Go toArchive
Browse byFacets
Bookbag ( 0 )
'Antioxidants' in keywords
Results  7 Items
Sorted by   
Publication Year
1999 (2)
1998 (3)
1995 (1)
1984 (1)
1Author    K. K. Arl-Josef, UnertRequires cookie*
 Title    The Diphenyl-Ether Herbicide Oxyfluorfen: A Potent Inducer of Lipid Peroxidation in Higher Plants  
 Abstract    Measurements o f ethane and ethylene as indices o f in vivo lipid peroxidation and o f chemically-induced stress, respectively, were done on mustard seedlings (Sinapis alba), treated with oxy-fluorfen[2-chloro-l-(3-ethoxy-4-nitrophenoxy)-4-(trifluorom ethyl)benzene]. W hen seedlings were exposed to low light intensity o f 14 W /m 2, only stress-ethylene production but not per­ oxidative ethane evolution was significantly higher over 1 0 days in herbicide-treated seedlings than in the untreated control. Exposure to high light intensity o f 390 W /m 2 did not increase stress-ethylene production in oxyfluorfen-treated plants after 24 h. Lipid peroxidation, however, measured as ethane evolution, was substantially higher after 24 h in herbicide-treated plants, exposed to high light intensity, than in the control, and peroxidation was directly related to strong oxidation o f antioxidants and to severe membrane dam age. 
  Reference    Z. Naturforsch. 39c, 476—481 (1984); received September 15 1983 
  Published    1984 
  Keywords    Herbicide, Diphenyl Ether, Peroxidation, Antioxidants 
  Similar Items    Find
 TEI-XML for    default:Reihe_C/39/ZNC-1984-39c-0476.pdf 
 Identifier    ZNC-1984-39c-0476 
 Volume    39 
2Author    J. Gabrielska, J. Sarapuk, S. PrzestalskiRequires cookie*
 Title    Antioxidant Protection of Egg Lecithin Liposomes during Sonication  
 Abstract    When model membranes are prepared by ultrasonic treatm ent of polyunsaturated phos­ pholipids, radical production can induce a partial degradation of the polyunsaturated fatty acyl chains and the formation of lipid hydroperoxides. A suitable antioxidant employed dur­ ing liposome preparation is able to protect them against lipid peroxidation. This work con­ tains the results of studies on egg lecithin liposomes with incorporated antioxidants that were supposed to play the protective role mentioned. As it has been shown the antioxidant com pounds used ensured a 40-60% , i.e., satisfactory protection of liposomes after 30 min sonication. Possible practical applications are discussed. 
  Reference    Z. Naturforsch. 50c, 561—564 (1995); received March 10/May 11 1995 
  Published    1995 
  Keywords    Lecithin, Sonication, Liposomes, Lipid Hydroperoxides, Antioxidants 
  Similar Items    Find
 TEI-XML for    default:Reihe_C/50/ZNC-1995-50c-0561.pdf 
 Identifier    ZNC-1995-50c-0561 
 Volume    50 
3Author    Janina Gabrielska3, Jan Oszmiańskib, Małgorzata Komorowskac, Marek Langner3Requires cookie*
 Title    Anthocyanin Extracts with Antioxidant and Radical Scavenging Effect  
 Abstract    The antioxidative activity of three anthocyanin pigments, extracted from the fruits of chokeberry, honeysuckle and sloe, were studied. Lipid oxidation in the liposome membrane, induced by UV radiation, was evaluated with a thiobarbituric acid-reactive substances assay. The antioxidant efficiency of the studied compounds follows this sequence: chokeberry > sloe > honeysuckle. The extract concentrations at which a 50% reduction of phosphatidylcho­ line oxidation was observed, were respectively: 48, 54 and 60 mg/1. The end products of lipid membrane oxidation were evaluated using HPLC. It was found that the antioxidative potency of anthocyanin extracts is concentration-dependent. As shown by E P R technique the effi­ ciency of the extracts to eliminate free radicals from the solution follows the order of the antioxidant activity. 
