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1Author    HartmutB. Stegmann, Hoang Dao-Ba, Klaus Scheffler, MartinG. PeterRequires cookie*
 Title    ESR and ENDOR Investigations of Adrenochrome Semiquinone and Related Amino-1,2-Benzosemiquinone Radicals  
 Abstract    Dimethyl or diethylamine reacts very smoothly in ethanol solution with catechols to the corre­ sponding aminoquinones. The paramagnetic intermediates, the semiquinones, are investigated by ESR and E N D O R spectroscopy using the spin stabilisation technique with diarylthallium cations. The spectra of these radicals show clearly the thallium and nitrogen coupling and the hydrogen hyperfine structure. For some examples the signs of the proton coupling constants are determined by T RIPLE resonance experiments. The results indicate a negative spin density in one position of the unsymmetrically substituted radical 3. With the results obtained for the monocyclic aminosemiquinones the hyperfine structure of the adrenochrome semiquinone is analysed. 
  Reference    Z. Naturforsch. 40c, 531 (1985); received January 31/March 27 1985 
  Published    1985 
  Keywords    ESR-, ENDOR-Spectroscopy, Semiquinones, Adrenochrome 
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 TEI-XML for    default:Reihe_C/40/ZNC-1985-40c-0531.pdf 
 Identifier    ZNC-1985-40c-0531 
 Volume    40 
2Author    Requires cookie*
 Title    An ESR-Study of the Peroxidation of Lecithin Multilayers  
 Abstract    G rzegorz B a rto sz* , G abriele C hrist, Harald B osse, R oland Stephan and H elm ut G ärtner E xperim entalphysik III, Fachbereich Physik, G esam thochschule Kassel, 3500 Kassel (G erm any) Z. N aturforsch. 43 a, 1381 -1 3 8 4 (1987); received O cto b er 19, 1987 By m eans of a set of fatty acid and fatty acid ester spinlabels we found th at spo n tan eo u s pero x id atio n of lecithin m ultilayers increases the rigidity of all regions of the lipid bilayer. H ow ever the p a rtitio n coefficient of T E M P O increased with peroxidation indicating a g reater affinity of T E M P O to the m odified bilayer. 
  Reference    Z. Naturforsch. 42a, 1381 (1987) 
  Published    1987 
  Keywords    Lecithin m ultilayers, peroxidation, ESR 
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 TEI-XML for    default:Reihe_A/42/ZNA-1987-42a-1381.pdf 
 Identifier    ZNA-1987-42a-1381 
 Volume    42 
3Author    Reinhard Schmidt, Hans-Dieter BrauerRequires cookie*
 Title    Über das Assoziationsverhalten des Schlenkschen Kohlenwasserstoffs About the Association of S c h 1 e n k's Hydrocarbon  
  Reference    (Z. Naturforsch. 27b, 1363—1370 [1972]; eingegangen am 14. April/18. August 1972) 
  Published    1972 
  Keywords    ESR, association, Schlenks hydrocarbon 
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 TEI-XML for    default:Reihe_B/27/ZNB-1972-27b-1363.pdf 
 Identifier    ZNB-1972-27b-1363 
 Volume    27 
4Author    H. J. Keller, W. Moroni, D. Nöthe, M. Scherz, J. WeissRequires cookie*
 Title    und 5.10-Dihydro-5.10-diethylphenaziniumtriiodid  
 Abstract    Molecular and Crystal Structure of 5.10-Dihydro-5,10-dimethylphenaziniumtriiodide and 5,10-Dihydro-5,10-diethylphenazinium triiodide Oxidation of 5,10-dihydro-5,10-dimethylphenazine and 5,10-dihydro-5,10-diethyl-phenazine under different reaction conditions leads to several iodine containing solids. The preparation and X-ray structure of two of them, 5,10-dihydro-5,10-dimethyl-phenaziniumtriiodide (3) and 5,10-dihydro-5,10-diethylphenaziniumtriiodide (4) are reported here. Compound 3 crystallizes in space group P 2i/n with lattice parameters a = 8.552(6) A, b = 16.953(2) A, c= 12.157(9) A and ß= 103.46(2)° with four formula units in the unit cell. The structure was refined to an i?-value of 0.046 using 2387 independent reflections. The lattice constains distinct, slightly distorted triiodide ions and bent 5,10-dihydro-5,10-dimethylphenazinium radical cations. Compound 4 crystallizes in the same space group P2i/n with lattice parameters a = 8.531(6) A, b = 8.332(21) A, c = 13.320(15) A and ß— 94.44(19)° with two formula units in the unit cell. The structure was refined to an i?-value of 0.076 using 1195 independent reflections. The lattice contains strictly linear symmetrical triiodide ions and planar centrosymmetrical 5,10-dihydro-5,10-diethyl-phenazinium radical cations. 
