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1Author    Norio Miyoshi, Giiti TomitaRequires cookie*
 Title    Production and Reaction of Singlet Oxygen in Aqueous Micellar Solutions Using Pyrene as Photosensitizer  
 Abstract    The reaction of singlet oxygen with 1,3-diphenylisobenzofuran was investigated in aqueous micellar solutions of sodium dodecyl sulfate and dodecyl trimethylammonium chloride using pyrene as photosensitizer. Singlet oxygen, produced by the photosensitiza-tion of pyrene bound to micelles, oxidized efficiently 1,3-diphenylisobenzofuran bound to micelles. The quantum yield for singlet oxygen production and the rate constant for furan oxidation were determined by the kinetic analysis for the oxidation reaction of furan. Quenching of singlet oxygen by sodium azide competed with the furan oxidation, and its rate constant was also determined. Results obtained were compared with those in methanolic solutions. The quantum yield for singlet oxygen production and the rate constant for furan oxidation were much higher in micellar solutions than those in methanolic solutions. Empty micelles w x as found to act as a considerably strong scavenger for singlet oxygen. The penetration probability of singlet oxygen from aqueous phase into the interior of micelles which bound furan was also estimated. 
  Reference    Z. Naturforsch. 33b, 622—627 (1978); received February 24 1978 
  Published    1978 
  Keywords    Singlet Oxygen, Pyrene, Diphenylisobenzofuran, Micelles 
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 TEI-XML for    default:Reihe_B/33/ZNB-1978-33b-0622.pdf 
 Identifier    ZNB-1978-33b-0622 
 Volume    33 
2Author    Norio Miyoshi, Giiti TomitaRequires cookie*
 Title    Quenching of Singlet Oxygen by Sodium Azide in Reversed Micellar Systems  
 Abstract    The oxidation reaction of singlet oxygen with 1,3-diphenylisobenzofuran was in-vestigated in cyclohexanic reversed micellar solutions of dodecylammonium propionate, using pyrene as photosensitizer. The furan oxidation was effectively inhibited by azide ion-bound reversed micelles. Empty reversed micelles also inhibited the furan oxidation to some extent. The inhibition of the furan oxidation was due to the quenching of singlet oxygen by azide ion-bound and empty reversed micelles. Such singlet oxygen quenching was dependent on the concentration of water added. Results obtained were discussed in connection with the polarity in the interior of reversed micelles, micellar size, the state of water solubilized in reversed micelles and the lifetime of singlet oxygen. The heavy atom effect on the quenching of singlet oxygen was also studied using heavy water. 
  Reference    Z. Naturforsch. 34b, 339—343 (1979); received October 4 1978 
  Published    1979 
  Keywords    Singlet Oxygen, Sodium Azide, Diphenylisobenzofuran, Reversed Micelles 
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 TEI-XML for    default:Reihe_B/34/ZNB-1979-34b-0339.pdf 
 Identifier    ZNB-1979-34b-0339 
 Volume    34 
3Author    Norio Miyoshi, Giiti TomitaRequires cookie*
 Title    Fluorescein-Photosensitized Furan Oxidation in Methanolic and Reversed Micellar Solutions, Part I Effects of Amines  
 Abstract    The 1,3-diphenylisobenzofuran oxidation reaction was investigated in methanolic and dodecylammonium propionate reversed micellar solutions using fluorescein sodium as photosensitizer. It was found that aniline remarkably enhanced the furan oxidation in methanolic solutions but inhibited it in reversed micellar solutions. This enhancement effect occurred more effectively at lower oxygen concentrations. It was proposed that, in the former solutions, the radical mechanism (Type I) might be involved in the furan oxidation in the presence of aniline besides singiet oxygen mechanism (Type II). The reversed micelle seems to inhibit the Type I reaction, resulting in no enhancement of the furan oxidation by aniline. 
  Reference    Z. Naturforsch. 34b, 1552—1555 (1979); received June 19 1979 
  Published    1979 
  Keywords    Singlet Oxygen, Radicals, Fluorescein, Diphenylisobenzofuran, Reversed Micelles 
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 TEI-XML for    default:Reihe_B/34/ZNB-1979-34b-1552.pdf 
 Identifier    ZNB-1979-34b-1552 
 Volume    34 
4Author    Norio Miyoshi, Giiti TomitaRequires cookie*
 Title    Fluorescein-photosensitized Furan Oxidation in Methanolic and Reversed Micellar Solutions, Part II Kinetic Analysis  
 Abstract    The 1,3-diphenylisobenzofuran oxidation was investigated in methanolic and dodecyl-ammonium propionate reversed micellar solutions using fluorescein sodium as photo-sensitizer. The furan oxidation was caused by the singlet oxygen mechanism (Type II). Aniline enhanced remarkably the furan oxidation in methanolic solutions, but inhibited highly this oxidation in the reversed micellar solutions. This enhancement of the furan oxidation was considered to be brought about by the occurrence of a radical mechanism (Type I) besides Type II mechanism. No Type I reaction occurred in the micellar solutions. The rate constants concerning with both reaction processes were evaluated by kinetic analysis, employing various aryl-and alkyl-amines. The reaction mechanism of Type I and the quenching mechanism of singlet oxygen by amines were discussed from the relationship between the rate constants, and the ionization potential of amines and the solvent polarity. 