  Reference    Z. Naturforsch. 54c, 319 (1999); received December 2 1998/January 22 1999 
  Published    1999 
  Keywords    Antioxidant, Anthocyanin, Liposome, TBA -Reactive Product 
  Similar Items    Find
 TEI-XML for    default:Reihe_C/54/ZNC-1999-54c-0319.pdf 
 Identifier    ZNC-1999-54c-0319 
 Volume    54 
4Author    UteR. Ohnert3, W. Erner Schneider5, ErichF. Elstner3Requires cookie*
 Title    Superoxide-Dependent and -Independent Nitrite Formation from Hydroxylamine: Inhibition by Plant Extracts  
 Abstract    Reactive oxygen species such as OH-, peroxynitrite and the non-radical, hypochlorous acid, play outstanding roles in many diseases. The formation of OH-(Fenton-)-type radicals is catalyzed by enzymes such as xanthine oxidase (X O D) via one-electron reduction of m o­ lecular oxygen producing superoxide radical anions (0 2 _). Subsequent transfer of one elec­ tron to hydrogen peroxide by Fe2+ or Cu+-ions yields OH-radicals measurable as ethene release from l-keto-4 methylthiobutyrate (KM B). Xanthine oxidase or activated neutrophils are prominent sources o f this strong oxidant produced at inflammatory sites. Many natural compounds such as salicylates or flavonoids interfere either with the pro­ duction of these activated oxygen species or function as radical scavengers and thus as antiox­ idants. Extracts from willow-bark (Salix spec.) and also other species such as ash-tree (Fraxi-nus spec.) or poplar (Populus spec.) have been used as antiinflammatory drugs since a long time. In this communication we wish to report on model reactions to demonstrate a) the radical scavenging activities of such plant extracts inhibiting ethene release from KMB induced by Fenton-type oxidants and b) the inhibition of the formation of nitrogen monoxide (N O) from hydroxylamine includ­ ing X O D either in the presence or absence of myoglobin (M YO) measurable as nitrite forma­ tion: In the absence of MYO, superoxide dismutase is an excellent inhibitor of nitrite forma­ tion but is inactive in its presence. Extracts from the willow-bark or the drug PhytodolorR, however, are inhibitory both in the presence and absence of MYO. As active principle, the flavonoid rutin included in these extracts is likely to function as one inhibitor of the X O D -mediated reaction. 
  Reference    Z. Naturforsch. 53c, 241 (1998); received December 19 1997/January 29 1998 
  Published    1998 
  Keywords    Reactive O xygen Species, Plant-Extracts, Antioxidants, NO-Formation, Xanthine Oxidase 
  Similar Items    Find
 TEI-XML for    default:Reihe_C/53/ZNC-1998-53c-0241.pdf 
 Identifier    ZNC-1998-53c-0241 
 Volume    53 
5Author    H. Kleszczyńska3, M. O. Święcimskab, S. W. Itekb, S. PrzestalskiaRequires cookie*
 Title    Inhibition of Lipid Peroxidation in the Erythrocyte Membrane by Quaternary Morpholinium Salts with Antioxidant Function  
 Abstract    The antioxidant activity of five new compounds from a group of quaternary ammonium salts with antioxidant function has been investigated. The effect of the compounds on the degree of lipid oxidation in the erythrocyte membrane subjected to UV radiation was studied. It was found that all the salts used decreased oxidation of the lipids in the erythrocyte mem­ brane. The antioxidant activity of the ammonium salts studied increased with their alkyl chain length. Three compounds with the longest alkyl chains were the most active antioxidants, and their antioxidant properties were comparable to those of a flavonoid extracted from haw­ thorn. The antioxidant effectiveness of the ten-carbon alkyl chain compound was comparable with that of the known antioxidant 3,5-di-t-butyl-4-hydroxytoluene (BHT). The least effective antioxidant studied proved to be the eight-carbon alkyl chain compound. The effect of these compounds on fluidity of the erythrocyte membrane has been studied, and for all an increase of fluidity of the membrane was observed. The changes in erythrocyte ghosts fluidity de­ pended both on concentration and type of compound. A fluorimetric study also indicated that rigidity of the erythrocyte membrane increased with degree of its oxidation, but with antioxidants present membrane rigidity increased less. 