  Reference    Z. Naturforsch. 33b, 838—842 (1978); eingegangen am 27. April 1978 
  Published    1978 
  Keywords    Radical Cations, Structure, ESR 
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 TEI-XML for    default:Reihe_B/33/ZNB-1978-33b-0838.pdf 
 Identifier    ZNB-1978-33b-0838 
 Volume    33 
5Author    VeliT. KasumovRequires cookie*
 Title    Oxovanadium(IV), Nickel(II) and Palladium(II) Complexes of Tridentate Salicylaldiminates Derived from 2,4-Di-terMmtyl-6-aminophenol  
 Abstract    Several new binuclear nickel(II), oxovanadium(IV) and palladium(II) complexes (MLX) of tridentate salicylaldimines (LX H2) obtained from substituted salicylaldehydes and 2,4-di-tert-butyl-6-aminophenol, as well as mononuclear nickel(II) and oxovanadium(IV), MQx nH20, complexes with hydrogenated LX H2 ligands (QXH2) have been prepared and their spectroscopic, magnetic and catalytic activity (for PdLx) have been investigated. NiLx and VOLx complexes when dissolved in pyridine, take up three or two pyridine molecules to form six coordinated complexes, respectively. The Ni(II) and VO(IV) complexes obtained from QXH2 can be formu­ lated as NiQx-3H20 and VOQx H2O. All VO(IV) complexes have been characterized by ESR parameters. It has been found that some PdLx complexes without any preliminary activation, in EtOH, THF and DMF exhibit high catalytic activity in the hydrogenation of nitrobenzene or cyclohexene at room temperature and at 30 -40 °C under 760 torr H2. When this reaction has been carried out in the ESR cavity at room temperature the triplet of 12 line multiplets due to the nitroxyl type coordinated radical (g = 2.013, AN = 10 G, A = 0.8 G) was detected. 
  Reference    Z. Naturforsch. 56b, 263—270 (2001); received July 27 2000 
  Published    2001 
  Keywords    Tridentate Salicylaldiminates, ESR, Catalytic Activity 
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 TEI-XML for    default:Reihe_B/56/ZNB-2001-56b-0263.pdf 
 Identifier    ZNB-2001-56b-0263 
 Volume    56 
6Author    H. J. Tochon-Danguy, G. Boivin, M. Geoffroy, C. Walzer, C. A. BaudRequires cookie*
 Title    Physical and Chemical Analyses of the Mineral Substance during the Development o f Two Experimental Cutaneous Calcifications in Rats: Topical Calciphylaxis and Topical Calcergy  
 Abstract    In subcutaneous calcinoses induced in rats by topical calciphylaxis and topical calcergy, the ultrastructural aspects related to the evolution o f calcified deposits were previously described. In the present study by m eans o f X-ray diffraction, infrared spectrometry and electron spin resonance, different biophysical analyses are performed on the mineral substance deposited during developm ent o f calciphylaxis and calcergy. A rapid evolution o f the calcium phosphate deposits into hydroxyapatite was noticed along the first 20 days o f the calcinoses; from then, there is no important m odification even at the later stages, and the characteristics o f the mineral substance are mostly sim ilar to that o f bone tissue. The concentration o f trace elem ents such as M g2+ and F e2+, is found higher in cutaneous calcinoses than in bone tissue. 
