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1.
Takashi Hanzawa Hiroyuki Nishimura Junya Mizutani 《Bioscience, biotechnology, and biochemistry》2013,77(10):2393-2398
From the comparisons of mass spectral fragmentations and gas chromatographic retention times with reference compounds, volatile flavor products from UV-photolysis of S-(cis-l-propenyl)-L-cysteine in oxygen-free aqueous solutions were identical with propanal, 2-methyl-2-pentenal, n-propyl mercaptan, allyl mercaptan, 1-propenyl mercaptan, 2-methylthiophene, 3-methylthiophene, 2,3-dimethylthiophene, 2,4-dimethylthiophene, 2,5-dimethylthiophene, 3,4-dimethylthiophene, n-propyl 1-propenyl sulfide and di- 1-propenyl sulfide. Moreover, from the comparison of two-dimentional thin-layer chromatograms with reference compounds, ninhydrin-positive products with interest in terms of the degradation mechanism were identical with alanine and cystine. It seems that above-mentioned thiophene derivatives are produced via 1-propenyl thiyl radicals. 相似文献
2.
Maleylacetoacetate cis-trans isomerase together with glutathione has been found to isomerize cis-trans isomers of monomethyl muconate. Isomerization about a single double bond and concerted double isomerization of the diene unit occurs. In addition to the variations in substrate structure previously identified the current results demonstrate that a cis,cis diene skeleton and a conjugated ester function are accepted by the enzyme. The present work and the fiding of trans,trans-muconic acid in the urine of benzene-fed mice ([16.] Xenobiotica 15, 211) suggest that maleylacetoacetate cis-trans isomerase may be responsible for the geometrical isomerization. However, cis,cis-muconaldehydic acid rather than cis,cis-muconic acid is suggested to be the early intermediate in benzene metabolism capable of rapid enzyme-catalyzed cis-trans isomerization. 相似文献
3.
Competition of cyclooctenes and cyclooctadienes for ethylene binding and activity in plants 总被引:1,自引:0,他引:1
trans-Cyclooctene, cis,trans-1,5-cyclooctadiene, and cis,trans-1,3-cyclooctadiene have been compared with the cis and cis,cis isomers and with 2,5-norbornadiene for competition with ethylene for binding in mung bean sprouts and tobacco and for action (induction of chlorophyll degradation) in banana. The compounds containing a trans double bond were much more effective in competition for binding and action than the cis and cis,cis compounds. trans-Cyclooctene and cis,trans-1,3-cyclooctadiene were in the general range of 50–90 times more effective than 2,5-norbornadiene.R.J. Reynolds Research Apprentice 相似文献
4.
Isomeric monohydroperoxides produced from autoxidized methyl linoleate were separated into two geometrical isomers (cis-trans and trans-trans) by silver nitrate TLC. Purified monohydroperoxides were converted into hydroxy octadecadienoates. Trimethylsilyl (TMS) derivatives of these compounds (four components) were separated into three peaks in the gas chromatogram; the mixture of 9-hydroxy-cis,trans-isomer and 13-hydroxy-cis,trans-isomer, 9-hydroxy-trans,trans-isomer and 13-hydroxy-trans,trans-isomer. The trans-trans isomers became more dominant than the cis-trans isomers in the later stage of autoxidation and with the rise of temperature. At the degradation of monohydroperoxides, the decrease of trans- trans isomers was apparently slower than that of cis-trans isomers. It is proposed that cis,trans isomerization of monohydroperoxides takes place at the process of autoxidation of methyl linoleate. 相似文献
5.
Takayuki Oritani Kyohei Yamashita 《Bioscience, biotechnology, and biochemistry》2013,77(10):1965-1971
By microorganisms or esterase they produce, (±)-1 and 2-decalyl acetates were asymmetrically hydrolyzed to (?)-1-(R)-trans,cis-1-decalol (IIa), (+)-1-(S)-cis,cis-1-decalol (IIIb), (+)-1-(R)-cis,trans-1-decalol (IVa) and (+)-1-(S)-trans,trans-2-decalol (VIIb), (?)-cis,cis-2-decalol (IXb) with the acetates of their antipodes, whereas the axial acetates of (±)-decalols were scarecely hydrolyzed. 相似文献
6.
