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'Mass Spectrometry' in keywords Facet   Publication Year 1981  [X]
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1981[X]
1Author    Hartmut Klein, Wittko Francke, WilfriedA. KönigRequires cookie*
 Title    Studien über Wespengift, I Niedermolekulare Bestandteile des Giftblasenextraktes von Paravespula vulgaris Studies on Wasp Venom, I Low Molecular Weight Constituents of Venom Sac Extracts from Paravespula vulgaris  
 Abstract    Low molecular weight constituents of 3400 venom sacs of Paravespula vulgaris were extracted with water, diluted acetic acid, and methanol. After conversion to volatile derivatives carbohydrates, amino acids, fatty acids, other constituents of phospho lipids, and biogenic amines were identified by gas chromatography and mass spectrometry. Quantitative analysis was achieved for amino acids by amino acid analysis and for glucose by an enzymatic assay. Results are discussed with regard to biosynthesis of wasp toxins and phylogenetic aspects of hymenopteran venoms. 
  Reference    Z. Naturforsch. 36b, 757—762 (1981); eingegangen am 11. Februar 1981 
  Published    1981 
  Keywords    Wasp Venom, Gas Chromatography, Mass Spectrometry 
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 TEI-XML for    default:Reihe_B/36/ZNB-1981-36b-0757.pdf 
 Identifier    ZNB-1981-36b-0757 
 Volume    36 
2Author    Bernhard Ciommer, Helmut Schwarz, Azzedine Maaroufi, ManfredT. Reetz, Karsten LevsenRequires cookie*
 Title    Silyl-Assistierte Etherspaltung bei Radikalkationen von Hydroxylaminderivaten [1] Silyl-Assisted Ether Cleavage in Radical Cations of Hydroxylamine Derivatives [1]  
 Abstract    It is demonstrad by means of various mass spectrometric techniques that the dissociative ionization of N.N-bis-silylated hydroxylamine derivatives (5 a) and (5 b), giving rise to the cleavage of the (O-C) bond, is anchimerically assisted by migration of the trimethylsilyl group to the ether oxygen, thus generating ion (7). 
  Reference    Z. Naturforsch. 36b, 771—773 (1981); eingegangen am 11. März 1981 
  Published    1981 
  Keywords    Mass Spectrometry, Collisional Activation, Anchimeric Assistance, Silyl Ether 
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 TEI-XML for    default:Reihe_B/36/ZNB-1981-36b-0771_n.pdf 
 Identifier    ZNB-1981-36b-0771_n 
 Volume    36 
3Author    Boris JanistynRequires cookie*
 Title    Gaschromatographic, Mass-and Infrared-Spectrometric Identification of Cyclic Adenosine-3': 5'-monophosphate (c-AMP) in Maize Seedlings (Zea mays)  
 Abstract    Gaschromatographic, mass-and infrared-spectrometric evidence is presented for the iden­ tification of adenosine-3':5'-monophosphate (c-AMP) in maize seedlings (Zea mays). The genuine c-AMP content could be quantitated by GC-detection and refere to authentic c-AMP standards. 
  Reference    Z. Naturforsch. 36c, 193—196 (1981); received November 111980 
  Published    1981 
  Keywords    Maize, c-AMP, Gaschromatography, Mass Spectrometry, Infrared Spectrometry 
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 TEI-XML for    default:Reihe_C/36/ZNC-1981-36c-0193.pdf 
 Identifier    ZNC-1981-36c-0193 
 Volume    36 
4Author    GeorgH. Schmid, KlausP. Bader, Richard Gerster, Christian Triantaphylides, Marcel AndréRequires cookie*
 Title    Dependence of Photorespiration and Photosynthetic Unit Sizes on Two Interdependent Nuclear Gene Factors in Tobacco  
 Abstract    A new set of tobacco mutants was obtained by selfing a single variegated plant which emerged in a seed lot of Nicotiana tabacum var. Consolation. The seeds obtained from this mutant give rise to four phenotypes: variegated, yellow, yellow-green, and green seedlings. The green, yellow-green and yellow characters are due to two interdependent nuclear gene factors. The yellow-green phenotype is the homozygous (aabb) true breeding condition, whereas the green and the yellow phenotype are heterozygous (AaBb) with respect to both nuclear factors, the difference in the yellow and green phenotype being the addition of a labile gene factor pair, Cc, in the yellow condition. If photorespiration is measured as the Warburg effect or as 180 2-consumption by mass spectrometry it appears that the heterozygous green phenotype is the defective condition with high photorespiration. The three phenotypes differ with respect to chlorophyll content and photosynthetic unit sizes, the photosynthetic unit size in the yellow phenotype being approxi­ mately 1/10 of that of the green type. The gene expression for photorespiration (measured as 180 2-uptake for example) in the heterozygous green type is suppressed by the addition of the labile gene factor pair Cc in heterozygous condition which leads to the yellow phenotype. In the yellow and green phenotype the photosynthetic unit size is different but not the ratio of photosys­ tem I/photosystem II activity. Moreover, from the present studies it appears that the Warburg effect i. e. an increase of photo­ synthetic rate upon anoxia, can only partly be due to an inhibition of ribulose 1,5-biphosphate oxygenase or glycolate oxidase. 
