| | 2 | Author
| Wolfgang Lohmann, Jörg Schreiber, Walter Greulich, Leukemia | Requires cookie* | | | Title
| On the Possible Involvement of Ascorbic Acid and Copper Proteins in  | | | | Abstract
| The interaction between lyophilized samples of ascorbic acid and some copper proteins (ceru-loplasmin, cytochrome-c-oxidase, ascorbate-oxidase) has been investigated by means of ESR spec troscopy. The spectra obtained are identical to the one obtained with leukemic blood. The conse quences of this for the molecular events occuring in cancer are discussed. The model proposed can explain the experimental findings reported thus far (such as change in spin concentration with the development of cancer, the presence of a high concentration of antioxidants etc.) as well as recon-sile the two existing and seemingly contradictory hypothesis. Possible implications for lipid per oxidation and for the respiratory process are discussed. | | | |
Reference
| Z. Naturforsch. 34c, 550—554 (1979); received March 21/May 4 1979 | | | |
Published
| 1979 | | | |
Keywords
| Leukemia, ESR, Ascorbic Acid, Copper Proteins, Lipid Peroxidation | | | |
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| default:Reihe_C/34/ZNC-1979-34c-0550.pdf | | | | Identifier
| ZNC-1979-34c-0550 | | | | Volume
| 34 | |
| 3 | Author
| E. F. Elstner, H. P. Fischer, W. Osswald, G. Kwiatkowski | Requires cookie* | | | Title
| Superoxide-and Ethane-Formation in Subchloroplast Particles: Catalysis by Pyridinium Derivatives | | | | Abstract
| Oxygen reduction by chloroplast lamellae is catalyzed by low potential redox dyes with E'0 values between -0 .3 8 V and -0 .6 V. Compounds o f E'0 values o f -0 .6 7 V and lower are inactive. In subchloroplast particles with an active photosystem I but devoid of photosynthetic electron transport between the two photosystems, the active redox compounds enhance chlorophyll bleaching, superoxide formation and ethane production independent on exogenous substrates or electron donors. The activities o f these compounds decrease with decreasing redox potential, with one exception: 1-methyl-4,4'-bipyridini urn bromide with an E'0 value o f lower -1 V (and thus no electron acceptor o f photosystem I in chloroplast lamellae with intact electron transport) stimulates light dependent superoxide formation and unsaturated fatty acid peroxidation in sub chloroplast particles, maximal rates appearing after almost complete chlorophyll bleaching. Since this activity is not visible with compounds with redox potentials below -0 .6 V lacking the nitrogen atom at the 1-position o f the pyridinium substituent, we assume that 1 -methyl-4,4'-bi-pyridinium bromide is "activated" by a yet unknown light reaction. | | | |
Reference
| Z. Naturforsch. 35c, 770—775 (1980); received May 23/June 6 1980 | | | |
Published
| 1980 | | | |
Keywords
| Superoxide, Lipid Peroxidation, Ethane, Chloroplasts, Pyridinium Salts | | | |
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| | | | | TEI-XML for
| default:Reihe_C/35/ZNC-1980-35c-0770.pdf | | | | Identifier
| ZNC-1980-35c-0770 | | | | Volume
| 35 | |
| 4 | Author
| Georg Schmetterer | Requires cookie* | | | Title
| Formation of Hydrocarbons by Photobleaching Cyanobacterium, A nacystis nidulans | | | | Abstract
| The cyanobacterium Anacystis nidulans is bleached when subjected to both light and 0 2 to gether with suitable (pre)treatment o f the cells such as incubation at high (^ 4 8 °C) or low (S 17 °C) temperatures, or in presence o f metabolic inhibitors, or o f substances forming com plexes with divalent cations. Concomitantly degradation o f the intracellular membranes is ob served (G. Schmetterer, G. A. Peschek, Biochem. Physiol. Pflanzen 176, 9 0 —100 (1981)). The same three conditions cause formation o f hydrocarbons, mostly ethane, a characteristic product of lipid peroxidation. Ethane production is unchanged and still light-sensitive even when no more pigments can be detected in the cells. In "white" cells light-dependent 0 2-uptake is also observed. The action spectrum of this process suggests that "completely" bleached cells retain very small amounts of residual chlorophyll, which must be unusually resistant to photooxidation. | | | |
Reference
| Z. Naturforsch. 37c, 205 (1982); received November 51981 | | | |
Published
