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1.
The degradation products formed from methyl linoleate hydroperoxides by reaction with heme were fractionated by Sephadex LH-20
column chromatography and by reverse-phase high performance liquid chromatography, and the ability of each compound to form
fluorescent substances through reaction with amino compound was compared. Maximum formation of fluorescent substances was
obtained from monomeric degradation products with amino compound, but low molecular weight aldehydes such as hexanal, 2-hexenal
and 2,4-decadienal, formed only a small amount of fluorescent substances. However, the major monomeric degradation products
described previously, the hydroxy-, keto- and epoxy-derivatives, do not significantly contribute to the formation of fluorescent
substances through reaction with amino compound. It was suggested that formation of fluorescent substances from lipid peroxides
with amino compound may originate from a precursor present in monomeric degradation products formed from hydroperoxide of
methyl linoleate during lipid peroxidation, and that low molecular weight aliphatic aldehydes are not involved in fluorescent
substance formation. Moreover, the majority of TBA-reactive substances in secondary oxidation products prepared from autoxidized
methyl linoleate are also unrelated to the formation of fluorescent substances through reaction with amino compound. 相似文献
2.
Reaction of gossypol with amino acids and other amino compounds 总被引:1,自引:0,他引:1
The reactions of gossypol with certain amino acids and other amino compounds have been studied spectroscopically with respect
to the effect of time and pH in the range from 5.7 to 7.5 at 37 C. The rate of reaction of gossypol with amino acids increases
with increase in pH and has been shown to be related to the distance of the amino group from the carboxyl group within the
molecule. Reaction products of gossypol with amino acids and other amino compounds were subjected to various purification
procedures and analysis to determine combination ratios. In addition to the expected gossypol-to-amino compound ratio of 1:2,
dictated by the formation of Schiff base-type bonds with the two aldehyde groups of gossypol, compounds with ratios of 1:3
and 1:4 were isolated. These results indicate that each of the two aldehyde groups of gossypol can react with two amino groups
under the conditions studied.
Deceased March 9, 1969. 相似文献
3.
Commercial soybean lipoxygenase may be used under carefully controlled reaction conditions to give high yields of lipid hydroperoxides.
Lipid hydroperoxides so derived from γ-linolenic or arachidonic acid may be purified by high pressure liquid chromatography.
Thus, commercial lipoxygenase serves as a viable source for 100 mg quantities of lipid hydroperoxides. 相似文献
4.
5.
Toshiki Tsubota Yuta Hagiwara Naoya Murakami Teruhisa Ohno 《Diamond and Related Materials》2009,18(9):1174-1178
Various organic compounds can be immobilized on a diamond surface if a chemically active organic functional group, such as an NH2 group, is introduced on the diamond surface. We therefore attempted to introduce an NH2 group on a diamond surface by using chemical reaction of a hydrogenated diamond surface with an amino acid and NCS (N-chlorosuccinimide). From our previous experimental results (Diamond Relat. Mater., 15, 668 (2006)), we expected that a functional group could be introduced on the diamond surface. However, there was no peak assigned to the NH2 group in the IR spectra for diamond powder treated with amino acids. The diamond powder treated with L-serine, L(?)-threonine, L(?)-phenylalanine, L(+)-arginine, L-histidine, or L-asparagine monohydrate had a specific peak at 2275 cm? 1 in the IR spectra. Moreover, the diamond powder treated with L(?)-threonine had the highest intensity of the peak at 2275 cm? 1. Therefore, the chemical reaction of a hydrogenated diamond surface with L(?)-threonine was further examined in detail. Unfortunately, the assignment of the peak at 2275 cm? 1 was unclear. However, we speculate from the compounds in the chemical reaction process that the peak is assigned to the CN group, although the peak position is slightly different from that of the normal CN group. 相似文献
6.
7.
The cluster formation of several aromatic carboxylic acids, ferulic acid, vanillic acid, sinapinic acid, and 3,4-dihydroxybenzoic acid was investigated by means of laser desorption into a supersonic beam followed by multiphoton ionization-time-of-flight mass spectrometry. The formation of not only homogeneous clusters, but also of heterogeneous clusters with some small amino acids was studied. The different neutral clusters formed in the supersonic expansion were ionized by a multiphoton process employing either nano- or femtosecond laser pulses. Strong differences in the detection of cluster ions due to the laser pulse length employed for multiphoton ionization were observed. Only femtosecond activation led to mass spectra with intense signals of the cluster ions. In addition, in the case of femtosecond ionization, protonated amino acids were detected in the mass spectra. As direct ionization of the free amino acids is not possible under the chosen ionization conditions because they lack an adequate chromophore, these protonated amino acids are assumed to be formed via an intracluster proton transfer in the heterogeneous dimer and subsequent decay of the ionized cluster (dissociative proton transfer). Such well-known processes for heterogeneous clusters consisting of a substituted aromatic molecule and small polar solvent molecules may be involved in the matrixassisted laser desorption ionization (MALDI) process. 相似文献
8.
