共查询到20条相似文献,搜索用时 31 毫秒
1.
R. A. Grimm J. E. Menting A. J. Stirton J. K. Weil 《Journal of the American Oil Chemists' Society》1968,45(12):897-900
Chlorination of oleyl alcohol gives mainly 9,10-dichlorostearyl alcohol but a variety of other products are also formed. By-products
include 9(10)-(9,10-dichlorostearoxy)-10(9)-chlorostearyl alcohol (14%) and 9,10-dichlorostearyl 9,10-dichlorostearate (3–4%)
in addition to three or four less clearly defined products (12%). One group of products is apparently derived from participation
of the hydroxyl group in the chlorine addition step while the other products formed by the reaction of the hydroxyl group
with chlorine or chlorine and hydrogen chloride. 相似文献
2.
Saturated and unsaturated oligomers are formed by a side reaction during the thermal polymerization of styrene. MAYO has suggested that these oligomers are closely associated with the initiation step. Recently the structures of the dimer fraction were published by BROWN . By independent synthesis of the dimers we could confirm his results. The main components of the dimer fraction are trans- and cis-1.2-diphenylcyclobutane in a ratio of 3:1 ; also smaller amounts of 1.3-diphenylbutene-(3) and I-phenyltetralin were found. The aim of this work was to clarify the structures of the trimers. The trimer fraction contains about 30% of 1.3.5-triphenylhexene-(5), the structure of which was confirmed by independent synthesis. Furthermore we were able to show, that about 65% of the trimer fraction consists of the 4 optical inactive isomers of 1-phenyl-4-[1′-phenyläthyl-(1′)]-1.2.3.4.-tetrahydronaphthalene. Their structures were confirmed by dehydrogenation to 1-phenyl-4-[1′-phenyläthyl-(1′)]-naphthalene, which was identical to an independently synthesized sample. 相似文献
3.
Bitter-tasting phosphatidylcholines from hexane-defatted soybean flakes were chromatographically separable from ordinary soy
phosphatidylcholines (SPC). The bitter-tasting SPC contain 32% oxygenated fatty acids in addition to palmitic, stearic, oleic,
linoleic, and linolenic acids. Identification of these oxygenated acids was based on infrared, ultraviolet, proton nuclear
magnetic resonance, and mass spectral characteristics of methyl ester derivatives which were separated and purified by column
and thin layer chromatography. The fatty acid methyl esters identified were (a) 15, 16-epoxy-9, 12-octadecadienoate, (b) 12,
13-epoxy-9-octadecenoate, both with double bonds and epoxide groups predominantly ofcis configuration; (c) 13-oxo-9,11-and 9-oxo-10, 12-octadecadienoates; (d) 13-hydroxy-9, 11- and 9-hydroxy-10, 12-octadecadienoates;
(e) 9, 10, 13-trihydroxy-11- and 9,12,13-trihydroxy-10-octadecenoates. In addition, trace amounts of (f) 11-hydroxy-9,10-epoxy-12-and
11-hydroxy-12,13-epoxy-9-octadecenoates; (g) 13-oxo-9-hydroxy-10-and 9-oxo-13-hydroxy-11-octadecenoates; (h) 9,10-dihydroxy-12-
and 12, 13-dihydroxy-9-octadecenoates; and (i) 9,12,13-dihydroxyethoxy-10- and 9,10,13-dihydroxyethoxy-11-octadecenoates were
indicated by mass spectrometry. Dihydroxyethoxy compounds (i) were possibly formed upon extraction of the SPC from flakes
by 80% ethanol. Except for the first two epoxy compounds, labelled a and b, the oxygenated fatty acids are similar to the
products formed by homolytic decomposition of linoleic acid hydroperoxide. The first two compounds with predominantlycis configuration may occur by action of fatty acid hydroperoxides on an unsaturated fatty acid.
Presented in part at the 13th World Congress of the International Society for Fat Research, Marseille, France, August 31–September
4, 1976. 相似文献
4.