| 1982 | | | |
Keywords
| Photooxidation, Ethane Production, Cyanobacterium, Anacystis nidulans, Lipid Peroxidation | | | |
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| default:Reihe_C/37/ZNC-1982-37c-0205.pdf | | | | Identifier
| ZNC-1982-37c-0205 | | | | Volume
| 37 | |
| 5 | Author
| Ingo Rath, Wolfgang Barz | Requires cookie* | | | Title
| The Role of Lipid Peroxidation in Aluminium Toxicity in Soybean Cell Suspension Cultures | | | | Abstract
| The primary reactions leading to Al toxicity in plant cells have not yet been elucidated. We used soybean (Glycine max [L.] Merr.) cell suspension cultures to address the question whether lipid peroxidation plays an important role in Al toxicity. Upon transfer to an Al-containing culture medium with a calculated Al3+ activity of 15 fiM soybean cells showed a distinct and longtime increase in lipid peroxidation within 4h. At the same time a drastic loss of cell viability was observed. Butylated hydroxyanisole (BHA) and /V,/V'-diphenyl-p-phenylenediamine (D PPD), two lipophilic antioxidants, were able to almost completely sup press lipid peroxidation in A l-treated cells at a concentration of 20 ^m. This effect was dose-dependent for DPPD and was observed at minimum concentrations of 1 -2 |.i m . When lipid peroxidation was suppressed by DPPD or BHA cell viability remained high even in the presence of toxic Al concentrations. These results suggest that Al-induced enhancement of lipid peroxidation is a decisive factor for Al toxicity in suspension cultured soybean cells. | | | |
Reference
| Z. Naturforsch. 55c, 957—964 (2000); received July 20/August 29 2000 | | | |
Published
| 2000 | | | |
Keywords
| Lipid Peroxidation, Aluminium Toxicity, Glycine max | | | |
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| default:Reihe_C/55/ZNC-2000-55c-0957.pdf | | | | Identifier
| ZNC-2000-55c-0957 | | | | Volume
| 55 | |
| 6 | Author
| Krzysztof Lichszteld, Zygmunt Machoy, Anna Stępińska | Requires cookie* | | | Title
| Chemiluminescence in the Coupled Oxidation of Lecithin and Ascorbate | | | | Abstract
| Chem ilum inescence (CL) that appears during oxidation o f lecithin and ascorbate has been studied. A simple system consisting only o f purified lecithin, which has one double bond, and ascorbate as a physiological reductant with a low redox potential, was used. The CL spectrum o f lecithin contain a strong band lying in the near infrared, and three bands at 20 900 cm -1, 17 700 cm -1 and 15 800 cm -1, being characteristic o f singlet m olecular oxygen (1O a). The effect o f * 0 2 quenchers on both autooxidation processes has also been investigated. The obtained results indicate that the main emitter is the *0 2. An addition o f ascorbate to the system lecithin plus buffer causes a decrease o f CL intensity. That is a result o f stronger quenching properties o f ascorbate and not due to efficiency o f the generation o f *0 2 . | | | |
Reference
| Z. Naturforsch. 40c, 223—226 (1985); received Septem ber 13 1984 | | | |
Published
| 1985 | | | |
Keywords
| Lipid Peroxidation, Singlet Oxygen, Chem ilum inescence, Lecithin, Ascorbic Acid | | | |
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| default:Reihe_C/40/ZNC-1985-40c-0223.pdf | | | | Identifier
| ZNC-1985-40c-0223 | | | | Volume
| 40 | |
| 7 | Author
| H. Nohl, L. Gille | Requires cookie* | | | Title
| Evaluation of the Antioxidant Capacity of Ubiquinol and Dihydrolipoic Acid | | | | Abstract
| Ubiquinone and a-lipoic acid are natural constitutents which are involved in mitochondrial energy metabolism. Their bioenergetic activities require redox-cycling. In the case o f a-lipoic acid redox-cycling leads to dihydrolipoic acid which occurs in multienzyme com plexes in volved in the citric acid cycle while U Q recycles through semi-and divalently reduced ubiqui nones in the respiratory chain. We have proved the validity of the concept about the antioxi dant function o f these natural compounds in their reduced form. Ubiquinol was found to interfere with lipid peroxidation o f liposomal membranes being itself degradated by two consecutive oxidation steps. Dihydrolipoic acid was found to totally recycle ubiquinone to the antioxidant active divalently reduced form. In contrast to the antioxidative derived reaction products of ubiquinols which in turn promoted lipid peroxidation, the antioxidant derived reaction product o f dihydrolipoic acid was the unreactive two electron oxidation product a-lipoic acid. Our experim ents demonstrate the existence of an dihydrolipoic acid driven recycl ing of U Q to the antioxidative-a c tiv e U Q H 2. The efficiency o f the antioxidative capacity of the latter was found to be diminished through prooxidant activities of the antioxidant-derived metabolites. | | | |
