gas chromatography. These fatty acids were isolated in their
methyl ester form by a combination of different chromatographic techniques (thin-layer chromatography/Ag+ and high-pressure liquid chromatography). The proton and carbon nuclear magnetic resonance analysis of these fatty acid methyl
esters showed some characteristic signals of the cyclopentenyl ring. The presence of these signals in the proton and/or carbon
nuclear magnetic resonance spectrum of an oil thus will allow us to confirm the presence of these cyclopentenyl fatty acids
in lipids. 相似文献
20.
The structure and dynamics of poly(vinyl alcohol) (PVA)-iodine complex hydrogels that were prepared from concentrated PVA solutions have been characterized by high-resolution solid-state 13C NMR spectroscopy. The fully relaxed dipolar decoupling (DD)/MAS 13C NMR spectrum indicates that the hydrogels contain at least two components, a highly mobile and broader components. The former is assigned to the soluble or well water-swollen PVA chains that are not closely associated with the PVA-iodine complexes, whereas the latter may be mainly ascribed to the aggregated PVA chains that are produced by the formation of the PVA-iodine complexes because no diffraction peaks due to the conventional PVA crystallites are observed by wide-angle X-ray diffractometry. Furthermore, 13C spin-lattice relaxation time (T1C) analyses reveal that the broader component is composed of the highly restricted component probably assignable to PVA molecular chain aggregates containing the PVA-iodine complexes and the less mobile component. As for the former component, their CH resonance line measured by the T1C-filtering method is successfully resolved into 7 constituent lines by the least-squares curve fitting. The statistical analysis of the integrated intensities of the constituent lines thus obtained also reveals that the probability fa for the formation of intramolecular hydrogen bonding in the successive two OH groups along each chain and another probability ft of the trans conformation are, respectively, as high as 0.86 and 0.88. This fact indicates that the PVA molecular chain aggregates containing the PVA-iodine complexes should be composed of PVA segments with the trans-rich conformation and the PVA-iodine complexes therein may also be formed with these several trans-rich segments surrounding the rod-like polyiodine cores in agreement with the so-called aggregation model. Moreover, several new diffraction peaks that should be interpreted in terms of the hexagonal structure are observed for the PVA-iodine complex hydrogels in the low 2θ region in the wide-angle X-ray diffraction (WAXD) profile measured by a strong X-ray source at SPring-8. This suggests the necessity of more detailed WAXD characterization to propose a new structure model, which should be referred to as the hexagonal aggregation model, for the PVA-iodine complexes. 相似文献