The absolute optical configuration of (−)-cis-9,10-epoxystearic acid has been verified as being L. Here (−)-erythro-9,10-dihydroxystearic acid, isolated from castor oil, was converted by stereospecific reactions to (+)-cis-9,10-epoxystearic acid and was thereby proved to be D-9,D-10-dihydroxystearic acid. Removal of the D-12-hydroxy group from
the higher meltingerythro-9,10,12-trihydroxystearate derived from ricinoleic acid, after protection of the glycol group, gave the L-9,L-10-dihydroxystearate
derivative. This proved the high melting diastereoisomer to be L-9,L-10,D-12-trihydroxystearate and directly verified the
supposition that the higher melting, arsenite-complexing diastereoisomer of such oxidation pairs has thetrans-10,12-diol grouping. On this basis, the higher meltingthreo-trihydroxystearate from ricinoleate must be D-9,L-10,D-12-trihydroxystearate and removal of the 12-hydroxy group must give
D-9,L-10-dihydroxystearate which proved to be the levorotatory enantiomer. The dextrorotatory L-9,D-10-dihydroxystearate was
transformed by stereospecific reactions to (+)-trans-9,10-epoxystearic acid, thereby defining the absolute configurations oftrans-9,10-epoxystearic acids. On the basis of these results conclusions may be drawn as to the stereospecificity and site of action
of enzymes which hydrate 9,10-epoxystearic acids. 相似文献
5.
One of the main compounds formed from 13L-hydroperoxy-9cis,11trans-octadecadienoic acid anaerobically at 100 C in aqueous ethanol was found to bethreo-11-hydroxy-12,13-epoxy-9-octadecenoic acid. The major part (ca. 90%) of this compound was formed from the fatty acid hydroperoxide
in a reaction involvingcis-addition to the Δ11 double bond of the proximally linked hydroperoxide oxygen and hydroxyl ion or hydroxyl radical from the solvent. A small
part (ca. 10%) was formed bycis-addition of the two hydroperoxide oxygens to the Δ11 double bond. 11-Hydroxy-12,13-epoxy-9-octadecenoic acid and its isomer, tentatively identified as 11-hydroxy-9,10-epoxy-12-octadecenoic
acid, also were isolated from a sample of autoxidized linoleic acid. 相似文献
6.
Per Fahistadius 《Lipids》1988,23(11):1015-1018
Racemiccis-9,10-epoxystearic acid was isolated from total lipids of human leukocytes. Identification of the epoxy acid was based mainly
on gas liquid chromatographicmass spectrometric analysis and on its chemical conversion intothreo-9,10-dihydroxystearic acid. A mass spectrometric method for quantitative determination ofcis-9,10-epoxystearic acid using the tetradeuterated compound as internal standard was developed. Using this method, nonstimulated
human leukocytes were found to contain 5.1±2.2 μg (SD) ofcis-9,10-epoxystearic acid per 109 cells (n=8). More than 90% of the epoxy acid occurred in its esterified form in leukocyte lipids. 相似文献
7.
Grechkin AN Mukhtarova LS Latypova LR Gogolev Y Toporkova YY Hamberg M 《Chembiochem : a European journal of chemical biology》2008,9(15):2498-2505
The mechanism of the recombinant tomato allene oxide synthase (LeAOS3, CYP74C3) was studied. Incubations of linoleic acid (9S)-hydroperoxide with dilute suspensions of LeAOS3 (10-20 s, 0 degrees C) yield mostly the expected allene oxide (12Z)-9,10-epoxy-10,12-octadecadienoic acid (9,10-EOD), which was detected as its methanol-trapping product. In contrast, the relative yield of 9,10-EOD progressively decreased when the incubations were performed with fourfold, tenfold, or 80-fold larger amounts of LeAOS3, while alpha-ketol and the cyclopentenone rac-cis-10-oxo-11-phytoenoic acid (10-oxo-PEA) became the predominant products. Both the alpha-ketol and 10-oxo-PEA were also produced when LeAOS3 was exposed to preformed 9,10-EOD, which was generated by maize allene oxide synthase (CYP74A). LeAOS3 also converted linoleic acid (13S)-hydroperoxide into the corresponding allene oxide, but with about tenfold lower yield of cyclopentenone. The results indicate that in contrast to the ordinary allene oxide synthases (CYP74A subfamily), LeAOS3 (CYP74C subfamily) is a multifunctional enzyme, catalyzing not only the synthesis, but also the hydrolysis and cyclization of allene oxide. 相似文献
8.
K. S. Tenny S. C. Gupta R. F. Nystrom F. A. Kummerow 《Journal of the American Oil Chemists' Society》1963,40(5):172-175
Tritium labeled 9,10-oleic acid was prepared from stearolic acid by reduction with tritium gas, in the presence of 5% Palladium
on Charcoal catalyst, at room temperature and under partial vacuum. No stearic or elaidic acids were formed. Unreacted stearolic
acid was removed by low temperature erystallization from Skellysolve F. The tritium labeledcis 9,10-oleic acid was prepared with a specificity of greater than 90% of the activity at the 9 and 10 positions. Specific radio-activity
of the oleic acid was 1000 me of Tritium/g. Tritium labeled stearic acid with a specific activity of 927 me of Tritium/g was
also prepared.