Reference
| Z. Naturforsch. 53c, 250 (1998); received D ecem ber 19 1997/February 3 1998 | | | |
Published
| 1998 | | | |
Keywords
| Ubiquinol, Coenzyme Q, Dihydrolipoic Acid, Lipid Peroxidation, Oxygen Radicals | | | |
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| default:Reihe_C/53/ZNC-1998-53c-0250.pdf | | | | Identifier
| ZNC-1998-53c-0250 | | | | Volume
| 53 | |
| 8 | Author
| Barbara Lederer, OliverCarsten Knörzer, Peter Böger | Requires cookie* | | | Title
| Differential Gene Expression in Plants Stressed by the Peroxidizing Herbicide Oxyfluorfen | | | | Abstract
| The response of plants to the peroxidizing herbicide oxyfluorfen was investigated. The action of this p-nitrodiphenyl ether is based on inhibition of plastidic protoporphyrinogen oxidase, which leads to accumulation of protoporphyrin IX in the cytosol yielding reactive oxygen species by light activation. The induction of activities of antioxidative enzymes was followed in Nicotiana tabacum plants, var. BelW 3. Glutathione reductase activity was ele vated by 75% compared to control, m onodehydroascorbate reductase by 65% and glutathi one 5-transferase by 110% . The mRNA of ascorbate peroxidase and catalase isoform 2 was induced, the catalase isoform 1 was reduced. These findings were confirmed and supported by measuring enzymatic activity changes in photoheterotrophically grown soybean (Glycine m ax) suspension cultures. To find a possible involvement of compounds regulating oxidative stress response, we investigated the influence of salicylic acid and BTH (benzo(l,2,3)thiadia-zole-7-carbothioic acid 5-m ethylester), both inducers of pathogen defense, on soybean cell suspension cultures. The specific activities of glutathione reductase, m onodehydroascorbate reductase and glutathione 5-transferase increased strongly, comparable to oxyfluorfen treat ment. Both compounds protected the cells against oxyfluorfen-induced lipid peroxidation and alleviated the accumulation of protoporphyrin IX. | | | |
Reference
| Z. Naturforsch. 54c, 764—7 (1999); received November 8 1998/M arch 6 1999 | | | |
Published
| 1999 | | | |
Keywords
| Antioxidative Enzymes, Lipid Peroxidation, Oxidative Stress, Oxyfluorfen, Protoporphyrin IX | | | |
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| default:Reihe_C/54/ZNC-1999-54c-0764.pdf | | | | Identifier
| ZNC-1999-54c-0764 | | | | Volume
| 54 | |
| 10 | Author
| MichaelP. Percival, A. Lan, D. D. Odge | Requires cookie* | | | Title
| Photodynamic Damage to Isolated Chloroplasts: A Possible Model for in vivo Effects of Photosynthetic Inhibitor Herbicides | | | | Abstract
| The breakdown o f chlorophylls, carotenoids, and linolenic acid together with the form ation o f malondialdehyde and ethane was followed in isolated pea chloroplast membranes. Breakdown was enhanced by light, oxygen, D 20 and rose bengal, but retarded by crocetin. The results are discussed in relationship to the role o f singlet oxygen in prom oting dam age in vivo. | | | |
Reference
| Z. Naturforsch. 39c, 482 (1984); received Decem ber 5 1983 | | | |
Published
| 1984 | | | |
Keywords
| Chloroplast Membranes, Lipid Peroxidation, Singlet O xygen, H erbicide D am age, Chloroplast Pigments | | | |
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| default:Reihe_C/39/ZNC-1984-39c-0482.pdf | | | | Identifier
| ZNC-1984-39c-0482 | | | | Volume
| 39 | |
| 11 | Author
| Werner Meyer, G.Erhard Spiteller | Requires cookie* | | | Title
| Increase of Caryophyllene Oxide in Ageing Lemon Balm Leaves (Melissa officinalis L.) -A Consequence of Lipid Peroxidation? | | | | Abstract