Masanosuke Takagi Masanari Mizutani Ichiro Matsuda Sôzaburo Ono 《Bioscience, biotechnology, and biochemistry》2013,77(5):793-796
The alkylation of α, β-unsaturated esters with n-butylbromide gave stereoselectively α-butyl-β, γ-cis-unsaturated esters in the presence of alkali amide in liquid ammonia. On the other hand, the alkylation of β, γ-cis or trans-unsaturated esters afforded α-butyl-β, cis or trans-unsaturated esters with retention of configuration. These alkylations provide a new synthetic method of preparing α-alkyl β, γ-cis or trans-unsaturated esters. 相似文献
7.
Misicka Aleksandra Verheyden Patricia M.F. Van Binst Georges 《International journal of peptide research and therapeutics》1998,5(5-6):375-377
Summary The conformationalcis-trans equilibrium around the peptide bond in model tripeptides has been determined by 2D NMR methods (HOHAHA, ROESY). The study
was limited to three different N-substituted amino acids in position 2, namely Pro (proline), Tic (1,2,3,4-tetrahydroisoquinoline-3-carboxylic
acid), and N-MePhe (N-methylphenylalanine). In all cases the amino acid in position 1 was tyrosine and in position 3, phenylalanine. The results
of our studies show that thecis-trans ratio depends mostly on the configuration of the amino acids forming the peptide bond undergoing thecis-trans isomerisation. The amino acid following the sequence (in position 3) does not have much influence on thecis-trans isomerisation, indicating that there is no interaction of the side chains between these amino acids. The model peptides with
the L-Tyr-L-AA-(L-or D-)Phe (where AA is N-substituted amino acid) chiralities give 80–100% more of thecis form in comparison to the corresponding peptides with the D-Tyr-L-AA-(L-or D-)Phe chiralities. These results indicate that
the incorporation of N-substituted amino acids in small peptides with the same chirality as the precedent amino acid involved
in the peptide bound undergoing thecis/trans isomerisation moves the equilibrium to a significant amount of thecis form. 相似文献
8.
Masanao Matsui Yasuhiro Yamada Meihan Nonoyama 《Bioscience, biotechnology, and biochemistry》2013,77(6):351-354
(±) -cis and trans-2,2-dimethyl-3- (2′-cyano-l′-propenyl) cyclopropane carboxylic acids and their optically active forms were synthesized starting from chrysanthemic acids via oximes of 2,2-dimethyl3- (2′-formyl-l′-propenyl) cyclopropane carboxylates. Their allethrolone esters were also prepared which showed insecticidal activity. 相似文献
9.
Substrate selectivity of lipases in the esterification of cis/trans-isomers and positional isomers of conjugated linoleic acid (CLA) 总被引:4,自引:0,他引:4
The substrate selectivity of several microbial lipases has been examined in the esterification of the conjugated linoleic acid (CLA) isomers cis-9,trans-11-, cis-9,cis-11-, trans-9,trans-11- and trans-10,cis-12-octadecadienoic acid with n-butanol in n-hexane. Lipases from Candida cylindracea and Mucor miehei had a preference for the cis-9,trans-11-octadecadienoic acid, while Chirazyme L-5, a Candida antarctica lipase A, accepted the trans-9,trans-11-fatty acid with a high selectivity. Moreover, lipase from Candida cylindracea and Chirazyme L-5 catalysed the esterification of the cis-9,trans-11-octadecadienoic acid with n-butanol faster than the corresponding reaction of the trans-10,cis-12-fatty acid. 相似文献
10.
Makoto Kandatsu Masaaki Horiguchi Masato Tamari 《Bioscience, biotechnology, and biochemistry》2013,77(8):779-780
Four alcohols, 1-penten-3-ol, n-amylalcohol, trans-2-hexenol and one of the linalool oxides, were newly identified as the components of carbonyl-free neutral fraction of the essential oil of black tea.On the gas chromatogram of carbonyl fraction three unknown peaks were identified with those of n-valeraldehyde, n-heptanal and trans-2-octenal.From these results almost all main components of carbonyl and carbonyl free fractions were clarified.Flavor change during the manufacture of black tea was investigated by gas chromatography. During withering, hexylalcohol, nerol, trans-2-hexenoic acid, trans-2-heхenol, linalool oxide (cis, furanoid), n-valeraldehyde, capronaldehyde, n-heptanal, trans-2-hexenal, trans-2-octenal, benzaldehyde, phenylacetaldehyde, n-butyric, isovaleric, n-caproic, cis-3-hexenoic and salicylic acids and o-cresol were increased, especially the former three greatly increased, while cis-2-pentenol, linalool, geraniol, benzylalcohol, phenylethanol and acetic acid diminished markedly. In the process of fermentation almost all constituents increased, especially, 1-penten-3-ol, cis-2-pentenol, benzylalcohol, trans-2-hexenal, benzaldehyde, n-caproic, cis-3-hexenoic and salicylic acids were remarkable.On firing, most alcohols, carbonyl and phenolic compounds decreased remarkably whereas acetic, propionic and isobutyric acids greatly increased. 相似文献
11.