Supported by Research Grant No. H-3063 from the National Institute of Health, U. S. Public Health Service, Department of Health,
Education, and Welfare, and the American Dairy Association.
Presented in part at the Federation of American Societies meeting for Experimental Biology, 1961. 相似文献
9.
10.
Atwell John L.; Breheney Kerry A.; Lawrence Lynne J.; McCoy Airlie J.; Kortt Alexander A.; Hudson Peter J. 《Protein engineering, design & selection : PEDS》1999,12(7):597-604
Single-chain Fv antibody fragments (scFvs) incorporate a polypeptidelinker to tether the VH and VL domains together. An scFv moleculewith a linker 512 residues long cannot fold into a functionalFv domain and instead associates with a second scFv moleculeto form a bivalent dimer (diabody). Direct ligation of VH andVL domains further restricts association and forces three scFvmolecules to associate into a trivalent trimer (triabody). Wehave defined the effect of linker length on scFv associationby constructing a series of scFvs from anti-neuraminidase antibodyNC10 in which the linker varied from one to four glycine residues.NC10 scFv molecules containing linkers of three and four residuesshowed a strong preference for dimer formation (diabodies),whereas a linker length of one or two glycine residues preventedthe formation of diabodies and directed scFv association intotrimers (triabodies). The data suggest a relatively strict transitionfrom dimer (diabody) to trimer (triabody) upon reduction ofthe linker length from three to two glycine residues. Modellingstudies are consistent with three residues as the minimum linkerlength compatible with diabody formation. Electron microscopeimages of complexes formed between the NC10 scFv multimers andan anti-idiotype Fab' showed that the dimer was bivalent forantigen binding and the trimer was trivalent. 相似文献
11.
G. Maerker E. T. Haeberer W. C. Ault 《Journal of the American Oil Chemists' Society》1964,41(9):585-588
Esters of 9,10-epoxystearic aeid (epoxidized oleic acid), dissolved in 1,4-dioxane, were treated at 15C, first with aqueoiis
acid and then with water to convert them to 9,10-dihydroxystearates in high yields. Ester functions remained intact. Glycidyl
9,10-epoxystearate, ethylene glycolbis-9,10-epoxystearate and catecholbis-9,10-epoxystearate were converted to the corresponding tetrahydroxy esters by this method. Treatment of methyl 9,10-epoxystearate
with diluted (24%) fluoboric acid gave methyl 9,10-dihydroxystearate in 89% yield. Under similar conditions glycidyl stearate
did not react and the internal epoxy group of glycidyl 9,10-epoxystea-rate was hydrated preferentially. Hydration of methyl
9,10-epoxystearate with coned H2SO4 led to the formation of considerable amt of byproducts, principally methyl 9(10)-ketostearate. Side reactions were inhibited
by diluting the acid-catalyst.
Presented at the AOCS Meeting, Minneapolis, 1963.
A laboratory of the B. Utiliz. Res.& Der. Dir., ABS, USDA. 相似文献
12.
介绍9,10-二氢-9-氧杂-10-磷杂菲-10-氧化物(DOPO)及其衍生物10-(2,5-二羟基苯基)-10-氢-9-氧杂-10-磷杂菲-10-氧化物(DOPO-HQ)分别反应阻燃聚乳酸(PLA)的机理和对PLA力学性能、阻燃性能、耐热性能的影响。结果表明,少量DOPO对PLA有良好的阻燃效果,少量过氧化二异丙苯(DCP)与DOPO-HQ并用能有效改善PLA的阻燃性能和热稳定性能。5%DOPO-HQ/0.5%DCP阻燃PLA具有良好的综合性能,拉伸强度为49.37MPa,断裂伸长率为5.03%,氧指数为32%,试样热失重5%、50%时的温度分别提高38、36℃。 相似文献
13.
Grubbs' ruthenium catalyst 2 has been employed in model studies of the acyclic diene metathesis (ADMET) polymerization of soybean oil. In the presence
of 0.1 mol% of catalyst 2, the ADMET polymerization of ethylene glycol dioleate afforded the isomerized (E)-dioleate (27%), dimer (18%), trimer (13%), tetramer (7%), pentamer (5%), hexamer (4%), heptamer (4%), and 9-octadecene (21%).
Only a trace of any intramolecular cyclized product was formed. Under the same conditions, glycerol trioleate underwent ADMET
polymerization to produce dimer, trimer, tetramer, pentamer, and monocyclic oligomers, with monocyclic oligomers predominating.