  Reference    Z. Naturforsch. 53c, 425—430 (1998); received January 26/March 16 1998 
  Published    1998 
  Keywords    Antioxidants, Lipid Oxidation, Erythrocyte Ghost, Quaternary Ammonium Salts, Plant Flavonoid 
  Similar Items    Find
 TEI-XML for    default:Reihe_C/53/ZNC-1998-53c-0425.pdf 
 Identifier    ZNC-1998-53c-0425 
 Volume    53 
6Author    Halina Kleszczyńska3, MałgorzataO. Święcimskab, Janusz Sarapuk3, Stanisław Witekb, Stanisław Przestalski3Requires cookie*
 Title    Protective Effect of Quaternary Piperidinium Salts on Lipid Oxidation in the Erythrocyte Membrane  
 Abstract    A new series of amphiphilic compounds with incorporated antioxidant functional group has been investigated. Piperidinium bromides, differing in the alkyl chain length (8, 10, 12, 14 and 16 carbon atoms in the chain) were synthesised to protect biological and/or model membranes against peroxidation and following negative consequences. Their antioxidant ac­ tivity was studied with erythrocytes subjected to UV radiation. The salts used inhibited lipid oxidation in the erythrocyte membrane. The degree of this inhibition depended on the alkyl chain length of the bromide used and increased with increasing alkyl chain length. A compar­ ison of the results obtained for piperidinium bromides with those obtained for the widely used antioxidant 3,5-di-r-butyl-4-hydroxytoluene (BH T) revealed that only two shortest alkyl chain salts were less efficient than BH T in protecting erythrocyte membranes. A similar comparison with antioxidant efficiency of flavonoids extracted from Rosa rugosa showed that they protected the membranes studied more weakly than the least effective eight-carbon alkyl chain piperidinium bromide. The three compounds of longest alkyl chains were the most active antioxidants. Their activities did not differ significantly. 
  Reference    Z. Naturforsch. 54c, 424 (1999); received January 22/February 24 1999 
  Published    1999 
  Keywords    Antioxidants, Lipid Oxidation, Erythrocyte Membrane, Quaternary Piperidinium Salts, Flavonoids 
  Similar Items    Find
 TEI-XML for    default:Reihe_C/54/ZNC-1999-54c-0424.pdf 
 Identifier    ZNC-1999-54c-0424 
 Volume    54 
7Author    UteR. Ohnert3, Dagmar Koske3, W. Erner Schneider5, ErichF. Elstner3Requires cookie*
 Title    Inhibition by Salix-Extracts and PhytodolorR of Copper-Catalyzed Oxidative Destructions  
 Abstract    Oxidation of low density lipoprotein (LD L) by copper ions is strongly inhibited by dif­ ferent aqueous extracts (Salix spec (SE); Fraxinus-Solidago-Populus (PhytodolorR)(P D)) in a concentration range between 4 and 7 [ig/ml. 10 to 50 [.i m salicylic acid (SA) stimulate LDL-oxidation whereas higher concentrations (10 to 500 [j,m) show no effect. Likewise ethene release from 2-keto-4-methylthiobutyrate (K M B) is strongly inhibited by the above extracts in a reaction driven by dihydroxyfumarate (D H F) in the presence of copper ions. This system may represent som e features of the diabetic situation where D H F as an endiole may stand for certain Amadori products. In order to find out whether the inhibitory effects are due to copper chelation we tested the copper-dependent conversion of photodynamic ethane release from a-linolenic acid into ethene formation. Copper chelation is apparently only partially involved in inhibition of copper-dependent oxidations and only at a certain concentration of extracts from Salix spec (SE) or extracts from Fraxinus-Solidago-Populus (Phyto-dolorR)(PD). 
  Reference    Z. Naturforsch. 53c, 233 (1998); received D ecem ber 19 1997/January 29 1998 
  Published    1998 
  Keywords    Reactive Oxygen Species, Copper Catalysis, Low Density Lipoprotein-Oxidation, Antioxidants, Sö//x-Extracts 
  Similar Items    Find
 TEI-XML for    default:Reihe_C/53/ZNC-1998-53c-0233.pdf 
 Identifier    ZNC-1998-53c-0233 
 Volume    53