  Reference    Z. Naturforsch. 38c, 135 (1983); received July 10 1982 
  Published    1983 
  Keywords    Calcification, Calciphylaxis, Calcergy, Apatite, ESR 
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 TEI-XML for    default:Reihe_C/38/ZNC-1983-38c-0135.pdf 
 Identifier    ZNC-1983-38c-0135 
 Volume    38 
7Author    N. Gulfo, R. Bartucci, L. SportelliRequires cookie*
 Title    Effect of Inhalation Anesthetics on Spin-Labeled Cholesterol Containing DPPC Vesicles  
 Abstract    We have investigated by means of electron spin resonance (ESR) spectroscopy the influence of three inhalation anesthetics, i.e. halothane, chloroform and diethyl ether, on the interfacial and hydrophobic region as well of 38 mol% cholesterol containing DPPC unilamellar vesicles. The study has been carried out in the temperature range 25-45 °C. The variation of the order parameter, S, vs temperature of the lipid phase indicates that with this content of cholesterol the characteristic gel liquid crystalline main phase transition of DPPC, normally occurring at T x ~ 41 °C, disappears. When halothane and chloroform are added to the vesicles suspension up to [DPPC]/[anesthetic] molar ratio of 1:1 the main phase transition, as detected with the stearic acid spin label 7(12,3), reappears again and it results down shifted at 7, ~ 35 and 39 °C, respectively. In presence of diethyl ether, instead, the main phase transition is not observable also at the highest concentration of anesthetic used. Moreover, halothane and chloroform affect similarly the hydrophobic core of choles-terol-!-DPPC vesicles which, in turn, results to be different from the action exerted by diethyl ether in the same region. The ESR findings are discussed in terms of competitive effects shown by cholesterol and inhalation anesthetics. Moreover, the interfacial region of CHOL + DPPC vesicles results to be the target of anesthetics. 
  Reference    Z. Naturforsch. 43c, 264—268 (1988); received August 12/November 24 1987 
  Published    1988 
  Keywords    Cholesterol, DPPC, Inhalation Anesthetics, ESR 
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 TEI-XML for    default:Reihe_C/43/ZNC-1988-43c-0264.pdf 
 Identifier    ZNC-1988-43c-0264 
 Volume    43 
8Author    Motohiro Mizuno, Tetsuo Asaji, Atsushi Tachikawa, The Late, Daiyu NakamuraRequires cookie*
 Abstract    h lo r in e N Q R S p in -L a ttic e R e la x a tio n a n d E le c tro n S p in D y n a m ic s in P a r a m a g n e tic [ C o (H 20) 6] I P tC l 6| Chlorine NQR spin-lattice relaxation times T1Q were determined for [Co(H,0)6][PtCl6] at 4.2 400 K. Above ca. 350 K, T1Q decreased rapidly showing the onset of a reorientation of [PtCl6]2-. The activation energy Ea of this reorientation was determined as 125 ± 15 kJ mol ~1. With decreasing temperature, Tlfi showed a maximum at ca. 250 K. Below ca. 200 K, Tl(. is governed by the magnetic dipolar interaction between chlorines and paramagnetic Co2+ ions and is inversely proportional to the electron spin correlation time re of Co2 . Te is shown to be determined by the electron spin-lattice relaxation time Tle and the temperature independent correlation time rs for the spin-exchange between neighbouring ions above and below ca. 50 K, respectively. The temperature dependence of Tle is explained by assuming the Orbach process with an energy gap A/k of 530 + 20 K as Tle = 5 x 10~14 exp(530/T)s. ts was estimated to be 0.9 x 10"10 s. The temperature dependence of the ESR linewidth of Mn2+ impurities in single crystal was also measured, intending to study Co2+ spin dynamics. The limit of the ESR method is discussed by comparing the obtained results with those of the NQR method. 