Linoleate is oxygenated by manganese-lipoxygenase (Mn-LO) to 11S-hydroperoxylinoleic acid and 13R-hydroperoxyoctadeca-9Z,11E-dienoic acid, whereas linoleate diol synthase (LDS) converts linoleate sequentially to 8R-hydroperoxylinoleate, through an 8-dioxygenase by insertion of molecular oxygen, and to 7S,8S-dihydroxylinoleate, through a hydroperoxide isomerase by intramolecular oxygen transfer. We have used liquid chromatography-mass
spectrometry (LC-MS) with an ion trap mass spectrometer to study the MSn mass spectra of the main metabolites of oleic, linoleic, α-linolenic and γ-linolenic acids, which are formed by Mn-LO and
by LDS. The enzymes were purified from the culture broth (Mn-LO) and mycelium (LDS) of the fungus Gaeumannomyces graminis. MS3 analysis of hydroperoxides and MS2 analysis of dihydroxy- and monohydroxy metabolites yielded many fragments with information on the position of oxygenated
carbons. Mn-LO oxygenated C-11 and C-13 of 18∶2n−6, 18∶3n−3, and 18∶3n−6 in a ratio of ∼1∶1–3 at high substrate concentrations.
8-Hydroxy-9(10)expoxystearate was identified as a novel metabolite of LDS and oleic acid by LC-MS and by gas chromatography-MS.
We conclude that LC-MS with MSn is a convenient tool for detection and identification of hydroperoxy fatty acids and other metabolites of these enzymes. 相似文献
9.
Kenji Fukuzawa Katsuya Kishikawa Akira Tokumura Hiroaki Tsukatani Masayuki Shibuya 《Lipids》1985,20(12):854-861
The fluorescent products formed on reaction of 12-oxo-cis-9-octadecenoic acid (12-keto-oleic acid) with about 20 different amino acids, polylysine and bovine serum albumin (BSA) were
studied. Besides glycine, only the basic amino acids histidine, lysine and arginine gave products with strong fluorescence.
N-Acetylation of amino acids greatly reduced the fluorescence of their reaction products. The formation of fluorescent products
was inhibited strongly by SH-amino acids such as N-acetyl-cysteine and glutathione. Polyacrylamide gel electrophoresis showed
that BSA treated with 12-keto-oleic acid was more acidic than untreated or ricinoleic acid-treated BSA, indicating that basic
amino acid residues in BSA were modified by reaction with the keto fatty acid. None of the structural analogs of 12-keto-oleic
acid tested–12-oxo-trans-10-octadecenoic acid, 12-oxo-octadecanoic acid, 12-hydroxy-cis-9-octadecenoic acid (ricinoleic acid),cis-9-octadecenoic acid (oleic acid) and linoleic acid—reacted with glycine to give a fluorescent product. The fluorescent products
formed on reaction of 12-keto-oleic acid methyl ester with benzyl amine and glycine methyl ester were shown to be 8-(N-substituted-4,5-dihydro-4-oxo-5-hexyl-5-hydroxy-2-pyrrolyl)
octanoic acid methyl esters. The fluorescence properties of these compounds were attributed to the chromophobic system NC=CC=O
which contains 6π electrons. This investigation contributes to insight of the mechanism of formation of fluorescent pigments,
probably by a similar reaction of other compounds of the β,γ-unsaturated carbonyl type. 相似文献
10.
Treatment of monofunctional aliphatic aldehydes (alkanals, 2-alkenals and 2,4-alkadienals) with methylamine at pH 7 produced
fluorescence with excitation maxima at 340–360 nm and emission maxima at 410–470 nm. The reaction of 1-butanal and methylamine
gave 2-ethyl-2-hexenal (ii), an aldol condensation product of 1-butanal, and 3,5-diethyl-2-propyl-1-methylpyridinium salt
(i). The fluorescence was formed by the reaction of 1-butanal and/or ii with methylamine in the presence of molecular oxygen.
Fluorescent products I, II and III formed by the reaction were partially purified. Fluorescence characteristics of I, II and
III were close to those of the fluorophores derived from the reaction of oxidized fatty acids and primary amines, with respect
to maximum wavelengths in excitation and emission, and the resistance to sodium borohydride reduction. 相似文献
11.