  Reference    (Z. Naturforsch. 35b, 107—111 [1980]; received July 27 1979) 
  Published    1980 
  Keywords    Singlet Oxygen, Radicals, Fluorescein, Diphenylisobenzofuran, Reversed Micelles 
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 TEI-XML for    default:Reihe_B/35/ZNB-1980-35b-0107.pdf 
 Identifier    ZNB-1980-35b-0107 
 Volume    35 
5Author    Norio Miyoshi, Giiti TomitaRequires cookie*
 Title    Singlet Oxygen Production Photosensitized by Fluorescein in Reversed Micellar Solutions  
 Abstract    The quantum yield of singlet oxygen production was investigated in dodecylammonium propionate reversed micellar solutions containing 1,3-diphenylisobenzofuran and fluo-rescein as photosensitizer. The quantum yield was highly enhanced by the binding of fluorescein to reversed micelles, and increased with decreasing the solubilized water content in reversed micelles. Results obtained was discussed with the optical properties of fluorescein (absorption, fluorescence and phosphorescence) in reversed micellar solutions. 
  Reference    Z. Naturforsch. 35b, 731—735 (1980); received December 7 1979 
  Published    1980 
  Keywords    Singlet Oxygen, Fluorescein, Diphenylisobenzofuran, Water Content, Reversed Micelles 
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 TEI-XML for    default:Reihe_B/35/ZNB-1980-35b-0731.pdf 
 Identifier    ZNB-1980-35b-0731 
 Volume    35 
6Author    NicolaasJ. De Mola, Johannes Reischb, G. Erardus, M. J. Beijersbergen, H. EnegouwRequires cookie*
 Title    On the Involvement of Singlet Oxygen in the Biosynthesis of Oxygenation Products of the Furocoumarin Imperatorine  
 Abstract    The role of singlet oxygen (' 0 2) in the photo-oxidation of the furocoumarin im peratorine was investigated in vitro. Irradiation with visible light and sensitization with methylene blue yielded the im peratorine oxidation product isogosferol and the corresponding ketone as main products. The involvement of ' 0 2 was dem onstrated by studying the rate of oxidation under conditions that affect the lifetime of ' 0 2. Com pared to a range of other furocoum arins, im peratorine appeared to be m oderately active as a '0 2 generator. The extent of ' 0 2 production correlated with the skin sensitizing activity. U pon irradiation of im peratorine itself with U VA light (360 nm) no isogos­ ferol formation is observed, probably as a consequence of its photochem ical instability. Irradia­ tion with visible light (A > 4 0 0 nm) of a chlorophyll chrom ophore containing sensitizer in the presence of im peratorine, yielded isogosferol and the corresponding ketone product. This dem on­ strates that in the form ation of ' 0 2 oxidation products of im peratorine in plants naturally occuring sensitizers e.g. chlorophyll and visible light are involved, rath er than ' 0 2 produced by im peratori-ne or other furocoumarins and U VA light. The protective effect on the chlorophyll sensitized im peratorine oxidation by the ' 0 2-and chlorophyll triplet quencher /3-carotene was dem onstrated in a lipophilic solvent. 
  Reference    Z. Naturforsch. 39b, 1433 (1984); received D ecem ber 12 1983 
  Published    1984 
  Keywords    Singlet Oxygen, Biosynthesis, Im peratorine, Isogosferol, Photo-oxygenation 
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 TEI-XML for    default:Reihe_B/39/ZNB-1984-39b-1433.pdf 
 Identifier    ZNB-1984-39b-1433 
 Volume    39 
7Author    I. Basic, KineticsHartmut Schmidt, Peter RosenkranzRequires cookie*
 Title    On the Mechanism of the Acridine Orange Sensitized Photodynamic Inactivation of Lysozyme  
 Abstract    The kinetics of the photodynamic desactivation of lysozyme in presence of acridine orange as the sensitizer have been investigated in detail varying oxygen, protein, dye concentration, ionic strength and pH value. The kinetics can be approximately described as an over all pseudo-first-order rate process. Changing the solvent from water to D20 or by quenching experiments in pres­ ence of azide ions it could be shown that the desactivation of lysozyme is caused exclusively by singlet oxygen. The excited oxygen occurs via the triplet state of the dye with a rate constant considerably lower than that to be expected for a diffusionally controlled reaction. Singlet oxygen reacts chemically (desactivation, k —2.9 x 107 M -1 sec-1) and physically (quenching process, k = 4.1 x 108 m — 1 sec-J) with the enzyme. The kinetical analysis shows that additional chemical reac­ tions between singlet oxygen and lysozyme would have only little influence on the kinetics of the desactivation as long as their products would be enzymatically active and their kinetical constants would be less than about 1 x 1 0 8 m -1 sec-1. 