  Reference    Z. Naturforsch. 46a, 1103 (1991); received September 17 1991 
  Published    1991 
  Keywords    Spin-lattice relaxation, NQR, ESR, Reorientation, Orbach process 
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 TEI-XML for    default:Reihe_A/46/ZNA-1991-46a-1103.pdf 
 Identifier    ZNA-1991-46a-1103 
 Volume    46 
9Author    Shozi Yamashita, Mizuki Yoshida, Giiti TomitaRequires cookie*
 Title    Photoionization of Indole in Alkaline Aqueous Solutions at 77 °K  
 Abstract    The photoionization process of indole in alkaline aqueous solutions at 77 °K and the recombination process of trapped electron with its mother molecule were investigated. The fluorescence spectrum of indole in these glassy media depended on the NaOH concentration; the disappearance of the 325 nm band at the NaOH concentrations higher than 5 M with the appearance of a fluorescence band at 375 nm. The latter emission is possibly ascribed to the fluorescence of indole anion formed by proton dissociation in the excited singlet state of indole. The intensities of the 375 nm band and the ESR signal due to trapped electrons were dependent on the NaOH concentration and increased steeply with increasing the NaOH concentration. There was a parallel relation between the indole anion concentration and the trapped electron density to some extent. The dependence of the ESR signal intensity on irradiation intensity suggested that the photoionization of indole in alkaline aqueous solution occurred through a two photon process. The presence of a photoactive intermediate for absorbing the second photon was further investigated with simultaneous irradiation of two different wavelength lights. The trapped electron was detrapped with the irradiation of visible light (e.g. 580 nm), and its recombination with mother molecule caused an emission with the same spectrum as indole phosphorescence. The molecular species of the photoactive intermediate in alkaline aqueous solutions seems to be the indole anion. The photoionization in NaOH aqueous solution at 77 °K was also compared with that in methanolic glassy solution. 
  Reference    (Z. Naturforsch. 31b, 361—366 [1976]; received April 28/July 22 1975) 
  Published    1976 
  Keywords    Photoionization, Phosphorescence, ESR, Trapped Electron, Indole 
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 TEI-XML for    default:Reihe_B/31/ZNB-1976-31b-0361.pdf 
 Identifier    ZNB-1976-31b-0361 
 Volume    31 
10Author    K. B. Ulmschneider, H. B. Stegmann, K. Scheffler, G. ViertelRequires cookie*
 Title    Ionenpaare von o-Semichinonen mit Diorganothallium(QI)-Kationen* Ion Pairs of Semiquinones with Diorgano Thallium (III) Cations  
 Abstract    Diorgano thallium hydroxide reacts very smoothly in organic solvents with catechols to stable paramagnetic ion pairs. This reaction has been investigated with two semiquinone anions and 13 different diorgano thallium cations. The data obtained indicate a strong dependence of the thallium coupling constant on the nature of the metal substituents. The effects observed are discussed in terms of electronic and steric interactions. All ion pairs indicate remarkable temperature dependence of the thallium splitting and the g-factor. These results are compared with the results obtained in alkali metal ion pairs using a model described in the literature. Einführung 
  Reference    Z. Naturforsch. 33b, 237—240 (1978); eingegangen am 4. November 1977 
  Published    1978 
  Keywords    Ion Pairs, ESR, Radicals, Thallium Organic Compounds 
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 TEI-XML for    default:Reihe_B/33/ZNB-1978-33b-0237.pdf 
 Identifier    ZNB-1978-33b-0237 
 Volume    33 
11Author    Maria Konieczny, CarlA. Olson, PeterL. Gutierrez, George SosnovskyRequires cookie*
 Title    In the Search for New Anticancer Drugs, V+ Study of the Binding of Spin-Labeled Thio-TEPA to Cells  
 Abstract    The spin labeled analog, SL-O-TT (2), of Thio-TEPA (1) inhibits (£N) 3 PIS) R0P(S)(N3) 2 the incorporation of 3 H-thymidine by 50% (IC50) at a dose of 2.6 X 10~ 4 M in L 1210 and at a dose of 6 X 10~ 4 M in P 388 murine leukemias. On the basis of cell fractionation studies, compound 2 was found to bind about equally to the cell nuclei, microsomes, and mito-chondria. ESR experiments indicate different degrees of immobilization of the label in various fractions. The efficiency of binding of 2 to cells appears to be at least 6 %. 