The high number of repeat units in the monocyclic oligomers (n≅6, 10, and 21) in dicates that cross-linking occurs readily in this process. Based on our model system studies, we have examined
the ADMET polymerization of soybean oil and succeeded in producing polymeric materials ranging from sticky oils to rubbers. 相似文献
14.
《Inorganic chemistry communications》2003,6(6):639-642
A method for polymerizing ferrocenylanthraquinone compounds was investigated, using a methodology developed originally for the polymerization of 9,10-anthracenedithiols. This procedure uses an in situ reaction of “Lawesson’s Reagent” (p-methoxyphenylthionophosphine sulphide dimer), with anthraquinone allowing polymerization to proceed across the 9- and 10-positions of the ferrocenylanthraquinones resulting in polymers with pendant ferrocene groups on the polymer backbone. Monomers used for these reactions were anthraquinone (literature comparison), 2-ferrocenylanthraquinone and 2,6-diferrocenylanthraquinone. 相似文献
15.
Super acid catalyzed dimerization of fatty acids derived from safflower oil and dehydrated castor oil 总被引:1,自引:0,他引:1
R. A. Rajadhyaksha D. D. Chaudharl G. W. Joshi 《Journal of the American Oil Chemists' Society》1988,65(5):793-797
Dimerization of fatty acids derived from dehydrated castor oil and safflower oil was carried out on the recently described
sulphate-treated zirconia catalyst and trifluoromethane sulphonic acid (triflic acid) under autogeneous pressure in the temperature
range of 160–240 C. Triflic acid was observed to be highly active; however, the product obtained was deeply colored. Zirconia
exhibited high activity for the reaction. The important features of this catalyst were the high selectivity for dimer (low
yields of trimer) and no significant coloration of the products. The zirconia catalyst shows promise for industrial use. 相似文献
16.
A reexamination of the flaxseed hydroperoxide isomerase reaction showed that a minor enzymic product (ca. 5%), identified
as a γ-ketol, was present. The substrates were the 13- or 9-hydroperoxides of linolenic acid, which were converted to 9-hydroxy-12-oxo-cis-15-trans-11-octadecadienoic acid, respectively. These compounds were formed in addition to the major products reported earlier: a
12,13-α-ketol and 12-oxo-cis-10,15-phytodienoic acid from the 13-isomer, and a 9,10-α-ketol from the 9-isomer. 相似文献
17.
Pyrolysis of p-xylene was carried out in a tubular reactor at partial pressures varying from 0.184 kPa to 2.199 kPa with steam as a diluent. The product stream was quenched in toluene, and the solid products formed in quenching were shown to consist of p-cyclophane (acetone insoluble) and linear dimer, linear trimer and one immovable component (in TLC analysis) constituting the acetone-soluble part. Their rates of formation in the quencher were experimentally determined. The kinetic model which was used to explain the rate data of p-cyclophane formation(1) was extended to include the formation of linear dimer and trimer of p-xylene. The rate expressions derived from the kinetic model were shown to be consistent with experimental results. 相似文献
18.
Fusarium oxysporum f. sp. tulipae (FOT) secretes (+)-7-iso-jasmonoyl-(S)-isoleucine ((+)-JA-Ile) to the growth medium together with about 10 times less 9,10-dihydro-(+)-7-iso-JA-Ile. Plants and fungi form (+)-JA-Ile from 18:3n-3 via 12-oxophytodienoic acid (12-OPDA), which is formed sequentially by 13S-lipoxygenase, allene oxide synthase (AOS), and allene oxide cyclase (AOC). Plant AOC does not accept linoleic acid (18:2n-6)-derived allene oxides and dihydrojasmonates are not commonly found in plants. This raises the question whether 18:2n-6 serves as the precursor of 9,10-dihydro-JA-Ile in Fusarium, or whether the latter arises by a putative reductase activity operating on the n-3 double bond of (+)-JA-Ile or one of its precursors. Incubation of pentadeuterated (d5) 18:3n-3 with mycelia led to the formation of d5-(+)-JA-Ile whereas d5-9,10-dihydro-JA-Ile was not detectable. In contrast, d5-9,10-dihydro-(+)-JA-Ile was produced following incubation of [17,17,18,18,18-2H5]linoleic acid (d5-18:2n-6). Furthermore, 9(S),13(S)-12-oxophytoenoic acid, the 15,16-dihydro analog of 12-OPDA, was formed upon incubation of unlabeled or d5-18:2n-6. Appearance of the α-ketol, 12-oxo-13-hydroxy-9-octadecenoic acid following incubation of unlabeled or [13C18]-labeled 13(S)-hydroperoxy-9(Z),11(E)-octadecadienoic acid confirmed the involvement of AOS and the biosynthesis of the allene oxide 12,13(S)-epoxy-9,11-octadecadienoic acid. The lack of conversion of this allene oxide by AOC in higher plants necessitates the conclusion that the fungal AOC is distinct from the corresponding plant enzyme. 相似文献
19.