Shigeo Kamiyama 《Bioscience, biotechnology, and biochemistry》2013,77(4):540-546
Leaf oil samples of four Japanese citrus species were analysed by gas chromatography to determine the detailed composition of each leaf oil. The following components were identified: α-pinene, α-thujene, camphene, β-pinene, sabinene, β-myrcene, α-terpinene, limonene, β-phellandrene, trans-2-hexen-1-al, γ-terpinene, p-cymene, terpinolene, cis-2-penten-1-ol, n-hexyl alcohol, cis-3-hexen-1-ol, trans-2-hexen-1-ol, p-α-dimethylstyrene linalool, linalyl acetate, β-elemene, terpinen-4-ol, caryophyllene, humulene, α-terpineol, neryl acetate, geranyl acetate, β-selinene, geraniol and thymol. Most components were contained in common in leaf oils of the four citrus species, but relative contents of some of the components; such as γ-terpinene, linalyl acetate, and thymol differed from species to species. For example, γ-terpinene was the major component (33.8%) of Hassaku, whereas it was only a minor component in Daidai. Daidai is characterized by a very high content of linalyl acetate (35%) which is only a trace in the other three species. Kishu-mikan is characterized by a high content of thymol (15%). 相似文献
12.
Kazuo Mukai Noriko Tsuzuki Kazuhiko Ishizu Setsuhiro Ouchi Kenji Fukuzawa 《Chemistry and physics of lipids》1984,35(3):199-208
Electron spin resonance (ESR) and electron nuclear double resonance (ENDOR) measurements were performed for the cation radicals obtained from the model compounds of α-, β-, γ- and δ-tocopherol (vitamin E) by oxidizing the tocopherol precursors in an AlCl3-CH2Cl2 solution. The proton hyperfine coupling constants g-values were precisely determined. The ENDOR spectra of the cation radicals of α-, β-, γ- and δ-tocopherol models in CH2Cl2 at ?100°C clearly show 10, 6, 6 and 12 different proton hyperfine couplings, respectively. By varying the temperature, the ESR spectra of the α- and δ-tocopherol model cations exhibit line-width alternation phenomena characteristic of the hindered rotation of the OH group. However, neither the β- nor the γ-tocopherol model cation radical ESR spectra show any sign of an alternative line-width effect. These results are interpreted by assuming that the β- and γ-tocopherol model cations are stabilized in the trans and cis conformations, respectively. On tocopherol model cations are stabilized in the trans and cis conformations, respectively. On the other hand, both the α- and δ-tocopherol model cations exist as cis and trans isomers. 相似文献
13.
《Redox report : communications in free radical research》2013,18(4):227-234
AbstractThe capacity of urocanic acid to interact with peroxyl radicals has been evaluated in several systems: oxidation in the presence of a free radical source (2,2′-azobis(2-amidinopropane; AAPH), protection of phycocyanin bleaching elicited by peroxyl radicals, and Cu(II)- and AAPH-promoted LDL oxidation. The results indicate that both isomers (cis and trans) are mild peroxyl radical scavengers. For example, trans-urocanic acid is nearly 400 times less efficient than Trolox in the protection of the peroxyl radical promoted bleaching of phycocyanin. Regarding the removal of urocanic acid by peroxyl radicals, nearly 100 μM trans-urocanic acid is required to trap half of the produced radicals under the employed conditions (10 mM AAPH, 37°C). Competitive experiments show that the cis-isomer traps peroxyl radicals ~30% less efficiently than the trans-isomer. Given the high concentrations that trans-urocanic acid reaches in skin, its capacity to trap peroxyl radicals could contribute to the protection of the tissue towards ROS-mediated processes. Furthermore, both isomers, and particularly the cis-isomer, protect LDL from Cu(II)-induced oxidation. 相似文献
14.