  Reference    Z. Naturforsch. 38b, 1142—1145 (1983); received August 30/December 24 1982 
  Published    1983 
  Keywords    Anticancer Drugs, Nitroxyl Label, Spin Labeled Thio-TEPA, ESR 
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 TEI-XML for    default:Reihe_B/38/ZNB-1983-38b-1142.pdf 
 Identifier    ZNB-1983-38b-1142 
 Volume    38 
12Author    Hartmut Schmidt, Axel LaßmannRequires cookie*
 Title    ESR-Untersuchungen zur Photochemie des Acridinorange ESR Investigations on the Photochemistry of Acridine Orange  
 Abstract    Acridinfarbstoffe werden in photochemischen und photobiologischen Reaktionen häufig als Sensibilisa­ toren eingesetzt. Im Falle der photodynamischen Desaktivierung von Lysozym in Gegenwart von Acri­ dinorange konnten wir zeigen *, daß der elektronisch angeregte Farbstoff Sauerstoff in den Singulett-zustand 1Ag überführt, der dann weiter mit dem Enzym reagiert. Im Verlauf der photodynamischen Reaktion wird jedoch auch der Farbstoff teilweise zerstört. Die Kinetik der Farbstoffbleichung läßt sich nicht allein auf der Grundlage des von uns postulier­ ten Reaktionsschemas verstehen 2. Von vielen Farbstoffen ist bekannt, daß bei Ein­ strahlung in die langwelligste Absorptionsbande intermediär semioxidierte und/oder semireduzierte Photoprodukte entstehen. Derartige radikalische Zwischenprodukte wurden blitzlichtspektroskopisch auch für Acridinorange nachgewiesen 3' 4 und müs­ sen bei einer detaillierteren Beschreibung des photo­ dynamischen Reaktionsverlaufs sicherlich berück­ sichtigt werden. Zum Nachweis derartiger Zwischenprodukte sollte die ESR-Spektroskopie besonders geeignet sein, da über die Hyperfeinstruktur unmittelbar Rück­ schlüsse auf die Struktur der Radikale möglich sind5. Die Anwendung dieser Methode scheitert meistens daran, daß bei kontinuierlicher Bestrah­ lung von Farbstofflösungen bei Zimmertemperatur die stationäre Konzentration der radikalischen Zwi­ schenprodukte unterhalb der Nachweisgrenze der herkömmlichen ESR-Spektrometer liegt. Diese Schwierigkeiten lassen sich durch Zusatz geeigneter Substanzen ("Spinfänger") umgehen, die mit kurz­ lebigen Radikalen unter Bildung langlebiger Sekun­ därradikale ("Spinaddukte") reagieren. Die primär gebildeten Zwischenprodukte lassen sich auf diese Weise auf Grund der Hyperfeinstruktur der Spin­ addukte identifizieren 6. 
  Reference    (Z. Naturforsch. 29c, 301—302 [1974]; eingegangen am 26. Februar 1974) 
  Published    1974 
  Keywords    Acridine Orange, ESR, Spin Trap, Nitromethane, Hydrogen Addition 
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 TEI-XML for    default:Reihe_C/29/ZNC-1974-29c-0301_n.pdf 
 Identifier    ZNC-1974-29c-0301_n 
 Volume    29 
13Author    Wolfgang Lohmann, Max Hillerbrand, Max KlenertRequires cookie*
 Title    Charge-Transfer Interactions between Nucleobases and Metal Ions: ESR and Optical Absorption Studies  
 Abstract    The charge-transfer interaction of different nucleobases with Cu2+ has been investigated by means of ESR and optical absorption studies. It could be shown that cytosine forms the strongest complex. The greatest reduction of Cu2+ (that is, spin concentration) was obtained, however, with adenine. Based on these results the following order for the electron donor strength of the nucleo­ bases has been obtained: Ade>Cyt!>Thy>Ura. In troduction 
  Reference    (Z. Naturforsch. 29c, 667 [1974]; received March 18/June 15 1974) 
  Published    1974 
  Keywords    CT-Interactions, Electron Donor, Nucleobases, ESR, Metal Ions 
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 TEI-XML for    default:Reihe_C/29/ZNC-1974-29c-0667.pdf 
 Identifier    ZNC-1974-29c-0667 
 Volume    29 
14Author    Wolfgang Lohmann, Rainer LangeRequires cookie*
 Title    On the Possible Involvement of Ascorbic Acid and Copper Proteins in Leukemia. III. ESR Investigations on the Interaction between Ascorbic Acid and Some Transition Metal Ions  
 Abstract    The interaction between lyophilized samples of ascorbic acid and Cu2+, Fe3+ or M n2+ has been investigated by means of ESR spectroscopy. All of the three transition metal ions form complexes with vitamin C, but only in the case of C u2+ and Fe3+ the interaction results in a reduction of the metal ions. C u2+ and ascorbic acid seem to form 2 : 1 complexes with an equilibrium constant of about K = 1 x 107 mol-1. None of these metal ion complexes exhibits, however, the ESR spectrum obtained with leukemic blood. 