| Oxidative processes, especially lipid peroxidation (LPO), are assumed to increase during ageing. In an attempt to provide experimental evidence for this assumption lemon balm plants (Melissa officinalis L.) of different age and location were analyzed for oxidatively caused changes in the etheric oil composition. The investigation revealed that the caryophyl lene oxide (CarO) content of lemon balm plants -a main constituent -depends on two factors: age and habitat. The content of CarO increased with age continuously up to a factor of 3. Poor nutritive conditions, as growth on unfertilized soil, also caused an increase in CarO content. Addition of Fe2+/ascorbate -enhancing oxidative processes -promoted the formation of CarO. Hydroperoxides of unsaturated fatty acids (L O O H s) in the lipid extract of lemon balm leaves were converted to corresponding hydroxy acids (LO H s) by sodium borohydride re duction. These were hydrogenated and subjected to GC/MS analysis after derivatisation. A surplus of 9-hydroxy-octadecanoic acid over the 13 isomer indicated at least in part enzymatic lipid peroxidation. Polarographie determination o f the oxygen consumption revealed a gen erally low but in ageing plants increased lipoxygenase activity. This indicates a contribution of lipid peroxidation in the epoxidation process of caryophyllene. | | | |
Reference
| Z. Naturforsch. 51c, 651 (1996); received May 17/June 12 1996 | | | |
Published
| 1996 | | | |
Keywords
| Melissa officinalis, Lemon Balm, Caryophyllene Oxide, Lipid Peroxidation, Lipoxygenase Activity, Ageing | | | |
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| default:Reihe_C/51/ZNC-1996-51c-0651.pdf | | | | Identifier
| ZNC-1996-51c-0651 | | | | Volume
| 51 | |
| 12 | Author
| C. Scheick, G. S. Piteller1, W. Fröhlichb | Requires cookie* | | | Title
| Human Neutrophil Chemotaxis in Response to Diepoxides o f Linolenic Acid | | | | Abstract
| Diepoxides of linolenic acid were found to be chemoattractants. The concentration that produces 50% of maximal chemotaxis was 4.5 IO 7 mol/1 for human neutrophils when investi gated in a chemotaxis test based on the method of spectrophotometric determ ination of myeloperoxidase activity with buffers containing bovine serum albumin. Leukotriene B4 was used as positive control. The concentration of leukotriene B4 that produces 50% of maximal chemotaxis was 1.8 nmol/1. No chemotactic activity was observed when monoepoxides of linoleic or linolenic acid, diepoxides of linoleic acid or triepoxides of linolenic acid were used. Mono-, di-and triepoxides of polyunsaturated fatty acids were synthesized with meta-chloroperbenzoic acid, separated by TLC and HPLC and identified by GC/MS. | | | |
Reference
| Z. Naturforsch. 51c, 877—882 (1996); received July 8/August 5 1996 | | | |
Published
| 1996 | | | |
Keywords
| Chemoattractants, H um an Neutrophils, Myeloperoxidase, Linolenic Acid Diepoxides, Lipid Peroxidation | | | |
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| default:Reihe_C/51/ZNC-1996-51c-0877.pdf | | | | Identifier
| ZNC-1996-51c-0877 | | | | Volume
| 51 | |
| 13 | Author
| Melánia Babincová3, Eva Machováb, Grigorij Koganb | Requires cookie* | | | Title
| Carboxymethylated Glucan Inhibits Lipid Peroxidation in Liposomes | | | | Abstract
| Protective capabilities were studied of carboxymethylated (1—*3)-ß-D-glucan from Sacchar omyces cerevisiae cell wall against lipid peroxidation in phosphatidylcholine liposomes in duced by O H radicals produced with Fenton's reagent (H 20 2/Fe2+) and also by microwave radiation using absorption UV-VIS spectrophotometry. A significant decrease in the conju gated diene production, quantified as Klein oxidation index, was observed in the presence of a moderate amount of added glucan. Increase of the oxidation index was accompanied with enhanced carboxyfluorescein leakage as a result of liposome membrane destabilization. This process was markedly suppressed with glucan present in the liposome suspension. There fore, glucan may be considered as a potent protector against microwave radiation-induced cell damage. | | | |
Reference
| Z. Naturforsch. 54c, 1084—1088 (1999); received July 5/July 27 1999 | | | |
Published
| 1999 | | | |
Keywords
| Liposomes, (l-^3)-ß-D-glucan, Microwave Radiation, Lipid Peroxidation, Membrane Destabilization | | | |
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| default:Reihe_C/54/ZNC-1999-54c-1084.pdf | | | | Identifier
| ZNC-1999-54c-1084 | | | | Volume
| 54 | |
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