  Reference    (Z. Naturforsch. 31c, 29 [1976]; received July 7/September 19 1975) 
  Published    1976 
  Keywords    Photodynamic Effect, Singlet Oxygen, Lysozyme, Acridine Orange, Kinetics 
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 TEI-XML for    default:Reihe_C/31/ZNC-1976-31c-0029.pdf 
 Identifier    ZNC-1976-31c-0029 
 Volume    31 
8Author    Wolfgang Weigand, Gabriele Bosla, Bernd Von Dielingenb, Klaus GollnickbRequires cookie*
 Title    Metallkomplexe mit funktionalisierten Schwefelliganden, VIII [1] 4-Phenyl-l,2-dithiolan-l-oxid, ein stabiles, fünfgliedriges cyclisches Thiosulfinat Metal Complexes o f Funetionalized Sulfur Containing Ligands, VIII [1] 4-Phenyl-1,2-dithiolane-l-oxide, a Stable, Five-Membered Cyclic Thiosulfinate  
 Abstract    Sensitized photooxidation of 4-phenyl-l,2-dithiolane 1 has been studied. Reacting it with 0.5 mole equivalents o f singlet oxygen, a mixture of 1, 4-phenyl-1,2-dithiolane-l-oxide 2, and 4-phenyl-l,2-dithiolane-2-dioxide 3 is produced. Using one mole equivalent of singlet oxygen, 3 is obtained in high yields. The chemical oxidation of 1 using H 20 2/H 0 A c yields pure 2. With 2 a diastereoselectivity of 10:1 is observed. The oxidative addition of 1 to L2Pt 072-C-,Hd) [L = PPh, (4), 1/2 dppe (5)] leads to the 3-phenyl-propane dithiolato complexes L?P t-S -C H ,-C H P h -C H -,-S 6a,b. The platinum(O) com pound 4 reacts with 2 to give the bimetallic compound [(P h ,P)P t-S (0)-C H T -C H P h -C H -,-/i-S ^ 7 and the monometallic spe­ cies c/s-(Ph3P)2P t -S (0) -C H 2-C H P h -C H 2-$ 8. These complexes contain the 3-sulfido-l-(2-phenyl)-propanesulfenato ligand. All com pounds have been characterized by their spec­ troscopic data. 
  Reference    Z. Naturforsch. 49b, 513—518 (1994); eingegangen am 14. Dezember 1993 
  Published    1994 
  Keywords    Thiosulfinate, Thiosulfonate, Sulfenato T hiolato Platinum Complexes, Singlet Oxygen 
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 TEI-XML for    default:Reihe_B/49/ZNB-1994-49b-0513.pdf 
 Identifier    ZNB-1994-49b-0513 
 Volume    49 
9Author    KennethE. Pallett, AlanD. DodgeRequires cookie*
 Title    The Role of Light and Oxygen in the Action of the Photosynthetic Inhibitor Herbicide Monuron  
 Abstract    Monuron treatment of detached flax cotyledons caused a rapid inhibition of C 02 fixation in darkness and light. Chlorophyll breakdown was promoted by increased light intensity. Ethane generation, an indicator of membrane damage, increased as the chlorophyll level decreased. The carotene pigments were destroyed more rapidly than the xanthophylls and chlorophylls. Treatment of cotyledons with monuron in the absence of oxygen almost prevented carotenoid and chlorophyll loss. The addition of the singlet oxygen quencher DABCO delayed chlorophyll breakdown. The results are discussed in relation to a role for singlet oxygen in the herbicidal action of monuron. 
  Reference    Z. Naturforsch. 34c, 1058—1061 (1979); received May 29 1979 
  Published    1979 
  Keywords    Herbicidal Action of Monuron, Light, Oxygen, Singlet Oxygen, Plant Pigments 
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 TEI-XML for    default:Reihe_C/34/ZNC-1979-34c-1058.pdf 
 Identifier    ZNC-1979-34c-1058 
 Volume    34 
10Author    Krzysztof Lichszteld, Zygmunt Machoy, Anna StępińskaRequires 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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 TEI-XML for    default:Reihe_C/40/ZNC-1985-40c-0223.pdf 
 Identifier    ZNC-1985-40c-0223 
 Volume    40