A new technique, high-performance liquid chromatography with reductive mode electrochemical detection on a mercury drop (HPLC-EC),
has been used for analyzing lipid hydroperoxide (LOOH) formation in photooxidatively stressed L1210 leukemia cells. Highly
specific and sensitive for peroxides (detection limits <0.5 pmol for cholesterol hydroperoxides and <50 pmol for phospholipid
hydroperoxides), this approach allows different classes of LOOH to be separated and determined in minimally damaged cells.
L1210 cells in serum-containing growth medium were irradiated in the presence of merocyanine 540 (MC540), a lipophilic photosensitizing
dye. Lipid extracts from cells exposed to a light fluence of 0.11 J/cm2 (which reduced clonally assessed survival by 30%) showed 12–15 well-defined peaks in HPLC-EC. None of these peaks was observed
when cells were irradiated without MC540 or when dye/light-treated samples were reduced with triphenylphosphine prior to analysis.
Three peaks of relatively low retention time (<12 min) were assigned to the following species by virtue of comigration with
authentic standards: 3β-hydroxy-5α-cholest-6-ene-5-hydroperoxide (5α-OOH), 3β-hydroxycholest-4-ene-6β-hydroperoxide (6β-OOH),
and 3β-hydroxycholest-5-ene-7α/7β-hydroperoxide (7α/7β-OOH). Formation of 5α-OOH and 6β-OOH (singlet oxygen adducts) was confirmed
by subjecting [14C]cholesterol-labeled cells to relatively high levels of photooxidation and analyzing extracted lipids by HPLC with radiochemical
detection. Material represented in a major peak at 18–22 min on HPLC-EC was isolated in relatively large amounts by semipreparative
HPLC and shown to contain phospholipid hydroperoxides (predominantly phosphatidylcholine species, PCOOH) according to the
following criteria: (i) decay of 18–22 min peak during Ca2+/phospholipase A2 treatment, with reciprocal appearance of fatty acid hydroperoxides; (ii) reduction of peroxide during treatment with reduced
glutathione and phospholipid hydroperoxide glutathione peroxidase, but not glutathione peroxidase; and (iii) comigration with
PCOOH standards in thin-layer chromatography. HPLC-EC analysis revealed quantifiable amounts ofPCOOH and ChOOH at a light
fluence that clonally inactivated <10% of the cells, which allows for the possibility that photoperoxidative damage plays
a causal role in cell killing.
This paper is based on a dissertation submitted by G.J. Bachowski in partial fulfillment of the requirements for a Ph.D. degree
in Biochemistry at the Medical College of Wisconsin (Milwaukee, WI). 相似文献
12.
A modified method for peroxide value (POV) determination of lipids was developed through the application of potentiometry
to conventional POV tests such as the official method of the Japan Oil Chemists’ Society (JOCS). The new method permits a
simple and reliable determination of low hydroperoxide levels in the initial stages of lipid autoxidation when only very small
amounts of sample are available, even when those levels are measured on less than 10 mg of lipid. Using the present method,
hydroperoxide levels as low as 20 nanoequivalents (neq) were determined with reasonable precision. This method is applicable
to all lipids tested including oils and fats, free fatty acids, phospholipids, glycolipids and cholesterol esters. 相似文献
13.
14.
A flow injection analysis (FIA) system coupled with a fluorescence detection system using diphenyl-1-pyrenylphosphine (DPPP)
was developed as a highly sensitive and reproducible quantitative method of total lipid hydroperoxide analysis. Fluorescence
analysis of DPPP oxide generated by the reaction of lipid hydroperoxides with DPPP enabled a quantitative determination of
the total amount of lipid hydroperoxides. Use of 1-myristoyl-2-(12-((7-nitro-2-1,3-benzoxadiazol-4-yl)amino) dodecanoyl)-sn-glycero-3-phosphocholine as the internal standard improved the sensitivity and reproducibility of the analysis. Several commercially
available edible oils, including soybean oil, rapeseed oil, olive oil, corn oil, canola oil, safflower oil, mixed vegetable
oils, cod liver oil, and sardine oil were analyzed by the FIA system for the quantitative determination of total lipid hydroperoxides.
The minimal amounts of sample oils required were 50 μg of soybean oil (PV=2.71 meq/kg) and 3 mg of sardine oil (PV=0.38 meq/kg)
for a single injection. Thus, sensitivity was sufficient for the detection of a small amount and/or low concentration of hydroperoxides
in common edible oils. The recovery of sample oils for the FIA system ranged between 87.2±2.6% and 102±5.1% when PV ranged
between 0.38 and 58.8 meq/kg. The CV in the analyses of soybean oil (PV=3.25 meq/kg), cod liver oil (PV=6.71 meq/kg), rapeseed
oil (PV=12.3 meq/kg), and sardine oil (PV=63.8 meq/kg) were 4.31, 5.66, 8.27, and 11.2%, respectively, demonstrating sufficient
reproducibility of the FIA system for the determination of lipid hydroperoxides. The squared correlation (r
2) between the FIA system and the official AOCS iodometric titration method in a linear regression analysis was estimated at
0.9976 within the range of 0.35−77.8 meq/kg of PV (n=42). Thus, the FIA system provided satisfactory detection limits, recovery, and reproducibility. The FIA system was further
applied to evaluate changes in the total amounts of lipid hydroperoxides in fish muscle stored on ice. 相似文献
15.