  Reference    Z. Naturforsch. 36c, 662—671 (1981); received March 23 1981 
  Published    1981 
  Keywords    Photorespiration, Mass Spectrometry, Photosynthetic Units, Tobacco Mutants 
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 TEI-XML for    default:Reihe_C/36/ZNC-1981-36c-0662.pdf 
 Identifier    ZNC-1981-36c-0662 
 Volume    36 
5Author    Ryuichi Ishii, GeorgH. SchmidRequires cookie*
 Title    The Kok Effect and Its Relationship to Photorespiration in Tobacco  
 Abstract    The Kok effect of photosynthesis was investigated in different tobacco mutants. It was found that the breaks in the light intensity curve were always at or around 1000 lux in all plants tested regardless o f the unit sizes which differed by a factor of 10. It was concluded that the photo­ receptor responsible for the effect must be present in the wild type and the chlorophyll deficient mutants in the same amount and is probably not chlorophyll. Due to the fact that the light dependency of the Hill reaction in isolated tobacco chloroplasts also shows a break at or around the "Kok intensity" it was concluded that probably a structural change of the photochemical apparatus around 1000 lux contributes to the effect. Measurement of 180 2-uptake by mass spectrometry at low light intensity shows at low C 0 2-concentration an enhancement of 180 2-uptake again at/around 1000 lux indicating that photorespiration starts to function at the "Kok intensity". Due to the fact that 180 2-uptake remains constant at high C 0 2-concentrations the break in the photosynthetic light intensity curve cannot be due to an inhibition o f "dark respiration" at low light intensities. 
  Reference    Z. Naturforsch. 36c, 450 (1981); received February 26 1981 
  Published    1981 
  Keywords    Kok Effect, Tobacco Mutants, 180 2-Uptake, Mass Spectrometry 
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 TEI-XML for    default:Reihe_C/36/ZNC-1981-36c-0450.pdf 
 Identifier    ZNC-1981-36c-0450 
 Volume    36 
6Author    Bernd Richter, Helmut SchwarzRequires cookie*
 Title    Zur McLafferty-Umlagerung bei Radikalkationen von Phenylpyridylalkanonen [1] On the McLafferty Rearrangement of Ionized Phenyl Pyridyl Alkanones [1]  
 Abstract    A detailed investigation concerning the genesis of McLafferty rearrangement products from molecular ions of phenyl pyridyl alkanones reveals the following features: 1) The various products are not formed by competitive dissociations of the molecular ion. Most of the relevant fragment ions are generated from the primary McLafferty product of a hydrogen transfer to the ionized carbonyl group (M +> ->m/z 163, ion k). The ion k plays a decisive role for the generation of the abundant product ions at m/z 93 (ion g) and m/z 106 (ion s) both of which are formed by further dissociation of k. Details of the mechanisms for the decomposition of k are obtained by investigating [D]-labelled isotopomers, the analysis of low and high resolution data, the application of MIKE and CA spectra. The problem of keto/enol tautomerism between some ions, relevant in this context, is discussed and it is shown that these isomerization processes are not involved. A detaüed description is given for the syntheses of various [D]-labelled phenyl pyridyl alkanones. 