  Reference    Z. Naturforsch. 34c, 546—549 (1979); received March 21/May 4 1979 
  Published    1979 
  Keywords    Leukemia, ESR, Ascorbic Acid, Transition Metal Ions 
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 TEI-XML for    default:Reihe_C/34/ZNC-1979-34c-0546.pdf 
 Identifier    ZNC-1979-34c-0546 
 Volume    34 
15Author    Wolfgang Lohmann, Jörg Schreiber, Walter Greulich, LeukemiaRequires 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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 TEI-XML for    default:Reihe_C/34/ZNC-1979-34c-0550.pdf 
 Identifier    ZNC-1979-34c-0550 
 Volume    34 
16Author    Wolfgang Flossmann, Herbert Zehner, Adolf MüllerRequires cookie*
 Title    Radicals Produced in Single Crystals of Thymine Derivatives by UV and X-Rays  
 Abstract    Single crystals o f anhydrous thym ine (T), thym ine monohydrate (T ■ H 20) , 5,6-dihydrothym ine (T H 2), 1-methylthymine (mT) and thym idine (dT) were irradiated with X-rays and UV between 77 K and 300 K. Six types o f radicals were analyzed by ESR-spectroscopy at 9.5 G H z and 35 G H z after exposure to X-rays. The anion radical occurred only in T • H 20 at 77 K, the 4-yl radical only in T H 2 at 77 K and the 1-yl radical only in T between 77 K and 300 K. The 6 -yl radical was found in T, T H 2 and mT. It was converted into the 5-yl radical irreversibly by heat or white light (A < 600 nm). The 5-yl radical appeared in all compounds at room temperature. The highest thermal stability was found for the 7-yl radical which was present at room temperature in all compounds except T H 2 . U V -irradiation (A = 320 nm) produced radicals only in three crystals (T, T H 2 , dT). In T the 5-yl radical was found after exposure at 300 K, and two other radicals, 1-yl and 7-yl, at 77 K. A lso at 77 K, the 7-yl radical was present in dT and the 5-yl radical in TH 2 and dT. 
  Reference    Z. Naturforsch. 35c, 20—2 (1980); received July 23 1979 
  Published    1980 
  Keywords    Radicals, Single Crystals, Thym ine, X-Rays, ESR 
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 TEI-XML for    default:Reihe_C/35/ZNC-1980-35c-0020.pdf 
 Identifier    ZNC-1980-35c-0020 
 Volume    35 
17Author    Wolfgang Lohmann, KlausG. Bensch, Jörg Schreiber, Elisabeth Müller, Konrad Schwemmle, Herbert Feustel, Rolf-Dieter FillerRequires cookie*
 Title    Paramagnetic Changes in Pulmonary Tumors  
 Abstract    Electron spin resonance studies on healthy and tum erous hum an lung samples have been con­ ducted in order to determ ine possible differences in free radical concentration and shape o f the spectra between the different sections o f the lung. It could be shown that in healthy lung tissue the signal caused by the sem idehydroascorbate (SDA) radical is not prom inent because o f the prevailing high partial oxygen pressure. On form ation o f a tumor, the spin concentration increases, possibly due to the higher metabolic rate; here, the SDA peak is also more pronounced which indicates alterations in the interaction between cell constituents and ascorbic acid. W ithin the tum or, the spin concentration is considerably reduced which is probably caused by a still higher concentration o f ascorbic acid. A ddition o f ascorbic acid to the different lung specimens enhanced the just described effect while oxidizing substances, such as H 2Oa, reversed it. 