Toshio Yoshida Shigeru Muraki Hiroshi Kawamura Akira Komatsu 《Bioscience, biotechnology, and biochemistry》2013,77(3):343-352
The main component of Japanese Ho-leaf oil has been shown to be (?)-linalool (80~90%), and the following twenty minor constituents newly have been identified; methyl vinyl ketone, methyl isobutyl ketone, mesityl oxide, β-pinene, myrcene, (+)-limonene, cis- and trans-ocimene, n-hexanol, cis-3-hexenol, cis- and trans-linalool oxide, (?)-1-terpinen-4-ol, (+)-cis and (+)-trans-2,6,6-trimethyl-2-vinyl-5-hydroxytetrahydropyran, citronellol, nerol, (+)-β-selinene, (+)-tagetonol and (?)-trans-hotrienol. (+)-Tagetonol and (?)-trans-hotrienol have been demonstrated to be (+)-3,7-dimethyl-3-hydroxy-1-octen-5-one (III) and (3R)-(?)-trans-3,7-dimethyl-3-hydroxy-1,5,7-octatriene (IX), respectively. 相似文献
15.
Michiko Nose Yoichi Nakatani Tei Yamanishi 《Bioscience, biotechnology, and biochemistry》2013,77(2):261-271
By continuing flavor analysis of green tea from a previous paper, further twenty seven compounds were newly identified. These compounds are limonene, α-cubebene, α-copaene, caryophyllene, α-humulene, α- and γ-muurolene, β-sesquiphellandrene, δ-cadinene, calamenene, cubenol, α-cadinol, α-terpineol, n-heptanol, n-nonanol, furfurylalcohol, n-nonanal, N-ethylformylpyrrole, pyrrylmethylketone, 6-methyl-trans-3,5-heptadien-2-one, 2′,2″-dihydro-α-ionone, 6,10,14-trimethyl-2-pentadecanone, cis-3-hexenylcaproate, cis-3-hexenylbenzoate, α-terpinylacetate, coumarin and diphenylamine.Relative quantities of known compounds in intermediate- and high-boiling fraction were determined. 相似文献
16.
Hiroyuki Nishimura Akio Asahi Kazuya Fujiwara Junya Mizutani Yataro Obata 《Bioscience, biotechnology, and biochemistry》2013,77(12):1831-1835
The effect of γ-irradiation on the flavor of Onions (Senshu Yellow) associated with sprout-inhibition has been investigated. The relative amounts of propionaldehyde, n-propyl mercaptan and di-n-propyl disulfide in onions stored for 0, 5, 10, 20 and 30 days, respectively, after irradiation were estimated by measurement of peak areas of gas chromatograms. It was observed that the lachrymatory character and the pungent flavor had been decreased by γ-irradiation (remarkably at 70 and 700 Krads). In this connection, the amounts of propionaldehyde and di-n-propyl disulfide were decreased with increasing radiation dose and storage period at room temperature (20 to 25°C) and at low temperature (4°C). Moreover, it was observed that the sweetness had been decreased by γ-irradiation, but the amount of n-propyl mercaptan was increased with radiation dose and storage period. Therefore it seems that there is no correlation between the sweetness of onion and the amount of n-propyl mercaptan. 相似文献
17.
AbstractThe biomimetic model of micelles of linoleic acid containing 2-mercaptoethanol and the antioxidant was examined under gamma irradiation up to 400?Gy in aerobic or deoxygenated conditions where thiyl radicals are the main reactive species. Lipid peroxidation was retarded by ascorbic acid and α-tocopherol, whereas this process was strongly inhibited by resveratrol as effectively as the ascorbic acid/α-tocopherol mixture. Furthermore, antioxidants have a much stronger inhibitory effect on the peroxidation in the presence of 2-mercaptoethanol, and at the same time show protective properties of the double bond, decreasing the cis–trans isomerization. Under anaerobic conditions, cis–trans isomerization occurred and antioxidants efficiency increased along the series: resveratrol < α-tocopherol?<?ascorbic acid. This result is explained taking into account the double bond localization in the hydrophobic core of the micelle and the need of co-localization of the antioxidant in order to get an anti-isomerizing activity and protection of the natural lipid geometry. 相似文献
18.