An isomeric mixture of linoleic acid hydroperoxides, 13-hydroperoxy-cis-9,trans-11-octadecadienoic acid (79%) and 9-hydroperoxy-cis-12,trans-10-octadecadienoic acid (21%), was decomposed homolytically by Fe(II) in an ethanol-water solution. In one series of experiments,
the hydroperoxides were decomposed by catalytic concentrations of Fe(II). The 10−5 M Fe(III) used to initiate the decomposition was kept reduced as Fe(II) by a high concentration of cysteine added to the
reaction in molar excess of the hydroperoxides. Nine different monomeric (no detectable dimeric) fatty acids were identified
from the reaction. Analyses of these fatty acids revealed that they were mixtures of positional isomers identified as follows:
(I) 13-oxo-trans,trans-(andcis,trans-) 9,11-octadecadienoic and 9-oxo-trans,trans- (andcis,trans-) 10,12-octadecadienoic acids; (II) 13-oxo-trans-9,10-epoxy-trans-11-octadecenoic and 9-oxo-trans-12, 13-epoxy-trans-10-octadecenoic acids; (III) 13-oxo-cis-9,10-epoxy-trans-11-octadecenoic and 9-oxo-cis-12, 13-epoxy-trans-10-octadecenoic acids; (IV) 13-hydroxy-9,11-octadecadienoic and 9-hydroxy-10,12-octadecadienoic acids; (V) 11-hydroxy-trans-12, 13-epoxy-cis-9-octadecenoic and 11-hydroxy-trans-9, 10-epoxy-cis-12-octadecenoic acids; (VI) 11-hydroxy-trans-12, 13-epoxy-trans-9-octadecenoic and 11-hydroxy-trans-9,10-epoxy-trans-12-octadecenoic acids; (VII) 13-oxo-9-hydroxy-trans-10-octadecenoic acids; (VIII) isomeric mixtures of 9, 12, 13-dihydroxyethoxy-trans-10-octadecenoic and 9, 10, 13-dihydroxyethoxy-trans-11-octadecenoic acids; and (IX) 9, 12, 13-trihydroxy-trans-10-octadecenoic and 9, 10, 13-trihydroxy-trans-11-octadecenoic acids. In another experiment, equimolar amounts of Fe(II) and hydroperoxide were reacted in the absence of
cysteine. A large proportion of dimeric fatty acids and a smaller amount of monomeric fatty acids resulted. The monomeric
fatty acids were examined by gas liquid chromatography-mass spectroscopy. Spectra indicated that the monomers were largely
similar to those produced by the Fe(III)-cysteine reaction.
Presented in part at the American Chemical Society Meeting, Los Angeles, March 1974.
ARS, USDA. 相似文献
20.
Sadao Matsuzawa 《Polycyclic Aromatic Compounds》2013,33(1-4):331-339
In order to obtain information about the degradability of oxygenated polycyclic aromatic hydrocarbons (oxy-PAHs) in environment, photodegradation in acetonitrile solution was studied on 9,10-phenanthrenequinone, 9-phenanthrenecarbaldehyde (phenanthrene-9-carboxaldehyde) and 1,8-naphthalenedicarboxylic anhydride (1,8-naphthalic anhydride), which are formed by fuel combustion or by photoirradiation of PAHs. A solution of the substrate was irradiated under atmospheric conditions using a xenon lamp. Photodegradation rates and information about products were obtained using HPLC with fluorescence and photodiode array detectors and GC/MS. 9,10-Phenanthrenequinone rapidly degraded by irradiation of light and yielded diphenic acid, diphenic acid anhydride, phthalic acid anhydride and some unknown compounds. Diphenic acid was a main product and it was produced at maximum upon 5-hour irradiation when degradation rate approached 100%. This reaction seems not to obey first-order equation. 9-Phenanthrenecarbaldehyde degraded slower than 9,10-phenanthrenequinone and yielded a polar unknown compound as a main product. While 1,8-naphthalenedicarboxylic anhydride showed quite stable character under irradiation of light. 相似文献