  Reference    Z. Naturforsch. 36c, 5—8 (1981); received Septem ber 9/O ctober 20 1980 
  Published    1981 
  Keywords    ESR, Pulmonary Tumors, Ascorbic Acid, Spin Concentration 
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 TEI-XML for    default:Reihe_C/36/ZNC-1981-36c-0005.pdf 
 Identifier    ZNC-1981-36c-0005 
 Volume    36 
18Author    Wolfgang LohmRequires cookie*
 Title    Ascorbate Oxidase and Its Possible Involvement in Cancer  
 Abstract    The electron spin resonance (ESR) spectrum of erythrocytes of a healthy male volunteer exhibited 2 min after intravenous administration of 1 g of ascorbic acid a considerable increase in spin concentration and a new signal at about g = 2.005 which we previously had found to correlate to the semidehydroascorbate (SDA) radical and which is not identical with the O j radical. Moreover, the vitamin C concentration in erythrocytes and plasma was considerably higher than in comparable samples of other volunteers treated identically. In the latter cases, the ESR spectrum of the erythrocytes was not modified at all. These findings suggest that there must be a substance which reacts with ascorbic acid specifically. It can be assumed that the enzyme ascorbate oxidase plays this decisive role in the ascorbic acid metabolism. For this reason, different amounts of ascorbate oxidase have been added to healthy erythrocytes treated in vitro with ascorbic acid and to tissue samples of lung cancer. As expected, the vitamin C effect as expressed by the appearance of the SDA signal and the increase in spin concentration could be reversed. It is suggested, therefore, that in special types of cancer, such as acute lymphatic leukemia and lung cancer, the concentration of ascorbate oxidase or of an enzyme acting like it is, primarily, diminished, while in other types it might be enlarged. 
  Reference    Z. Naturforsch. 36c, 804—808 (1981); received February 9/March 211981 
  Published    1981 
  Keywords    Ascorbic Acid, ESR, Copper Proteins, Leukemia, Lung Cancer 
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 TEI-XML for    default:Reihe_C/36/ZNC-1981-36c-0804.pdf 
 Identifier    ZNC-1981-36c-0804 
 Volume    36 
19Author    M. Aliyakal, E. John, RaymondN. Dubois, MichaelR W AtermanRequires cookie*
 Title    Altered Heme Environments in Opossum and Rabbit Methemoglobins  
 Abstract    The effect o f pH and inositol hexaphosphate (IHP) on the symmetry of the heme environments in opossum (Didelphius marsupialis) and New Zealand White rabbit hemoglobins has been studied using electron spin resonance (ESR). Each methemoglobin is found to contain two different heme environments as detected by the rhombicity observed in the ESR spectrum. In both cases the rhombic nature o f the ESR spectrum is influenced by pH and IHP binding, although in the case o f rabbit methemoglobin the high spin ESR signal disappears above pH 8.0. . In both hemoglobins, amino acid alterations in the ar-chains are known to affect the properties of the ferrous derivatives. It is concluded that these alterations also provide the basis for the ESR spectral properties observed with the methemoglobins. 
  Reference    Z. Naturforsch. 36c, 964—967 (1981); received May 121981 
  Published    1981 
  Keywords    Methemoglobin, ESR, Heme Environment, Inositol Hexaphosphate, Spin State 
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 TEI-XML for    default:Reihe_C/36/ZNC-1981-36c-0964.pdf 
 Identifier    ZNC-1981-36c-0964 
 Volume    36 
20Author    W. Lohmann, D. Holz, B. Kiefer, D. SchmidtRequires cookie*
 Title    On the Origin of the Non-Haemic Iron Transferrin ESR Signal: ESR Investigations on Histidine-Iron-Citric Acid Systems  
 Abstract    The nature o f the high spin ferric iron com plex located at g = 4.3 has been investigated by means o f electron spin resonance spectroscopy and polarography. It could be shown that two complexes each exist in the acid and alkaline pH region, and that the iron is bound to two histidines, three citric acids, and probably to one bicarbonate. These results agree well with previous findings according to which the ligand field o f iron should be com posed mainly o f oxygen and nitrogen atoms. Another low-field signal located at g = 3.6 appears in the pH range from 2 to 7 only and exhibits its m axim um where the g = 4.3 signal has its m inim um . Its exact nature is still unknown but it seem s to represent som e interm ediate state o f the ternary F e3+-histidine-citric acid complex. When citric acid is used, the spin concentration seem s to be always larger than in the case o f ascorbic acid. Since the effect obtained with ascorbic acid and citric acid seems to be similar, it may be concluded that the biological function o f both o f the acids might be somehow related to each other. 
  Reference    Z. Naturforsch. 38c, 926—928 (1983); received May 2 1983 
  Published    1983 
  Keywords    ESR, High Spin Ferric Ion Com plex, Citric Acid 
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 TEI-XML for    default:Reihe_C/38/ZNC-1983-38c-0926.pdf 
 Identifier    ZNC-1983-38c-0926 
 Volume    38