Masaru Ohsaku Junya Izumi Akiar Imamura 《International journal of biological macromolecules》1984,6(5):234-240
In order to investigate the relationship existing between the electronic structures of collagen and its biochemical functions in vivo, the semiempirical CNDO/2 SCF MO calculations were carried out on several model polymers of collagen, (Gly-Pro)n, (Gly-Hyp)n, (Ala-Pro)n, (Ala-Hyp)n, (Gly-Pro-Gly)n, (Gly-Hyp-Gly)n, (Gly-Pro-Pro)n and (Gly-Pro-Hyp)n. Geometries of the skeleton of these polymers were assumed to be the same as those of poly(l-proline) I (cis) and II (trans) and the calculations were performed only on infinite polymers in a single chain. The results show that the cis form is always more stable than the trans form for all the polymers treated. This energy difference between the cis and trans forms depends, for example, on the kind of amino acid residue, Gly or Ala, but this could not be seen in the Pro or Hyp residue. The flexibility or mobility of the collagen structure was explained using the energy difference between the cis and trans forms of the polymers, i.e. the cis-trans conversion of the collagen was discussed in connection with the energy difference. The reason why the collagen has the constitution of (Gly-Pro-Hyp)n is briefly discussed. 相似文献
19.
Wakako Tsuzuki 《Chemistry and physics of lipids》2010,163(7):741-745
We investigated the heat-induced cis/trans isomerization of double bonds in monounsaturated lipids. When triolein (9-cis, 18:1) was heated around 180 °C, small amounts of isomerization products were obtained depending on the heating period. The heat-induced isomerization of triolein was considerably suppressed by the addition of different antioxidants or under nitrogen stream, and these additives simultaneously inhibited the thermal oxidation of double bonds in triolein. Therefore, an intermediate of the thermal oxidation reaction might be responsible for the heat-induced isomerization of the double bonds in triolein. The thermodynamics of the heat-induced isomerization of triolein (9-cis, 18:1) and trielaidin (9-trans, 18:1) were investigated using Arrhenius plot. The Arrhenius activation energies of cis double bonds in triolein and trans double bonds in trielaidin were 106 kJ/mol and 137 kJ/mol, respectively. The calculated internal rotational barrier heights of these double bonds were similar to those of the double bond of 2-butene radical and significantly lower than those of non-radicalized double bonds in 2-butene. These results suggest that heat-induced cis/trans isomerization of triolein and trielaidin occurs mainly through the formation of radical species, which are the intermediates produced during thermal oxidation. The activation energy difference between the two forms suggests that trans trielaidin radicals are more stable than cis triolein radicals. The high thermodynamic stability of the trans double bonds in lipid radicals would influence the population of cis and trans isomers in edible oils and contribute to slight accumulation of trans-18:1 isomers during heating or industrial processing. 相似文献
20.
C. Lanvers G. Hempel G. Blaschke J. Boos 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》1996,685(2):471
All-trans-retinoic acid (all-trans-RA) and 13-cis-retinoic acid (13-cis-RA), due to their effects on cell differentiation, proliferation and angiogenesis, improved treatment results in some malignancies. Pharmacokinetic studies of all-trans-RA and 13-cis-RA along with monitoring of retinoic acid metabolites may help to optimize retinoic acid therapy and to develop new effective strategies for the use of retinoic acids in cancer treatment. Therefore, we developed a HPLC method for the simultaneous determination in human plasma of the physiologically important retinoic acid isomers, all-trans-, 13-cis- and 9-cis-retinoic acid, their 4-oxo metabolites, 13-cis-4-oxoretinoic acid (13-cis-4-oxo-RA) and all-trans-4-oxoretinoic acid (all-trans-4-oxo-RA), and vitamin A (all-trans-retinol). Analysis performed on a silica gel column with UV detection at 350 nm using a binary multistep gradient composed on n-hexane, 2-propanolol and glacial acetic acid. For liquid-liquid extraction a mixture of n-hexane, dichloromethane and 2-propanolol was used. The limits of detection were 0.5 ng/ml for retinoic acids and 10 ng/ml for all-trans-retinol. The method showed good reproducibility for all components (within-day C.V.: 3.02–11.70%; day-to-day C.V.: 0.01–11.34%. Furthermore, 9-cis-4-oxoretinoic acid (9-cis-4-oxo-RA) is separated from all-trans-4-oxo-RA and 13-cis-4-oxo-RA. In case of clinical use of 9-cis-retinoic acid (9-cis-RA) the pharmacokinetics and metabolism of this retinoic acid isomer can also be examined. 相似文献