  Reference    Z. Naturforsch. 36b, 865—877 (1981); eingegangen am 16. Dezember 1980 
  Published    1981 
  Keywords    Mass Spectrometry, Hydrogen Rearrangement, Keto Enol Tautomerism, Metastable Ions, Collisional Activation 
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 TEI-XML for    default:Reihe_B/36/ZNB-1981-36b-0865.pdf 
 Identifier    ZNB-1981-36b-0865 
 Volume    36 
7Author    Wilfried Franke, Helmut Schwarz, Chrysostomos WesdemiotisRequires cookie*
 Title    Elf stabile C5H9+-Kationen in der Gasphase. Zur dissoziativen Ionisierung von 31 isomeren C6H9Br-Verbindungen Eleven Stable CsHo 4 " Cations in the Gas Phase. On the Dissociative Ionization of 31 Isomeric CsHgBr Compounds  
 Abstract    Collisional activation mass spectrometry (CA) reveals the existence of 11 stable CsH9+ cations in the gas phase, e. g. the substituted allyl cations a, b, c, d,and e, the sub-stituted vinyl cations f, g, h, and i, the methyl cyclobutyl cation j and the cyclopentyl cation k, respectively. The ethyl substituted allyl cation a is formed via dissociative ionization of the isomeric precursors 1, 3, 4, 5, 18, 19, 20, 22, and 28 by means of various mechanistic processes, whereas the 1,3-dimethylallyl cation b is generated from both 2 (by allylic cleavage) and in part from the stereoisomeric cyclopropan derivatives 25, 26 and 27. 6"l + -gives a mixture of the vinyl cations 1 and g. From 13 and 14 the main product generated is the 1,2-dimethylallyl cation d, which is formed directly from 11 and also by quite complicated processes from 13, 14 and to a certain extent from 25, 26 and 27. The dissociative ionization of 9, 15, 16, 21, 24 and (in part) 23 give rise to the formation of the substituted vinyl cation h. Decomposition of 23"!+ • results not only in formation of h but generates also the 1,1-dimethylallyl cation e. From 291+-and 30~l +-both the methylcyclo-butyl cation j and cyclopentyl cation k are produced, whereas the isomeric precursor 28 gives mainly the substituted allyl cation a and a second, as yet, unidentified CsH^ cation. In general, it can be stated that the gas phase chemistry of cation radicals of substituted cyclopropanes is characterised by multistep-reactions, commencing with spontaneous ring opening. The so formed intermediates undergo various rearrangements (including hydrogen and alkyl shifts) prior to expulsion of Br\ Direct elimination of Br' from intact cyclopropan-like structures, followed by ring opening of the intermediate cyclopropyl cation, cannot compete with the above-mentioned multistep-sequences. 
  Reference    Z. Naturforsch. 36b, 1315—1323 (1981); eingegangen am 2. Juni 1981 
  Published    1981 
  Keywords    Isolated Carbocations, Ion Structures, Gas Phase Ion Chemistry, Mass Spectrometry, Collisional Activation 
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 TEI-XML for    default:Reihe_B/36/ZNB-1981-36b-1315.pdf 
 Identifier    ZNB-1981-36b-1315 
 Volume    36 
8Author    Henryk Zegota++, Clemens Von SonntagRequires cookie*
 Title    Radical-Induced Dephosphorylation of Fructose Phosphates in Aqueous Solution +  
 Abstract    Oxygen free N20-saturated aqueous solutions of D-fructose-1-phosphate and D-fructose-6-phosphate were y-irradiated. Inorganic phosphate and phosphate free sugars (containing four to six carbon atoms) were identified and their G-values measured. D-Fructose-1-phosphate yields (G-values in parentheses) inorganic phosphate (1.6), hexos-2-ulose (0.12), 6-deoxy-2,5-hexodiulose (0.16), tetrulose (0.05) and 3-deoxytetrulose (0.15). D-Fructose-6-phosphate yields inorganic phosphate (1.7), hexos-5-ulose (0.1), 6-deoxy-2,5-hexodiulose (0.36), 3-deoxy-2,5-hexodiulose and 2-deoxyhexos-5-ulose (together 0.18). On treatment with alkaline phosphatase further deoxy sugars were re-cognized and in fructose-1-phosphate G(6-deoxy-2,5-hexodiulose) was increased to a G-value of 0.4. Dephosphorylation is considered to occur mainly after OH attack at C-5 and C-l in fructose-1-phosphate and at C-5 and C-6 in fructose-6-phosphate. Reaction mechanisms are discussed. 
  Reference    Z. Naturforsch. 36b, 1331—1337 (1981); received May 29 1981 
  Published    1981 
  Keywords    D-Fructo8e-l-phosphate, D-Fructose-6-phosphate, y-Irradiation, Radical Reactions, Mass Spectrometry 
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 TEI-XML for    default:Reihe_B/36/ZNB-1981-36b-1331.pdf 
 Identifier    ZNB-1981-36b-1331 
 Volume    36