A fluorescent image analysis method was developed to evaluate lipid hydroperoxide formation in fish muscle. The lipid hydroperoxides
generated in white and dark fish muscles during storage at 5–6°C oxidized 3-perylene diphenylphosphine located in the tissue
to yield the fluorescent derivative, 3-perylene diphenylphosphine oxide (3-PeDPPO). 3-PeDPPO thus obtained was determined
by digital fluorescent image analysis. The 3-PeDPPO fluorescence intensity of white and dark muscle increased during low-temperature
storage (0–24 h) and was clearly correlated with total lipid hydroperoxide levels in muscle extracts, which were determined
by using HPLC based on a triphenylphosphine oxidation method (R
2=0.954). These results suggest that 3-PeDPPO fluorescence, coupled with fluorescent image analysis, is a novel tool for direct
determination of lipid hydroperoxides in fish muscle without a need for extraction of lipid. 相似文献
16.
17.
The coloring reaction of the thiobarbituric acid test for hydroperoxides was completely inhibited by the addition of EDTA.
Therefore, it was necessary to add a metal salt to the reaction mixture to complete the reaction and also to add an antioxidant
to prevent autoxidation when unoxidized unsaturated fatty acids co-exist. The optimal pH of the reaction was found at 3.6
using glycine-hydrochloric acid buffer. 相似文献
18.
NO‐induced decomposition of hydroperoxides in solid polypropylene and cumyl hydroperoxide, dissolved in n‐decane, at 25°C was studied. Analysis of kinetic regularities of hydroperoxide decomposition and nitroxide radical accumulation leads to the conclusion that both in solids and in solutions these reactions have the autoaccelerated character. The induction periods are determined by trace amounts of impurities (probably of higher nitrogen oxides).The maximum rate of the process depends on the NO pressure. The possible reaction mechanisms are supposed, and the key role is assigned to the formed nitrosocompounds. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 407–414, 2001 相似文献
19.
Y. Yamamoto E. Niki R. Tanimura Y. Kamiya 《Journal of the American Oil Chemists' Society》1985,62(8):1248-1250
Sodium hypochlorite (NaOCl) induced decomposition of organic hydroperoxides gave strong chemiluminescence. Chemiluminescence
intensity reached its maximum a few seconds after the addition of sodium hypochlorite and decreased to the background level
in three min. Good linear relationships were observed between total chemiluminescence counts in three min and the amounts
of hydroperoxides. This chemiluminescence method can be applied to the detection of low levels of lipid hydroperoxides. 相似文献
20.
Klaus Vosmann Erhard Schulte Erika Klein Nikolaus Weber 《European Journal of Lipid Science and Technology》1998,100(8):334-342
Base-catalyzed transesterification of acyl lipids with methanol in the presence of trimethylsulfonium hydroxide (TMSH) is an easy and convenient method for the preparation of fatty acid methyl esters for GC analyses. However, lipids containing functional groups such as amino, amide and hydroxy groups are converted in varying degrees to the corresponding N- and O-methyl derivatives by the pyrolytic reaction of TMSH occurring in the injector of the gas chromatograph. For example, lipids containing amino or amide groups are converted into the corresponding N-methyl and N,N-dimethyl derivatives, fatty acid ethanolamides to the corresponding N-methyl, O-methyl and N,O-dimethyl derivatives, whereas alkyl methyl ethers are formed from long-chain alcohols. Furthermore, 2-O- and 3-O-monomethyl ethers as well as 2,3-di-O-methyl ethers are formed from 1-O-alkylglycerols, methoxy fatty acid methyl esters from hydroxy fatty acids as well as steryl 3β-O-methyl ethers from cholesterol and other sterols. Since some of the mentioned artefacts may interfere with fatty acid methyl esters in GC separations the TMSH derivatization method is recommended only with caution for lipids containing amino, amide and hydroxy groups. The methylation reactions, which finally lead to the corresponding N-methyl, O-methyl, N,N-dimethyl or N,O-dimethyl derivatives of fatty acids and lipids may, however, be of some diagnostic value for the structural analysis of such lipids by GC/MS. 相似文献